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1 /* |
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2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #include "precompiled.hpp" |
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26 #include "classfile/classLoader.hpp" |
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27 #include "classfile/javaClasses.hpp" |
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28 #include "classfile/systemDictionary.hpp" |
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29 #include "classfile/vmSymbols.hpp" |
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30 #include "code/scopeDesc.hpp" |
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31 #include "compiler/compileBroker.hpp" |
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32 #include "interpreter/interpreter.hpp" |
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33 #include "interpreter/linkResolver.hpp" |
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34 #include "interpreter/oopMapCache.hpp" |
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35 #include "jvmtifiles/jvmtiEnv.hpp" |
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36 #include "memory/gcLocker.inline.hpp" |
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37 #include "memory/metaspaceShared.hpp" |
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38 #include "memory/oopFactory.hpp" |
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39 #include "memory/universe.inline.hpp" |
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40 #include "oops/instanceKlass.hpp" |
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41 #include "oops/objArrayOop.hpp" |
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42 #include "oops/oop.inline.hpp" |
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43 #include "oops/symbol.hpp" |
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44 #include "prims/jvm_misc.hpp" |
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45 #include "prims/jvmtiExport.hpp" |
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46 #include "prims/jvmtiThreadState.hpp" |
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47 #include "prims/privilegedStack.hpp" |
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48 #include "runtime/arguments.hpp" |
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49 #include "runtime/biasedLocking.hpp" |
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50 #include "runtime/deoptimization.hpp" |
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51 #include "runtime/fprofiler.hpp" |
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52 #include "runtime/frame.inline.hpp" |
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53 #include "runtime/init.hpp" |
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54 #include "runtime/interfaceSupport.hpp" |
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55 #include "runtime/java.hpp" |
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56 #include "runtime/javaCalls.hpp" |
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57 #include "runtime/jniPeriodicChecker.hpp" |
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58 #include "runtime/memprofiler.hpp" |
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59 #include "runtime/mutexLocker.hpp" |
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60 #include "runtime/objectMonitor.hpp" |
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61 #include "runtime/osThread.hpp" |
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62 #include "runtime/safepoint.hpp" |
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63 #include "runtime/sharedRuntime.hpp" |
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64 #include "runtime/statSampler.hpp" |
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65 #include "runtime/stubRoutines.hpp" |
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66 #include "runtime/task.hpp" |
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67 #include "runtime/thread.inline.hpp" |
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68 #include "runtime/threadCritical.hpp" |
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69 #include "runtime/threadLocalStorage.hpp" |
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70 #include "runtime/vframe.hpp" |
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71 #include "runtime/vframeArray.hpp" |
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72 #include "runtime/vframe_hp.hpp" |
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73 #include "runtime/vmThread.hpp" |
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74 #include "runtime/vm_operations.hpp" |
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75 #include "services/attachListener.hpp" |
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76 #include "services/management.hpp" |
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77 #include "services/memTracker.hpp" |
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78 #include "services/threadService.hpp" |
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79 #include "trace/tracing.hpp" |
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80 #include "trace/traceMacros.hpp" |
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81 #include "utilities/defaultStream.hpp" |
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82 #include "utilities/dtrace.hpp" |
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83 #include "utilities/events.hpp" |
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84 #include "utilities/preserveException.hpp" |
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85 #include "utilities/macros.hpp" |
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86 #ifdef TARGET_OS_FAMILY_linux |
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87 # include "os_linux.inline.hpp" |
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88 #endif |
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89 #ifdef TARGET_OS_FAMILY_solaris |
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90 # include "os_solaris.inline.hpp" |
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91 #endif |
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92 #ifdef TARGET_OS_FAMILY_windows |
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93 # include "os_windows.inline.hpp" |
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94 #endif |
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95 #ifdef TARGET_OS_FAMILY_bsd |
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96 # include "os_bsd.inline.hpp" |
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97 #endif |
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98 #if INCLUDE_ALL_GCS |
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99 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp" |
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100 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp" |
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101 #include "gc_implementation/parallelScavenge/pcTasks.hpp" |
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102 #endif // INCLUDE_ALL_GCS |
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103 #ifdef COMPILER1 |
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104 #include "c1/c1_Compiler.hpp" |
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105 #endif |
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106 #ifdef COMPILER2 |
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107 #include "opto/c2compiler.hpp" |
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108 #include "opto/idealGraphPrinter.hpp" |
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109 #endif |
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110 #if INCLUDE_RTM_OPT |
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111 #include "runtime/rtmLocking.hpp" |
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112 #endif |
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113 |
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114 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
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115 |
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116 #ifdef DTRACE_ENABLED |
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117 |
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118 // Only bother with this argument setup if dtrace is available |
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119 |
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120 #ifndef USDT2 |
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121 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin); |
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122 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end); |
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123 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t, |
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124 intptr_t, intptr_t, bool); |
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125 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t, |
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126 intptr_t, intptr_t, bool); |
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127 |
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128 #define DTRACE_THREAD_PROBE(probe, javathread) \ |
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129 { \ |
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130 ResourceMark rm(this); \ |
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131 int len = 0; \ |
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132 const char* name = (javathread)->get_thread_name(); \ |
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133 len = strlen(name); \ |
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134 HS_DTRACE_PROBE5(hotspot, thread__##probe, \ |
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135 name, len, \ |
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136 java_lang_Thread::thread_id((javathread)->threadObj()), \ |
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137 (javathread)->osthread()->thread_id(), \ |
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138 java_lang_Thread::is_daemon((javathread)->threadObj())); \ |
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139 } |
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140 |
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141 #else /* USDT2 */ |
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142 |
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143 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_PROBE_START |
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144 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_PROBE_STOP |
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145 |
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146 #define DTRACE_THREAD_PROBE(probe, javathread) \ |
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147 { \ |
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148 ResourceMark rm(this); \ |
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149 int len = 0; \ |
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150 const char* name = (javathread)->get_thread_name(); \ |
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151 len = strlen(name); \ |
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152 HOTSPOT_THREAD_PROBE_##probe( /* probe = start, stop */ \ |
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153 (char *) name, len, \ |
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154 java_lang_Thread::thread_id((javathread)->threadObj()), \ |
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155 (uintptr_t) (javathread)->osthread()->thread_id(), \ |
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156 java_lang_Thread::is_daemon((javathread)->threadObj())); \ |
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157 } |
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158 |
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159 #endif /* USDT2 */ |
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160 |
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161 #else // ndef DTRACE_ENABLED |
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162 |
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163 #define DTRACE_THREAD_PROBE(probe, javathread) |
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164 |
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165 #endif // ndef DTRACE_ENABLED |
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166 |
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167 |
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168 // Class hierarchy |
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169 // - Thread |
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170 // - VMThread |
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171 // - WatcherThread |
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172 // - ConcurrentMarkSweepThread |
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173 // - JavaThread |
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174 // - CompilerThread |
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175 |
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176 // ======= Thread ======== |
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177 // Support for forcing alignment of thread objects for biased locking |
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178 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) { |
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179 if (UseBiasedLocking) { |
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180 const int alignment = markOopDesc::biased_lock_alignment; |
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181 size_t aligned_size = size + (alignment - sizeof(intptr_t)); |
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182 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC) |
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183 : AllocateHeap(aligned_size, flags, CURRENT_PC, |
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184 AllocFailStrategy::RETURN_NULL); |
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185 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment); |
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186 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <= |
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187 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size), |
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188 "JavaThread alignment code overflowed allocated storage"); |
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189 if (TraceBiasedLocking) { |
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190 if (aligned_addr != real_malloc_addr) |
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191 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT, |
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192 real_malloc_addr, aligned_addr); |
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193 } |
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194 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr; |
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195 return aligned_addr; |
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196 } else { |
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197 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC) |
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198 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL); |
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199 } |
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200 } |
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201 |
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202 void Thread::operator delete(void* p) { |
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203 if (UseBiasedLocking) { |
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204 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address; |
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205 FreeHeap(real_malloc_addr, mtThread); |
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206 } else { |
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207 FreeHeap(p, mtThread); |
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208 } |
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209 } |
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210 |
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211 |
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212 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread, |
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213 // JavaThread |
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214 |
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215 |
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216 Thread::Thread() { |
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217 // stack and get_thread |
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218 set_stack_base(NULL); |
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219 set_stack_size(0); |
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220 set_self_raw_id(0); |
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221 set_lgrp_id(-1); |
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222 |
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223 // allocated data structures |
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224 set_osthread(NULL); |
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225 set_resource_area(new (mtThread)ResourceArea()); |
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226 DEBUG_ONLY(_current_resource_mark = NULL;) |
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227 set_handle_area(new (mtThread) HandleArea(NULL)); |
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228 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true)); |
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229 set_active_handles(NULL); |
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230 set_free_handle_block(NULL); |
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231 set_last_handle_mark(NULL); |
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232 |
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233 // This initial value ==> never claimed. |
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234 _oops_do_parity = 0; |
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235 |
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236 // the handle mark links itself to last_handle_mark |
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237 new HandleMark(this); |
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238 |
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239 // plain initialization |
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240 debug_only(_owned_locks = NULL;) |
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241 debug_only(_allow_allocation_count = 0;) |
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242 NOT_PRODUCT(_allow_safepoint_count = 0;) |
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243 NOT_PRODUCT(_skip_gcalot = false;) |
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244 _jvmti_env_iteration_count = 0; |
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245 set_allocated_bytes(0); |
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246 _vm_operation_started_count = 0; |
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247 _vm_operation_completed_count = 0; |
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248 _current_pending_monitor = NULL; |
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249 _current_pending_monitor_is_from_java = true; |
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250 _current_waiting_monitor = NULL; |
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251 _num_nested_signal = 0; |
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252 omFreeList = NULL ; |
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253 omFreeCount = 0 ; |
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254 omFreeProvision = 32 ; |
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255 omInUseList = NULL ; |
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256 omInUseCount = 0 ; |
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257 |
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258 #ifdef ASSERT |
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259 _visited_for_critical_count = false; |
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260 #endif |
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261 |
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262 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true); |
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263 _suspend_flags = 0; |
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264 |
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265 // thread-specific hashCode stream generator state - Marsaglia shift-xor form |
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266 _hashStateX = os::random() ; |
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267 _hashStateY = 842502087 ; |
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268 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ; |
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269 _hashStateW = 273326509 ; |
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270 |
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271 _OnTrap = 0 ; |
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272 _schedctl = NULL ; |
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273 _Stalled = 0 ; |
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274 _TypeTag = 0x2BAD ; |
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275 |
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276 // Many of the following fields are effectively final - immutable |
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277 // Note that nascent threads can't use the Native Monitor-Mutex |
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278 // construct until the _MutexEvent is initialized ... |
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279 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents |
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280 // we might instead use a stack of ParkEvents that we could provision on-demand. |
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281 // The stack would act as a cache to avoid calls to ParkEvent::Allocate() |
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282 // and ::Release() |
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283 _ParkEvent = ParkEvent::Allocate (this) ; |
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284 _SleepEvent = ParkEvent::Allocate (this) ; |
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285 _MutexEvent = ParkEvent::Allocate (this) ; |
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286 _MuxEvent = ParkEvent::Allocate (this) ; |
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287 |
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288 #ifdef CHECK_UNHANDLED_OOPS |
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289 if (CheckUnhandledOops) { |
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290 _unhandled_oops = new UnhandledOops(this); |
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291 } |
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292 #endif // CHECK_UNHANDLED_OOPS |
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293 #ifdef ASSERT |
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294 if (UseBiasedLocking) { |
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295 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed"); |
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296 assert(this == _real_malloc_address || |
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297 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment), |
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298 "bug in forced alignment of thread objects"); |
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299 } |
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300 #endif /* ASSERT */ |
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301 } |
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302 |
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303 void Thread::initialize_thread_local_storage() { |
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304 // Note: Make sure this method only calls |
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305 // non-blocking operations. Otherwise, it might not work |
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306 // with the thread-startup/safepoint interaction. |
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307 |
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308 // During Java thread startup, safepoint code should allow this |
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309 // method to complete because it may need to allocate memory to |
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310 // store information for the new thread. |
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311 |
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312 // initialize structure dependent on thread local storage |
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313 ThreadLocalStorage::set_thread(this); |
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314 } |
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315 |
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316 void Thread::record_stack_base_and_size() { |
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317 set_stack_base(os::current_stack_base()); |
