src/share/vm/runtime/os.cpp

Thu, 12 Oct 2017 21:27:07 +0800

author
aoqi
date
Thu, 12 Oct 2017 21:27:07 +0800
changeset 7535
7ae4e26cb1e0
parent 7344
787c9c28311f
parent 6876
710a3c8b516e
child 7994
04ff2f6cd0eb
permissions
-rw-r--r--

merge

     1 /*
     2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "classfile/classLoader.hpp"
    27 #include "classfile/javaClasses.hpp"
    28 #include "classfile/systemDictionary.hpp"
    29 #include "classfile/vmSymbols.hpp"
    30 #include "code/icBuffer.hpp"
    31 #include "code/vtableStubs.hpp"
    32 #include "gc_implementation/shared/vmGCOperations.hpp"
    33 #include "interpreter/interpreter.hpp"
    34 #include "memory/allocation.inline.hpp"
    35 #ifdef ASSERT
    36 #include "memory/guardedMemory.hpp"
    37 #endif
    38 #include "oops/oop.inline.hpp"
    39 #include "prims/jvm.h"
    40 #include "prims/jvm_misc.hpp"
    41 #include "prims/privilegedStack.hpp"
    42 #include "runtime/arguments.hpp"
    43 #include "runtime/frame.inline.hpp"
    44 #include "runtime/interfaceSupport.hpp"
    45 #include "runtime/java.hpp"
    46 #include "runtime/javaCalls.hpp"
    47 #include "runtime/mutexLocker.hpp"
    48 #include "runtime/os.hpp"
    49 #include "runtime/stubRoutines.hpp"
    50 #include "runtime/thread.inline.hpp"
    51 #include "services/attachListener.hpp"
    52 #include "services/nmtCommon.hpp"
    53 #include "services/mallocTracker.hpp"
    54 #include "services/memTracker.hpp"
    55 #include "services/threadService.hpp"
    56 #include "utilities/defaultStream.hpp"
    57 #include "utilities/events.hpp"
    58 #ifdef TARGET_OS_FAMILY_linux
    59 # include "os_linux.inline.hpp"
    60 #endif
    61 #ifdef TARGET_OS_FAMILY_solaris
    62 # include "os_solaris.inline.hpp"
    63 #endif
    64 #ifdef TARGET_OS_FAMILY_windows
    65 # include "os_windows.inline.hpp"
    66 #endif
    67 #ifdef TARGET_OS_FAMILY_bsd
    68 # include "os_bsd.inline.hpp"
    69 #endif
    71 # include <signal.h>
    73 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
    75 OSThread*         os::_starting_thread    = NULL;
    76 address           os::_polling_page       = NULL;
    77 volatile int32_t* os::_mem_serialize_page = NULL;
    78 uintptr_t         os::_serialize_page_mask = 0;
    79 long              os::_rand_seed          = 1;
    80 int               os::_processor_count    = 0;
    81 size_t            os::_page_sizes[os::page_sizes_max];
    83 #ifndef PRODUCT
    84 julong os::num_mallocs = 0;         // # of calls to malloc/realloc
    85 julong os::alloc_bytes = 0;         // # of bytes allocated
    86 julong os::num_frees = 0;           // # of calls to free
    87 julong os::free_bytes = 0;          // # of bytes freed
    88 #endif
    90 static juint cur_malloc_words = 0;  // current size for MallocMaxTestWords
    92 void os_init_globals() {
    93   // Called from init_globals().
    94   // See Threads::create_vm() in thread.cpp, and init.cpp.
    95   os::init_globals();
    96 }
    98 // Fill in buffer with current local time as an ISO-8601 string.
    99 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
   100 // Returns buffer, or NULL if it failed.
   101 // This would mostly be a call to
   102 //     strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
   103 // except that on Windows the %z behaves badly, so we do it ourselves.
   104 // Also, people wanted milliseconds on there,
   105 // and strftime doesn't do milliseconds.
   106 char* os::iso8601_time(char* buffer, size_t buffer_length) {
   107   // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
   108   //                                      1         2
   109   //                             12345678901234567890123456789
   110   static const char* iso8601_format =
   111     "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
   112   static const size_t needed_buffer = 29;
   114   // Sanity check the arguments
   115   if (buffer == NULL) {
   116     assert(false, "NULL buffer");
   117     return NULL;
   118   }
   119   if (buffer_length < needed_buffer) {
   120     assert(false, "buffer_length too small");
   121     return NULL;
   122   }
   123   // Get the current time
   124   jlong milliseconds_since_19700101 = javaTimeMillis();
   125   const int milliseconds_per_microsecond = 1000;
   126   const time_t seconds_since_19700101 =
   127     milliseconds_since_19700101 / milliseconds_per_microsecond;
   128   const int milliseconds_after_second =
   129     milliseconds_since_19700101 % milliseconds_per_microsecond;
   130   // Convert the time value to a tm and timezone variable
   131   struct tm time_struct;
   132   if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
   133     assert(false, "Failed localtime_pd");
   134     return NULL;
   135   }
   136 #if defined(_ALLBSD_SOURCE)
   137   const time_t zone = (time_t) time_struct.tm_gmtoff;
   138 #else
   139   const time_t zone = timezone;
   140 #endif
   142   // If daylight savings time is in effect,
   143   // we are 1 hour East of our time zone
   144   const time_t seconds_per_minute = 60;
   145   const time_t minutes_per_hour = 60;
   146   const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
   147   time_t UTC_to_local = zone;
   148   if (time_struct.tm_isdst > 0) {
   149     UTC_to_local = UTC_to_local - seconds_per_hour;
   150   }
   151   // Compute the time zone offset.