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318 set_stack_size(os::current_stack_size()); |
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319 if (is_Java_thread()) { |
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320 ((JavaThread*) this)->set_stack_overflow_limit(); |
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321 } |
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322 // CR 7190089: on Solaris, primordial thread's stack is adjusted |
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323 // in initialize_thread(). Without the adjustment, stack size is |
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324 // incorrect if stack is set to unlimited (ulimit -s unlimited). |
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325 // So far, only Solaris has real implementation of initialize_thread(). |
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326 // |
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327 // set up any platform-specific state. |
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328 os::initialize_thread(this); |
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329 |
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330 #if INCLUDE_NMT |
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331 // record thread's native stack, stack grows downward |
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332 address stack_low_addr = stack_base() - stack_size(); |
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333 MemTracker::record_thread_stack(stack_low_addr, stack_size(), this, |
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334 CURRENT_PC); |
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335 #endif // INCLUDE_NMT |
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336 } |
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337 |
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338 |
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339 Thread::~Thread() { |
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340 // Reclaim the objectmonitors from the omFreeList of the moribund thread. |
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341 ObjectSynchronizer::omFlush (this) ; |
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342 |
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343 EVENT_THREAD_DESTRUCT(this); |
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344 |
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345 // stack_base can be NULL if the thread is never started or exited before |
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346 // record_stack_base_and_size called. Although, we would like to ensure |
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347 // that all started threads do call record_stack_base_and_size(), there is |
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348 // not proper way to enforce that. |
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349 #if INCLUDE_NMT |
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350 if (_stack_base != NULL) { |
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351 address low_stack_addr = stack_base() - stack_size(); |
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352 MemTracker::release_thread_stack(low_stack_addr, stack_size(), this); |
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353 #ifdef ASSERT |
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354 set_stack_base(NULL); |
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355 #endif |
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356 } |
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357 #endif // INCLUDE_NMT |
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358 |
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359 // deallocate data structures |
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360 delete resource_area(); |
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361 // since the handle marks are using the handle area, we have to deallocated the root |
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362 // handle mark before deallocating the thread's handle area, |
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363 assert(last_handle_mark() != NULL, "check we have an element"); |
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364 delete last_handle_mark(); |
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365 assert(last_handle_mark() == NULL, "check we have reached the end"); |
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366 |
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367 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads. |
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368 // We NULL out the fields for good hygiene. |
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369 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ; |
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370 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ; |
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371 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ; |
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372 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ; |
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373 |
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374 delete handle_area(); |
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375 delete metadata_handles(); |
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376 |
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377 // osthread() can be NULL, if creation of thread failed. |
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378 if (osthread() != NULL) os::free_thread(osthread()); |
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379 |
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380 delete _SR_lock; |
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381 |
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382 // clear thread local storage if the Thread is deleting itself |
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383 if (this == Thread::current()) { |
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384 ThreadLocalStorage::set_thread(NULL); |
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385 } else { |
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386 // In the case where we're not the current thread, invalidate all the |
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387 // caches in case some code tries to get the current thread or the |
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388 // thread that was destroyed, and gets stale information. |
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389 ThreadLocalStorage::invalidate_all(); |
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390 } |
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391 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();) |
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392 } |
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393 |
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394 // NOTE: dummy function for assertion purpose. |
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395 void Thread::run() { |
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396 ShouldNotReachHere(); |
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397 } |
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398 |
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399 #ifdef ASSERT |
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400 // Private method to check for dangling thread pointer |
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401 void check_for_dangling_thread_pointer(Thread *thread) { |
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402 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(), |
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403 "possibility of dangling Thread pointer"); |
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404 } |
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405 #endif |
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406 |
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407 |
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408 #ifndef PRODUCT |
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409 // Tracing method for basic thread operations |
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410 void Thread::trace(const char* msg, const Thread* const thread) { |
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411 if (!TraceThreadEvents) return; |
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412 ResourceMark rm; |
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413 ThreadCritical tc; |
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414 const char *name = "non-Java thread"; |
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415 int prio = -1; |
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416 if (thread->is_Java_thread() |
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417 && !thread->is_Compiler_thread()) { |
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418 // The Threads_lock must be held to get information about |
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419 // this thread but may not be in some situations when |
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420 // tracing thread events. |
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421 bool release_Threads_lock = false; |
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422 if (!Threads_lock->owned_by_self()) { |
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423 Threads_lock->lock(); |
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424 release_Threads_lock = true; |
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425 } |
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426 JavaThread* jt = (JavaThread *)thread; |
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427 name = (char *)jt->get_thread_name(); |
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428 oop thread_oop = jt->threadObj(); |
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429 if (thread_oop != NULL) { |
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430 prio = java_lang_Thread::priority(thread_oop); |
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431 } |
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432 if (release_Threads_lock) { |
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433 Threads_lock->unlock(); |
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434 } |
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435 } |
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436 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio); |
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437 } |
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438 #endif |
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439 |
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440 |
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441 ThreadPriority Thread::get_priority(const Thread* const thread) { |
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442 trace("get priority", thread); |
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443 ThreadPriority priority; |
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444 // Can return an error! |
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445 (void)os::get_priority(thread, priority); |
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446 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found"); |
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447 return priority; |
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448 } |
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449 |
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450 void Thread::set_priority(Thread* thread, ThreadPriority priority) { |
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451 trace("set priority", thread); |
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452 debug_only(check_for_dangling_thread_pointer(thread);) |
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453 // Can return an error! |
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454 (void)os::set_priority(thread, priority); |
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455 } |
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456 |
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457 |
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458 void Thread::start(Thread* thread) { |
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459 trace("start", thread); |
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460 // Start is different from resume in that its safety is guaranteed by context or |
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461 // being called from a Java method synchronized on the Thread object. |
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462 if (!DisableStartThread) { |
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463 if (thread->is_Java_thread()) { |
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464 // Initialize the thread state to RUNNABLE before starting this thread. |
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465 // Can not set it after the thread started because we do not know the |
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466 // exact thread state at that time. It could be in MONITOR_WAIT or |
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467 // in SLEEPING or some other state. |
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468 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(), |
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469 java_lang_Thread::RUNNABLE); |
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470 } |
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471 os::start_thread(thread); |
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472 } |
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473 } |
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474 |
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475 // Enqueue a VM_Operation to do the job for us - sometime later |
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476 void Thread::send_async_exception(oop java_thread, oop java_throwable) { |
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477 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable); |
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478 VMThread::execute(vm_stop); |
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479 } |
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480 |
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481 |
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482 // |
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483 // Check if an external suspend request has completed (or has been |
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484 // cancelled). Returns true if the thread is externally suspended and |
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485 // false otherwise. |
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486 // |
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487 // The bits parameter returns information about the code path through |
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488 // the routine. Useful for debugging: |
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489 // |
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490 // set in is_ext_suspend_completed(): |
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491 // 0x00000001 - routine was entered |
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492 // 0x00000010 - routine return false at end |
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493 // 0x00000100 - thread exited (return false) |
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494 // 0x00000200 - suspend request cancelled (return false) |
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495 // 0x00000400 - thread suspended (return true) |
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496 // 0x00001000 - thread is in a suspend equivalent state (return true) |
|
497 // 0x00002000 - thread is native and walkable (return true) |
|
498 // 0x00004000 - thread is native_trans and walkable (needed retry) |
|
499 // |
|
500 // set in wait_for_ext_suspend_completion(): |
|
501 // 0x00010000 - routine was entered |
|
502 // 0x00020000 - suspend request cancelled before loop (return false) |
|
503 // 0x00040000 - thread suspended before loop (return true) |
|
504 // 0x00080000 - suspend request cancelled in loop (return false) |
|
505 // 0x00100000 - thread suspended in loop (return true) |
|
506 // 0x00200000 - suspend not completed during retry loop (return false) |
|
507 // |
|
508 |
|
509 // Helper class for tracing suspend wait debug bits. |
|
510 // |
|
511 // 0x00000100 indicates that the target thread exited before it could |
|
512 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and |
|
513 // 0x00080000 each indicate a cancelled suspend request so they don't |
|
514 // count as wait failures either. |
|
515 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000) |
|
516 |
|
517 class TraceSuspendDebugBits : public StackObj { |
|
518 private: |
|
519 JavaThread * jt; |
|
520 bool is_wait; |
|
521 bool called_by_wait; // meaningful when !is_wait |
|
522 uint32_t * bits; |
|
523 |
|
524 public: |
|
525 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait, |
|
526 uint32_t *_bits) { |
|
527 jt = _jt; |
|
528 is_wait = _is_wait; |
|
529 called_by_wait = _called_by_wait; |
|
530 bits = _bits; |
|
531 } |
|
532 |
|
533 ~TraceSuspendDebugBits() { |
|
534 if (!is_wait) { |
|
535 #if 1 |
|
536 // By default, don't trace bits for is_ext_suspend_completed() calls. |
|
537 // That trace is very chatty. |
|
538 return; |
|
539 #else |
|
540 if (!called_by_wait) { |
|
541 // If tracing for is_ext_suspend_completed() is enabled, then only |
|
542 // trace calls to it from wait_for_ext_suspend_completion() |
|
543 return; |
|
544 } |
|
545 #endif |
|
546 } |
|
547 |
|
548 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) { |
|
549 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) { |
|
550 MutexLocker ml(Threads_lock); // needed for get_thread_name() |
|
551 ResourceMark rm; |
|
552 |
|
553 tty->print_cr( |
|
554 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)", |
|
555 jt->get_thread_name(), *bits); |
|
556 |
|
557 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed"); |
|
558 } |
|
559 } |
|
560 } |
|
561 }; |
|
562 #undef DEBUG_FALSE_BITS |
|
563 |
|
564 |
|
565 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) { |
|
566 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits); |
|
567 |
|
568 bool did_trans_retry = false; // only do thread_in_native_trans retry once |
|
569 bool do_trans_retry; // flag to force the retry |
|
570 |
|
571 *bits |= 0x00000001; |
|
572 |
|
573 do { |
|
574 do_trans_retry = false; |
|
575 |
|
576 if (is_exiting()) { |
|
577 // Thread is in the process of exiting. This is always checked |
|
578 // first to reduce the risk of dereferencing a freed JavaThread. |
|
579 *bits |= 0x00000100; |
|
580 return false; |
|
581 } |
|
582 |
|
583 if (!is_external_suspend()) { |
|
584 // Suspend request is cancelled. This is always checked before |
|
585 // is_ext_suspended() to reduce the risk of a rogue resume |
|
586 // confusing the thread that made the suspend request. |
|
587 *bits |= 0x00000200; |
|
588 return false; |
|
589 } |
|
590 |
|
591 if (is_ext_suspended()) { |
|
592 // thread is suspended |
|
593 *bits |= 0x00000400; |
|
594 return true; |
|
595 } |
|
596 |
|
597 // Now that we no longer do hard suspends of threads running |
|
598 // native code, the target thread can be changing thread state |
|
599 // while we are in this routine: |
|
600 // |
|
601 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked |
|
602 // |
|
603 // We save a copy of the thread state as observed at this moment |
|
604 // and make our decision about suspend completeness based on the |
|
605 // copy. This closes the race where the thread state is seen as |
|
606 // _thread_in_native_trans in the if-thread_blocked check, but is |
|
607 // seen as _thread_blocked in if-thread_in_native_trans check. |
|
608 JavaThreadState save_state = thread_state(); |
|
609 |
|
610 if (save_state == _thread_blocked && is_suspend_equivalent()) { |
|
611 // If the thread's state is _thread_blocked and this blocking |
|
612 // condition is known to be equivalent to a suspend, then we can |
|
613 // consider the thread to be externally suspended. This means that |
|
614 // the code that sets _thread_blocked has been modified to do |
|
615 // self-suspension if the blocking condition releases. We also |
|
616 // used to check for CONDVAR_WAIT here, but that is now covered by |
|
617 // the _thread_blocked with self-suspension check. |
|
618 // |
|
619 // Return true since we wouldn't be here unless there was still an |
|
620 // external suspend request. |
|
621 *bits |= 0x00001000; |
|
622 return true; |
|
623 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) { |
|
624 // Threads running native code will self-suspend on native==>VM/Java |
|
625 // transitions. If its stack is walkable (should always be the case |
|
626 // unless this function is called before the actual java_suspend() |
|
627 // call), then the wait is done. |
|
628 *bits |= 0x00002000; |
|
629 return true; |
|
630 } else if (!called_by_wait && !did_trans_retry && |
|
631 save_state == _thread_in_native_trans && |
|
632 frame_anchor()->walkable()) { |
|
633 // The thread is transitioning from thread_in_native to another |
|
634 // thread state. check_safepoint_and_suspend_for_native_trans() |
|
635 // will force the thread to self-suspend. If it hasn't gotten |
|
636 // there yet we may have caught the thread in-between the native |
|
637 // code check above and the self-suspend. Lucky us. If we were |
|
638 // called by wait_for_ext_suspend_completion(), then it |
|
639 // will be doing the retries so we don't have to. |
|
640 // |
|
641 // Since we use the saved thread state in the if-statement above, |
|
642 // there is a chance that the thread has already transitioned to |
|
643 // _thread_blocked by the time we get here. In that case, we will |
|
644 // make a single unnecessary pass through the logic below. This |
|
645 // doesn't hurt anything since we still do the trans retry. |
|
646 |
|
647 *bits |= 0x00004000; |
|
648 |
|
649 // Once the thread leaves thread_in_native_trans for another |
|
650 // thread state, we break out of this retry loop. We shouldn't |
|
651 // need this flag to prevent us from getting back here, but |
|
652 // sometimes paranoia is good. |
|
653 did_trans_retry = true; |
|
654 |
|
655 // We wait for the thread to transition to a more usable state. |
|
656 for (int i = 1; i <= SuspendRetryCount; i++) { |
|
657 // We used to do an "os::yield_all(i)" call here with the intention |
|
658 // that yielding would increase on each retry. However, the parameter |
|
659 // is ignored on Linux which means the yield didn't scale up. Waiting |
|
660 // on the SR_lock below provides a much more predictable scale up for |
|
661 // the delay. It also provides a simple/direct point to check for any |
|
662 // safepoint requests from the VMThread |
|
663 |
|
664 // temporarily drops SR_lock while doing wait with safepoint check |
|
665 // (if we're a JavaThread - the WatcherThread can also call this) |
|
666 // and increase delay with each retry |
|
667 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); |
|
668 |
|
669 // check the actual thread state instead of what we saved above |
|
670 if (thread_state() != _thread_in_native_trans) { |
|
671 // the thread has transitioned to another thread state so |
|
672 // try all the checks (except this one) one more time. |
|
673 do_trans_retry = true; |
|
674 break; |
|
675 } |
|
676 } // end retry loop |
|
677 |
|
678 |
|
679 } |
|
680 } while (do_trans_retry); |
|
681 |
|
682 *bits |= 0x00000010; |
|
683 return false; |
|
684 } |
|
685 |
|
686 // |
|
687 // Wait for an external suspend request to complete (or be cancelled). |
|
688 // Returns true if the thread is externally suspended and false otherwise. |
|
689 // |
|
690 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay, |
|
691 uint32_t *bits) { |
|
692 TraceSuspendDebugBits tsdb(this, true /* is_wait */, |
|
693 false /* !called_by_wait */, bits); |
|
694 |
|
695 // local flag copies to minimize SR_lock hold time |
|
696 bool is_suspended; |
|
697 bool pending; |
|
698 uint32_t reset_bits; |
|
699 |
|
700 // set a marker so is_ext_suspend_completed() knows we are the caller |
|
701 *bits |= 0x00010000; |
|
702 |
|
703 // We use reset_bits to reinitialize the bits value at the top of |
|
704 // each retry loop. This allows the caller to make use of any |
|
705 // unused bits for their own marking purposes. |
|
706 reset_bits = *bits; |
|
707 |
|
708 { |
|
709 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); |
|
710 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, |
|
711 delay, bits); |
|
712 pending = is_external_suspend(); |
|
713 } |
|
714 // must release SR_lock to allow suspension to complete |
|
715 |
|
716 if (!pending) { |
|
717 // A cancelled suspend request is the only false return from |
|
718 // is_ext_suspend_completed() that keeps us from entering the |
|
719 // retry loop. |
|
720 *bits |= 0x00020000; |
|
721 return false; |
|
722 } |
|
723 |
|
724 if (is_suspended) { |
|
725 *bits |= 0x00040000; |
|
726 return true; |
|
727 } |
|
728 |
|
729 for (int i = 1; i <= retries; i++) { |
|
730 *bits = reset_bits; // reinit to only track last retry |
|
731 |
|
732 // We used to do an "os::yield_all(i)" call here with the intention |
|
733 // that yielding would increase on each retry. However, the parameter |
|
734 // is ignored on Linux which means the yield didn't scale up. Waiting |
|
735 // on the SR_lock below provides a much more predictable scale up for |
|
736 // the delay. It also provides a simple/direct point to check for any |
|
737 // safepoint requests from the VMThread |
|
738 |
|
739 { |
|
740 MutexLocker ml(SR_lock()); |
|
741 // wait with safepoint check (if we're a JavaThread - the WatcherThread |
|
742 // can also call this) and increase delay with each retry |
|
743 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay); |
|
744 |
|
745 is_suspended = is_ext_suspend_completed(true /* called_by_wait */, |
|
746 delay, bits); |
|
747 |
|
748 // It is possible for the external suspend request to be cancelled |
|
749 // (by a resume) before the actual suspend operation is completed. |
|
750 // Refresh our local copy to see if we still need to wait. |
|
751 pending = is_external_suspend(); |
|
752 } |
|
753 |
|
754 if (!pending) { |
|
755 // A cancelled suspend request is the only false return from |
|
756 // is_ext_suspend_completed() that keeps us from staying in the |
|
757 // retry loop. |
|
758 *bits |= 0x00080000; |
|
759 return false; |
|
760 } |
|
761 |
|
762 if (is_suspended) { |
|
763 *bits |= 0x00100000; |
|
764 return true; |
|
765 } |
|
766 } // end retry loop |
|
767 |
|
768 // thread did not suspend after all our retries |
|
769 *bits |= 0x00200000; |
|
770 return false; |
|
771 } |
|
772 |
|
773 #ifndef PRODUCT |
|
774 void JavaThread::record_jump(address target, address instr, const char* file, int line) { |
|
775 |
|
776 // This should not need to be atomic as the only way for simultaneous |
|
777 // updates is via interrupts. Even then this should be rare or non-existant |
|
778 // and we don't care that much anyway. |
|
779 |
|
780 int index = _jmp_ring_index; |
|
781 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1); |
|
782 _jmp_ring[index]._target = (intptr_t) target; |
|
783 _jmp_ring[index]._instruction = (intptr_t) instr; |
|
784 _jmp_ring[index]._file = file; |
|
785 _jmp_ring[index]._line = line; |
|
786 } |
|
787 #endif /* PRODUCT */ |
|
788 |
|
789 // Called by flat profiler |
|
790 // Callers have already called wait_for_ext_suspend_completion |
|
791 // The assertion for that is currently too complex to put here: |
|
792 bool JavaThread::profile_last_Java_frame(frame* _fr) { |
|
793 bool gotframe = false; |
|
794 // self suspension saves needed state. |
|
795 if (has_last_Java_frame() && _anchor.walkable()) { |
|
796 *_fr = pd_last_frame(); |
|
797 gotframe = true; |
|
798 } |
|
799 return gotframe; |
|
800 } |
|
801 |
|
802 void Thread::interrupt(Thread* thread) { |
|
803 trace("interrupt", thread); |
|
804 debug_only(check_for_dangling_thread_pointer(thread);) |
|
805 os::interrupt(thread); |
|
806 } |
|
807 |
|
808 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) { |
|
809 trace("is_interrupted", thread); |
|
810 debug_only(check_for_dangling_thread_pointer(thread);) |
|
811 // Note: If clear_interrupted==false, this simply fetches and |
|
812 // returns the value of the field osthread()->interrupted(). |
|
813 return os::is_interrupted(thread, clear_interrupted); |
|
814 } |
|
815 |
|
816 |
|
817 // GC Support |
|
818 bool Thread::claim_oops_do_par_case(int strong_roots_parity) { |
|
819 jint thread_parity = _oops_do_parity; |
|
820 if (thread_parity != strong_roots_parity) { |
|
821 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity); |
|
822 if (res == thread_parity) { |
|
823 return true; |
|
824 } else { |
|
825 guarantee(res == strong_roots_parity, "Or else what?"); |
|
826 assert(SharedHeap::heap()->workers()->active_workers() > 0, |
|
827 "Should only fail when parallel."); |
|
828 return false; |
|
829 } |
|
830 } |
|
831 assert(SharedHeap::heap()->workers()->active_workers() > 0, |
|
832 "Should only fail when parallel."); |
|
833 return false; |
|
834 } |
|
835 |
|
836 void Thread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) { |
|
837 active_handles()->oops_do(f); |
|
838 // Do oop for ThreadShadow |
|
839 f->do_oop((oop*)&_pending_exception); |
|
840 handle_area()->oops_do(f); |
|
841 } |
|
842 |
|
843 void Thread::nmethods_do(CodeBlobClosure* cf) { |
|
844 // no nmethods in a generic thread... |
|
845 } |
|
846 |
|
847 void Thread::metadata_do(void f(Metadata*)) { |
|
848 if (metadata_handles() != NULL) { |
|
849 for (int i = 0; i< metadata_handles()->length(); i++) { |
|
850 f(metadata_handles()->at(i)); |
|
851 } |
|
852 } |
|
853 } |
|
854 |
|
855 void Thread::print_on(outputStream* st) const { |
|
856 // get_priority assumes osthread initialized |
|
857 if (osthread() != NULL) { |
|
858 int os_prio; |
|
859 if (os::get_native_priority(this, &os_prio) == OS_OK) { |
|
860 st->print("os_prio=%d ", os_prio); |
|
861 } |
|
862 st->print("tid=" INTPTR_FORMAT " ", this); |
|
863 osthread()->print_on(st); |
|
864 } |
|
865 debug_only(if (WizardMode) print_owned_locks_on(st);) |
|
866 } |
|
867 |
|
868 // Thread::print_on_error() is called by fatal error handler. Don't use |
|
869 // any lock or allocate memory. |
|
870 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const { |
|
871 if (is_VM_thread()) st->print("VMThread"); |
|
872 else if (is_Compiler_thread()) st->print("CompilerThread"); |
|
873 else if (is_Java_thread()) st->print("JavaThread"); |
|
874 else if (is_GC_task_thread()) st->print("GCTaskThread"); |
|
875 else if (is_Watcher_thread()) st->print("WatcherThread"); |
|
876 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread"); |
|
877 else st->print("Thread"); |
|
878 |
|
879 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]", |
|
880 _stack_base - _stack_size, _stack_base); |
|
881 |
|
882 if (osthread()) { |
|
883 st->print(" [id=%d]", osthread()->thread_id()); |
|
884 } |
|
885 } |
|
886 |
|
887 #ifdef ASSERT |
|
888 void Thread::print_owned_locks_on(outputStream* st) const { |
|
889 Monitor *cur = _owned_locks; |
|
890 if (cur == NULL) { |
|
891 st->print(" (no locks) "); |
|
892 } else { |
|
893 st->print_cr(" Locks owned:"); |
|
894 while(cur) { |
|
895 cur->print_on(st); |
|
896 cur = cur->next(); |
|
897 } |
|
898 } |
|
899 } |
|
900 |
|
901 static int ref_use_count = 0; |
|
902 |
|
903 bool Thread::owns_locks_but_compiled_lock() const { |
|
904 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { |
|
905 if (cur != Compile_lock) return true; |
|
906 } |
|
907 return false; |
|
908 } |
|
909 |
|
910 |
|
911 #endif |
|
912 |
|
913 #ifndef PRODUCT |
|
914 |
|
915 // The flag: potential_vm_operation notifies if this particular safepoint state could potential |
|
916 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that |
|
917 // no threads which allow_vm_block's are held |
|
918 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) { |
|
919 // Check if current thread is allowed to block at a safepoint |
|
920 if (!(_allow_safepoint_count == 0)) |
|
921 fatal("Possible safepoint reached by thread that does not allow it"); |
|
922 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) { |
|
923 fatal("LEAF method calling lock?"); |
|
924 } |
|
925 |
|
926 #ifdef ASSERT |
|
927 if (potential_vm_operation && is_Java_thread() |
|
928 && !Universe::is_bootstrapping()) { |
|
929 // Make sure we do not hold any locks that the VM thread also uses. |
|
930 // This could potentially lead to deadlocks |
|
931 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) { |
|
932 // Threads_lock is special, since the safepoint synchronization will not start before this is |
|
933 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock, |
|
934 // since it is used to transfer control between JavaThreads and the VMThread |
|
935 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first! |
|
936 if ( (cur->allow_vm_block() && |
|
937 cur != Threads_lock && |
|
938 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation |
|
939 cur != VMOperationRequest_lock && |
|
940 cur != VMOperationQueue_lock) || |
|
941 cur->rank() == Mutex::special) { |
|
942 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name()); |
|
943 } |
|
944 } |
|
945 } |
|
946 |
|
947 if (GCALotAtAllSafepoints) { |
|
948 // We could enter a safepoint here and thus have a gc |
|
949 InterfaceSupport::check_gc_alot(); |
|
950 } |
|
951 #endif |
|
952 } |
|
953 #endif |
|
954 |
|
955 bool Thread::is_in_stack(address adr) const { |
|
956 assert(Thread::current() == this, "is_in_stack can only be called from current thread"); |
|
957 address end = os::current_stack_pointer(); |
|
958 // Allow non Java threads to call this without stack_base |
|
959 if (_stack_base == NULL) return true; |
|
960 if (stack_base() >= adr && adr >= end) return true; |
|
961 |
|
962 return false; |
|
963 } |
|
964 |
|
965 |
|
966 bool Thread::is_in_usable_stack(address adr) const { |
|
967 size_t stack_guard_size = os::uses_stack_guard_pages() ? (StackYellowPages + StackRedPages) * os::vm_page_size() : 0; |
|
968 size_t usable_stack_size = _stack_size - stack_guard_size; |
|
969 |
|
970 return ((adr < stack_base()) && (adr >= stack_base() - usable_stack_size)); |
|
971 } |
|
972 |
|
973 |
|
974 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter |
|
975 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being |
|
976 // used for compilation in the future. If that change is made, the need for these methods |
|
977 // should be revisited, and they should be removed if possible. |
|
978 |
|
979 bool Thread::is_lock_owned(address adr) const { |
|
980 return on_local_stack(adr); |
|
981 } |
|
982 |
|
983 bool Thread::set_as_starting_thread() { |
|
984 // NOTE: this must be called inside the main thread. |
|
985 return os::create_main_thread((JavaThread*)this); |
|
986 } |
|
987 |
|
988 static void initialize_class(Symbol* class_name, TRAPS) { |
|
989 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); |
|
990 InstanceKlass::cast(klass)->initialize(CHECK); |
|
991 } |
|
992 |
|
993 |
|
994 // Creates the initial ThreadGroup |
|
995 static Handle create_initial_thread_group(TRAPS) { |
|
996 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH); |
|
997 instanceKlassHandle klass (THREAD, k); |
|
998 |
|
999 Handle system_instance = klass->allocate_instance_handle(CHECK_NH); |
|
1000 { |
|
1001 JavaValue result(T_VOID); |
|
1002 JavaCalls::call_special(&result, |
|
1003 system_instance, |
|
1004 klass, |
|
1005 vmSymbols::object_initializer_name(), |
|
1006 vmSymbols::void_method_signature(), |
|
1007 CHECK_NH); |
|
1008 } |
|
1009 Universe::set_system_thread_group(system_instance()); |
|
1010 |
|
1011 Handle main_instance = klass->allocate_instance_handle(CHECK_NH); |
|
1012 { |
|
1013 JavaValue result(T_VOID); |
|
1014 Handle string = java_lang_String::create_from_str("main", CHECK_NH); |
|
1015 JavaCalls::call_special(&result, |
|
1016 main_instance, |
|
1017 klass, |
|
1018 vmSymbols::object_initializer_name(), |
|
1019 vmSymbols::threadgroup_string_void_signature(), |
|
1020 system_instance, |
|
1021 string, |
|
1022 CHECK_NH); |
|
1023 } |
|
1024 return main_instance; |
|
1025 } |
|
1026 |
|
1027 // Creates the initial Thread |
|
1028 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) { |
|
1029 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL); |
|
1030 instanceKlassHandle klass (THREAD, k); |
|
1031 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL); |
|
1032 |
|
1033 java_lang_Thread::set_thread(thread_oop(), thread); |
|
1034 java_lang_Thread::set_priority(thread_oop(), NormPriority); |
|
1035 thread->set_threadObj(thread_oop()); |
|
1036 |
|
1037 Handle string = java_lang_String::create_from_str("main", CHECK_NULL); |
|
1038 |
|
1039 JavaValue result(T_VOID); |
|
1040 JavaCalls::call_special(&result, thread_oop, |
|
1041 klass, |
|
1042 vmSymbols::object_initializer_name(), |
|
1043 vmSymbols::threadgroup_string_void_signature(), |
|
1044 thread_group, |
|
1045 string, |
|
1046 CHECK_NULL); |
|
1047 return thread_oop(); |
|
1048 } |
|
1049 |
|
1050 static void call_initializeSystemClass(TRAPS) { |
|
1051 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK); |
|
1052 instanceKlassHandle klass (THREAD, k); |
|
1053 |
|
1054 JavaValue result(T_VOID); |
|
1055 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(), |
|
1056 vmSymbols::void_method_signature(), CHECK); |
|
1057 } |
|
1058 |
|
1059 char java_runtime_name[128] = ""; |
|
1060 char java_runtime_version[128] = ""; |
|
1061 |
|
1062 // extract the JRE name from sun.misc.Version.java_runtime_name |
|
1063 static const char* get_java_runtime_name(TRAPS) { |
|
1064 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(), |
|
1065 Handle(), Handle(), CHECK_AND_CLEAR_NULL); |
|
1066 fieldDescriptor fd; |
|
1067 bool found = k != NULL && |
|
1068 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(), |
|
1069 vmSymbols::string_signature(), &fd); |
|
1070 if (found) { |
|
1071 oop name_oop = k->java_mirror()->obj_field(fd.offset()); |
|
1072 if (name_oop == NULL) |
|
1073 return NULL; |
|
1074 const char* name = java_lang_String::as_utf8_string(name_oop, |
|
1075 java_runtime_name, |
|
1076 sizeof(java_runtime_name)); |
|
1077 return name; |
|
1078 } else { |
|
1079 return NULL; |
|
1080 } |
|
1081 } |
|
1082 |
|
1083 // extract the JRE version from sun.misc.Version.java_runtime_version |
|
1084 static const char* get_java_runtime_version(TRAPS) { |
|
1085 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(), |
|
1086 Handle(), Handle(), CHECK_AND_CLEAR_NULL); |
|
1087 fieldDescriptor fd; |
|
1088 bool found = k != NULL && |
|
1089 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(), |
|
1090 vmSymbols::string_signature(), &fd); |
|
1091 if (found) { |
|
1092 oop name_oop = k->java_mirror()->obj_field(fd.offset()); |
|
1093 if (name_oop == NULL) |
|
1094 return NULL; |
|
1095 const char* name = java_lang_String::as_utf8_string(name_oop, |
|
1096 java_runtime_version, |
|
1097 sizeof(java_runtime_version)); |
|
1098 return name; |
|
1099 } else { |
|
1100 return NULL; |
|
1101 } |
|
1102 } |
|
1103 |
|
1104 // General purpose hook into Java code, run once when the VM is initialized. |
|
1105 // The Java library method itself may be changed independently from the VM. |
|
1106 static void call_postVMInitHook(TRAPS) { |
|
1107 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_PostVMInitHook(), THREAD); |
|
1108 instanceKlassHandle klass (THREAD, k); |
|
1109 if (klass.not_null()) { |
|
1110 JavaValue result(T_VOID); |
|
1111 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(), |
|
1112 vmSymbols::void_method_signature(), |
|
1113 CHECK); |
|
1114 } |
|
1115 } |
|
1116 |
|
1117 static void reset_vm_info_property(TRAPS) { |
|
1118 // the vm info string |
|
1119 ResourceMark rm(THREAD); |
|
1120 const char *vm_info = VM_Version::vm_info_string(); |
|
1121 |
|
1122 // java.lang.System class |
|
1123 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK); |
|
1124 instanceKlassHandle klass (THREAD, k); |
|
1125 |
|
1126 // setProperty arguments |
|
1127 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK); |
|
1128 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK); |
|
1129 |
|
1130 // return value |
|
1131 JavaValue r(T_OBJECT); |
|
1132 |
|
1133 // public static String setProperty(String key, String value); |
|
1134 JavaCalls::call_static(&r, |
|
1135 klass, |
|
1136 vmSymbols::setProperty_name(), |
|
1137 vmSymbols::string_string_string_signature(), |
|
1138 key_str, |
|
1139 value_str, |
|
1140 CHECK); |
|
1141 } |
|
1142 |
|
1143 |
|
1144 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) { |
|
1145 assert(thread_group.not_null(), "thread group should be specified"); |
|
1146 assert(threadObj() == NULL, "should only create Java thread object once"); |
|
1147 |
|
1148 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); |
|
1149 instanceKlassHandle klass (THREAD, k); |
|
1150 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); |
|
1151 |
|
1152 java_lang_Thread::set_thread(thread_oop(), this); |
|
1153 java_lang_Thread::set_priority(thread_oop(), NormPriority); |
|
1154 set_threadObj(thread_oop()); |
|
1155 |
|
1156 JavaValue result(T_VOID); |
|
1157 if (thread_name != NULL) { |
|
1158 Handle name = java_lang_String::create_from_str(thread_name, CHECK); |
|
1159 // Thread gets assigned specified name and null target |
|
1160 JavaCalls::call_special(&result, |
|
1161 thread_oop, |
|
1162 klass, |
|
1163 vmSymbols::object_initializer_name(), |
|
1164 vmSymbols::threadgroup_string_void_signature(), |
|
1165 thread_group, // Argument 1 |
|
1166 name, // Argument 2 |
|
1167 THREAD); |
|
1168 } else { |
|
1169 // Thread gets assigned name "Thread-nnn" and null target |
|
1170 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) |
|
1171 JavaCalls::call_special(&result, |
|
1172 thread_oop, |
|
1173 klass, |
|
1174 vmSymbols::object_initializer_name(), |
|
1175 vmSymbols::threadgroup_runnable_void_signature(), |
|
1176 thread_group, // Argument 1 |
|
1177 Handle(), // Argument 2 |
|
1178 THREAD); |
|
1179 } |
|
1180 |
|
1181 |
|
1182 if (daemon) { |
|
1183 java_lang_Thread::set_daemon(thread_oop()); |
|
1184 } |
|
1185 |
|
1186 if (HAS_PENDING_EXCEPTION) { |
|
1187 return; |
|
1188 } |
|
1189 |
|
1190 KlassHandle group(this, SystemDictionary::ThreadGroup_klass()); |
|
1191 Handle threadObj(this, this->threadObj()); |
|
1192 |
|
1193 JavaCalls::call_special(&result, |
|
1194 thread_group, |
|
1195 group, |
|
1196 vmSymbols::add_method_name(), |
|
1197 vmSymbols::thread_void_signature(), |
|
1198 threadObj, // Arg 1 |
|
1199 THREAD); |
|
1200 |
|
1201 |
|
1202 } |
|
1203 |
|
1204 // NamedThread -- non-JavaThread subclasses with multiple |
|
1205 // uniquely named instances should derive from this. |
|
1206 NamedThread::NamedThread() : Thread() { |
|
1207 _name = NULL; |
|
1208 _processed_thread = NULL; |
|
1209 } |
|
1210 |
|
1211 NamedThread::~NamedThread() { |
|
1212 if (_name != NULL) { |
|
1213 FREE_C_HEAP_ARRAY(char, _name, mtThread); |
|
1214 _name = NULL; |
|
1215 } |
|
1216 } |
|
1217 |
|
1218 void NamedThread::set_name(const char* format, ...) { |
|
1219 guarantee(_name == NULL, "Only get to set name once."); |
|
1220 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread); |
|
1221 guarantee(_name != NULL, "alloc failure"); |
|
1222 va_list ap; |
|
1223 va_start(ap, format); |
|
1224 jio_vsnprintf(_name, max_name_len, format, ap); |
|
1225 va_end(ap); |
|
1226 } |
|
1227 |
|
1228 // ======= WatcherThread ======== |
|
1229 |
|
1230 // The watcher thread exists to simulate timer interrupts. It should |
|
1231 // be replaced by an abstraction over whatever native support for |
|
1232 // timer interrupts exists on the platform. |
|
1233 |
|
1234 WatcherThread* WatcherThread::_watcher_thread = NULL; |
|
1235 bool WatcherThread::_startable = false; |
|
1236 volatile bool WatcherThread::_should_terminate = false; |
|
1237 |
|
1238 WatcherThread::WatcherThread() : Thread(), _crash_protection(NULL) { |
|
1239 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread"); |
|
1240 if (os::create_thread(this, os::watcher_thread)) { |
|
1241 _watcher_thread = this; |
|
1242 |
|
1243 // Set the watcher thread to the highest OS priority which should not be |
|
1244 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY |
|
1245 // is created. The only normal thread using this priority is the reference |
|
1246 // handler thread, which runs for very short intervals only. |
|
1247 // If the VMThread's priority is not lower than the WatcherThread profiling |
|
1248 // will be inaccurate. |
|
1249 os::set_priority(this, MaxPriority); |
|
1250 if (!DisableStartThread) { |
|
1251 os::start_thread(this); |
|
1252 } |
|
1253 } |
|
1254 } |
|
1255 |
|
1256 int WatcherThread::sleep() const { |
|
1257 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag); |
|
1258 |
|
1259 // remaining will be zero if there are no tasks, |
|
1260 // causing the WatcherThread to sleep until a task is |
|
1261 // enrolled |
|
1262 int remaining = PeriodicTask::time_to_wait(); |
|
1263 int time_slept = 0; |
|
1264 |
|
1265 // we expect this to timeout - we only ever get unparked when |
|
1266 // we should terminate or when a new task has been enrolled |
|
1267 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); |
|
1268 |
|
1269 jlong time_before_loop = os::javaTimeNanos(); |
|
1270 |
|
1271 for (;;) { |
|
1272 bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag, remaining); |
|
1273 jlong now = os::javaTimeNanos(); |
|
1274 |
|
1275 if (remaining == 0) { |
|
1276 // if we didn't have any tasks we could have waited for a long time |
|
1277 // consider the time_slept zero and reset time_before_loop |
|
1278 time_slept = 0; |
|
1279 time_before_loop = now; |
|
1280 } else { |
|
1281 // need to recalulate since we might have new tasks in _tasks |
|
1282 time_slept = (int) ((now - time_before_loop) / 1000000); |
|
1283 } |
|
1284 |
|
1285 // Change to task list or spurious wakeup of some kind |
|
1286 if (timedout || _should_terminate) { |
|
1287 break; |
|
1288 } |
|
1289 |
|
1290 remaining = PeriodicTask::time_to_wait(); |
|
1291 if (remaining == 0) { |
|
1292 // Last task was just disenrolled so loop around and wait until |
|
1293 // another task gets enrolled |
|
1294 continue; |
|
1295 } |
|
1296 |
|
1297 remaining -= time_slept; |
|
1298 if (remaining <= 0) |
|
1299 break; |
|
1300 } |
|
1301 |
|
1302 return time_slept; |
|
1303 } |
|
1304 |
|
1305 void WatcherThread::run() { |
|
1306 assert(this == watcher_thread(), "just checking"); |
|
1307 |
|
1308 this->record_stack_base_and_size(); |
|
1309 this->initialize_thread_local_storage(); |
|
1310 this->set_active_handles(JNIHandleBlock::allocate_block()); |
|
1311 while(!_should_terminate) { |
|
1312 assert(watcher_thread() == Thread::current(), "thread consistency check"); |
|
1313 assert(watcher_thread() == this, "thread consistency check"); |
|
1314 |
|
1315 // Calculate how long it'll be until the next PeriodicTask work |
|
1316 // should be done, and sleep that amount of time. |
|
1317 int time_waited = sleep(); |
|
1318 |
|
1319 if (is_error_reported()) { |
|
1320 // A fatal error has happened, the error handler(VMError::report_and_die) |
|
1321 // should abort JVM after creating an error log file. However in some |
|
1322 // rare cases, the error handler itself might deadlock. Here we try to |
|
1323 // kill JVM if the fatal error handler fails to abort in 2 minutes. |
|
1324 // |
|
1325 // This code is in WatcherThread because WatcherThread wakes up |
|
1326 // periodically so the fatal error handler doesn't need to do anything; |
|
1327 // also because the WatcherThread is less likely to crash than other |
|
1328 // threads. |
|
1329 |
|
1330 for (;;) { |
|
1331 if (!ShowMessageBoxOnError |
|
1332 && (OnError == NULL || OnError[0] == '\0') |
|
1333 && Arguments::abort_hook() == NULL) { |
|
1334 os::sleep(this, 2 * 60 * 1000, false); |
|
1335 fdStream err(defaultStream::output_fd()); |
|
1336 err.print_raw_cr("# [ timer expired, abort... ]"); |
|
1337 // skip atexit/vm_exit/vm_abort hooks |
|
1338 os::die(); |
|
1339 } |
|
1340 |
|
1341 // Wake up 5 seconds later, the fatal handler may reset OnError or |
|
1342 // ShowMessageBoxOnError when it is ready to abort. |
|
1343 os::sleep(this, 5 * 1000, false); |
|
1344 } |
|
1345 } |
|
1346 |
|
1347 PeriodicTask::real_time_tick(time_waited); |
|
1348 } |
|
1349 |
|
1350 // Signal that it is terminated |
|
1351 { |
|
1352 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag); |
|
1353 _watcher_thread = NULL; |
|
1354 Terminator_lock->notify(); |
|
1355 } |
|
1356 |
|
1357 // Thread destructor usually does this.. |
|
1358 ThreadLocalStorage::set_thread(NULL); |
|
1359 } |
|
1360 |
|
1361 void WatcherThread::start() { |
|
1362 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required"); |
|
1363 |
|
1364 if (watcher_thread() == NULL && _startable) { |
|
1365 _should_terminate = false; |
|
1366 // Create the single instance of WatcherThread |
|
1367 new WatcherThread(); |
|
1368 } |
|
1369 } |
|
1370 |
|
1371 void WatcherThread::make_startable() { |
|
1372 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required"); |
|
1373 _startable = true; |
|
1374 } |
|
1375 |
|
1376 void WatcherThread::stop() { |
|
1377 { |
|
1378 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag); |
|
1379 _should_terminate = true; |
|
1380 OrderAccess::fence(); // ensure WatcherThread sees update in main loop |
|
1381 |
|
1382 WatcherThread* watcher = watcher_thread(); |
|
1383 if (watcher != NULL) |
|
1384 watcher->unpark(); |
|
1385 } |
|
1386 |
|
1387 // it is ok to take late safepoints here, if needed |
|
1388 MutexLocker mu(Terminator_lock); |
|
1389 |
|
1390 while(watcher_thread() != NULL) { |
|
1391 // This wait should make safepoint checks, wait without a timeout, |
|
1392 // and wait as a suspend-equivalent condition. |
|
1393 // |
|
1394 // Note: If the FlatProfiler is running, then this thread is waiting |
|
1395 // for the WatcherThread to terminate and the WatcherThread, via the |
|
1396 // FlatProfiler task, is waiting for the external suspend request on |
|
1397 // this thread to complete. wait_for_ext_suspend_completion() will |
|
1398 // eventually timeout, but that takes time. Making this wait a |
|
1399 // suspend-equivalent condition solves that timeout problem. |
|
1400 // |
|
1401 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0, |
|
1402 Mutex::_as_suspend_equivalent_flag); |
|
1403 } |
|
1404 } |
|
1405 |
|
1406 void WatcherThread::unpark() { |
|
1407 MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ? NULL : PeriodicTask_lock, Mutex::_no_safepoint_check_flag); |
|
1408 PeriodicTask_lock->notify(); |
|
1409 } |
|
1410 |
|
1411 void WatcherThread::print_on(outputStream* st) const { |
|
1412 st->print("\"%s\" ", name()); |
|
1413 Thread::print_on(st); |
|
1414 st->cr(); |
|
1415 } |
|
1416 |
|
1417 // ======= JavaThread ======== |
|
1418 |
|
1419 // A JavaThread is a normal Java thread |
|
1420 |
|
1421 void JavaThread::initialize() { |
|
1422 // Initialize fields |
|
1423 |
|
1424 // Set the claimed par_id to UINT_MAX (ie not claiming any par_ids) |
|
1425 set_claimed_par_id(UINT_MAX); |
|
1426 |
|
1427 set_saved_exception_pc(NULL); |
|
1428 set_threadObj(NULL); |
|
1429 _anchor.clear(); |
|