   152   //    localtime_pd() sets timezone to the difference (in seconds)
   153   //    between UTC and and local time.
   154   //    ISO 8601 says we need the difference between local time and UTC,
   155   //    we change the sign of the localtime_pd() result.
   156   const time_t local_to_UTC = -(UTC_to_local);
   157   // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
   158   char sign_local_to_UTC = '+';
   159   time_t abs_local_to_UTC = local_to_UTC;
   160   if (local_to_UTC < 0) {
   161     sign_local_to_UTC = '-';
   162     abs_local_to_UTC = -(abs_local_to_UTC);
   163   }
   164   // Convert time zone offset seconds to hours and minutes.
   165   const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
   166   const time_t zone_min =
   167     ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
   169   // Print an ISO 8601 date and time stamp into the buffer
   170   const int year = 1900 + time_struct.tm_year;
   171   const int month = 1 + time_struct.tm_mon;
   172   const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
   173                                    year,
   174                                    month,
   175                                    time_struct.tm_mday,
   176                                    time_struct.tm_hour,
   177                                    time_struct.tm_min,
   178                                    time_struct.tm_sec,
   179                                    milliseconds_after_second,
   180                                    sign_local_to_UTC,
   181                                    zone_hours,
   182                                    zone_min);
   183   if (printed == 0) {
   184     assert(false, "Failed jio_printf");
   185     return NULL;
   186   }
   187   return buffer;
   188 }
   190 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
   191 #ifdef ASSERT
   192   if (!(!thread->is_Java_thread() ||
   193          Thread::current() == thread  ||
   194          Threads_lock->owned_by_self()
   195          || thread->is_Compiler_thread()
   196         )) {
   197     assert(false, "possibility of dangling Thread pointer");
   198   }
   199 #endif
   201   if (p >= MinPriority && p <= MaxPriority) {
   202     int priority = java_to_os_priority[p];
   203     return set_native_priority(thread, priority);
   204   } else {
   205     assert(false, "Should not happen");
   206     return OS_ERR;
   207   }
   208 }
   210 // The mapping from OS priority back to Java priority may be inexact because
   211 // Java priorities can map M:1 with native priorities. If you want the definite
   212 // Java priority then use JavaThread::java_priority()
   213 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
   214   int p;
   215   int os_prio;
   216   OSReturn ret = get_native_priority(thread, &os_prio);
   217   if (ret != OS_OK) return ret;
   219   if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
   220     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
   221   } else {
   222     // niceness values are in reverse order
   223     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
   224   }
   225   priority = (ThreadPriority)p;
   226   return OS_OK;
   227 }
   230 // --------------------- sun.misc.Signal (optional) ---------------------
   233 // SIGBREAK is sent by the keyboard to query the VM state
   234 #ifndef SIGBREAK
   235 #define SIGBREAK SIGQUIT
   236 #endif
   238 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
   241 static void signal_thread_entry(JavaThread* thread, TRAPS) {
   242   os::set_priority(thread, NearMaxPriority);
   243   while (true) {
   244     int sig;
   245     {
   246       // FIXME : Currently we have not decieded what should be the status
   247       //         for this java thread blocked here. Once we decide about
   248       //         that we should fix this.
   249       sig = os::signal_wait();
   250     }
   251     if (sig == os::sigexitnum_pd()) {
   252        // Terminate the signal thread
   253        return;
   254     }
   256     switch (sig) {
   257       case SIGBREAK: {
   258         // Check if the signal is a trigger to start the Attach Listener - in that
   259         // case don't print stack traces.
   260         if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
   261           continue;
   262         }
   263         // Print stack traces
   264         // Any SIGBREAK operations added here should make sure to flush
   265         // the output stream (e.g. tty->flush()) after output.  See 4803766.
   266         // Each module also prints an extra carriage return after its output.