1430 set_entry_point(NULL); |
|
1431 set_jni_functions(jni_functions()); |
|
1432 set_callee_target(NULL); |
|
1433 set_vm_result(NULL); |
|
1434 set_vm_result_2(NULL); |
|
1435 set_vframe_array_head(NULL); |
|
1436 set_vframe_array_last(NULL); |
|
1437 set_deferred_locals(NULL); |
|
1438 set_deopt_mark(NULL); |
|
1439 set_deopt_nmethod(NULL); |
|
1440 clear_must_deopt_id(); |
|
1441 set_monitor_chunks(NULL); |
|
1442 set_next(NULL); |
|
1443 set_thread_state(_thread_new); |
|
1444 #if INCLUDE_NMT |
|
1445 set_recorder(NULL); |
|
1446 #endif |
|
1447 _terminated = _not_terminated; |
|
1448 _privileged_stack_top = NULL; |
|
1449 _array_for_gc = NULL; |
|
1450 _suspend_equivalent = false; |
|
1451 _in_deopt_handler = 0; |
|
1452 _doing_unsafe_access = false; |
|
1453 _stack_guard_state = stack_guard_unused; |
|
1454 (void)const_cast<oop&>(_exception_oop = NULL); |
|
1455 _exception_pc = 0; |
|
1456 _exception_handler_pc = 0; |
|
1457 _is_method_handle_return = 0; |
|
1458 _jvmti_thread_state= NULL; |
|
1459 _should_post_on_exceptions_flag = JNI_FALSE; |
|
1460 _jvmti_get_loaded_classes_closure = NULL; |
|
1461 _interp_only_mode = 0; |
|
1462 _special_runtime_exit_condition = _no_async_condition; |
|
1463 _pending_async_exception = NULL; |
|
1464 _thread_stat = NULL; |
|
1465 _thread_stat = new ThreadStatistics(); |
|
1466 _blocked_on_compilation = false; |
|
1467 _jni_active_critical = 0; |
|
1468 _do_not_unlock_if_synchronized = false; |
|
1469 _cached_monitor_info = NULL; |
|
1470 _parker = Parker::Allocate(this) ; |
|
1471 |
|
1472 #ifndef PRODUCT |
|
1473 _jmp_ring_index = 0; |
|
1474 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) { |
|
1475 record_jump(NULL, NULL, NULL, 0); |
|
1476 } |
|
1477 #endif /* PRODUCT */ |
|
1478 |
|
1479 set_thread_profiler(NULL); |
|
1480 if (FlatProfiler::is_active()) { |
|
1481 // This is where we would decide to either give each thread it's own profiler |
|
1482 // or use one global one from FlatProfiler, |
|
1483 // or up to some count of the number of profiled threads, etc. |
|
1484 ThreadProfiler* pp = new ThreadProfiler(); |
|
1485 pp->engage(); |
|
1486 set_thread_profiler(pp); |
|
1487 } |
|
1488 |
|
1489 // Setup safepoint state info for this thread |
|
1490 ThreadSafepointState::create(this); |
|
1491 |
|
1492 debug_only(_java_call_counter = 0); |
|
1493 |
|
1494 // JVMTI PopFrame support |
|
1495 _popframe_condition = popframe_inactive; |
|
1496 _popframe_preserved_args = NULL; |
|
1497 _popframe_preserved_args_size = 0; |
|
1498 |
|
1499 pd_initialize(); |
|
1500 } |
|
1501 |
|
1502 #if INCLUDE_ALL_GCS |
|
1503 SATBMarkQueueSet JavaThread::_satb_mark_queue_set; |
|
1504 DirtyCardQueueSet JavaThread::_dirty_card_queue_set; |
|
1505 #endif // INCLUDE_ALL_GCS |
|
1506 |
|
1507 JavaThread::JavaThread(bool is_attaching_via_jni) : |
|
1508 Thread() |
|
1509 #if INCLUDE_ALL_GCS |
|
1510 , _satb_mark_queue(&_satb_mark_queue_set), |
|
1511 _dirty_card_queue(&_dirty_card_queue_set) |
|
1512 #endif // INCLUDE_ALL_GCS |
|
1513 { |
|
1514 initialize(); |
|
1515 if (is_attaching_via_jni) { |
|
1516 _jni_attach_state = _attaching_via_jni; |
|
1517 } else { |
|
1518 _jni_attach_state = _not_attaching_via_jni; |
|
1519 } |
|
1520 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor"); |
|
1521 _safepoint_visible = false; |
|
1522 } |
|
1523 |
|
1524 bool JavaThread::reguard_stack(address cur_sp) { |
|
1525 if (_stack_guard_state != stack_guard_yellow_disabled) { |
|
1526 return true; // Stack already guarded or guard pages not needed. |
|
1527 } |
|
1528 |
|
1529 if (register_stack_overflow()) { |
|
1530 // For those architectures which have separate register and |
|
1531 // memory stacks, we must check the register stack to see if |
|
1532 // it has overflowed. |
|
1533 return false; |
|
1534 } |
|
1535 |
|
1536 // Java code never executes within the yellow zone: the latter is only |
|
1537 // there to provoke an exception during stack banging. If java code |
|
1538 // is executing there, either StackShadowPages should be larger, or |
|
1539 // some exception code in c1, c2 or the interpreter isn't unwinding |
|
1540 // when it should. |
|
1541 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages"); |
|
1542 |
|
1543 enable_stack_yellow_zone(); |
|
1544 return true; |
|
1545 } |
|
1546 |
|
1547 bool JavaThread::reguard_stack(void) { |
|
1548 return reguard_stack(os::current_stack_pointer()); |
|
1549 } |
|
1550 |
|
1551 |
|
1552 void JavaThread::block_if_vm_exited() { |
|
1553 if (_terminated == _vm_exited) { |
|
1554 // _vm_exited is set at safepoint, and Threads_lock is never released |
|
1555 // we will block here forever |
|
1556 Threads_lock->lock_without_safepoint_check(); |
|
1557 ShouldNotReachHere(); |
|
1558 } |
|
1559 } |
|
1560 |
|
1561 |
|
1562 // Remove this ifdef when C1 is ported to the compiler interface. |
|
1563 static void compiler_thread_entry(JavaThread* thread, TRAPS); |
|
1564 |
|
1565 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : |
|
1566 Thread() |
|
1567 #if INCLUDE_ALL_GCS |
|
1568 , _satb_mark_queue(&_satb_mark_queue_set), |
|
1569 _dirty_card_queue(&_dirty_card_queue_set) |
|
1570 #endif // INCLUDE_ALL_GCS |
|
1571 { |
|
1572 if (TraceThreadEvents) { |
|
1573 tty->print_cr("creating thread %p", this); |
|
1574 } |
|
1575 initialize(); |
|
1576 _jni_attach_state = _not_attaching_via_jni; |
|
1577 set_entry_point(entry_point); |
|
1578 // Create the native thread itself. |
|
1579 // %note runtime_23 |
|
1580 os::ThreadType thr_type = os::java_thread; |
|
1581 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread : |
|
1582 os::java_thread; |
|
1583 os::create_thread(this, thr_type, stack_sz); |
|
1584 _safepoint_visible = false; |
|
1585 // The _osthread may be NULL here because we ran out of memory (too many threads active). |
|
1586 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller |
|
1587 // may hold a lock and all locks must be unlocked before throwing the exception (throwing |
|
1588 // the exception consists of creating the exception object & initializing it, initialization |
|
1589 // will leave the VM via a JavaCall and then all locks must be unlocked). |
|
1590 // |
|
1591 // The thread is still suspended when we reach here. Thread must be explicit started |
|
1592 // by creator! Furthermore, the thread must also explicitly be added to the Threads list |
|
1593 // by calling Threads:add. The reason why this is not done here, is because the thread |
|
1594 // object must be fully initialized (take a look at JVM_Start) |
|
1595 } |
|
1596 |
|
1597 JavaThread::~JavaThread() { |
|
1598 if (TraceThreadEvents) { |
|
1599 tty->print_cr("terminate thread %p", this); |
|
1600 } |
|
1601 |
|
1602 // By now, this thread should already be invisible to safepoint, |
|
1603 // and its per-thread recorder also collected. |
|
1604 assert(!is_safepoint_visible(), "wrong state"); |
|
1605 #if INCLUDE_NMT |
|
1606 assert(get_recorder() == NULL, "Already collected"); |
|
1607 #endif // INCLUDE_NMT |
|
1608 |
|
1609 // JSR166 -- return the parker to the free list |
|
1610 Parker::Release(_parker); |
|
1611 _parker = NULL ; |
|
1612 |
|
1613 // Free any remaining previous UnrollBlock |
|
1614 vframeArray* old_array = vframe_array_last(); |
|
1615 |
|
1616 if (old_array != NULL) { |
|
1617 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); |
|
1618 old_array->set_unroll_block(NULL); |
|
1619 delete old_info; |
|
1620 delete old_array; |
|
1621 } |
|
1622 |
|
1623 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals(); |
|
1624 if (deferred != NULL) { |
|
1625 // This can only happen if thread is destroyed before deoptimization occurs. |
|
1626 assert(deferred->length() != 0, "empty array!"); |
|
1627 do { |
|
1628 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0); |
|
1629 deferred->remove_at(0); |
|
1630 // individual jvmtiDeferredLocalVariableSet are CHeapObj's |
|
1631 delete dlv; |
|
1632 } while (deferred->length() != 0); |
|
1633 delete deferred; |
|
1634 } |
|
1635 |
|
1636 // All Java related clean up happens in exit |
|
1637 ThreadSafepointState::destroy(this); |
|
1638 if (_thread_profiler != NULL) delete _thread_profiler; |
|
1639 if (_thread_stat != NULL) delete _thread_stat; |
|
1640 } |
|
1641 |
|
1642 |
|
1643 // The first routine called by a new Java thread |
|
1644 void JavaThread::run() { |
|
1645 // initialize thread-local alloc buffer related fields |
|
1646 this->initialize_tlab(); |
|
1647 |
|
1648 // used to test validitity of stack trace backs |
|
1649 this->record_base_of_stack_pointer(); |
|
1650 |
|
1651 // Record real stack base and size. |
|
1652 this->record_stack_base_and_size(); |
|
1653 |
|
1654 // Initialize thread local storage; set before calling MutexLocker |
|
1655 this->initialize_thread_local_storage(); |
|
1656 |
|
1657 this->create_stack_guard_pages(); |
|
1658 |
|
1659 this->cache_global_variables(); |
|
1660 |
|
1661 // Thread is now sufficient initialized to be handled by the safepoint code as being |
|
1662 // in the VM. Change thread state from _thread_new to _thread_in_vm |
|
1663 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm); |
|
1664 |
|
1665 assert(JavaThread::current() == this, "sanity check"); |
|
1666 assert(!Thread::current()->owns_locks(), "sanity check"); |
|
1667 |
|
1668 DTRACE_THREAD_PROBE(start, this); |
|
1669 |
|
1670 // This operation might block. We call that after all safepoint checks for a new thread has |
|
1671 // been completed. |
|
1672 this->set_active_handles(JNIHandleBlock::allocate_block()); |
|
1673 |
|
1674 if (JvmtiExport::should_post_thread_life()) { |
|
1675 JvmtiExport::post_thread_start(this); |
|
1676 } |
|
1677 |
|
1678 EventThreadStart event; |
|
1679 if (event.should_commit()) { |
|
1680 event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj())); |
|
1681 event.commit(); |
|
1682 } |
|
1683 |
|
1684 // We call another function to do the rest so we are sure that the stack addresses used |
|
1685 // from there will be lower than the stack base just computed |
|
1686 thread_main_inner(); |
|
1687 |
|
1688 // Note, thread is no longer valid at this point! |
|
1689 } |
|
1690 |
|
1691 |
|
1692 void JavaThread::thread_main_inner() { |
|
1693 assert(JavaThread::current() == this, "sanity check"); |
|
1694 assert(this->threadObj() != NULL, "just checking"); |
|
1695 |
|
1696 // Execute thread entry point unless this thread has a pending exception |
|
1697 // or has been stopped before starting. |
|
1698 // Note: Due to JVM_StopThread we can have pending exceptions already! |
|
1699 if (!this->has_pending_exception() && |
|
1700 !java_lang_Thread::is_stillborn(this->threadObj())) { |
|
1701 { |
|
1702 ResourceMark rm(this); |
|
1703 this->set_native_thread_name(this->get_thread_name()); |
|
1704 } |
|
1705 HandleMark hm(this); |
|
1706 this->entry_point()(this, this); |
|
1707 } |
|
1708 |
|
1709 DTRACE_THREAD_PROBE(stop, this); |
|
1710 |
|
1711 this->exit(false); |
|
1712 delete this; |
|
1713 } |
|
1714 |
|
1715 |
|
1716 static void ensure_join(JavaThread* thread) { |
|
1717 // We do not need to grap the Threads_lock, since we are operating on ourself. |
|
1718 Handle threadObj(thread, thread->threadObj()); |
|
1719 assert(threadObj.not_null(), "java thread object must exist"); |
|
1720 ObjectLocker lock(threadObj, thread); |
|
1721 // Ignore pending exception (ThreadDeath), since we are exiting anyway |
|
1722 thread->clear_pending_exception(); |
|
1723 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. |
|
1724 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED); |
|
1725 // Clear the native thread instance - this makes isAlive return false and allows the join() |
|
1726 // to complete once we've done the notify_all below |
|
1727 java_lang_Thread::set_thread(threadObj(), NULL); |
|
1728 lock.notify_all(thread); |
|
1729 // Ignore pending exception (ThreadDeath), since we are exiting anyway |
|
1730 thread->clear_pending_exception(); |
|
1731 } |
|
1732 |
|
1733 |
|
1734 // For any new cleanup additions, please check to see if they need to be applied to |
|
1735 // cleanup_failed_attach_current_thread as well. |
|
1736 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { |
|
1737 assert(this == JavaThread::current(), "thread consistency check"); |
|
1738 |
|
1739 HandleMark hm(this); |
|
1740 Handle uncaught_exception(this, this->pending_exception()); |
|
1741 this->clear_pending_exception(); |
|
1742 Handle threadObj(this, this->threadObj()); |
|
1743 assert(threadObj.not_null(), "Java thread object should be created"); |
|
1744 |
|
1745 if (get_thread_profiler() != NULL) { |
|
1746 get_thread_profiler()->disengage(); |
|
1747 ResourceMark rm; |
|
1748 get_thread_profiler()->print(get_thread_name()); |
|
1749 } |
|
1750 |
|
1751 |
|
1752 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place |
|
1753 { |
|
1754 EXCEPTION_MARK; |
|
1755 |
|
1756 CLEAR_PENDING_EXCEPTION; |
|
1757 } |
|
1758 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This |
|
1759 // has to be fixed by a runtime query method |
|
1760 if (!destroy_vm || JDK_Version::is_jdk12x_version()) { |
|
1761 // JSR-166: change call from from ThreadGroup.uncaughtException to |
|
1762 // java.lang.Thread.dispatchUncaughtException |
|
1763 if (uncaught_exception.not_null()) { |
|
1764 Handle group(this, java_lang_Thread::threadGroup(threadObj())); |
|
1765 { |
|
1766 EXCEPTION_MARK; |
|
1767 // Check if the method Thread.dispatchUncaughtException() exists. If so |
|
1768 // call it. Otherwise we have an older library without the JSR-166 changes, |
|
1769 // so call ThreadGroup.uncaughtException() |
|
1770 KlassHandle recvrKlass(THREAD, threadObj->klass()); |
|
1771 CallInfo callinfo; |
|
1772 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); |
|
1773 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass, |
|
1774 vmSymbols::dispatchUncaughtException_name(), |
|
1775 vmSymbols::throwable_void_signature(), |
|
1776 KlassHandle(), false, false, THREAD); |
|
1777 CLEAR_PENDING_EXCEPTION; |
|
1778 methodHandle method = callinfo.selected_method(); |
|
1779 if (method.not_null()) { |
|
1780 JavaValue result(T_VOID); |
|
1781 JavaCalls::call_virtual(&result, |
|
1782 threadObj, thread_klass, |
|
1783 vmSymbols::dispatchUncaughtException_name(), |
|
1784 vmSymbols::throwable_void_signature(), |
|
1785 uncaught_exception, |
|
1786 THREAD); |
|
1787 } else { |
|
1788 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass()); |
|
1789 JavaValue result(T_VOID); |
|
1790 JavaCalls::call_virtual(&result, |
|
1791 group, thread_group, |
|
1792 vmSymbols::uncaughtException_name(), |
|
1793 vmSymbols::thread_throwable_void_signature(), |
|
1794 threadObj, // Arg 1 |
|
1795 uncaught_exception, // Arg 2 |
|
1796 THREAD); |
|
1797 } |
|
1798 if (HAS_PENDING_EXCEPTION) { |
|
1799 ResourceMark rm(this); |
|
1800 jio_fprintf(defaultStream::error_stream(), |
|
1801 "\nException: %s thrown from the UncaughtExceptionHandler" |
|
1802 " in thread \"%s\"\n", |
|
1803 pending_exception()->klass()->external_name(), |
|
1804 get_thread_name()); |
|
1805 CLEAR_PENDING_EXCEPTION; |
|
1806 } |
|
1807 } |
|
1808 } |
|
1809 |
|
1810 // Called before the java thread exit since we want to read info |
|
1811 // from java_lang_Thread object |
|
1812 EventThreadEnd event; |
|
1813 if (event.should_commit()) { |
|
1814 event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj())); |
|
1815 event.commit(); |
|
1816 } |
|
1817 |
|
1818 // Call after last event on thread |
|
1819 EVENT_THREAD_EXIT(this); |
|
1820 |
|
1821 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during |
|
1822 // the execution of the method. If that is not enough, then we don't really care. Thread.stop |
|
1823 // is deprecated anyhow. |
|
1824 if (!is_Compiler_thread()) { |
|
1825 int count = 3; |
|
1826 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) { |
|
1827 EXCEPTION_MARK; |
|
1828 JavaValue result(T_VOID); |
|
1829 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass()); |
|
1830 JavaCalls::call_virtual(&result, |
|
1831 threadObj, thread_klass, |
|
1832 vmSymbols::exit_method_name(), |
|
1833 vmSymbols::void_method_signature(), |
|
1834 THREAD); |
|
1835 CLEAR_PENDING_EXCEPTION; |
|
1836 } |
|
1837 } |
|
1838 // notify JVMTI |
|
1839 if (JvmtiExport::should_post_thread_life()) { |
|
1840 JvmtiExport::post_thread_end(this); |
|
1841 } |
|
1842 |
|
1843 // We have notified the agents that we are exiting, before we go on, |
|
1844 // we must check for a pending external suspend request and honor it |
|
1845 // in order to not surprise the thread that made the suspend request. |
|
1846 while (true) { |
|
1847 { |
|
1848 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); |
|
1849 if (!is_external_suspend()) { |
|
1850 set_terminated(_thread_exiting); |
|
1851 ThreadService::current_thread_exiting(this); |
|
1852 break; |
|
1853 } |
|
1854 // Implied else: |
|
1855 // Things get a little tricky here. We have a pending external |
|
1856 // suspend request, but we are holding the SR_lock so we |
|
1857 // can't just self-suspend. So we temporarily drop the lock |
|
1858 // and then self-suspend. |
|
1859 } |
|
1860 |
|
1861 ThreadBlockInVM tbivm(this); |
|
1862 java_suspend_self(); |
|
1863 |
|
1864 // We're done with this suspend request, but we have to loop around |
|
1865 // and check again. Eventually we will get SR_lock without a pending |
|
1866 // external suspend request and will be able to mark ourselves as |
|
1867 // exiting. |
|
1868 } |
|
1869 // no more external suspends are allowed at this point |
|
1870 } else { |
|
1871 // before_exit() has already posted JVMTI THREAD_END events |
|
1872 } |
|
1873 |
|
1874 // Notify waiters on thread object. This has to be done after exit() is called |
|
1875 // on the thread (if the thread is the last thread in a daemon ThreadGroup the |
|
1876 // group should have the destroyed bit set before waiters are notified). |
|
1877 ensure_join(this); |
|
1878 assert(!this->has_pending_exception(), "ensure_join should have cleared"); |
|
1879 |
|
1880 // 6282335 JNI DetachCurrentThread spec states that all Java monitors |
|
1881 // held by this thread must be released. A detach operation must only |
|
1882 // get here if there are no Java frames on the stack. Therefore, any |
|
1883 // owned monitors at this point MUST be JNI-acquired monitors which are |
|
1884 // pre-inflated and in the monitor cache. |
|
1885 // |
|
1886 // ensure_join() ignores IllegalThreadStateExceptions, and so does this. |
|
1887 if (exit_type == jni_detach && JNIDetachReleasesMonitors) { |
|
1888 assert(!this->has_last_Java_frame(), "detaching with Java frames?"); |
|
1889 ObjectSynchronizer::release_monitors_owned_by_thread(this); |
|
1890 assert(!this->has_pending_exception(), "release_monitors should have cleared"); |
|
1891 } |
|
1892 |
|
1893 // These things needs to be done while we are still a Java Thread. Make sure that thread |
|
1894 // is in a consistent state, in case GC happens |
|
1895 assert(_privileged_stack_top == NULL, "must be NULL when we get here"); |
|
1896 |
|
1897 if (active_handles() != NULL) { |
|
1898 JNIHandleBlock* block = active_handles(); |
|
1899 set_active_handles(NULL); |
|
1900 JNIHandleBlock::release_block(block); |
|
1901 } |
|
1902 |
|
1903 if (free_handle_block() != NULL) { |
|
1904 JNIHandleBlock* block = free_handle_block(); |
|
1905 set_free_handle_block(NULL); |
|
1906 JNIHandleBlock::release_block(block); |
|
1907 } |
|
1908 |
|
1909 // These have to be removed while this is still a valid thread. |
|
1910 remove_stack_guard_pages(); |
|
1911 |
|
1912 if (UseTLAB) { |
|
1913 tlab().make_parsable(true); // retire TLAB |
|
1914 } |
|
1915 |
|
1916 if (JvmtiEnv::environments_might_exist()) { |
|
1917 JvmtiExport::cleanup_thread(this); |
|
1918 } |
|
1919 |
|
1920 // We must flush any deferred card marks before removing a thread from |
|
1921 // the list of active threads. |
|
1922 Universe::heap()->flush_deferred_store_barrier(this); |
|
1923 assert(deferred_card_mark().is_empty(), "Should have been flushed"); |
|
1924 |
|
1925 #if INCLUDE_ALL_GCS |
|
1926 // We must flush the G1-related buffers before removing a thread |
|
1927 // from the list of active threads. We must do this after any deferred |
|
1928 // card marks have been flushed (above) so that any entries that are |
|
1929 // added to the thread's dirty card queue as a result are not lost. |
|
1930 if (UseG1GC) { |
|
1931 flush_barrier_queues(); |
|
1932 } |
|
1933 #endif // INCLUDE_ALL_GCS |
|
1934 |
|
1935 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread |
|
1936 Threads::remove(this); |
|
1937 } |
|
1938 |
|
1939 #if INCLUDE_ALL_GCS |
|
1940 // Flush G1-related queues. |
|
1941 void JavaThread::flush_barrier_queues() { |
|
1942 satb_mark_queue().flush(); |
|
1943 dirty_card_queue().flush(); |
|
1944 } |
|
1945 |
|
1946 void JavaThread::initialize_queues() { |
|
1947 assert(!SafepointSynchronize::is_at_safepoint(), |
|
1948 "we should not be at a safepoint"); |
|
1949 |
|
1950 ObjPtrQueue& satb_queue = satb_mark_queue(); |
|
1951 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set(); |
|
1952 // The SATB queue should have been constructed with its active |
|
1953 // field set to false. |
|
1954 assert(!satb_queue.is_active(), "SATB queue should not be active"); |
|
1955 assert(satb_queue.is_empty(), "SATB queue should be empty"); |
|
1956 // If we are creating the thread during a marking cycle, we should |
|
1957 // set the active field of the SATB queue to true. |
|
1958 if (satb_queue_set.is_active()) { |
|
1959 satb_queue.set_active(true); |
|
1960 } |
|
1961 |
|
1962 DirtyCardQueue& dirty_queue = dirty_card_queue(); |
|
1963 // The dirty card queue should have been constructed with its |
|
1964 // active field set to true. |
|
1965 assert(dirty_queue.is_active(), "dirty card queue should be active"); |
|
1966 } |
|
1967 #endif // INCLUDE_ALL_GCS |
|
1968 |
|
1969 void JavaThread::cleanup_failed_attach_current_thread() { |
|
1970 if (get_thread_profiler() != NULL) { |
|
1971 get_thread_profiler()->disengage(); |
|
1972 ResourceMark rm; |
|
1973 get_thread_profiler()->print(get_thread_name()); |
|
1974 } |
|
1975 |
|
1976 if (active_handles() != NULL) { |
|
1977 JNIHandleBlock* block = active_handles(); |
|
1978 set_active_handles(NULL); |
|
1979 JNIHandleBlock::release_block(block); |
|
1980 } |
|
1981 |
|
1982 if (free_handle_block() != NULL) { |
|
1983 JNIHandleBlock* block = free_handle_block(); |
|
1984 set_free_handle_block(NULL); |
|
1985 JNIHandleBlock::release_block(block); |
|
1986 } |
|
1987 |
|
1988 // These have to be removed while this is still a valid thread. |
|
1989 remove_stack_guard_pages(); |
|
1990 |
|
1991 if (UseTLAB) { |
|
1992 tlab().make_parsable(true); // retire TLAB, if any |
|
1993 } |
|
1994 |
|
1995 #if INCLUDE_ALL_GCS |
|
1996 if (UseG1GC) { |
|
1997 flush_barrier_queues(); |
|
1998 } |
|
1999 #endif // INCLUDE_ALL_GCS |
|
2000 |
|
2001 Threads::remove(this); |
|
2002 delete this; |
|
2003 } |
|
2004 |
|
2005 |
|
2006 |
|
2007 |
|
2008 JavaThread* JavaThread::active() { |
|
2009 Thread* thread = ThreadLocalStorage::thread(); |
|
2010 assert(thread != NULL, "just checking"); |
|
2011 if (thread->is_Java_thread()) { |
|
2012 return (JavaThread*) thread; |
|
2013 } else { |
|
2014 assert(thread->is_VM_thread(), "this must be a vm thread"); |
|
2015 VM_Operation* op = ((VMThread*) thread)->vm_operation(); |
|
2016 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread(); |
|
2017 assert(ret->is_Java_thread(), "must be a Java thread"); |
|
2018 return ret; |
|
2019 } |
|
2020 } |
|
2021 |
|
2022 bool JavaThread::is_lock_owned(address adr) const { |
|
2023 if (Thread::is_lock_owned(adr)) return true; |
|
2024 |
|
2025 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { |
|
2026 if (chunk->contains(adr)) return true; |
|
2027 } |
|
2028 |
|
2029 return false; |
|
2030 } |
|
2031 |
|
2032 |
|
2033 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { |
|
2034 chunk->set_next(monitor_chunks()); |
|
2035 set_monitor_chunks(chunk); |
|
2036 } |
|
2037 |
|
2038 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { |
|
2039 guarantee(monitor_chunks() != NULL, "must be non empty"); |
|
2040 if (monitor_chunks() == chunk) { |
|
2041 set_monitor_chunks(chunk->next()); |
|
2042 } else { |
|
2043 MonitorChunk* prev = monitor_chunks(); |
|
2044 while (prev->next() != chunk) prev = prev->next(); |
|
2045 prev->set_next(chunk->next()); |
|
2046 } |
|
2047 } |
|
2048 |
|
2049 // JVM support. |
|
2050 |
|
2051 // Note: this function shouldn't block if it's called in |
|
2052 // _thread_in_native_trans state (such as from |
|
2053 // check_special_condition_for_native_trans()). |
|
2054 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) { |
|
2055 |
|
2056 if (has_last_Java_frame() && has_async_condition()) { |
|
2057 // If we are at a polling page safepoint (not a poll return) |
|
2058 // then we must defer async exception because live registers |
|
2059 // will be clobbered by the exception path. Poll return is |
|
2060 // ok because the call we a returning from already collides |
|
2061 // with exception handling registers and so there is no issue. |
|
2062 // (The exception handling path kills call result registers but |
|
2063 // this is ok since the exception kills the result anyway). |
|
2064 |
|
2065 if (is_at_poll_safepoint()) { |
|
2066 // if the code we are returning to has deoptimized we must defer |
|
2067 // the exception otherwise live registers get clobbered on the |
|
2068 // exception path before deoptimization is able to retrieve them. |
|
2069 // |
|
2070 RegisterMap map(this, false); |
|
2071 frame caller_fr = last_frame().sender(&map); |
|
2072 assert(caller_fr.is_compiled_frame(), "what?"); |
|
2073 if (caller_fr.is_deoptimized_frame()) { |
|
2074 if (TraceExceptions) { |
|
2075 ResourceMark rm; |
|
2076 tty->print_cr("deferred async exception at compiled safepoint"); |
|
2077 } |
|
2078 return; |
|
2079 } |
|
2080 } |
|
2081 } |
|
2082 |
|
2083 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition(); |
|
2084 if (condition == _no_async_condition) { |
|
2085 // Conditions have changed since has_special_runtime_exit_condition() |
|
2086 // was called: |
|
2087 // - if we were here only because of an external suspend request, |
|
2088 // then that was taken care of above (or cancelled) so we are done |
|
2089 // - if we were here because of another async request, then it has |
|
2090 // been cleared between the has_special_runtime_exit_condition() |
|
2091 // and now so again we are done |
|
2092 return; |
|
2093 } |
|
2094 |
|
2095 // Check for pending async. exception |
|
2096 if (_pending_async_exception != NULL) { |
|
2097 // Only overwrite an already pending exception, if it is not a threadDeath. |
|
2098 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) { |
|
2099 |
|
2100 // We cannot call Exceptions::_throw(...) here because we cannot block |
|
2101 set_pending_exception(_pending_async_exception, __FILE__, __LINE__); |
|
2102 |
|
2103 if (TraceExceptions) { |
|
2104 ResourceMark rm; |
|
2105 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this); |
|
2106 if (has_last_Java_frame() ) { |
|
2107 frame f = last_frame(); |
|
2108 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp()); |
|
2109 } |
|
2110 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name()); |
|
2111 } |
|
2112 _pending_async_exception = NULL; |
|
2113 clear_has_async_exception(); |
|
2114 } |
|
2115 } |
|
2116 |
|
2117 if (check_unsafe_error && |
|
2118 condition == _async_unsafe_access_error && !has_pending_exception()) { |
|
2119 condition = _no_async_condition; // done |
|
2120 switch (thread_state()) { |
|
2121 case _thread_in_vm: |
|
2122 { |
|
2123 JavaThread* THREAD = this; |
|
2124 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); |
|
2125 } |
|
2126 case _thread_in_native: |
|
2127 { |
|
2128 ThreadInVMfromNative tiv(this); |
|
2129 JavaThread* THREAD = this; |
|
2130 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation"); |
|
2131 } |
|
2132 case _thread_in_Java: |
|
2133 { |
|
2134 ThreadInVMfromJava tiv(this); |
|
2135 JavaThread* THREAD = this; |
|
2136 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code"); |
|
2137 } |
|
2138 default: |
|
2139 ShouldNotReachHere(); |
|
2140 } |
|
2141 } |
|
2142 |
|
2143 assert(condition == _no_async_condition || has_pending_exception() || |
|
2144 (!check_unsafe_error && condition == _async_unsafe_access_error), |
|
2145 "must have handled the async condition, if no exception"); |
|
2146 } |
|
2147 |
|
2148 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) { |
|
2149 // |
|
2150 // Check for pending external suspend. Internal suspend requests do |
|
2151 // not use handle_special_runtime_exit_condition(). |
|
2152 // If JNIEnv proxies are allowed, don't self-suspend if the target |
|
2153 // thread is not the current thread. In older versions of jdbx, jdbx |
|
2154 // threads could call into the VM with another thread's JNIEnv so we |
|
2155 // can be here operating on behalf of a suspended thread (4432884). |
|
2156 bool do_self_suspend = is_external_suspend_with_lock(); |
|
2157 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) { |
|
2158 // |
|
2159 // Because thread is external suspended the safepoint code will count |
|
2160 // thread as at a safepoint. This can be odd because we can be here |
|
2161 // as _thread_in_Java which would normally transition to _thread_blocked |
|
2162 // at a safepoint. We would like to mark the thread as _thread_blocked |
|
2163 // before calling java_suspend_self like all other callers of it but |
|
2164 // we must then observe proper safepoint protocol. (We can't leave |
|
2165 // _thread_blocked with a safepoint in progress). However we can be |
|
2166 // here as _thread_in_native_trans so we can't use a normal transition |
|
2167 // constructor/destructor pair because they assert on that type of |
|
2168 // transition. We could do something like: |
|
2169 // |
|
2170 // JavaThreadState state = thread_state(); |
|
2171 // set_thread_state(_thread_in_vm); |
|
2172 // { |
|
2173 // ThreadBlockInVM tbivm(this); |
|
2174 // java_suspend_self() |
|
2175 // } |
|
2176 // set_thread_state(_thread_in_vm_trans); |
|
2177 // if (safepoint) block; |
|
2178 // set_thread_state(state); |
|
2179 // |
|
2180 // but that is pretty messy. Instead we just go with the way the |
|
2181 // code has worked before and note that this is the only path to |
|
2182 // java_suspend_self that doesn't put the thread in _thread_blocked |
|
2183 // mode. |
|
2184 |
|
2185 frame_anchor()->make_walkable(this); |
|
2186 java_suspend_self(); |
|
2187 |
|
2188 // We might be here for reasons in addition to the self-suspend request |
|
2189 // so check for other async requests. |
|
2190 } |
|
2191 |
|
2192 if (check_asyncs) { |
|
2193 check_and_handle_async_exceptions(); |
|
2194 } |
|
2195 } |
|
2196 |
|
2197 void JavaThread::send_thread_stop(oop java_throwable) { |
|
2198 assert(Thread::current()->is_VM_thread(), "should be in the vm thread"); |
|
2199 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code"); |
|
2200 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); |
|
2201 |
|
2202 // Do not throw asynchronous exceptions against the compiler thread |
|
2203 // (the compiler thread should not be a Java thread -- fix in 1.4.2) |
|
2204 if (is_Compiler_thread()) return; |
|
2205 |
|
2206 { |
|
2207 // Actually throw the Throwable against the target Thread - however |
|
2208 // only if there is no thread death exception installed already. |
|
2209 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) { |
|
2210 // If the topmost frame is a runtime stub, then we are calling into |
|
2211 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) |
|
2212 // must deoptimize the caller before continuing, as the compiled exception handler table |
|
2213 // may not be valid |
|
2214 if (has_last_Java_frame()) { |
|
2215 frame f = last_frame(); |
|
2216 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) { |
|
2217 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass |
|
2218 RegisterMap reg_map(this, UseBiasedLocking); |
|
2219 frame compiled_frame = f.sender(®_map); |
|
2220 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) { |
|
2221 Deoptimization::deoptimize(this, compiled_frame, ®_map); |
|
2222 } |
|
2223 } |
|
2224 } |
|
2225 |
|
2226 // Set async. pending exception in thread. |
|
2227 set_pending_async_exception(java_throwable); |
|
2228 |
|
2229 if (TraceExceptions) { |
|
2230 ResourceMark rm; |
|
2231 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name()); |
|
2232 } |
|
2233 // for AbortVMOnException flag |
|
2234 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name())); |
|
2235 } |
|
2236 } |
|
2237 |
|
2238 |
|
2239 // Interrupt thread so it will wake up from a potential wait() |
|
2240 Thread::interrupt(this); |
|
2241 } |
|
2242 |
|
2243 // External suspension mechanism. |
|
2244 // |
|
2245 // Tell the VM to suspend a thread when ever it knows that it does not hold on |
|
2246 // to any VM_locks and it is at a transition |
|
2247 // Self-suspension will happen on the transition out of the vm. |
|
2248 // Catch "this" coming in from JNIEnv pointers when the thread has been freed |
|
2249 // |
|
2250 // Guarantees on return: |
|
2251 // + Target thread will not execute any new bytecode (that's why we need to |
|
2252 // force a safepoint) |
|
2253 // + Target thread will not enter any new monitors |
|
2254 // |
|
2255 void JavaThread::java_suspend() { |
|
2256 { MutexLocker mu(Threads_lock); |
|
2257 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) { |
|
2258 return; |
|
2259 } |
|
2260 } |
|
2261 |
|
2262 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); |
|
2263 if (!is_external_suspend()) { |
|
2264 // a racing resume has cancelled us; bail out now |
|
2265 return; |
|
2266 } |
|
2267 |
|
2268 // suspend is done |
|
2269 uint32_t debug_bits = 0; |
|
2270 // Warning: is_ext_suspend_completed() may temporarily drop the |
|
2271 // SR_lock to allow the thread to reach a stable thread state if |
|
2272 // it is currently in a transient thread state. |
|
2273 if (is_ext_suspend_completed(false /* !called_by_wait */, |
|
2274 SuspendRetryDelay, &debug_bits) ) { |
|
2275 return; |
|
2276 } |
|
2277 } |
|
2278 |
|
2279 VM_ForceSafepoint vm_suspend; |
|
2280 VMThread::execute(&vm_suspend); |
|
2281 } |
|
2282 |
|
2283 // Part II of external suspension. |
|
2284 // A JavaThread self suspends when it detects a pending external suspend |
|
2285 // request. This is usually on transitions. It is also done in places |
|
2286 // where continuing to the next transition would surprise the caller, |
|
2287 // e.g., monitor entry. |
|
2288 // |
|
2289 // Returns the number of times that the thread self-suspended. |
|
2290 // |
|
2291 // Note: DO NOT call java_suspend_self() when you just want to block current |
|
2292 // thread. java_suspend_self() is the second stage of cooperative |
|
2293 // suspension for external suspend requests and should only be used |
|
2294 // to complete an external suspend request. |
|
2295 // |
|
2296 int JavaThread::java_suspend_self() { |
|
2297 int ret = 0; |
|
2298 |
|
2299 // we are in the process of exiting so don't suspend |
|
2300 if (is_exiting()) { |
|
2301 clear_external_suspend(); |
|
2302 return ret; |
|
2303 } |
|
2304 |
|
2305 assert(_anchor.walkable() || |
|
2306 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()), |
|
2307 "must have walkable stack"); |
|
2308 |
|
2309 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); |
|
2310 |
|
2311 assert(!this->is_ext_suspended(), |
|
2312 "a thread trying to self-suspend should not already be suspended"); |
|
2313 |
|
2314 if (this->is_suspend_equivalent()) { |
|
2315 // If we are self-suspending as a result of the lifting of a |
|
2316 // suspend equivalent condition, then the suspend_equivalent |
|
2317 // flag is not cleared until we set the ext_suspended flag so |
|
2318 // that wait_for_ext_suspend_completion() returns consistent |
|
2319 // results. |
|
2320 this->clear_suspend_equivalent(); |
|
2321 } |
|
2322 |
|
2323 // A racing resume may have cancelled us before we grabbed SR_lock |
|
2324 // above. Or another external suspend request could be waiting for us |
|
2325 // by the time we return from SR_lock()->wait(). The thread |
|
2326 // that requested the suspension may already be trying to walk our |
|
2327 // stack and if we return now, we can change the stack out from under |
|
2328 // it. This would be a "bad thing (TM)" and cause the stack walker |
|
2329 // to crash. We stay self-suspended until there are no more pending |
|
2330 // external suspend requests. |
|
2331 while (is_external_suspend()) { |
|
2332 ret++; |
|
2333 this->set_ext_suspended(); |
|
2334 |
|
2335 // _ext_suspended flag is cleared by java_resume() |
|
2336 while (is_ext_suspended()) { |
|
2337 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag); |
|
2338 } |
|
2339 } |
|
2340 |
|
2341 return ret; |
|
2342 } |
|
2343 |
|
2344 #ifdef ASSERT |
|
2345 // verify the JavaThread has not yet been published in the Threads::list, and |
|
2346 // hence doesn't need protection from concurrent access at this stage |
|
2347 void JavaThread::verify_not_published() { |
|
2348 if (!Threads_lock->owned_by_self()) { |
|
2349 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag); |
|
2350 assert( !Threads::includes(this), |
|
2351 "java thread shouldn't have been published yet!"); |
|
2352 } |
|
2353 else { |
|
2354 assert( !Threads::includes(this), |
|
2355 "java thread shouldn't have been published yet!"); |
|
2356 } |
|
2357 } |
|
2358 #endif |
|
2359 |
|
2360 // Slow path when the native==>VM/Java barriers detect a safepoint is in |
|
2361 // progress or when _suspend_flags is non-zero. |
|
2362 // Current thread needs to self-suspend if there is a suspend request and/or |
|
2363 // block if a safepoint is in progress. |
|
2364 // Async exception ISN'T checked. |
|
2365 // Note only the ThreadInVMfromNative transition can call this function |
|
2366 // directly and when thread state is _thread_in_native_trans |
|
2367 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) { |
|
2368 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); |
|
2369 |
|
2370 JavaThread *curJT = JavaThread::current(); |
|
2371 bool do_self_suspend = thread->is_external_suspend(); |
|
2372 |
|
2373 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition"); |
|
2374 |
|
2375 // If JNIEnv proxies are allowed, don't self-suspend if the target |
|
2376 // thread is not the current thread. In older versions of jdbx, jdbx |
|
2377 // threads could call into the VM with another thread's JNIEnv so we |
|
2378 // can be here operating on behalf of a suspended thread (4432884). |
|
2379 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) { |
|
2380 JavaThreadState state = thread->thread_state(); |
|
2381 |
|
2382 // We mark this thread_blocked state as a suspend-equivalent so |
|
2383 // that a caller to is_ext_suspend_completed() won't be confused. |
|
2384 // The suspend-equivalent state is cleared by java_suspend_self(). |
|
2385 thread->set_suspend_equivalent(); |
|
2386 |
|
2387 // If the safepoint code sees the _thread_in_native_trans state, it will |
|
2388 // wait until the thread changes to other thread state. There is no |
|
2389 // guarantee on how soon we can obtain the SR_lock and complete the |
|
2390 // self-suspend request. It would be a bad idea to let safepoint wait for |
|
2391 // too long. Temporarily change the state to _thread_blocked to |
|
2392 // let the VM thread know that this thread is ready for GC. The problem |
|
2393 // of changing thread state is that safepoint could happen just after |
|
2394 // java_suspend_self() returns after being resumed, and VM thread will |
|
2395 // see the _thread_blocked state. We must check for safepoint |
|
2396 // after restoring the state and make sure we won't leave while a safepoint |
|
2397 // is in progress. |
|
2398 thread->set_thread_state(_thread_blocked); |
|
2399 thread->java_suspend_self(); |
|
2400 thread->set_thread_state(state); |
|
2401 // Make sure new state is seen by VM thread |
|
2402 if (os::is_MP()) { |
|
2403 if (UseMembar) { |
|
2404 // Force a fence between the write above and read below |
|
2405 OrderAccess::fence(); |
|
2406 } else { |
|
2407 // Must use this rather than serialization page in particular on Windows |
|
2408 InterfaceSupport::serialize_memory(thread); |
|
2409 } |
|
2410 } |
|
2411 } |
|
2412 |
|
2413 if (SafepointSynchronize::do_call_back()) { |
|
2414 // If we are safepointing, then block the caller which may not be |
|
2415 // the same as the target thread (see above). |
|
2416 SafepointSynchronize::block(curJT); |
|
2417 } |
|
2418 |
|
2419 if (thread->is_deopt_suspend()) { |
|
2420 thread->clear_deopt_suspend(); |
|
2421 RegisterMap map(thread, false); |
|
2422 frame f = thread->last_frame(); |
|
2423 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) { |
|
2424 f = f.sender(&map); |
|
2425 } |
|
2426 if (f.id() == thread->must_deopt_id()) { |
|
2427 thread->clear_must_deopt_id(); |
|
2428 f.deoptimize(thread); |
|
2429 } else { |
|
2430 fatal("missed deoptimization!"); |
|
2431 } |
|
2432 } |
|
2433 } |
|
2434 |
|
2435 // Slow path when the native==>VM/Java barriers detect a safepoint is in |
|
2436 // progress or when _suspend_flags is non-zero. |
|
2437 // Current thread needs to self-suspend if there is a suspend request and/or |
|
2438 // block if a safepoint is in progress. |
|
2439 // Also check for pending async exception (not including unsafe access error). |
|
2440 // Note only the native==>VM/Java barriers can call this function and when |
|
2441 // thread state is _thread_in_native_trans. |
|
2442 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { |
|
2443 check_safepoint_and_suspend_for_native_trans(thread); |
|
2444 |
|
2445 if (thread->has_async_exception()) { |
|
2446 // We are in _thread_in_native_trans state, don't handle unsafe |
|
2447 // access error since that may block. |
|
2448 thread->check_and_handle_async_exceptions(false); |
|
2449 } |
|
2450 } |
|
2451 |
|
2452 // This is a variant of the normal |
|
2453 // check_special_condition_for_native_trans with slightly different |
|
2454 // semantics for use by critical native wrappers. It does all the |
|
2455 // normal checks but also performs the transition back into |
|
2456 // thread_in_Java state. This is required so that critical natives |
|
2457 // can potentially block and perform a GC if they are the last thread |
|
2458 // exiting the GC_locker. |
|
2459 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) { |
|
2460 check_special_condition_for_native_trans(thread); |
|
2461 |
|
2462 // Finish the transition |
|
2463 thread->set_thread_state(_thread_in_Java); |
|
2464 |
|
2465 if (thread->do_critical_native_unlock()) { |
|
2466 ThreadInVMfromJavaNoAsyncException tiv(thread); |
|
2467 GC_locker::unlock_critical(thread); |
|
2468 thread->clear_critical_native_unlock(); |
|
2469 } |
|
2470 } |
|
2471 |
|
2472 // We need to guarantee the Threads_lock here, since resumes are not |
|
2473 // allowed during safepoint synchronization |
|
2474 // Can only resume from an external suspension |
|
2475 void JavaThread::java_resume() { |
|
2476 assert_locked_or_safepoint(Threads_lock); |
|
2477 |
|
2478 // Sanity check: thread is gone, has started exiting or the thread |
|
2479 // was not externally suspended. |
|
2480 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) { |
|
2481 return; |
|
2482 } |
|
2483 |
|
2484 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); |
|
2485 |
|
2486 clear_external_suspend(); |
|
2487 |
|
2488 if (is_ext_suspended()) { |
|
2489 clear_ext_suspended(); |
|
2490 SR_lock()->notify_all(); |
|
2491 } |
|
2492 } |
|
2493 |
|
2494 void JavaThread::create_stack_guard_pages() { |
|
2495 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return; |
|
2496 address low_addr = stack_base() - stack_size(); |
|
2497 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); |
|
2498 |
|
2499 int allocate = os::allocate_stack_guard_pages(); |
|
2500 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len); |
|
2501 |
|
2502 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) { |
|
2503 warning("Attempt to allocate stack guard pages failed."); |
|
2504 return; |
|
2505 } |
|
2506 |
|
2507 if (os::guard_memory((char *) low_addr, len)) { |
|
2508 _stack_guard_state = stack_guard_enabled; |
|
2509 } else { |
|
2510 warning("Attempt to protect stack guard pages failed."); |
|
2511 if (os::uncommit_memory((char *) low_addr, len)) { |
|
2512 warning("Attempt to deallocate stack guard pages failed."); |
|
2513 } |
|
2514 } |
|
2515 } |
|
2516 |
|
2517 void JavaThread::remove_stack_guard_pages() { |
|
2518 assert(Thread::current() == this, "from different thread"); |
|
2519 if (_stack_guard_state == stack_guard_unused) return; |
|
2520 address low_addr = stack_base() - stack_size(); |
|
2521 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size(); |
|
2522 |
|
2523 if (os::allocate_stack_guard_pages()) { |
|
2524 if (os::remove_stack_guard_pages((char *) low_addr, len)) { |
|
2525 _stack_guard_state = stack_guard_unused; |
|
2526 } else { |
|
2527 warning("Attempt to deallocate stack guard pages failed."); |
|
2528 } |
|
2529 } else { |
|
2530 if (_stack_guard_state == stack_guard_unused) return; |
|
2531 if (os::unguard_memory((char *) low_addr, len)) { |
|
2532 _stack_guard_state = stack_guard_unused; |
|
2533 } else { |
|
2534 warning("Attempt to unprotect stack guard pages failed."); |
|
2535 } |
|
2536 } |
|
2537 } |
|
2538 |
|
2539 void JavaThread::enable_stack_yellow_zone() { |
|
2540 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); |
|
2541 assert(_stack_guard_state != stack_guard_enabled, "already enabled"); |
|
2542 |
|
2543 // The base notation is from the stacks point of view, growing downward. |
|
2544 // We need to adjust it to work correctly with guard_memory() |
|
2545 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); |
|
2546 |
|
2547 guarantee(base < stack_base(),"Error calculating stack yellow zone"); |
|
2548 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone"); |
|
2549 |
|
2550 if (os::guard_memory((char *) base, stack_yellow_zone_size())) { |
|
2551 _stack_guard_state = stack_guard_enabled; |
|
2552 } else { |
|
2553 warning("Attempt to guard stack yellow zone failed."); |
|
2554 } |
|
2555 enable_register_stack_guard(); |
|
2556 } |
|
2557 |
|
2558 void JavaThread::disable_stack_yellow_zone() { |
|
2559 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); |
|
2560 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled"); |
|
2561 |
|
2562 // Simply return if called for a thread that does not use guard pages. |
|
2563 if (_stack_guard_state == stack_guard_unused) return; |
|
2564 |
|
2565 // The base notation is from the stacks point of view, growing downward. |
|
2566 // We need to adjust it to work correctly with guard_memory() |
|
2567 address base = stack_yellow_zone_base() - stack_yellow_zone_size(); |
|
2568 |
|
2569 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) { |
|
2570 _stack_guard_state = stack_guard_yellow_disabled; |
|
2571 } else { |
|
2572 warning("Attempt to unguard stack yellow zone failed."); |
|
2573 } |
|
2574 disable_register_stack_guard(); |
|
2575 } |
|
2576 |
|
2577 void JavaThread::enable_stack_red_zone() { |
|
2578 // The base notation is from the stacks point of view, growing downward. |
|
2579 // We need to adjust it to work correctly with guard_memory() |
|
2580 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); |
|
2581 address base = stack_red_zone_base() - stack_red_zone_size(); |
|
2582 |
|
2583 guarantee(base < stack_base(),"Error calculating stack red zone"); |
|
2584 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone"); |
|
2585 |
|
2586 if(!os::guard_memory((char *) base, stack_red_zone_size())) { |
|
2587 warning("Attempt to guard stack red zone failed."); |
|
2588 } |
|
2589 } |
|
2590 |
|
2591 void JavaThread::disable_stack_red_zone() { |
|
2592 // The base notation is from the stacks point of view, growing downward. |
|
2593 // We need to adjust it to work correctly with guard_memory() |
|
2594 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages."); |
|
2595 address base = stack_red_zone_base() - stack_red_zone_size(); |
|
2596 if (!os::unguard_memory((char *)base, stack_red_zone_size())) { |
|
2597 warning("Attempt to unguard stack red zone failed."); |
|
2598 } |
|
2599 } |
|
2600 |
|
2601 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { |
|
2602 // ignore is there is no stack |
|
2603 if (!has_last_Java_frame()) return; |
|
2604 // traverse the stack frames. Starts from top frame. |
|
2605 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { |
|
2606 frame* fr = fst.current(); |
|
2607 f(fr, fst.register_map()); |
|
2608 } |
|
2609 } |
|
2610 |
|
2611 |
|
2612 #ifndef PRODUCT |
|
2613 // Deoptimization |
|
2614 // Function for testing deoptimization |
|
2615 void JavaThread::deoptimize() { |
|
2616 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass |
|
2617 StackFrameStream fst(this, UseBiasedLocking); |
|
2618 bool deopt = false; // Dump stack only if a deopt actually happens. |
|
2619 bool only_at = strlen(DeoptimizeOnlyAt) > 0; |
|
2620 // Iterate over all frames in the thread and deoptimize |
|
2621 for(; !fst.is_done(); fst.next()) { |
|
2622 if(fst.current()->can_be_deoptimized()) { |
|
2623 |
|
2624 if (only_at) { |
|
2625 // Deoptimize only at particular bcis. DeoptimizeOnlyAt |
|
2626 // consists of comma or carriage return separated numbers so |
|
2627 // search for the current bci in that string. |
|
2628 address pc = fst.current()->pc(); |
|
2629 nmethod* nm = (nmethod*) fst.current()->cb(); |
|
2630 ScopeDesc* sd = nm->scope_desc_at( pc); |
|
2631 char buffer[8]; |
|
2632 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); |
|
2633 size_t len = strlen(buffer); |
|
2634 const char * found = strstr(DeoptimizeOnlyAt, buffer); |
|
2635 while (found != NULL) { |
|
2636 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && |
|
2637 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { |
|
2638 // Check that the bci found is bracketed by terminators. |
|
2639 break; |
|
2640 } |
|
2641 found = strstr(found + 1, buffer); |
|
2642 } |
|
2643 if (!found) { |
|
2644 continue; |
|
2645 } |
|
2646 } |
|
2647 |
|
2648 if (DebugDeoptimization && !deopt) { |
|
2649 deopt = true; // One-time only print before deopt |
|
2650 tty->print_cr("[BEFORE Deoptimization]"); |
|
2651 trace_frames(); |
|
2652 trace_stack(); |
|
2653 } |
|
2654 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); |
|
2655 } |
|
2656 } |
|
2657 |
|
2658 if (DebugDeoptimization && deopt) { |
|
2659 tty->print_cr("[AFTER Deoptimization]"); |
|
2660 trace_frames(); |
|
2661 } |
|
2662 } |
|
2663 |
|
2664 |
|
2665 // Make zombies |
|
2666 void JavaThread::make_zombies() { |
|
2667 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { |
|
2668 if (fst.current()->can_be_deoptimized()) { |
|
2669 // it is a Java nmethod |
|
2670 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); |
|
2671 nm->make_not_entrant(); |
|
2672 } |
|
2673 } |
|
2674 } |
|
2675 #endif // PRODUCT |
|
2676 |
|
2677 |
|
2678 void JavaThread::deoptimized_wrt_marked_nmethods() { |
|
2679 if (!has_last_Java_frame()) return; |
|
2680 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass |
|
2681 StackFrameStream fst(this, UseBiasedLocking); |
|
2682 for(; !fst.is_done(); fst.next()) { |
|
2683 if (fst.current()->should_be_deoptimized()) { |
|
2684 if (LogCompilation && xtty != NULL) { |
|
2685 nmethod* nm = fst.current()->cb()->as_nmethod_or_null(); |
|
2686 xtty->elem("deoptimized thread='" UINTX_FORMAT "' compile_id='%d'", |
|
2687 this->name(), nm != NULL ? nm->compile_id() : -1); |
|
2688 } |
|
2689 |
|
2690 Deoptimization::deoptimize(this, *fst.current(), fst.register_map()); |
|
2691 } |
|
2692 } |
|
2693 } |
|
2694 |
|
2695 |
|
2696 // GC support |
|
2697 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); } |
|
2698 |
|
2699 void JavaThread::gc_epilogue() { |
|
2700 frames_do(frame_gc_epilogue); |
|
2701 } |
|
2702 |
|
2703 |