   267         VM_PrintThreads op;
   268         VMThread::execute(&op);
   269         VM_PrintJNI jni_op;
   270         VMThread::execute(&jni_op);
   271         VM_FindDeadlocks op1(tty);
   272         VMThread::execute(&op1);
   273         Universe::print_heap_at_SIGBREAK();
   274         if (PrintClassHistogram) {
   275           VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
   276           VMThread::execute(&op1);
   277         }
   278         if (JvmtiExport::should_post_data_dump()) {
   279           JvmtiExport::post_data_dump();
   280         }
   281         break;
   282       }
   283       default: {
   284         // Dispatch the signal to java
   285         HandleMark hm(THREAD);
   286         Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
   287         KlassHandle klass (THREAD, k);
   288         if (klass.not_null()) {
   289           JavaValue result(T_VOID);
   290           JavaCallArguments args;
   291           args.push_int(sig);
   292           JavaCalls::call_static(
   293             &result,
   294             klass,
   295             vmSymbols::dispatch_name(),
   296             vmSymbols::int_void_signature(),
   297             &args,
   298             THREAD
   299           );
   300         }
   301         if (HAS_PENDING_EXCEPTION) {
   302           // tty is initialized early so we don't expect it to be null, but
   303           // if it is we can't risk doing an initialization that might
   304           // trigger additional out-of-memory conditions
   305           if (tty != NULL) {
   306             char klass_name[256];
   307             char tmp_sig_name[16];
   308             const char* sig_name = "UNKNOWN";
   309             InstanceKlass::cast(PENDING_EXCEPTION->klass())->
   310               name()->as_klass_external_name(klass_name, 256);
   311             if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
   312               sig_name = tmp_sig_name;
   313             warning("Exception %s occurred dispatching signal %s to handler"
   314                     "- the VM may need to be forcibly terminated",
   315                     klass_name, sig_name );
   316           }
   317           CLEAR_PENDING_EXCEPTION;
   318         }
   319       }
   320     }
   321   }
   322 }
   324 void os::init_before_ergo() {
   325   // We need to initialize large page support here because ergonomics takes some
   326   // decisions depending on large page support and the calculated large page size.
   327   large_page_init();
   328 }
   330 void os::signal_init() {
   331   if (!ReduceSignalUsage) {
   332     // Setup JavaThread for processing signals
   333     EXCEPTION_MARK;
   334     Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
   335     instanceKlassHandle klass (THREAD, k);
   336     instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
   338     const char thread_name[] = "Signal Dispatcher";
   339     Handle string = java_lang_String::create_from_str(thread_name, CHECK);
   341     // Initialize thread_oop to put it into the system threadGroup
   342     Handle thread_group (THREAD, Universe::system_thread_group());
   343     JavaValue result(T_VOID);
   344     JavaCalls::call_special(&result, thread_oop,
   345                            klass,
   346                            vmSymbols::object_initializer_name(),
   347                            vmSymbols::threadgroup_string_void_signature(),
   348                            thread_group,
   349                            string,
   350                            CHECK);
   352     KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
   353     JavaCalls::call_special(&result,
   354                             thread_group,
   355                             group,
   356                             vmSymbols::add_method_name(),
   357                             vmSymbols::thread_void_signature(),
   358                             thread_oop,         // ARG 1
   359                             CHECK);
   361     os::signal_init_pd();
   363     { MutexLocker mu(Threads_lock);
   364       JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
   366       // At this point it may be possible that no osthread was created for the
   367       // JavaThread due to lack of memory. We would have to throw an exception
   368       // in that case. However, since this must work and we do not allow
   369       // exceptions anyway, check and abort if this fails.
   370       if (signal_thread == NULL || signal_thread->osthread() == NULL) {
   371         vm_exit_during_initialization("java.lang.OutOfMemoryError",
   372                                       "unable to create new native thread");
   373       }
   375       java_lang_Thread::set_thread(thread_oop(), signal_thread);
   376       java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
   377       java_lang_Thread::set_daemon(thread_oop());
   379       signal_thread->set_threadObj(thread_oop());
   380       Threads::add(signal_thread);
   381       Thread::start(signal_thread);
   382     }
   383     // Handle ^BREAK
   384     os::signal(SIGBREAK, os::user_handler());
   385   }
   386 }
   389 void os::terminate_signal_thread() {
   390   if (!ReduceSignalUsage)
   391     signal_notify(sigexitnum_pd());
   392 }
   395 // --------------------- loading libraries ---------------------
   397 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
   398 extern struct JavaVM_ main_vm;
   400 static void* _native_java_library = NULL;
   402 void* os::native_java_library() {
   403   if (_native_java_library == NULL) {
   404     char buffer[JVM_MAXPATHLEN];
   405     char ebuf[1024];
   407     // Try to load verify dll first. In 1.3 java dll depends on it and is not
   408     // always able to find it when the loading executable is outside the JDK.
   409     // In order to keep working with 1.2 we ignore any loading errors.