|
2704 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); } |
|
2705 |
|
2706 void JavaThread::gc_prologue() { |
|
2707 frames_do(frame_gc_prologue); |
|
2708 } |
|
2709 |
|
2710 // If the caller is a NamedThread, then remember, in the current scope, |
|
2711 // the given JavaThread in its _processed_thread field. |
|
2712 class RememberProcessedThread: public StackObj { |
|
2713 NamedThread* _cur_thr; |
|
2714 public: |
|
2715 RememberProcessedThread(JavaThread* jthr) { |
|
2716 Thread* thread = Thread::current(); |
|
2717 if (thread->is_Named_thread()) { |
|
2718 _cur_thr = (NamedThread *)thread; |
|
2719 _cur_thr->set_processed_thread(jthr); |
|
2720 } else { |
|
2721 _cur_thr = NULL; |
|
2722 } |
|
2723 } |
|
2724 |
|
2725 ~RememberProcessedThread() { |
|
2726 if (_cur_thr) { |
|
2727 _cur_thr->set_processed_thread(NULL); |
|
2728 } |
|
2729 } |
|
2730 }; |
|
2731 |
|
2732 void JavaThread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) { |
|
2733 // Verify that the deferred card marks have been flushed. |
|
2734 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); |
|
2735 |
|
2736 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do |
|
2737 // since there may be more than one thread using each ThreadProfiler. |
|
2738 |
|
2739 // Traverse the GCHandles |
|
2740 Thread::oops_do(f, cld_f, cf); |
|
2741 |
|
2742 assert( (!has_last_Java_frame() && java_call_counter() == 0) || |
|
2743 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); |
|
2744 |
|
2745 if (has_last_Java_frame()) { |
|
2746 // Record JavaThread to GC thread |
|
2747 RememberProcessedThread rpt(this); |
|
2748 |
|
2749 // Traverse the privileged stack |
|
2750 if (_privileged_stack_top != NULL) { |
|
2751 _privileged_stack_top->oops_do(f); |
|
2752 } |
|
2753 |
|
2754 // traverse the registered growable array |
|
2755 if (_array_for_gc != NULL) { |
|
2756 for (int index = 0; index < _array_for_gc->length(); index++) { |
|
2757 f->do_oop(_array_for_gc->adr_at(index)); |
|
2758 } |
|
2759 } |
|
2760 |
|
2761 // Traverse the monitor chunks |
|
2762 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) { |
|
2763 chunk->oops_do(f); |
|
2764 } |
|
2765 |
|
2766 // Traverse the execution stack |
|
2767 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { |
|
2768 fst.current()->oops_do(f, cld_f, cf, fst.register_map()); |
|
2769 } |
|
2770 } |
|
2771 |
|
2772 // callee_target is never live across a gc point so NULL it here should |
|
2773 // it still contain a methdOop. |
|
2774 |
|
2775 set_callee_target(NULL); |
|
2776 |
|
2777 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!"); |
|
2778 // If we have deferred set_locals there might be oops waiting to be |
|
2779 // written |
|
2780 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals(); |
|
2781 if (list != NULL) { |
|
2782 for (int i = 0; i < list->length(); i++) { |
|
2783 list->at(i)->oops_do(f); |
|
2784 } |
|
2785 } |
|
2786 |
|
2787 // Traverse instance variables at the end since the GC may be moving things |
|
2788 // around using this function |
|
2789 f->do_oop((oop*) &_threadObj); |
|
2790 f->do_oop((oop*) &_vm_result); |
|
2791 f->do_oop((oop*) &_exception_oop); |
|
2792 f->do_oop((oop*) &_pending_async_exception); |
|
2793 |
|
2794 if (jvmti_thread_state() != NULL) { |
|
2795 jvmti_thread_state()->oops_do(f); |
|
2796 } |
|
2797 } |
|
2798 |
|
2799 void JavaThread::nmethods_do(CodeBlobClosure* cf) { |
|
2800 Thread::nmethods_do(cf); // (super method is a no-op) |
|
2801 |
|
2802 assert( (!has_last_Java_frame() && java_call_counter() == 0) || |
|
2803 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!"); |
|
2804 |
|
2805 if (has_last_Java_frame()) { |
|
2806 // Traverse the execution stack |
|
2807 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { |
|
2808 fst.current()->nmethods_do(cf); |
|
2809 } |
|
2810 } |
|
2811 } |
|
2812 |
|
2813 void JavaThread::metadata_do(void f(Metadata*)) { |
|
2814 Thread::metadata_do(f); |
|
2815 if (has_last_Java_frame()) { |
|
2816 // Traverse the execution stack to call f() on the methods in the stack |
|
2817 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { |
|
2818 fst.current()->metadata_do(f); |
|
2819 } |
|
2820 } else if (is_Compiler_thread()) { |
|
2821 // need to walk ciMetadata in current compile tasks to keep alive. |
|
2822 CompilerThread* ct = (CompilerThread*)this; |
|
2823 if (ct->env() != NULL) { |
|
2824 ct->env()->metadata_do(f); |
|
2825 } |
|
2826 } |
|
2827 } |
|
2828 |
|
2829 // Printing |
|
2830 const char* _get_thread_state_name(JavaThreadState _thread_state) { |
|
2831 switch (_thread_state) { |
|
2832 case _thread_uninitialized: return "_thread_uninitialized"; |
|
2833 case _thread_new: return "_thread_new"; |
|
2834 case _thread_new_trans: return "_thread_new_trans"; |
|
2835 case _thread_in_native: return "_thread_in_native"; |
|
2836 case _thread_in_native_trans: return "_thread_in_native_trans"; |
|
2837 case _thread_in_vm: return "_thread_in_vm"; |
|
2838 case _thread_in_vm_trans: return "_thread_in_vm_trans"; |
|
2839 case _thread_in_Java: return "_thread_in_Java"; |
|
2840 case _thread_in_Java_trans: return "_thread_in_Java_trans"; |
|
2841 case _thread_blocked: return "_thread_blocked"; |
|
2842 case _thread_blocked_trans: return "_thread_blocked_trans"; |
|
2843 default: return "unknown thread state"; |
|
2844 } |
|
2845 } |
|
2846 |
|
2847 #ifndef PRODUCT |
|
2848 void JavaThread::print_thread_state_on(outputStream *st) const { |
|
2849 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); |
|
2850 }; |
|
2851 void JavaThread::print_thread_state() const { |
|
2852 print_thread_state_on(tty); |
|
2853 }; |
|
2854 #endif // PRODUCT |
|
2855 |
|
2856 // Called by Threads::print() for VM_PrintThreads operation |
|
2857 void JavaThread::print_on(outputStream *st) const { |
|
2858 st->print("\"%s\" ", get_thread_name()); |
|
2859 oop thread_oop = threadObj(); |
|
2860 if (thread_oop != NULL) { |
|
2861 st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop)); |
|
2862 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); |
|
2863 st->print("prio=%d ", java_lang_Thread::priority(thread_oop)); |
|
2864 } |
|
2865 Thread::print_on(st); |
|
2866 // print guess for valid stack memory region (assume 4K pages); helps lock debugging |
|
2867 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); |
|
2868 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) { |
|
2869 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); |
|
2870 } |
|
2871 #ifndef PRODUCT |
|
2872 print_thread_state_on(st); |
|
2873 _safepoint_state->print_on(st); |
|
2874 #endif // PRODUCT |
|
2875 } |
|
2876 |
|
2877 // Called by fatal error handler. The difference between this and |
|
2878 // JavaThread::print() is that we can't grab lock or allocate memory. |
|
2879 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { |
|
2880 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen)); |
|
2881 oop thread_obj = threadObj(); |
|
2882 if (thread_obj != NULL) { |
|
2883 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon"); |
|
2884 } |
|
2885 st->print(" ["); |
|
2886 st->print("%s", _get_thread_state_name(_thread_state)); |
|
2887 if (osthread()) { |
|
2888 st->print(", id=%d", osthread()->thread_id()); |
|
2889 } |
|
2890 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")", |
|
2891 _stack_base - _stack_size, _stack_base); |
|
2892 st->print("]"); |
|
2893 return; |
|
2894 } |
|
2895 |
|
2896 // Verification |
|
2897 |
|
2898 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } |
|
2899 |
|
2900 void JavaThread::verify() { |
|
2901 // Verify oops in the thread. |
|
2902 oops_do(&VerifyOopClosure::verify_oop, NULL, NULL); |
|
2903 |
|
2904 // Verify the stack frames. |
|
2905 frames_do(frame_verify); |
|
2906 } |
|
2907 |
|
2908 // CR 6300358 (sub-CR 2137150) |
|
2909 // Most callers of this method assume that it can't return NULL but a |
|
2910 // thread may not have a name whilst it is in the process of attaching to |
|
2911 // the VM - see CR 6412693, and there are places where a JavaThread can be |
|
2912 // seen prior to having it's threadObj set (eg JNI attaching threads and |
|
2913 // if vm exit occurs during initialization). These cases can all be accounted |
|
2914 // for such that this method never returns NULL. |
|
2915 const char* JavaThread::get_thread_name() const { |
|
2916 #ifdef ASSERT |
|
2917 // early safepoints can hit while current thread does not yet have TLS |
|
2918 if (!SafepointSynchronize::is_at_safepoint()) { |
|
2919 Thread *cur = Thread::current(); |
|
2920 if (!(cur->is_Java_thread() && cur == this)) { |
|
2921 // Current JavaThreads are allowed to get their own name without |
|
2922 // the Threads_lock. |
|
2923 assert_locked_or_safepoint(Threads_lock); |
|
2924 } |
|
2925 } |
|
2926 #endif // ASSERT |
|
2927 return get_thread_name_string(); |
|
2928 } |
|
2929 |
|
2930 // Returns a non-NULL representation of this thread's name, or a suitable |
|
2931 // descriptive string if there is no set name |
|
2932 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { |
|
2933 const char* name_str; |
|
2934 oop thread_obj = threadObj(); |
|
2935 if (thread_obj != NULL) { |
|
2936 typeArrayOop name = java_lang_Thread::name(thread_obj); |
|
2937 if (name != NULL) { |
|
2938 if (buf == NULL) { |
|
2939 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); |
|
2940 } |
|
2941 else { |
|
2942 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen); |
|
2943 } |
|
2944 } |
|
2945 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306 |
|
2946 name_str = "<no-name - thread is attaching>"; |
|
2947 } |
|
2948 else { |
|
2949 name_str = Thread::name(); |
|
2950 } |
|
2951 } |
|
2952 else { |
|
2953 name_str = Thread::name(); |
|
2954 } |
|
2955 assert(name_str != NULL, "unexpected NULL thread name"); |
|
2956 return name_str; |
|
2957 } |
|
2958 |
|
2959 |
|
2960 const char* JavaThread::get_threadgroup_name() const { |
|
2961 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) |
|
2962 oop thread_obj = threadObj(); |
|
2963 if (thread_obj != NULL) { |
|
2964 oop thread_group = java_lang_Thread::threadGroup(thread_obj); |
|
2965 if (thread_group != NULL) { |
|
2966 typeArrayOop name = java_lang_ThreadGroup::name(thread_group); |
|
2967 // ThreadGroup.name can be null |
|
2968 if (name != NULL) { |
|
2969 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); |
|
2970 return str; |
|
2971 } |
|
2972 } |
|
2973 } |
|
2974 return NULL; |
|
2975 } |
|
2976 |
|
2977 const char* JavaThread::get_parent_name() const { |
|
2978 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);) |
|
2979 oop thread_obj = threadObj(); |
|
2980 if (thread_obj != NULL) { |
|
2981 oop thread_group = java_lang_Thread::threadGroup(thread_obj); |
|
2982 if (thread_group != NULL) { |
|
2983 oop parent = java_lang_ThreadGroup::parent(thread_group); |
|
2984 if (parent != NULL) { |
|
2985 typeArrayOop name = java_lang_ThreadGroup::name(parent); |
|
2986 // ThreadGroup.name can be null |
|
2987 if (name != NULL) { |
|
2988 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length()); |
|
2989 return str; |
|
2990 } |
|
2991 } |
|
2992 } |
|
2993 } |
|
2994 return NULL; |
|
2995 } |
|
2996 |
|
2997 ThreadPriority JavaThread::java_priority() const { |
|
2998 oop thr_oop = threadObj(); |
|
2999 if (thr_oop == NULL) return NormPriority; // Bootstrapping |
|
3000 ThreadPriority priority = java_lang_Thread::priority(thr_oop); |
|
3001 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); |
|
3002 return priority; |
|
3003 } |
|
3004 |
|
3005 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { |
|
3006 |
|
3007 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); |
|
3008 // Link Java Thread object <-> C++ Thread |
|
3009 |
|
3010 // Get the C++ thread object (an oop) from the JNI handle (a jthread) |
|
3011 // and put it into a new Handle. The Handle "thread_oop" can then |
|
3012 // be used to pass the C++ thread object to other methods. |
|
3013 |
|
3014 // Set the Java level thread object (jthread) field of the |
|
3015 // new thread (a JavaThread *) to C++ thread object using the |
|
3016 // "thread_oop" handle. |
|
3017 |
|
3018 // Set the thread field (a JavaThread *) of the |
|
3019 // oop representing the java_lang_Thread to the new thread (a JavaThread *). |
|
3020 |
|
3021 Handle thread_oop(Thread::current(), |
|
3022 JNIHandles::resolve_non_null(jni_thread)); |
|
3023 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(), |
|
3024 "must be initialized"); |
|
3025 set_threadObj(thread_oop()); |
|
3026 java_lang_Thread::set_thread(thread_oop(), this); |
|
3027 |
|
3028 if (prio == NoPriority) { |
|
3029 prio = java_lang_Thread::priority(thread_oop()); |
|
3030 assert(prio != NoPriority, "A valid priority should be present"); |
|
3031 } |
|
3032 |
|
3033 // Push the Java priority down to the native thread; needs Threads_lock |
|
3034 Thread::set_priority(this, prio); |
|
3035 |
|
3036 // Add the new thread to the Threads list and set it in motion. |
|
3037 // We must have threads lock in order to call Threads::add. |
|
3038 // It is crucial that we do not block before the thread is |
|
3039 // added to the Threads list for if a GC happens, then the java_thread oop |
|
3040 // will not be visited by GC. |
|
3041 Threads::add(this); |
|
3042 } |
|
3043 |
|
3044 oop JavaThread::current_park_blocker() { |
|
3045 // Support for JSR-166 locks |
|
3046 oop thread_oop = threadObj(); |
|
3047 if (thread_oop != NULL && |
|
3048 JDK_Version::current().supports_thread_park_blocker()) { |
|
3049 return java_lang_Thread::park_blocker(thread_oop); |
|
3050 } |
|
3051 return NULL; |
|
3052 } |
|
3053 |
|
3054 |
|
3055 void JavaThread::print_stack_on(outputStream* st) { |
|
3056 if (!has_last_Java_frame()) return; |
|
3057 ResourceMark rm; |
|
3058 HandleMark hm; |
|
3059 |
|
3060 RegisterMap reg_map(this); |
|
3061 vframe* start_vf = last_java_vframe(®_map); |
|
3062 int count = 0; |
|
3063 for (vframe* f = start_vf; f; f = f->sender() ) { |
|
3064 if (f->is_java_frame()) { |
|
3065 javaVFrame* jvf = javaVFrame::cast(f); |
|
3066 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); |
|
3067 |
|
3068 // Print out lock information |
|
3069 if (JavaMonitorsInStackTrace) { |
|
3070 jvf->print_lock_info_on(st, count); |
|
3071 } |
|
3072 } else { |
|
3073 // Ignore non-Java frames |
|
3074 } |
|
3075 |
|
3076 // Bail-out case for too deep stacks |
|
3077 count++; |
|
3078 if (MaxJavaStackTraceDepth == count) return; |
|
3079 } |
|
3080 } |
|
3081 |
|
3082 |
|
3083 // JVMTI PopFrame support |
|
3084 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { |
|
3085 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments"); |
|
3086 if (in_bytes(size_in_bytes) != 0) { |
|
3087 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread); |
|
3088 _popframe_preserved_args_size = in_bytes(size_in_bytes); |
|
3089 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); |
|
3090 } |
|
3091 } |
|
3092 |
|
3093 void* JavaThread::popframe_preserved_args() { |
|
3094 return _popframe_preserved_args; |
|
3095 } |
|
3096 |
|
3097 ByteSize JavaThread::popframe_preserved_args_size() { |
|
3098 return in_ByteSize(_popframe_preserved_args_size); |
|
3099 } |
|
3100 |
|
3101 WordSize JavaThread::popframe_preserved_args_size_in_words() { |
|
3102 int sz = in_bytes(popframe_preserved_args_size()); |
|
3103 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); |
|
3104 return in_WordSize(sz / wordSize); |
|
3105 } |
|
3106 |
|
3107 void JavaThread::popframe_free_preserved_args() { |
|
3108 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice"); |
|
3109 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread); |
|
3110 _popframe_preserved_args = NULL; |
|
3111 _popframe_preserved_args_size = 0; |
|
3112 } |
|
3113 |
|
3114 #ifndef PRODUCT |
|
3115 |
|
3116 void JavaThread::trace_frames() { |
|
3117 tty->print_cr("[Describe stack]"); |
|
3118 int frame_no = 1; |
|
3119 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) { |
|
3120 tty->print(" %d. ", frame_no++); |
|
3121 fst.current()->print_value_on(tty,this); |
|
3122 tty->cr(); |
|
3123 } |
|
3124 } |
|
3125 |
|
3126 class PrintAndVerifyOopClosure: public OopClosure { |
|
3127 protected: |
|
3128 template <class T> inline void do_oop_work(T* p) { |
|
3129 oop obj = oopDesc::load_decode_heap_oop(p); |
|
3130 if (obj == NULL) return; |
|
3131 tty->print(INTPTR_FORMAT ": ", p); |
|
3132 if (obj->is_oop_or_null()) { |
|
3133 if (obj->is_objArray()) { |
|
3134 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj); |
|
3135 } else { |
|
3136 obj->print(); |
|
3137 } |
|
3138 } else { |
|
3139 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj); |
|
3140 } |
|
3141 tty->cr(); |
|
3142 } |
|
3143 public: |
|
3144 virtual void do_oop(oop* p) { do_oop_work(p); } |
|
3145 virtual void do_oop(narrowOop* p) { do_oop_work(p); } |
|
3146 }; |
|
3147 |
|
3148 |
|
3149 static void oops_print(frame* f, const RegisterMap *map) { |
|
3150 PrintAndVerifyOopClosure print; |
|
3151 f->print_value(); |
|
3152 f->oops_do(&print, NULL, NULL, (RegisterMap*)map); |
|
3153 } |
|
3154 |
|
3155 // Print our all the locations that contain oops and whether they are |
|
3156 // valid or not. This useful when trying to find the oldest frame |
|
3157 // where an oop has gone bad since the frame walk is from youngest to |
|
3158 // oldest. |
|
3159 void JavaThread::trace_oops() { |
|
3160 tty->print_cr("[Trace oops]"); |
|
3161 frames_do(oops_print); |
|
3162 } |
|
3163 |
|
3164 |
|
3165 #ifdef ASSERT |
|
3166 // Print or validate the layout of stack frames |
|
3167 void JavaThread::print_frame_layout(int depth, bool validate_only) { |
|
3168 ResourceMark rm; |
|
3169 PRESERVE_EXCEPTION_MARK; |
|
3170 FrameValues values; |
|
3171 int frame_no = 0; |
|
3172 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) { |
|
3173 fst.current()->describe(values, ++frame_no); |
|
3174 if (depth == frame_no) break; |
|
3175 } |
|
3176 if (validate_only) { |
|
3177 values.validate(); |
|
3178 } else { |
|
3179 tty->print_cr("[Describe stack layout]"); |
|
3180 values.print(this); |
|
3181 } |
|
3182 } |
|
3183 #endif |
|
3184 |
|
3185 void JavaThread::trace_stack_from(vframe* start_vf) { |
|
3186 ResourceMark rm; |
|
3187 int vframe_no = 1; |
|
3188 for (vframe* f = start_vf; f; f = f->sender() ) { |
|
3189 if (f->is_java_frame()) { |
|
3190 javaVFrame::cast(f)->print_activation(vframe_no++); |
|
3191 } else { |
|
3192 f->print(); |
|
3193 } |
|
3194 if (vframe_no > StackPrintLimit) { |
|
3195 tty->print_cr("...<more frames>..."); |
|
3196 return; |
|
3197 } |
|
3198 } |
|
3199 } |
|
3200 |
|
3201 |
|
3202 void JavaThread::trace_stack() { |
|
3203 if (!has_last_Java_frame()) return; |
|
3204 ResourceMark rm; |
|
3205 HandleMark hm; |
|
3206 RegisterMap reg_map(this); |
|
3207 trace_stack_from(last_java_vframe(®_map)); |
|
3208 } |
|
3209 |
|
3210 |
|
3211 #endif // PRODUCT |
|
3212 |
|
3213 |
|
3214 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) { |
|
3215 assert(reg_map != NULL, "a map must be given"); |
|
3216 frame f = last_frame(); |
|
3217 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) { |
|
3218 if (vf->is_java_frame()) return javaVFrame::cast(vf); |
|
3219 } |
|
3220 return NULL; |
|
3221 } |
|
3222 |
|
3223 |
|
3224 Klass* JavaThread::security_get_caller_class(int depth) { |
|
3225 vframeStream vfst(this); |
|
3226 vfst.security_get_caller_frame(depth); |
|
3227 if (!vfst.at_end()) { |
|
3228 return vfst.method()->method_holder(); |
|
3229 } |
|
3230 return NULL; |
|
3231 } |
|
3232 |
|
3233 static void compiler_thread_entry(JavaThread* thread, TRAPS) { |
|
3234 assert(thread->is_Compiler_thread(), "must be compiler thread"); |
|
3235 CompileBroker::compiler_thread_loop(); |
|
3236 } |
|
3237 |
|
3238 // Create a CompilerThread |
|
3239 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters) |
|
3240 : JavaThread(&compiler_thread_entry) { |
|
3241 _env = NULL; |
|
3242 _log = NULL; |
|
3243 _task = NULL; |
|
3244 _queue = queue; |
|
3245 _counters = counters; |
|
3246 _buffer_blob = NULL; |
|
3247 _scanned_nmethod = NULL; |
|
3248 _compiler = NULL; |
|
3249 |
|
3250 #ifndef PRODUCT |
|
3251 _ideal_graph_printer = NULL; |
|
3252 #endif |
|
3253 } |
|
3254 |
|
3255 void CompilerThread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) { |
|
3256 JavaThread::oops_do(f, cld_f, cf); |
|
3257 if (_scanned_nmethod != NULL && cf != NULL) { |
|
3258 // Safepoints can occur when the sweeper is scanning an nmethod so |
|
3259 // process it here to make sure it isn't unloaded in the middle of |
|
3260 // a scan. |
|
3261 cf->do_code_blob(_scanned_nmethod); |
|
3262 } |
|
3263 } |
|
3264 |
|
3265 |
|
3266 // ======= Threads ======== |
|
3267 |
|
3268 // The Threads class links together all active threads, and provides |
|
3269 // operations over all threads. It is protected by its own Mutex |
|
3270 // lock, which is also used in other contexts to protect thread |
|
3271 // operations from having the thread being operated on from exiting |
|
3272 // and going away unexpectedly (e.g., safepoint synchronization) |
|
3273 |
|
3274 JavaThread* Threads::_thread_list = NULL; |
|
3275 int Threads::_number_of_threads = 0; |
|
3276 int Threads::_number_of_non_daemon_threads = 0; |
|
3277 int Threads::_return_code = 0; |
|
3278 size_t JavaThread::_stack_size_at_create = 0; |
|
3279 #ifdef ASSERT |
|
3280 bool Threads::_vm_complete = false; |
|
3281 #endif |
|
3282 |
|
3283 // All JavaThreads |
|
3284 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next()) |
|
3285 |
|
3286 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system) |
|
3287 void Threads::threads_do(ThreadClosure* tc) { |
|
3288 assert_locked_or_safepoint(Threads_lock); |
|
3289 // ALL_JAVA_THREADS iterates through all JavaThreads |
|
3290 ALL_JAVA_THREADS(p) { |
|
3291 tc->do_thread(p); |
|
3292 } |
|
3293 // Someday we could have a table or list of all non-JavaThreads. |
|
3294 // For now, just manually iterate through them. |
|
3295 tc->do_thread(VMThread::vm_thread()); |
|
3296 Universe::heap()->gc_threads_do(tc); |
|
3297 WatcherThread *wt = WatcherThread::watcher_thread(); |
|
3298 // Strictly speaking, the following NULL check isn't sufficient to make sure |
|
3299 // the data for WatcherThread is still valid upon being examined. However, |
|
3300 // considering that WatchThread terminates when the VM is on the way to |
|
3301 // exit at safepoint, the chance of the above is extremely small. The right |
|
3302 // way to prevent termination of WatcherThread would be to acquire |
|
3303 // Terminator_lock, but we can't do that without violating the lock rank |
|
3304 // checking in some cases. |
|
3305 if (wt != NULL) |
|
3306 tc->do_thread(wt); |
|
3307 |
|
3308 // If CompilerThreads ever become non-JavaThreads, add them here |
|
3309 } |
|
3310 |
|
3311 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) { |
|
3312 |
|
3313 extern void JDK_Version_init(); |
|
3314 |
|
3315 // Check version |
|
3316 if (!is_supported_jni_version(args->version)) return JNI_EVERSION; |
|
3317 |
|
3318 // Initialize the output stream module |
|
3319 ostream_init(); |
|
3320 |
|
3321 // Process java launcher properties. |
|
3322 Arguments::process_sun_java_launcher_properties(args); |
|
3323 |
|
3324 // Initialize the os module before using TLS |
|
3325 os::init(); |
|
3326 |
|
3327 // Initialize system properties. |
|
3328 Arguments::init_system_properties(); |
|
3329 |
|
3330 // So that JDK version can be used as a discrimintor when parsing arguments |
|
3331 JDK_Version_init(); |
|
3332 |
|
3333 // Update/Initialize System properties after JDK version number is known |
|
3334 Arguments::init_version_specific_system_properties(); |
|
3335 |
|
3336 // Parse arguments |
|
3337 jint parse_result = Arguments::parse(args); |
|
3338 if (parse_result != JNI_OK) return parse_result; |
|
3339 |
|
3340 os::init_before_ergo(); |
|
3341 |
|
3342 jint ergo_result = Arguments::apply_ergo(); |
|
3343 if (ergo_result != JNI_OK) return ergo_result; |
|
3344 |
|
3345 if (PauseAtStartup) { |
|
3346 os::pause(); |
|
3347 } |
|
3348 |
|
3349 #ifndef USDT2 |
|
3350 HS_DTRACE_PROBE(hotspot, vm__init__begin); |
|
3351 #else /* USDT2 */ |
|
3352 HOTSPOT_VM_INIT_BEGIN(); |
|
3353 #endif /* USDT2 */ |
|
3354 |
|
3355 // Record VM creation timing statistics |
|
3356 TraceVmCreationTime create_vm_timer; |
|
3357 create_vm_timer.start(); |
|
3358 |
|
3359 // Timing (must come after argument parsing) |
|
3360 TraceTime timer("Create VM", TraceStartupTime); |
|
3361 |
|
3362 // Initialize the os module after parsing the args |
|
3363 jint os_init_2_result = os::init_2(); |
|
3364 if (os_init_2_result != JNI_OK) return os_init_2_result; |
|
3365 |
|
3366 jint adjust_after_os_result = Arguments::adjust_after_os(); |
|
3367 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result; |
|
3368 |
|
3369 // intialize TLS |
|
3370 ThreadLocalStorage::init(); |
|
3371 |
|
3372 // Bootstrap native memory tracking, so it can start recording memory |
|
3373 // activities before worker thread is started. This is the first phase |
|
3374 // of bootstrapping, VM is currently running in single-thread mode. |
|
3375 MemTracker::bootstrap_single_thread(); |
|
3376 |
|
3377 // Initialize output stream logging |
|
3378 ostream_init_log(); |
|
3379 |
|
3380 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad |
|
3381 // Must be before create_vm_init_agents() |
|
3382 if (Arguments::init_libraries_at_startup()) { |
|
3383 convert_vm_init_libraries_to_agents(); |
|
3384 } |
|
3385 |
|
3386 // Launch -agentlib/-agentpath and converted -Xrun agents |
|
3387 if (Arguments::init_agents_at_startup()) { |
|
3388 create_vm_init_agents(); |
|
3389 } |
|
3390 |
|
3391 // Initialize Threads state |
|
3392 _thread_list = NULL; |
|
3393 _number_of_threads = 0; |
|
3394 _number_of_non_daemon_threads = 0; |
|
3395 |
|
3396 // Initialize global data structures and create system classes in heap |
|
3397 vm_init_globals(); |
|
3398 |
|
3399 // Attach the main thread to this os thread |
|
3400 JavaThread* main_thread = new JavaThread(); |
|
3401 main_thread->set_thread_state(_thread_in_vm); |