   410     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
   411                        "verify")) {
   412       dll_load(buffer, ebuf, sizeof(ebuf));
   413     }
   415     // Load java dll
   416     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
   417                        "java")) {
   418       _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
   419     }
   420     if (_native_java_library == NULL) {
   421       vm_exit_during_initialization("Unable to load native library", ebuf);
   422     }
   424 #if defined(__OpenBSD__)
   425     // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
   426     // ignore errors
   427     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
   428                        "net")) {
   429       dll_load(buffer, ebuf, sizeof(ebuf));
   430     }
   431 #endif
   432   }
   433   static jboolean onLoaded = JNI_FALSE;
   434   if (onLoaded) {
   435     // We may have to wait to fire OnLoad until TLS is initialized.
   436     if (ThreadLocalStorage::is_initialized()) {
   437       // The JNI_OnLoad handling is normally done by method load in
   438       // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
   439       // explicitly so we have to check for JNI_OnLoad as well
   440       const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
   441       JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
   442           JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
   443       if (JNI_OnLoad != NULL) {
   444         JavaThread* thread = JavaThread::current();
   445         ThreadToNativeFromVM ttn(thread);
   446         HandleMark hm(thread);
   447         jint ver = (*JNI_OnLoad)(&main_vm, NULL);
   448         onLoaded = JNI_TRUE;
   449         if (!Threads::is_supported_jni_version_including_1_1(ver)) {
   450           vm_exit_during_initialization("Unsupported JNI version");
   451         }
   452       }
   453     }
   454   }
   455   return _native_java_library;
   456 }
   458 /*
   459  * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
   460  * If check_lib == true then we are looking for an
   461  * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
   462  * this library is statically linked into the image.
   463  * If check_lib == false then we will look for the appropriate symbol in the
   464  * executable if agent_lib->is_static_lib() == true or in the shared library
   465  * referenced by 'handle'.
   466  */
   467 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
   468                               const char *syms[], size_t syms_len) {
   469   assert(agent_lib != NULL, "sanity check");
   470   const char *lib_name;
   471   void *handle = agent_lib->os_lib();
   472   void *entryName = NULL;
   473   char *agent_function_name;
   474   size_t i;
   476   // If checking then use the agent name otherwise test is_static_lib() to
   477   // see how to process this lookup
   478   lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
   479   for (i = 0; i < syms_len; i++) {
   480     agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
   481     if (agent_function_name == NULL) {
   482       break;
   483     }
   484     entryName = dll_lookup(handle, agent_function_name);
   485     FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
   486     if (entryName != NULL) {
   487       break;
   488     }
   489   }
   490   return entryName;
   491 }
   493 // See if the passed in agent is statically linked into the VM image.
   494 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
   495                             size_t syms_len) {
   496   void *ret;
   497   void *proc_handle;
   498   void *save_handle;
   500   assert(agent_lib != NULL, "sanity check");
   501   if (agent_lib->name() == NULL) {
   502     return false;
   503   }
   504   proc_handle = get_default_process_handle();
   505   // Check for Agent_OnLoad/Attach_lib_name function
   506   save_handle = agent_lib->os_lib();
   507   // We want to look in this process' symbol table.
   508   agent_lib->set_os_lib(proc_handle);
   509   ret = find_agent_function(agent_lib, true, syms, syms_len);
   510   if (ret != NULL) {
   511     // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
   512     agent_lib->set_valid();
   513     agent_lib->set_static_lib(true);
   514     return true;
   515   }
   516   agent_lib->set_os_lib(save_handle);
   517   return false;
   518 }
   520 // --------------------- heap allocation utilities ---------------------
   522 char *os::strdup(const char *str, MEMFLAGS flags) {
   523   size_t size = strlen(str);
   524   char *dup_str = (char *)malloc(size + 1, flags);
   525   if (dup_str == NULL) return NULL;
   526   strcpy(dup_str, str);
   527   return dup_str;
   528 }
   532 #define paranoid                 0  /* only set to 1 if you suspect checking code has bug */
   534 #ifdef ASSERT
   535 static void verify_memory(void* ptr) {
   536   GuardedMemory guarded(ptr);
   537   if (!guarded.verify_guards()) {
   538     tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
   539     tty->print_cr("## memory stomp:");
   540     guarded.print_on(tty);
   541     fatal("memory stomping error");
   542   }
   543 }
   544 #endif
   546 //
   547 // This function supports testing of the malloc out of memory
   548 // condition without really running the system out of memory.
   549 //
   550 static u_char* testMalloc(size_t alloc_size) {
   551   assert(MallocMaxTestWords > 0, "sanity check");
   553   if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
   554     return NULL;
   555   }
   557   u_char* ptr = (u_char*)::malloc(alloc_size);
   559   if (ptr != NULL) {
   560     Atomic::add(((jint) (alloc_size / BytesPerWord)),
   561                 (volatile jint *) &cur_malloc_words);
   562   }
   563   return ptr;
   564 }
   566 void* os::malloc(size_t size, MEMFLAGS flags) {
   567   return os::malloc(size, flags, CALLER_PC);
   568 }
   570 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
   571   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
   572   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
   574 #ifdef ASSERT
   575   // checking for the WatcherThread and crash_protection first
   576   // since os::malloc can be called when the libjvm.{dll,so} is
   577   // first loaded and we don't have a thread yet.
   578   // try to find the thread after we see that the watcher thread
   579   // exists and has crash protection.
   580   WatcherThread *wt = WatcherThread::watcher_thread();
   581   if (wt != NULL && wt->has_crash_protection()) {
   582     Thread* thread = ThreadLocalStorage::get_thread_slow();
   583     if (thread == wt) {
   584       assert(!wt->has_crash_protection(),
   585           "Can't malloc with crash protection from WatcherThread");
   586     }
   587   }
   588 #endif
   590   if (size == 0) {
   591     // return a valid pointer if size is zero
   592     // if NULL is returned the calling functions assume out of memory.
   593     size = 1;
   594   }
   596   // NMT support
   597   NMT_TrackingLevel level = MemTracker::tracking_level();
   598   size_t            nmt_header_size = MemTracker::malloc_header_size(level);
   600 #ifndef ASSERT
   601   const size_t alloc_size = size + nmt_header_size;
   602 #else
   603   const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
   604   if (size + nmt_header_size > alloc_size) { // Check for rollover.
   605     return NULL;
   606   }
   607 #endif
   609   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   611   u_char* ptr;
   612   if (MallocMaxTestWords > 0) {
   613     ptr = testMalloc(alloc_size);
   614   } else {
   615     ptr = (u_char*)::malloc(alloc_size);
   616   }
   618 #ifdef ASSERT
   619   if (ptr == NULL) {
   620     return NULL;
   621   }
   622   // Wrap memory with guard
   623   GuardedMemory guarded(ptr, size + nmt_header_size);
   624   ptr = guarded.get_user_ptr();
   625 #endif
   626   if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
   627     tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
   628     breakpoint();
   629   }
   630   debug_only(if (paranoid) verify_memory(ptr));
   631   if (PrintMalloc && tty != NULL) {
   632     tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
   633   }
   635   // we do not track guard memory
   636   return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
   637 }
   639 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
   640   return os::realloc(memblock, size, flags, CALLER_PC);
   641 }
   643 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
   645 #ifndef ASSERT
   646   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
   647   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
   648    // NMT support
   649   void* membase = MemTracker::record_free(memblock);
   650   NMT_TrackingLevel level = MemTracker::tracking_level();
   651   size_t  nmt_header_size = MemTracker::malloc_header_size(level);
   652   void* ptr = ::realloc(membase, size + nmt_header_size);
   653   return MemTracker::record_malloc(ptr, size, memflags, stack, level);
   654 #else
   655   if (memblock == NULL) {
   656     return os::malloc(size, memflags, stack);
   657   }
   658   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
   659     tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
   660     breakpoint();
   661   }
   662   // NMT support
   663   void* membase = MemTracker::malloc_base(memblock);
   664   verify_memory(membase);
   665   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   666   if (size == 0) {
   667     return NULL;
   668   }
   669   // always move the block
   670   void* ptr = os::malloc(size, memflags, stack);
   671   if (PrintMalloc) {
   672     tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
   673   }
   674   // Copy to new memory if malloc didn't fail
   675   if ( ptr != NULL ) {
   676     GuardedMemory guarded(MemTracker::malloc_base(memblock));
   677     // Guard's user data contains NMT header
   678     size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
   679     memcpy(ptr, memblock, MIN2(size, memblock_size));
   680     if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
   681     if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
   682       tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
   683       breakpoint();
   684     }
   685     os::free(memblock);
   686   }
   687   return ptr;
   688 #endif
   689 }
   692 void  os::free(void *memblock, MEMFLAGS memflags) {
   693   NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
   694 #ifdef ASSERT
   695   if (memblock == NULL) return;
   696   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
   697     if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
   698     breakpoint();
   699   }
   700   void* membase = MemTracker::record_free(memblock);
   701   verify_memory(membase);
   702   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   704   GuardedMemory guarded(membase);
   705   size_t size = guarded.get_user_size();
   706   inc_stat_counter(&free_bytes, size);
   707   membase = guarded.release_for_freeing();
   708   if (PrintMalloc && tty != NULL) {
   709       fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
   710   }
   711   ::free(membase);
   712 #else
   713   void* membase = MemTracker::record_free(memblock);
   714   ::free(membase);
   715 #endif
   716 }
   718 void os::init_random(long initval) {
   719   _rand_seed = initval;
   720 }
   723 long os::random() {
   724   /* standard, well-known linear congruential random generator with
   725    * next_rand = (16807*seed) mod (2**31-1)
   726    * see
   727    * (1) "Random Number Generators: Good Ones Are Hard to Find",
   728    *      S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
   729    * (2) "Two Fast Implementations of the 'Minimal Standard' Random
   730    *     Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
   731   */
   732   const long a = 16807;
   733   const unsigned long m = 2147483647;
   734   const long q = m / a;        assert(q == 127773, "weird math");
   735   const long r = m % a;        assert(r == 2836, "weird math");
   737   // compute az=2^31p+q
   738   unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
   739   unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
   740   lo += (hi & 0x7FFF) << 16;
   742   // if q overflowed, ignore the overflow and increment q
   743   if (lo > m) {
   744     lo &= m;
   745     ++lo;
   746   }
   747   lo += hi >> 15;
   749   // if (p+q) overflowed, ignore the overflow and increment (p+q)
   750   if (lo > m) {
   751     lo &= m;
   752     ++lo;
   753   }
   754   return (_rand_seed = lo);
   755 }
   757 // The INITIALIZED state is distinguished from the SUSPENDED state because the
   758 // conditions in which a thread is first started are different from those in which
   759 // a suspension is resumed.  These differences make it hard for us to apply the
   760 // tougher checks when starting threads that we want to do when resuming them.