|
3402 // must do this before set_active_handles and initialize_thread_local_storage |
|
3403 // Note: on solaris initialize_thread_local_storage() will (indirectly) |
|
3404 // change the stack size recorded here to one based on the java thread |
|
3405 // stacksize. This adjusted size is what is used to figure the placement |
|
3406 // of the guard pages. |
|
3407 main_thread->record_stack_base_and_size(); |
|
3408 main_thread->initialize_thread_local_storage(); |
|
3409 |
|
3410 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); |
|
3411 |
|
3412 if (!main_thread->set_as_starting_thread()) { |
|
3413 vm_shutdown_during_initialization( |
|
3414 "Failed necessary internal allocation. Out of swap space"); |
|
3415 delete main_thread; |
|
3416 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again |
|
3417 return JNI_ENOMEM; |
|
3418 } |
|
3419 |
|
3420 // Enable guard page *after* os::create_main_thread(), otherwise it would |
|
3421 // crash Linux VM, see notes in os_linux.cpp. |
|
3422 main_thread->create_stack_guard_pages(); |
|
3423 |
|
3424 // Initialize Java-Level synchronization subsystem |
|
3425 ObjectMonitor::Initialize() ; |
|
3426 |
|
3427 // Second phase of bootstrapping, VM is about entering multi-thread mode |
|
3428 MemTracker::bootstrap_multi_thread(); |
|
3429 |
|
3430 // Initialize global modules |
|
3431 jint status = init_globals(); |
|
3432 if (status != JNI_OK) { |
|
3433 delete main_thread; |
|
3434 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again |
|
3435 return status; |
|
3436 } |
|
3437 |
|
3438 // Should be done after the heap is fully created |
|
3439 main_thread->cache_global_variables(); |
|
3440 |
|
3441 HandleMark hm; |
|
3442 |
|
3443 { MutexLocker mu(Threads_lock); |
|
3444 Threads::add(main_thread); |
|
3445 } |
|
3446 |
|
3447 // Any JVMTI raw monitors entered in onload will transition into |
|
3448 // real raw monitor. VM is setup enough here for raw monitor enter. |
|
3449 JvmtiExport::transition_pending_onload_raw_monitors(); |
|
3450 |
|
3451 // Fully start NMT |
|
3452 MemTracker::start(); |
|
3453 |
|
3454 // Create the VMThread |
|
3455 { TraceTime timer("Start VMThread", TraceStartupTime); |
|
3456 VMThread::create(); |
|
3457 Thread* vmthread = VMThread::vm_thread(); |
|
3458 |
|
3459 if (!os::create_thread(vmthread, os::vm_thread)) |
|
3460 vm_exit_during_initialization("Cannot create VM thread. Out of system resources."); |
|
3461 |
|
3462 // Wait for the VM thread to become ready, and VMThread::run to initialize |
|
3463 // Monitors can have spurious returns, must always check another state flag |
|
3464 { |
|
3465 MutexLocker ml(Notify_lock); |
|
3466 os::start_thread(vmthread); |
|
3467 while (vmthread->active_handles() == NULL) { |
|
3468 Notify_lock->wait(); |
|
3469 } |
|
3470 } |
|
3471 } |
|
3472 |
|
3473 assert (Universe::is_fully_initialized(), "not initialized"); |
|
3474 if (VerifyDuringStartup) { |
|
3475 // Make sure we're starting with a clean slate. |
|
3476 VM_Verify verify_op; |
|
3477 VMThread::execute(&verify_op); |
|
3478 } |
|
3479 |
|
3480 EXCEPTION_MARK; |
|
3481 |
|
3482 // At this point, the Universe is initialized, but we have not executed |
|
3483 // any byte code. Now is a good time (the only time) to dump out the |
|
3484 // internal state of the JVM for sharing. |
|
3485 if (DumpSharedSpaces) { |
|
3486 MetaspaceShared::preload_and_dump(CHECK_0); |
|
3487 ShouldNotReachHere(); |
|
3488 } |
|
3489 |
|
3490 // Always call even when there are not JVMTI environments yet, since environments |
|
3491 // may be attached late and JVMTI must track phases of VM execution |
|
3492 JvmtiExport::enter_start_phase(); |
|
3493 |
|
3494 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. |
|
3495 JvmtiExport::post_vm_start(); |
|
3496 |
|
3497 { |
|
3498 TraceTime timer("Initialize java.lang classes", TraceStartupTime); |
|
3499 |
|
3500 if (EagerXrunInit && Arguments::init_libraries_at_startup()) { |
|
3501 create_vm_init_libraries(); |
|
3502 } |
|
3503 |
|
3504 initialize_class(vmSymbols::java_lang_String(), CHECK_0); |
|
3505 |
|
3506 // Initialize java_lang.System (needed before creating the thread) |
|
3507 initialize_class(vmSymbols::java_lang_System(), CHECK_0); |
|
3508 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0); |
|
3509 Handle thread_group = create_initial_thread_group(CHECK_0); |
|
3510 Universe::set_main_thread_group(thread_group()); |
|
3511 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0); |
|
3512 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0); |
|
3513 main_thread->set_threadObj(thread_object); |
|
3514 // Set thread status to running since main thread has |
|
3515 // been started and running. |
|
3516 java_lang_Thread::set_thread_status(thread_object, |
|
3517 java_lang_Thread::RUNNABLE); |
|
3518 |
|
3519 // The VM creates & returns objects of this class. Make sure it's initialized. |
|
3520 initialize_class(vmSymbols::java_lang_Class(), CHECK_0); |
|
3521 |
|
3522 // The VM preresolves methods to these classes. Make sure that they get initialized |
|
3523 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0); |
|
3524 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0); |
|
3525 call_initializeSystemClass(CHECK_0); |
|
3526 |
|
3527 // get the Java runtime name after java.lang.System is initialized |
|
3528 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD)); |
|
3529 JDK_Version::set_runtime_version(get_java_runtime_version(THREAD)); |
|
3530 |
|
3531 // an instance of OutOfMemory exception has been allocated earlier |
|
3532 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0); |
|
3533 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0); |
|
3534 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0); |
|
3535 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0); |
|
3536 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0); |
|
3537 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0); |
|
3538 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0); |
|
3539 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0); |
|
3540 } |
|
3541 |
|
3542 // See : bugid 4211085. |
|
3543 // Background : the static initializer of java.lang.Compiler tries to read |
|
3544 // property"java.compiler" and read & write property "java.vm.info". |
|
3545 // When a security manager is installed through the command line |
|
3546 // option "-Djava.security.manager", the above properties are not |
|
3547 // readable and the static initializer for java.lang.Compiler fails |
|
3548 // resulting in a NoClassDefFoundError. This can happen in any |
|
3549 // user code which calls methods in java.lang.Compiler. |
|
3550 // Hack : the hack is to pre-load and initialize this class, so that only |
|
3551 // system domains are on the stack when the properties are read. |
|
3552 // Currently even the AWT code has calls to methods in java.lang.Compiler. |
|
3553 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT. |
|
3554 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and |
|
3555 // read and write"java.vm.info" in the default policy file. See bugid 4211383 |
|
3556 // Once that is done, we should remove this hack. |
|
3557 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0); |
|
3558 |
|
3559 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to |
|
3560 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot |
|
3561 // compiler does not get loaded through java.lang.Compiler). "java -version" with the |
|
3562 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here. |
|
3563 // This should also be taken out as soon as 4211383 gets fixed. |
|
3564 reset_vm_info_property(CHECK_0); |
|
3565 |
|
3566 quicken_jni_functions(); |
|
3567 |
|
3568 // Must be run after init_ft which initializes ft_enabled |
|
3569 if (TRACE_INITIALIZE() != JNI_OK) { |
|
3570 vm_exit_during_initialization("Failed to initialize tracing backend"); |
|
3571 } |
|
3572 |
|
3573 // Set flag that basic initialization has completed. Used by exceptions and various |
|
3574 // debug stuff, that does not work until all basic classes have been initialized. |
|
3575 set_init_completed(); |
|
3576 |
|
3577 Metaspace::post_initialize(); |
|
3578 |
|
3579 #ifndef USDT2 |
|
3580 HS_DTRACE_PROBE(hotspot, vm__init__end); |
|
3581 #else /* USDT2 */ |
|
3582 HOTSPOT_VM_INIT_END(); |
|
3583 #endif /* USDT2 */ |
|
3584 |
|
3585 // record VM initialization completion time |
|
3586 #if INCLUDE_MANAGEMENT |
|
3587 Management::record_vm_init_completed(); |
|
3588 #endif // INCLUDE_MANAGEMENT |
|
3589 |
|
3590 // Compute system loader. Note that this has to occur after set_init_completed, since |
|
3591 // valid exceptions may be thrown in the process. |
|
3592 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and |
|
3593 // set_init_completed has just been called, causing exceptions not to be shortcut |
|
3594 // anymore. We call vm_exit_during_initialization directly instead. |
|
3595 SystemDictionary::compute_java_system_loader(THREAD); |
|
3596 if (HAS_PENDING_EXCEPTION) { |
|
3597 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); |
|
3598 } |
|
3599 |
|
3600 #if INCLUDE_ALL_GCS |
|
3601 // Support for ConcurrentMarkSweep. This should be cleaned up |
|
3602 // and better encapsulated. The ugly nested if test would go away |
|
3603 // once things are properly refactored. XXX YSR |
|
3604 if (UseConcMarkSweepGC || UseG1GC) { |
|
3605 if (UseConcMarkSweepGC) { |
|
3606 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD); |
|
3607 } else { |
|
3608 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD); |
|
3609 } |
|
3610 if (HAS_PENDING_EXCEPTION) { |
|
3611 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION)); |
|
3612 } |
|
3613 } |
|
3614 #endif // INCLUDE_ALL_GCS |
|
3615 |
|
3616 // Always call even when there are not JVMTI environments yet, since environments |
|
3617 // may be attached late and JVMTI must track phases of VM execution |
|
3618 JvmtiExport::enter_live_phase(); |
|
3619 |
|
3620 // Signal Dispatcher needs to be started before VMInit event is posted |
|
3621 os::signal_init(); |
|
3622 |
|
3623 // Start Attach Listener if +StartAttachListener or it can't be started lazily |
|
3624 if (!DisableAttachMechanism) { |
|
3625 AttachListener::vm_start(); |
|
3626 if (StartAttachListener || AttachListener::init_at_startup()) { |
|
3627 AttachListener::init(); |
|
3628 } |
|
3629 } |
|
3630 |
|
3631 // Launch -Xrun agents |
|
3632 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP |
|
3633 // back-end can launch with -Xdebug -Xrunjdwp. |
|
3634 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) { |
|
3635 create_vm_init_libraries(); |
|
3636 } |
|
3637 |
|
3638 // Notify JVMTI agents that VM initialization is complete - nop if no agents. |
|
3639 JvmtiExport::post_vm_initialized(); |
|
3640 |
|
3641 if (TRACE_START() != JNI_OK) { |
|
3642 vm_exit_during_initialization("Failed to start tracing backend."); |
|
3643 } |
|
3644 |
|
3645 if (CleanChunkPoolAsync) { |
|
3646 Chunk::start_chunk_pool_cleaner_task(); |
|
3647 } |
|
3648 |
|
3649 // initialize compiler(s) |
|
3650 #if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK) |
|
3651 CompileBroker::compilation_init(); |
|
3652 #endif |
|
3653 |
|
3654 if (EnableInvokeDynamic) { |
|
3655 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading. |
|
3656 // It is done after compilers are initialized, because otherwise compilations of |
|
3657 // signature polymorphic MH intrinsics can be missed |
|
3658 // (see SystemDictionary::find_method_handle_intrinsic). |
|
3659 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK_0); |
|
3660 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK_0); |
|
3661 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK_0); |
|
3662 } |
|
3663 |
|
3664 #if INCLUDE_MANAGEMENT |
|
3665 Management::initialize(THREAD); |
|
3666 #endif // INCLUDE_MANAGEMENT |
|
3667 |
|
3668 if (HAS_PENDING_EXCEPTION) { |
|
3669 // management agent fails to start possibly due to |
|
3670 // configuration problem and is responsible for printing |
|
3671 // stack trace if appropriate. Simply exit VM. |
|
3672 vm_exit(1); |
|
3673 } |
|
3674 |
|
3675 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true); |
|
3676 if (MemProfiling) MemProfiler::engage(); |
|
3677 StatSampler::engage(); |
|
3678 if (CheckJNICalls) JniPeriodicChecker::engage(); |
|
3679 |
|
3680 BiasedLocking::init(); |
|
3681 |
|
3682 #if INCLUDE_RTM_OPT |
|
3683 RTMLockingCounters::init(); |
|
3684 #endif |
|
3685 |
|
3686 if (JDK_Version::current().post_vm_init_hook_enabled()) { |
|
3687 call_postVMInitHook(THREAD); |
|
3688 // The Java side of PostVMInitHook.run must deal with all |
|
3689 // exceptions and provide means of diagnosis. |
|
3690 if (HAS_PENDING_EXCEPTION) { |
|
3691 CLEAR_PENDING_EXCEPTION; |
|
3692 } |
|
3693 } |
|
3694 |
|
3695 { |
|
3696 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag); |
|
3697 // Make sure the watcher thread can be started by WatcherThread::start() |
|
3698 // or by dynamic enrollment. |
|
3699 WatcherThread::make_startable(); |
|
3700 // Start up the WatcherThread if there are any periodic tasks |
|
3701 // NOTE: All PeriodicTasks should be registered by now. If they |
|
3702 // aren't, late joiners might appear to start slowly (we might |
|
3703 // take a while to process their first tick). |
|
3704 if (PeriodicTask::num_tasks() > 0) { |
|
3705 WatcherThread::start(); |
|
3706 } |
|
3707 } |
|
3708 |
|
3709 // Give os specific code one last chance to start |
|
3710 os::init_3(); |
|
3711 |
|
3712 create_vm_timer.end(); |
|
3713 #ifdef ASSERT |
|
3714 _vm_complete = true; |
|
3715 #endif |
|
3716 return JNI_OK; |
|
3717 } |
|
3718 |
|
3719 // type for the Agent_OnLoad and JVM_OnLoad entry points |
|
3720 extern "C" { |
|
3721 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *); |
|
3722 } |
|
3723 // Find a command line agent library and return its entry point for |
|
3724 // -agentlib: -agentpath: -Xrun |
|
3725 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array. |
|
3726 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) { |
|
3727 OnLoadEntry_t on_load_entry = NULL; |
|
3728 void *library = NULL; |
|
3729 |
|
3730 if (!agent->valid()) { |
|
3731 char buffer[JVM_MAXPATHLEN]; |
|
3732 char ebuf[1024]; |
|
3733 const char *name = agent->name(); |
|
3734 const char *msg = "Could not find agent library "; |
|
3735 |
|
3736 // First check to see if agent is statically linked into executable |
|
3737 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) { |
|
3738 library = agent->os_lib(); |
|
3739 } else if (agent->is_absolute_path()) { |
|
3740 library = os::dll_load(name, ebuf, sizeof ebuf); |
|
3741 if (library == NULL) { |
|
3742 const char *sub_msg = " in absolute path, with error: "; |
|
3743 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1; |
|
3744 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread); |
|
3745 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf); |
|
3746 // If we can't find the agent, exit. |
|
3747 vm_exit_during_initialization(buf, NULL); |
|
3748 FREE_C_HEAP_ARRAY(char, buf, mtThread); |
|
3749 } |
|
3750 } else { |
|
3751 // Try to load the agent from the standard dll directory |
|
3752 if (os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), |
|
3753 name)) { |
|
3754 library = os::dll_load(buffer, ebuf, sizeof ebuf); |
|
3755 } |
|
3756 if (library == NULL) { // Try the local directory |
|
3757 char ns[1] = {0}; |
|
3758 if (os::dll_build_name(buffer, sizeof(buffer), ns, name)) { |
|
3759 library = os::dll_load(buffer, ebuf, sizeof ebuf); |
|
3760 } |
|
3761 if (library == NULL) { |
|
3762 const char *sub_msg = " on the library path, with error: "; |
|
3763 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1; |
|
3764 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread); |
|
3765 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf); |
|
3766 // If we can't find the agent, exit. |
|
3767 vm_exit_during_initialization(buf, NULL); |
|
3768 FREE_C_HEAP_ARRAY(char, buf, mtThread); |
|
3769 } |
|
3770 } |
|
3771 } |
|
3772 agent->set_os_lib(library); |
|
3773 agent->set_valid(); |
|
3774 } |
|
3775 |
|
3776 // Find the OnLoad function. |
|
3777 on_load_entry = |
|
3778 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent, |
|
3779 false, |
|
3780 on_load_symbols, |
|
3781 num_symbol_entries)); |
|
3782 return on_load_entry; |
|
3783 } |
|
3784 |
|
3785 // Find the JVM_OnLoad entry point |
|
3786 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) { |
|
3787 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS; |
|
3788 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); |
|
3789 } |
|
3790 |
|
3791 // Find the Agent_OnLoad entry point |
|
3792 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) { |
|
3793 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS; |
|
3794 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); |
|
3795 } |
|
3796 |
|
3797 // For backwards compatibility with -Xrun |
|
3798 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be |
|
3799 // treated like -agentpath: |
|
3800 // Must be called before agent libraries are created |
|
3801 void Threads::convert_vm_init_libraries_to_agents() { |
|
3802 AgentLibrary* agent; |
|
3803 AgentLibrary* next; |
|
3804 |
|
3805 for (agent = Arguments::libraries(); agent != NULL; agent = next) { |
|
3806 next = agent->next(); // cache the next agent now as this agent may get moved off this list |
|
3807 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); |
|
3808 |
|
3809 // If there is an JVM_OnLoad function it will get called later, |
|
3810 // otherwise see if there is an Agent_OnLoad |
|
3811 if (on_load_entry == NULL) { |
|
3812 on_load_entry = lookup_agent_on_load(agent); |
|
3813 if (on_load_entry != NULL) { |
|
3814 // switch it to the agent list -- so that Agent_OnLoad will be called, |
|
3815 // JVM_OnLoad won't be attempted and Agent_OnUnload will |
|
3816 Arguments::convert_library_to_agent(agent); |
|
3817 } else { |
|
3818 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name()); |
|
3819 } |
|
3820 } |
|
3821 } |
|
3822 } |
|
3823 |
|
3824 // Create agents for -agentlib: -agentpath: and converted -Xrun |
|
3825 // Invokes Agent_OnLoad |
|
3826 // Called very early -- before JavaThreads exist |
|
3827 void Threads::create_vm_init_agents() { |
|
3828 extern struct JavaVM_ main_vm; |
|
3829 AgentLibrary* agent; |
|
3830 |
|
3831 JvmtiExport::enter_onload_phase(); |
|
3832 |
|
3833 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { |
|
3834 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent); |
|
3835 |
|
3836 if (on_load_entry != NULL) { |
|
3837 // Invoke the Agent_OnLoad function |
|
3838 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); |
|
3839 if (err != JNI_OK) { |
|
3840 vm_exit_during_initialization("agent library failed to init", agent->name()); |
|
3841 } |
|
3842 } else { |
|
3843 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name()); |
|
3844 } |
|
3845 } |
|
3846 JvmtiExport::enter_primordial_phase(); |
|
3847 } |
|
3848 |
|
3849 extern "C" { |
|
3850 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *); |
|
3851 } |
|
3852 |
|
3853 void Threads::shutdown_vm_agents() { |
|
3854 // Send any Agent_OnUnload notifications |
|
3855 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS; |
|
3856 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols); |
|
3857 extern struct JavaVM_ main_vm; |
|
3858 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) { |
|
3859 |
|
3860 // Find the Agent_OnUnload function. |
|
3861 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t, |
|
3862 os::find_agent_function(agent, |
|
3863 false, |
|
3864 on_unload_symbols, |
|
3865 num_symbol_entries)); |
|
3866 |
|
3867 // Invoke the Agent_OnUnload function |
|
3868 if (unload_entry != NULL) { |
|
3869 JavaThread* thread = JavaThread::current(); |
|
3870 ThreadToNativeFromVM ttn(thread); |
|
3871 HandleMark hm(thread); |
|
3872 (*unload_entry)(&main_vm); |
|
3873 } |
|
3874 } |
|
3875 } |
|
3876 |
|
3877 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries |
|
3878 // Invokes JVM_OnLoad |
|
3879 void Threads::create_vm_init_libraries() { |
|
3880 extern struct JavaVM_ main_vm; |
|
3881 AgentLibrary* agent; |
|
3882 |
|
3883 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) { |
|
3884 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); |
|
3885 |
|
3886 if (on_load_entry != NULL) { |
|
3887 // Invoke the JVM_OnLoad function |
|
3888 JavaThread* thread = JavaThread::current(); |
|
3889 ThreadToNativeFromVM ttn(thread); |
|
3890 HandleMark hm(thread); |
|
3891 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL); |
|
3892 if (err != JNI_OK) { |
|
3893 vm_exit_during_initialization("-Xrun library failed to init", agent->name()); |
|
3894 } |
|
3895 } else { |
|
3896 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name()); |
|
3897 } |
|
3898 } |
|
3899 } |
|
3900 |
|
3901 // Last thread running calls java.lang.Shutdown.shutdown() |
|
3902 void JavaThread::invoke_shutdown_hooks() { |
|
3903 HandleMark hm(this); |
|
3904 |
|
3905 // We could get here with a pending exception, if so clear it now. |
|
3906 if (this->has_pending_exception()) { |
|
3907 this->clear_pending_exception(); |
|
3908 } |
|
3909 |
|
3910 EXCEPTION_MARK; |
|
3911 Klass* k = |
|
3912 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(), |
|
3913 THREAD); |
|
3914 if (k != NULL) { |
|
3915 // SystemDictionary::resolve_or_null will return null if there was |
|
3916 // an exception. If we cannot load the Shutdown class, just don't |
|
3917 // call Shutdown.shutdown() at all. This will mean the shutdown hooks |
|
3918 // and finalizers (if runFinalizersOnExit is set) won't be run. |
|
3919 // Note that if a shutdown hook was registered or runFinalizersOnExit |
|
3920 // was called, the Shutdown class would have already been loaded |
|
3921 // (Runtime.addShutdownHook and runFinalizersOnExit will load it). |
|
3922 instanceKlassHandle shutdown_klass (THREAD, k); |
|
3923 JavaValue result(T_VOID); |
|
3924 JavaCalls::call_static(&result, |
|
3925 shutdown_klass, |
|
3926 vmSymbols::shutdown_method_name(), |
|
3927 vmSymbols::void_method_signature(), |
|
3928 THREAD); |
|
3929 } |
|
3930 CLEAR_PENDING_EXCEPTION; |
|
3931 } |
|
3932 |
|
3933 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when |
|
3934 // the program falls off the end of main(). Another VM exit path is through |
|
3935 // vm_exit() when the program calls System.exit() to return a value or when |
|
3936 // there is a serious error in VM. The two shutdown paths are not exactly |
|
3937 // the same, but they share Shutdown.shutdown() at Java level and before_exit() |
|
3938 // and VM_Exit op at VM level. |
|
3939 // |
|
3940 // Shutdown sequence: |
|
3941 // + Shutdown native memory tracking if it is on |
|
3942 // + Wait until we are the last non-daemon thread to execute |
|
3943 // <-- every thing is still working at this moment --> |
|
3944 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level |
|
3945 // shutdown hooks, run finalizers if finalization-on-exit |
|
3946 // + Call before_exit(), prepare for VM exit |
|
3947 // > run VM level shutdown hooks (they are registered through JVM_OnExit(), |
|
3948 // currently the only user of this mechanism is File.deleteOnExit()) |
|
3949 // > stop flat profiler, StatSampler, watcher thread, CMS threads, |
|
3950 // post thread end and vm death events to JVMTI, |
|
3951 // stop signal thread |
|
3952 // + Call JavaThread::exit(), it will: |
|
3953 // > release JNI handle blocks, remove stack guard pages |
|
3954 // > remove this thread from Threads list |
|
3955 // <-- no more Java code from this thread after this point --> |
|
3956 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop |
|
3957 // the compiler threads at safepoint |
|
3958 // <-- do not use anything that could get blocked by Safepoint --> |
|
3959 // + Disable tracing at JNI/JVM barriers |
|
3960 // + Set _vm_exited flag for threads that are still running native code |
|
3961 // + Delete this thread |
|
3962 // + Call exit_globals() |
|
3963 // > deletes tty |
|
3964 // > deletes PerfMemory resources |
|
3965 // + Return to caller |
|
3966 |
|
3967 bool Threads::destroy_vm() { |
|
3968 JavaThread* thread = JavaThread::current(); |
|
3969 |
|
3970 #ifdef ASSERT |
|
3971 _vm_complete = false; |
|
3972 #endif |
|
3973 // Wait until we are the last non-daemon thread to execute |
|
3974 { MutexLocker nu(Threads_lock); |
|
3975 while (Threads::number_of_non_daemon_threads() > 1 ) |
|
3976 // This wait should make safepoint checks, wait without a timeout, |
|
3977 // and wait as a suspend-equivalent condition. |
|
3978 // |
|
3979 // Note: If the FlatProfiler is running and this thread is waiting |
|
3980 // for another non-daemon thread to finish, then the FlatProfiler |
|
3981 // is waiting for the external suspend request on this thread to |
|
3982 // complete. wait_for_ext_suspend_completion() will eventually |
|
3983 // timeout, but that takes time. Making this wait a suspend- |
|
3984 // equivalent condition solves that timeout problem. |
|
3985 // |
|
3986 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0, |
|
3987 Mutex::_as_suspend_equivalent_flag); |
|
3988 } |
|
3989 |
|
3990 // Hang forever on exit if we are reporting an error. |
|
3991 if (ShowMessageBoxOnError && is_error_reported()) { |
|
3992 os::infinite_sleep(); |
|
3993 } |
|
3994 os::wait_for_keypress_at_exit(); |
|
3995 |
|
3996 if (JDK_Version::is_jdk12x_version()) { |
|
3997 // We are the last thread running, so check if finalizers should be run. |
|
3998 // For 1.3 or later this is done in thread->invoke_shutdown_hooks() |
|
3999 HandleMark rm(thread); |
|
4000 Universe::run_finalizers_on_exit(); |
|
4001 } else { |
|
4002 // run Java level shutdown hooks |
|
4003 thread->invoke_shutdown_hooks(); |
|
4004 } |
|
4005 |
|
4006 before_exit(thread); |
|
4007 |
|
4008 thread->exit(true); |
|
4009 |
|
4010 // Stop VM thread. |
|
4011 { |
|
4012 // 4945125 The vm thread comes to a safepoint during exit. |
|