   761 // However, when start_thread is called as a result of Thread.start, on a Java
   762 // thread, the operation is synchronized on the Java Thread object.  So there
   763 // cannot be a race to start the thread and hence for the thread to exit while
   764 // we are working on it.  Non-Java threads that start Java threads either have
   765 // to do so in a context in which races are impossible, or should do appropriate
   766 // locking.
   768 void os::start_thread(Thread* thread) {
   769   // guard suspend/resume
   770   MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
   771   OSThread* osthread = thread->osthread();
   772   osthread->set_state(RUNNABLE);
   773   pd_start_thread(thread);
   774 }
   776 //---------------------------------------------------------------------------
   777 // Helper functions for fatal error handler
   779 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
   780   assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
   782   int cols = 0;
   783   int cols_per_line = 0;
   784   switch (unitsize) {
   785     case 1: cols_per_line = 16; break;
   786     case 2: cols_per_line = 8;  break;
   787     case 4: cols_per_line = 4;  break;
   788     case 8: cols_per_line = 2;  break;
   789     default: return;
   790   }
   792   address p = start;
   793   st->print(PTR_FORMAT ":   ", start);
   794   while (p < end) {
   795     switch (unitsize) {
   796       case 1: st->print("%02x", *(u1*)p); break;
   797       case 2: st->print("%04x", *(u2*)p); break;
   798       case 4: st->print("%08x", *(u4*)p); break;
   799       case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
   800     }
   801     p += unitsize;
   802     cols++;
   803     if (cols >= cols_per_line && p < end) {
   804        cols = 0;
   805        st->cr();
   806        st->print(PTR_FORMAT ":   ", p);
   807     } else {
   808        st->print(" ");
   809     }
   810   }
   811   st->cr();
   812 }
   814 void os::print_environment_variables(outputStream* st, const char** env_list,
   815                                      char* buffer, int len) {
   816   if (env_list) {
   817     st->print_cr("Environment Variables:");
   819     for (int i = 0; env_list[i] != NULL; i++) {
   820       if (getenv(env_list[i], buffer, len)) {
   821         st->print("%s", env_list[i]);
   822         st->print("=");
   823         st->print_cr("%s", buffer);
   824       }
   825     }
   826   }
   827 }
   829 void os::print_cpu_info(outputStream* st) {
   830   // cpu
   831   st->print("CPU:");
   832   st->print("total %d", os::processor_count());
   833   // It's not safe to query number of active processors after crash
   834   // st->print("(active %d)", os::active_processor_count());
   835   st->print(" %s", VM_Version::cpu_features());
   836   st->cr();
   837   pd_print_cpu_info(st);
   838 }
   840 void os::print_date_and_time(outputStream *st) {
   841   const int secs_per_day  = 86400;
   842   const int secs_per_hour = 3600;
   843   const int secs_per_min  = 60;
   845   time_t tloc;
   846   (void)time(&tloc);
   847   st->print("time: %s", ctime(&tloc));  // ctime adds newline.
   849   double t = os::elapsedTime();
   850   // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
   851   //       Linux. Must be a bug in glibc ? Workaround is to round "t" to int
   852   //       before printf. We lost some precision, but who cares?
   853   int eltime = (int)t;  // elapsed time in seconds
   855   // print elapsed time in a human-readable format:
   856   int eldays = eltime / secs_per_day;
   857   int day_secs = eldays * secs_per_day;
   858   int elhours = (eltime - day_secs) / secs_per_hour;
   859   int hour_secs = elhours * secs_per_hour;
   860   int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
   861   int minute_secs = elmins * secs_per_min;
   862   int elsecs = (eltime - day_secs - hour_secs - minute_secs);
   863   st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
   864 }
   866 // moved from debug.cpp (used to be find()) but still called from there
   867 // The verbose parameter is only set by the debug code in one case
   868 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
   869   address addr = (address)x;
   870   CodeBlob* b = CodeCache::find_blob_unsafe(addr);
   871   if (b != NULL) {
   872     if (b->is_buffer_blob()) {
   873       // the interpreter is generated into a buffer blob
   874       InterpreterCodelet* i = Interpreter::codelet_containing(addr);
   875       if (i != NULL) {
   876         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
   877         i->print_on(st);
   878         return;
   879       }
   880       if (Interpreter::contains(addr)) {
   881         st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
   882                      " (not bytecode specific)", addr);
   883         return;
   884       }
   885       //
   886       if (AdapterHandlerLibrary::contains(b)) {
   887         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
   888         AdapterHandlerLibrary::print_handler_on(st, b);
   889       }
   890       // the stubroutines are generated into a buffer blob
   891       StubCodeDesc* d = StubCodeDesc::desc_for(addr);
   892       if (d != NULL) {
   893         st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
   894         d->print_on(st);
   895         st->cr();
   896         return;
   897       }
   898       if (StubRoutines::contains(addr)) {
   899         st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
   900                      "stub routine", addr);
   901         return;
   902       }
   903       // the InlineCacheBuffer is using stubs generated into a buffer blob
   904       if (InlineCacheBuffer::contains(addr)) {
   905         st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
   906         return;
   907       }
   908       VtableStub* v = VtableStubs::stub_containing(addr);
   909       if (v != NULL) {
   910         st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
   911         v->print_on(st);
   912         st->cr();
   913         return;
   914       }
   915     }
   916     nmethod* nm = b->as_nmethod_or_null();
   917     if (nm != NULL) {
   918       ResourceMark rm;
   919       st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
   920                 addr, (int)(addr - nm->entry_point()), nm);
   921       if (verbose) {
   922         st->print(" for ");
   923         nm->method()->print_value_on(st);
   924       }
   925       st->cr();
   926       nm->print_nmethod(verbose);
   927       return;
   928     }
   929     st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
   930     b->print_on(st);
   931     return;
   932   }
   934   if (Universe::heap()->is_in(addr)) {
   935     HeapWord* p = Universe::heap()->block_start(addr);
   936     bool print = false;
   937     // If we couldn't find it it just may mean that heap wasn't parseable
   938     // See if we were just given an oop directly
   939     if (p != NULL && Universe::heap()->block_is_obj(p)) {
   940       print = true;
   941     } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
   942       p = (HeapWord*) addr;
   943       print = true;
   944     }
   945     if (print) {
   946       if (p == (HeapWord*) addr) {
   947         st->print_cr(INTPTR_FORMAT " is an oop", addr);
   948       } else {
   949         st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
   950       }
   951       oop(p)->print_on(st);
   952       return;
   953     }
   954   } else {
   955     if (Universe::heap()->is_in_reserved(addr)) {
   956       st->print_cr(INTPTR_FORMAT " is an unallocated location "
   957                    "in the heap", addr);
   958       return;
   959     }
   960   }
   961   if (JNIHandles::is_global_handle((jobject) addr)) {
   962     st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
   963     return;
   964   }
   965   if (JNIHandles::is_weak_global_handle((jobject) addr)) {
   966     st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
   967     return;
   968   }
   969 #ifndef PRODUCT
   970   // we don't keep the block list in product mode
   971   if (JNIHandleBlock::any_contains((jobject) addr)) {
   972     st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
   973     return;
   974   }
   975 #endif
   977   for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
   978     // Check for privilege stack
   979     if (thread->privileged_stack_top() != NULL &&
   980         thread->privileged_stack_top()->contains(addr)) {
   981       st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
   982                    "for thread: " INTPTR_FORMAT, addr, thread);
   983       if (verbose) thread->print_on(st);
   984       return;
   985     }
   986     // If the addr is a java thread print information about that.
   987     if (addr == (address)thread) {
   988       if (verbose) {
   989         thread->print_on(st);
   990       } else {
   991         st->print_cr(INTPTR_FORMAT " is a thread", addr);
   992       }
   993       return;
   994     }
   995     // If the addr is in the stack region for this thread then report that
   996     // and print thread info
   997     if (thread->stack_base() >= addr &&
   998         addr > (thread->stack_base() - thread->stack_size())) {
   999       st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
  1000                    INTPTR_FORMAT, addr, thread);
  1001       if (verbose) thread->print_on(st);
  1002       return;
  1007   // Check if in metaspace and print types that have vptrs (only method now)
  1008   if (Metaspace::contains(addr)) {
  1009     if (Method::has_method_vptr((const void*)addr)) {
  1010       ((Method*)addr)->print_value_on(st);
  1011       st->cr();
  1012     } else {
  1013       // Use addr->print() from the debugger instead (not here)
  1014       st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
  1016     return;
  1019   // Try an OS specific find
  1020   if (os::find(addr, st)) {
  1021     return;
  1024   st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
  1027 // Looks like all platforms except IA64 can use the same function to check
  1028 // if C stack is walkable beyond current frame. The check for fp() is not
  1029 // necessary on Sparc, but it's harmless.