4013 // GC vm_operations can get caught at the safepoint, and the |
|
4014 // heap is unparseable if they are caught. Grab the Heap_lock |
|
4015 // to prevent this. The GC vm_operations will not be able to |
|
4016 // queue until after the vm thread is dead. After this point, |
|
4017 // we'll never emerge out of the safepoint before the VM exits. |
|
4018 |
|
4019 MutexLocker ml(Heap_lock); |
|
4020 |
|
4021 VMThread::wait_for_vm_thread_exit(); |
|
4022 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); |
|
4023 VMThread::destroy(); |
|
4024 } |
|
4025 |
|
4026 // clean up ideal graph printers |
|
4027 #if defined(COMPILER2) && !defined(PRODUCT) |
|
4028 IdealGraphPrinter::clean_up(); |
|
4029 #endif |
|
4030 |
|
4031 // Now, all Java threads are gone except daemon threads. Daemon threads |
|
4032 // running Java code or in VM are stopped by the Safepoint. However, |
|
4033 // daemon threads executing native code are still running. But they |
|
4034 // will be stopped at native=>Java/VM barriers. Note that we can't |
|
4035 // simply kill or suspend them, as it is inherently deadlock-prone. |
|
4036 |
|
4037 #ifndef PRODUCT |
|
4038 // disable function tracing at JNI/JVM barriers |
|
4039 TraceJNICalls = false; |
|
4040 TraceJVMCalls = false; |
|
4041 TraceRuntimeCalls = false; |
|
4042 #endif |
|
4043 |
|
4044 VM_Exit::set_vm_exited(); |
|
4045 |
|
4046 notify_vm_shutdown(); |
|
4047 |
|
4048 delete thread; |
|
4049 |
|
4050 // exit_globals() will delete tty |
|
4051 exit_globals(); |
|
4052 |
|
4053 return true; |
|
4054 } |
|
4055 |
|
4056 |
|
4057 jboolean Threads::is_supported_jni_version_including_1_1(jint version) { |
|
4058 if (version == JNI_VERSION_1_1) return JNI_TRUE; |
|
4059 return is_supported_jni_version(version); |
|
4060 } |
|
4061 |
|
4062 |
|
4063 jboolean Threads::is_supported_jni_version(jint version) { |
|
4064 if (version == JNI_VERSION_1_2) return JNI_TRUE; |
|
4065 if (version == JNI_VERSION_1_4) return JNI_TRUE; |
|
4066 if (version == JNI_VERSION_1_6) return JNI_TRUE; |
|
4067 if (version == JNI_VERSION_1_8) return JNI_TRUE; |
|
4068 return JNI_FALSE; |
|
4069 } |
|
4070 |
|
4071 |
|
4072 void Threads::add(JavaThread* p, bool force_daemon) { |
|
4073 // The threads lock must be owned at this point |
|
4074 assert_locked_or_safepoint(Threads_lock); |
|
4075 |
|
4076 // See the comment for this method in thread.hpp for its purpose and |
|
4077 // why it is called here. |
|
4078 p->initialize_queues(); |
|
4079 p->set_next(_thread_list); |
|
4080 _thread_list = p; |
|
4081 _number_of_threads++; |
|
4082 oop threadObj = p->threadObj(); |
|
4083 bool daemon = true; |
|
4084 // Bootstrapping problem: threadObj can be null for initial |
|
4085 // JavaThread (or for threads attached via JNI) |
|
4086 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) { |
|
4087 _number_of_non_daemon_threads++; |
|
4088 daemon = false; |
|
4089 } |
|
4090 |
|
4091 p->set_safepoint_visible(true); |
|
4092 |
|
4093 ThreadService::add_thread(p, daemon); |
|
4094 |
|
4095 // Possible GC point. |
|
4096 Events::log(p, "Thread added: " INTPTR_FORMAT, p); |
|
4097 } |
|
4098 |
|
4099 void Threads::remove(JavaThread* p) { |
|
4100 // Extra scope needed for Thread_lock, so we can check |
|
4101 // that we do not remove thread without safepoint code notice |
|
4102 { MutexLocker ml(Threads_lock); |
|
4103 |
|
4104 assert(includes(p), "p must be present"); |
|
4105 |
|
4106 JavaThread* current = _thread_list; |
|
4107 JavaThread* prev = NULL; |
|
4108 |
|
4109 while (current != p) { |
|
4110 prev = current; |
|
4111 current = current->next(); |
|
4112 } |
|
4113 |
|
4114 if (prev) { |
|
4115 prev->set_next(current->next()); |
|
4116 } else { |
|
4117 _thread_list = p->next(); |
|
4118 } |
|
4119 _number_of_threads--; |
|
4120 oop threadObj = p->threadObj(); |
|
4121 bool daemon = true; |
|
4122 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) { |
|
4123 _number_of_non_daemon_threads--; |
|
4124 daemon = false; |
|
4125 |
|
4126 // Only one thread left, do a notify on the Threads_lock so a thread waiting |
|
4127 // on destroy_vm will wake up. |
|
4128 if (number_of_non_daemon_threads() == 1) |
|
4129 Threads_lock->notify_all(); |
|
4130 } |
|
4131 ThreadService::remove_thread(p, daemon); |
|
4132 |
|
4133 // Make sure that safepoint code disregard this thread. This is needed since |
|
4134 // the thread might mess around with locks after this point. This can cause it |
|
4135 // to do callbacks into the safepoint code. However, the safepoint code is not aware |
|
4136 // of this thread since it is removed from the queue. |
|
4137 p->set_terminated_value(); |
|
4138 |
|
4139 // Now, this thread is not visible to safepoint |
|
4140 p->set_safepoint_visible(false); |
|
4141 // once the thread becomes safepoint invisible, we can not use its per-thread |
|
4142 // recorder. And Threads::do_threads() no longer walks this thread, so we have |
|
4143 // to release its per-thread recorder here. |
|
4144 MemTracker::thread_exiting(p); |
|
4145 } // unlock Threads_lock |
|
4146 |
|
4147 // Since Events::log uses a lock, we grab it outside the Threads_lock |
|
4148 Events::log(p, "Thread exited: " INTPTR_FORMAT, p); |
|
4149 } |
|
4150 |
|
4151 // Threads_lock must be held when this is called (or must be called during a safepoint) |
|
4152 bool Threads::includes(JavaThread* p) { |
|
4153 assert(Threads_lock->is_locked(), "sanity check"); |
|
4154 ALL_JAVA_THREADS(q) { |
|
4155 if (q == p ) { |
|
4156 return true; |
|
4157 } |
|
4158 } |
|
4159 return false; |
|
4160 } |
|
4161 |
|
4162 // Operations on the Threads list for GC. These are not explicitly locked, |
|
4163 // but the garbage collector must provide a safe context for them to run. |
|
4164 // In particular, these things should never be called when the Threads_lock |
|
4165 // is held by some other thread. (Note: the Safepoint abstraction also |
|
4166 // uses the Threads_lock to gurantee this property. It also makes sure that |
|
4167 // all threads gets blocked when exiting or starting). |
|
4168 |
|
4169 void Threads::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) { |
|
4170 ALL_JAVA_THREADS(p) { |
|
4171 p->oops_do(f, cld_f, cf); |
|
4172 } |
|
4173 VMThread::vm_thread()->oops_do(f, cld_f, cf); |
|
4174 } |
|
4175 |
|
4176 void Threads::possibly_parallel_oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) { |
|
4177 // Introduce a mechanism allowing parallel threads to claim threads as |
|
4178 // root groups. Overhead should be small enough to use all the time, |
|
4179 // even in sequential code. |
|
4180 SharedHeap* sh = SharedHeap::heap(); |
|
4181 // Cannot yet substitute active_workers for n_par_threads |
|
4182 // because of G1CollectedHeap::verify() use of |
|
4183 // SharedHeap::process_strong_roots(). n_par_threads == 0 will |
|
4184 // turn off parallelism in process_strong_roots while active_workers |
|
4185 // is being used for parallelism elsewhere. |
|
4186 bool is_par = sh->n_par_threads() > 0; |
|
4187 assert(!is_par || |
|
4188 (SharedHeap::heap()->n_par_threads() == |
|
4189 SharedHeap::heap()->workers()->active_workers()), "Mismatch"); |
|
4190 int cp = SharedHeap::heap()->strong_roots_parity(); |
|
4191 ALL_JAVA_THREADS(p) { |
|
4192 if (p->claim_oops_do(is_par, cp)) { |
|
4193 p->oops_do(f, cld_f, cf); |
|
4194 } |
|
4195 } |
|
4196 VMThread* vmt = VMThread::vm_thread(); |
|
4197 if (vmt->claim_oops_do(is_par, cp)) { |
|
4198 vmt->oops_do(f, cld_f, cf); |
|
4199 } |
|
4200 } |
|
4201 |
|
4202 #if INCLUDE_ALL_GCS |
|
4203 // Used by ParallelScavenge |
|
4204 void Threads::create_thread_roots_tasks(GCTaskQueue* q) { |
|
4205 ALL_JAVA_THREADS(p) { |
|
4206 q->enqueue(new ThreadRootsTask(p)); |
|
4207 } |
|
4208 q->enqueue(new ThreadRootsTask(VMThread::vm_thread())); |
|
4209 } |
|
4210 |
|
4211 // Used by Parallel Old |
|
4212 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) { |
|
4213 ALL_JAVA_THREADS(p) { |
|
4214 q->enqueue(new ThreadRootsMarkingTask(p)); |
|
4215 } |
|
4216 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread())); |
|
4217 } |
|
4218 #endif // INCLUDE_ALL_GCS |
|
4219 |
|
4220 void Threads::nmethods_do(CodeBlobClosure* cf) { |
|
4221 ALL_JAVA_THREADS(p) { |
|
4222 p->nmethods_do(cf); |
|
4223 } |
|
4224 VMThread::vm_thread()->nmethods_do(cf); |
|
4225 } |
|
4226 |
|
4227 void Threads::metadata_do(void f(Metadata*)) { |
|
4228 ALL_JAVA_THREADS(p) { |
|
4229 p->metadata_do(f); |
|
4230 } |
|
4231 } |
|
4232 |
|
4233 void Threads::gc_epilogue() { |
|
4234 ALL_JAVA_THREADS(p) { |
|
4235 p->gc_epilogue(); |
|
4236 } |
|
4237 } |
|
4238 |
|
4239 void Threads::gc_prologue() { |
|
4240 ALL_JAVA_THREADS(p) { |
|
4241 p->gc_prologue(); |
|
4242 } |
|
4243 } |
|
4244 |
|
4245 void Threads::deoptimized_wrt_marked_nmethods() { |
|
4246 ALL_JAVA_THREADS(p) { |
|
4247 p->deoptimized_wrt_marked_nmethods(); |
|
4248 } |
|
4249 } |
|
4250 |
|
4251 |
|
4252 // Get count Java threads that are waiting to enter the specified monitor. |
|
4253 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count, |
|
4254 address monitor, bool doLock) { |
|
4255 assert(doLock || SafepointSynchronize::is_at_safepoint(), |
|
4256 "must grab Threads_lock or be at safepoint"); |
|
4257 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); |
|
4258 |
|
4259 int i = 0; |
|
4260 { |
|
4261 MutexLockerEx ml(doLock ? Threads_lock : NULL); |
|
4262 ALL_JAVA_THREADS(p) { |
|
4263 if (p->is_Compiler_thread()) continue; |
|
4264 |
|
4265 address pending = (address)p->current_pending_monitor(); |
|
4266 if (pending == monitor) { // found a match |
|
4267 if (i < count) result->append(p); // save the first count matches |
|
4268 i++; |
|
4269 } |
|
4270 } |
|
4271 } |
|
4272 return result; |
|
4273 } |
|
4274 |
|
4275 |
|
4276 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) { |
|
4277 assert(doLock || |
|
4278 Threads_lock->owned_by_self() || |
|
4279 SafepointSynchronize::is_at_safepoint(), |
|
4280 "must grab Threads_lock or be at safepoint"); |
|
4281 |
|
4282 // NULL owner means not locked so we can skip the search |
|
4283 if (owner == NULL) return NULL; |
|
4284 |
|
4285 { |
|
4286 MutexLockerEx ml(doLock ? Threads_lock : NULL); |
|
4287 ALL_JAVA_THREADS(p) { |
|
4288 // first, see if owner is the address of a Java thread |
|
4289 if (owner == (address)p) return p; |
|
4290 } |
|
4291 } |
|
4292 // Cannot assert on lack of success here since this function may be |
|
4293 // used by code that is trying to report useful problem information |
|
4294 // like deadlock detection. |
|
4295 if (UseHeavyMonitors) return NULL; |
|
4296 |
|
4297 // |
|
4298 // If we didn't find a matching Java thread and we didn't force use of |
|
4299 // heavyweight monitors, then the owner is the stack address of the |
|
4300 // Lock Word in the owning Java thread's stack. |
|
4301 // |
|
4302 JavaThread* the_owner = NULL; |
|
4303 { |
|
4304 MutexLockerEx ml(doLock ? Threads_lock : NULL); |
|
4305 ALL_JAVA_THREADS(q) { |
|
4306 if (q->is_lock_owned(owner)) { |
|
4307 the_owner = q; |
|
4308 break; |
|
4309 } |
|
4310 } |
|
4311 } |
|
4312 // cannot assert on lack of success here; see above comment |
|
4313 return the_owner; |
|
4314 } |
|
4315 |
|
4316 // Threads::print_on() is called at safepoint by VM_PrintThreads operation. |
|
4317 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) { |
|
4318 char buf[32]; |
|
4319 st->print_cr("%s", os::local_time_string(buf, sizeof(buf))); |
|
4320 |
|
4321 st->print_cr("Full thread dump %s (%s %s):", |
|
4322 Abstract_VM_Version::vm_name(), |
|
4323 Abstract_VM_Version::vm_release(), |
|
4324 Abstract_VM_Version::vm_info_string() |
|
4325 ); |
|
4326 st->cr(); |
|
4327 |
|
4328 #if INCLUDE_ALL_GCS |
|
4329 // Dump concurrent locks |
|
4330 ConcurrentLocksDump concurrent_locks; |
|
4331 if (print_concurrent_locks) { |
|
4332 concurrent_locks.dump_at_safepoint(); |
|
4333 } |
|
4334 #endif // INCLUDE_ALL_GCS |
|
4335 |
|
4336 ALL_JAVA_THREADS(p) { |
|
4337 ResourceMark rm; |
|
4338 p->print_on(st); |
|
4339 if (print_stacks) { |
|
4340 if (internal_format) { |
|
4341 p->trace_stack(); |
|
4342 } else { |
|
4343 p->print_stack_on(st); |
|
4344 } |
|
4345 } |
|
4346 st->cr(); |
|
4347 #if INCLUDE_ALL_GCS |
|
4348 if (print_concurrent_locks) { |
|
4349 concurrent_locks.print_locks_on(p, st); |
|
4350 } |
|
4351 #endif // INCLUDE_ALL_GCS |
|
4352 } |
|
4353 |
|
4354 VMThread::vm_thread()->print_on(st); |
|
4355 st->cr(); |
|
4356 Universe::heap()->print_gc_threads_on(st); |
|
4357 WatcherThread* wt = WatcherThread::watcher_thread(); |
|
4358 if (wt != NULL) { |
|
4359 wt->print_on(st); |
|
4360 st->cr(); |
|
4361 } |
|
4362 CompileBroker::print_compiler_threads_on(st); |
|
4363 st->flush(); |
|
4364 } |
|
4365 |
|
4366 // Threads::print_on_error() is called by fatal error handler. It's possible |
|
4367 // that VM is not at safepoint and/or current thread is inside signal handler. |
|
4368 // Don't print stack trace, as the stack may not be walkable. Don't allocate |
|
4369 // memory (even in resource area), it might deadlock the error handler. |
|
4370 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) { |
|
4371 bool found_current = false; |
|
4372 st->print_cr("Java Threads: ( => current thread )"); |
|
4373 ALL_JAVA_THREADS(thread) { |
|
4374 bool is_current = (current == thread); |
|
4375 found_current = found_current || is_current; |
|
4376 |
|
4377 st->print("%s", is_current ? "=>" : " "); |
|
4378 |
|
4379 st->print(PTR_FORMAT, thread); |
|
4380 st->print(" "); |
|
4381 thread->print_on_error(st, buf, buflen); |
|
4382 st->cr(); |
|
4383 } |
|
4384 st->cr(); |
|
4385 |
|
4386 st->print_cr("Other Threads:"); |
|
4387 if (VMThread::vm_thread()) { |
|
4388 bool is_current = (current == VMThread::vm_thread()); |
|
4389 found_current = found_current || is_current; |
|
4390 st->print("%s", current == VMThread::vm_thread() ? "=>" : " "); |
|
4391 |
|
4392 st->print(PTR_FORMAT, VMThread::vm_thread()); |
|
4393 st->print(" "); |
|
4394 VMThread::vm_thread()->print_on_error(st, buf, buflen); |
|
4395 st->cr(); |
|
4396 } |
|
4397 WatcherThread* wt = WatcherThread::watcher_thread(); |
|
4398 if (wt != NULL) { |
|
4399 bool is_current = (current == wt); |
|
4400 found_current = found_current || is_current; |
|
4401 st->print("%s", is_current ? "=>" : " "); |
|
4402 |
|
4403 st->print(PTR_FORMAT, wt); |
|
4404 st->print(" "); |
|
4405 wt->print_on_error(st, buf, buflen); |
|
4406 st->cr(); |
|
4407 } |
|
4408 if (!found_current) { |
|
4409 st->cr(); |
|
4410 st->print("=>" PTR_FORMAT " (exited) ", current); |
|
4411 current->print_on_error(st, buf, buflen); |
|
4412 st->cr(); |
|
4413 } |
|
4414 } |
|
4415 |
|
4416 // Internal SpinLock and Mutex |
|
4417 // Based on ParkEvent |
|
4418 |
|
4419 // Ad-hoc mutual exclusion primitives: SpinLock and Mux |
|
4420 // |
|
4421 // We employ SpinLocks _only for low-contention, fixed-length |
|
4422 // short-duration critical sections where we're concerned |
|
4423 // about native mutex_t or HotSpot Mutex:: latency. |
|
4424 // The mux construct provides a spin-then-block mutual exclusion |
|
4425 // mechanism. |
|
4426 // |
|
4427 // Testing has shown that contention on the ListLock guarding gFreeList |
|
4428 // is common. If we implement ListLock as a simple SpinLock it's common |
|
4429 // for the JVM to devolve to yielding with little progress. This is true |
|
4430 // despite the fact that the critical sections protected by ListLock are |
|
4431 // extremely short. |
|
4432 // |
|
4433 // TODO-FIXME: ListLock should be of type SpinLock. |
|
4434 // We should make this a 1st-class type, integrated into the lock |
|
4435 // hierarchy as leaf-locks. Critically, the SpinLock structure |
|
4436 // should have sufficient padding to avoid false-sharing and excessive |
|
4437 // cache-coherency traffic. |
|
4438 |
|
4439 |
|
4440 typedef volatile int SpinLockT ; |
|
4441 |
|
4442 void Thread::SpinAcquire (volatile int * adr, const char * LockName) { |
|
4443 if (Atomic::cmpxchg (1, adr, 0) == 0) { |
|
4444 return ; // normal fast-path return |
|
4445 } |
|
4446 |
|
4447 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy. |
|
4448 TEVENT (SpinAcquire - ctx) ; |
|
4449 int ctr = 0 ; |
|
4450 int Yields = 0 ; |
|
4451 for (;;) { |
|
4452 while (*adr != 0) { |
|
4453 ++ctr ; |
|
4454 if ((ctr & 0xFFF) == 0 || !os::is_MP()) { |
|
4455 if (Yields > 5) { |
|
4456 os::naked_short_sleep(1); |
|
4457 } else { |
|
4458 os::NakedYield() ; |
|
4459 ++Yields ; |
|
4460 } |
|
4461 } else { |
|
4462 SpinPause() ; |
|
4463 } |
|
4464 } |
|
4465 if (Atomic::cmpxchg (1, adr, 0) == 0) return ; |
|
4466 } |
|
4467 } |
|
4468 |
|
4469 void Thread::SpinRelease (volatile int * adr) { |
|
4470 assert (*adr != 0, "invariant") ; |
|
4471 OrderAccess::fence() ; // guarantee at least release consistency. |
|
4472 // Roach-motel semantics. |
|
4473 // It's safe if subsequent LDs and STs float "up" into the critical section, |
|
4474 // but prior LDs and STs within the critical section can't be allowed |
|
4475 // to reorder or float past the ST that releases the lock. |
|
4476 *adr = 0 ; |
|
4477 } |
|
4478 |
|
4479 // muxAcquire and muxRelease: |
|
4480 // |
|
4481 // * muxAcquire and muxRelease support a single-word lock-word construct. |
|
4482 // The LSB of the word is set IFF the lock is held. |
|
4483 // The remainder of the word points to the head of a singly-linked list |
|
4484 // of threads blocked on the lock. |
|
4485 // |
|
4486 // * The current implementation of muxAcquire-muxRelease uses its own |
|
4487 // dedicated Thread._MuxEvent instance. If we're interested in |
|
4488 // minimizing the peak number of extant ParkEvent instances then |
|
4489 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long |
|
4490 // as certain invariants were satisfied. Specifically, care would need |
|
4491 // to be taken with regards to consuming unpark() "permits". |
|
4492 // A safe rule of thumb is that a thread would never call muxAcquire() |
|
4493 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently |
|
4494 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could |
|
4495 // consume an unpark() permit intended for monitorenter, for instance. |
|
4496 // One way around this would be to widen the restricted-range semaphore |
|
4497 // implemented in park(). Another alternative would be to provide |
|
4498 // multiple instances of the PlatformEvent() for each thread. One |
|
4499 // instance would be dedicated to muxAcquire-muxRelease, for instance. |
|
4500 // |
|
4501 // * Usage: |
|
4502 // -- Only as leaf locks |
|
4503 // -- for short-term locking only as muxAcquire does not perform |
|
4504 // thread state transitions. |
|
4505 // |
|
4506 // Alternatives: |
|
4507 // * We could implement muxAcquire and muxRelease with MCS or CLH locks |
|
4508 // but with parking or spin-then-park instead of pure spinning. |
|
4509 // * Use Taura-Oyama-Yonenzawa locks. |
|
4510 // * It's possible to construct a 1-0 lock if we encode the lockword as |
|
4511 // (List,LockByte). Acquire will CAS the full lockword while Release |
|
4512 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so |
|
4513 // acquiring threads use timers (ParkTimed) to detect and recover from |
|
4514 // the stranding window. Thread/Node structures must be aligned on 256-byte |
|
4515 // boundaries by using placement-new. |
|
4516 // * Augment MCS with advisory back-link fields maintained with CAS(). |
|
4517 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner. |
|
4518 // The validity of the backlinks must be ratified before we trust the value. |
|
4519 // If the backlinks are invalid the exiting thread must back-track through the |
|
4520 // the forward links, which are always trustworthy. |
|
4521 // * Add a successor indication. The LockWord is currently encoded as |
|
4522 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable |
|
4523 // to provide the usual futile-wakeup optimization. |
|
4524 // See RTStt for details. |
|
4525 // * Consider schedctl.sc_nopreempt to cover the critical section. |
|
4526 // |
|
4527 |
|
4528 |
|
4529 typedef volatile intptr_t MutexT ; // Mux Lock-word |
|
4530 enum MuxBits { LOCKBIT = 1 } ; |
|
4531 |
|
4532 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) { |
|
4533 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ; |
|
4534 if (w == 0) return ; |
|
4535 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { |
|
4536 return ; |
|
4537 } |
|
4538 |
|
4539 TEVENT (muxAcquire - Contention) ; |
|
4540 ParkEvent * const Self = Thread::current()->_MuxEvent ; |
|
4541 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ; |
|
4542 for (;;) { |
|
4543 int its = (os::is_MP() ? 100 : 0) + 1 ; |
|
4544 |
|
4545 // Optional spin phase: spin-then-park strategy |
|
4546 while (--its >= 0) { |
|
4547 w = *Lock ; |
|
4548 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { |
|
4549 return ; |
|
4550 } |
|
4551 } |
|
4552 |
|
4553 Self->reset() ; |
|
4554 Self->OnList = intptr_t(Lock) ; |
|
4555 // The following fence() isn't _strictly necessary as the subsequent |
|
4556 // CAS() both serializes execution and ratifies the fetched *Lock value. |
|
4557 OrderAccess::fence(); |
|
4558 for (;;) { |
|
4559 w = *Lock ; |
|
4560 if ((w & LOCKBIT) == 0) { |
|
4561 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { |
|
4562 Self->OnList = 0 ; // hygiene - allows stronger asserts |
|
4563 return ; |
|
4564 } |
|
4565 continue ; // Interference -- *Lock changed -- Just retry |
|
4566 } |
|
4567 assert (w & LOCKBIT, "invariant") ; |
|
4568 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT ); |
|
4569 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ; |
|
4570 } |
|
4571 |
|
4572 while (Self->OnList != 0) { |
|
4573 Self->park() ; |
|
4574 } |
|
4575 } |
|
4576 } |
|
4577 |
|
4578 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) { |
|
4579 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ; |
|
4580 if (w == 0) return ; |
|
4581 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { |
|
4582 return ; |
|
4583 } |
|
4584 |
|
4585 TEVENT (muxAcquire - Contention) ; |
|
4586 ParkEvent * ReleaseAfter = NULL ; |
|
4587 if (ev == NULL) { |
|
4588 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ; |
|
4589 } |
|
4590 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ; |
|
4591 for (;;) { |
|
4592 guarantee (ev->OnList == 0, "invariant") ; |
|
4593 int its = (os::is_MP() ? 100 : 0) + 1 ; |
|
4594 |
|
4595 // Optional spin phase: spin-then-park strategy |
|
4596 while (--its >= 0) { |
|
4597 w = *Lock ; |
|
4598 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { |
|
4599 if (ReleaseAfter != NULL) { |
|
4600 ParkEvent::Release (ReleaseAfter) ; |
|
4601 } |
|
4602 return ; |
|
4603 } |
|
4604 } |
|
4605 |
|
4606 ev->reset() ; |
|
4607 ev->OnList = intptr_t(Lock) ; |
|
4608 // The following fence() isn't _strictly necessary as the subsequent |
|
4609 // CAS() both serializes execution and ratifies the fetched *Lock value. |
|
4610 OrderAccess::fence(); |
|
4611 for (;;) { |
|
4612 w = *Lock ; |
|
4613 if ((w & LOCKBIT) == 0) { |
|
4614 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) { |
|
4615 ev->OnList = 0 ; |
|
4616 // We call ::Release while holding the outer lock, thus |
|
4617 // artificially lengthening the critical section. |
|
4618 // Consider deferring the ::Release() until the subsequent unlock(), |
|
4619 // after we've dropped the outer lock. |
|
4620 if (ReleaseAfter != NULL) { |
|
4621 ParkEvent::Release (ReleaseAfter) ; |
|
4622 } |
|
4623 return ; |
|
4624 } |
|
4625 continue ; // Interference -- *Lock changed -- Just retry |
|
4626 } |
|
4627 assert (w & LOCKBIT, "invariant") ; |
|
4628 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT ); |
|
4629 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ; |
|
4630 } |
|
4631 |
|
4632 while (ev->OnList != 0) { |
|
4633 ev->park() ; |
|
4634 } |
|
4635 } |
|
4636 } |
|
4637 |
|
4638 // Release() must extract a successor from the list and then wake that thread. |
|
4639 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme |
|
4640 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based |
|
4641 // Release() would : |
|
4642 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list. |
|
4643 // (B) Extract a successor from the private list "in-hand" |
|
4644 // (C) attempt to CAS() the residual back into *Lock over null. |
|
4645 // If there were any newly arrived threads and the CAS() would fail. |
|
4646 // In that case Release() would detach the RATs, re-merge the list in-hand |
|
4647 // with the RATs and repeat as needed. Alternately, Release() might |
|
4648 // detach and extract a successor, but then pass the residual list to the wakee. |
|
4649 // The wakee would be responsible for reattaching and remerging before it |
|
4650 // competed for the lock. |
|
4651 // |
|
4652 // Both "pop" and DMR are immune from ABA corruption -- there can be |
|
4653 // multiple concurrent pushers, but only one popper or detacher. |
|
4654 // This implementation pops from the head of the list. This is unfair, |
|
4655 // but tends to provide excellent throughput as hot threads remain hot. |
|
4656 // (We wake recently run threads first). |
|
4657 |
|
4658 void Thread::muxRelease (volatile intptr_t * Lock) { |
|
4659 for (;;) { |
|
4660 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ; |
|
4661 assert (w & LOCKBIT, "invariant") ; |
|
4662 if (w == LOCKBIT) return ; |
|
4663 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ; |
|
4664 assert (List != NULL, "invariant") ; |
|
4665 assert (List->OnList == intptr_t(Lock), "invariant") ; |
|
4666 ParkEvent * nxt = List->ListNext ; |
|
4667 |
|
4668 // The following CAS() releases the lock and pops the head element. |
|
4669 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) { |
|
4670 continue ; |
|
4671 } |
|
4672 List->OnList = 0 ; |
|
4673 OrderAccess::fence() ; |
|
4674 List->unpark () ; |
|
4675 return ; |
|
4676 } |
|
4677 } |
|
4678 |
|
4679 |
|
4680 void Threads::verify() { |
|
4681 ALL_JAVA_THREADS(p) { |
|
4682 p->verify(); |
|
4683 } |
|
4684 VMThread* thread = VMThread::vm_thread(); |
|
4685 if (thread != NULL) thread->verify(); |
|
4686 } |