  1030 bool os::is_first_C_frame(frame* fr) {
  1031 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
  1032   // On IA64 we have to check if the callers bsp is still valid
  1033   // (i.e. within the register stack bounds).
  1034   // Notice: this only works for threads created by the VM and only if
  1035   // we walk the current stack!!! If we want to be able to walk
  1036   // arbitrary other threads, we'll have to somehow store the thread
  1037   // object in the frame.
  1038   Thread *thread = Thread::current();
  1039   if ((address)fr->fp() <=
  1040       thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
  1041     // This check is a little hacky, because on Linux the first C
  1042     // frame's ('start_thread') register stack frame starts at
  1043     // "register_stack_base + 0x48" while on HPUX, the first C frame's
  1044     // ('__pthread_bound_body') register stack frame seems to really
  1045     // start at "register_stack_base".
  1046     return true;
  1047   } else {
  1048     return false;
  1050 #elif defined(IA64) && defined(_WIN32)
  1051   return true;
  1052 #else
  1053   // Load up sp, fp, sender sp and sender fp, check for reasonable values.
  1054   // Check usp first, because if that's bad the other accessors may fault
  1055   // on some architectures.  Ditto ufp second, etc.
  1056   uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
  1057   // sp on amd can be 32 bit aligned.
  1058   uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
  1060   uintptr_t usp    = (uintptr_t)fr->sp();
  1061   if ((usp & sp_align_mask) != 0) return true;
  1063   uintptr_t ufp    = (uintptr_t)fr->fp();
  1064   if ((ufp & fp_align_mask) != 0) return true;
  1066   uintptr_t old_sp = (uintptr_t)fr->sender_sp();
  1067   if ((old_sp & sp_align_mask) != 0) return true;
  1068   if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
  1070   uintptr_t old_fp = (uintptr_t)fr->link();
  1071   if ((old_fp & fp_align_mask) != 0) return true;
  1072   if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
  1074   // stack grows downwards; if old_fp is below current fp or if the stack
  1075   // frame is too large, either the stack is corrupted or fp is not saved
  1076   // on stack (i.e. on x86, ebp may be used as general register). The stack
  1077   // is not walkable beyond current frame.
  1078   if (old_fp < ufp) return true;
  1079   if (old_fp - ufp > 64 * K) return true;
  1081   return false;
  1082 #endif
  1085 #ifdef ASSERT
  1086 extern "C" void test_random() {
  1087   const double m = 2147483647;
  1088   double mean = 0.0, variance = 0.0, t;
  1089   long reps = 10000;
  1090   unsigned long seed = 1;
  1092   tty->print_cr("seed %ld for %ld repeats...", seed, reps);
  1093   os::init_random(seed);
  1094   long num;
  1095   for (int k = 0; k < reps; k++) {
  1096     num = os::random();
  1097     double u = (double)num / m;
  1098     assert(u >= 0.0 && u <= 1.0, "bad random number!");
  1100     // calculate mean and variance of the random sequence
  1101     mean += u;
  1102     variance += (u*u);
  1104   mean /= reps;
  1105   variance /= (reps - 1);
  1107   assert(num == 1043618065, "bad seed");
  1108   tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
  1109   tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
  1110   const double eps = 0.0001;
  1111   t = fabsd(mean - 0.5018);
  1112   assert(t < eps, "bad mean");
  1113   t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
  1114   assert(t < eps, "bad variance");
  1116 #endif
  1119 // Set up the boot classpath.
  1121 char* os::format_boot_path(const char* format_string,
  1122                            const char* home,
  1123                            int home_len,
  1124                            char fileSep,
  1125                            char pathSep) {
  1126     assert((fileSep == '/' && pathSep == ':') ||
  1127            (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
  1129     // Scan the format string to determine the length of the actual
  1130     // boot classpath, and handle platform dependencies as well.
  1131     int formatted_path_len = 0;
  1132     const char* p;
  1133     for (p = format_string; *p != 0; ++p) {
  1134         if (*p == '%') formatted_path_len += home_len - 1;
  1135         ++formatted_path_len;
  1138     char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
  1139     if (formatted_path == NULL) {
  1140         return NULL;
  1143     // Create boot classpath from format, substituting separator chars and
  1144     // java home directory.
  1145     char* q = formatted_path;
  1146     for (p = format_string; *p != 0; ++p) {
  1147         switch (*p) {
  1148         case '%':
  1149             strcpy(q, home);
  1150             q += home_len;
  1151             break;
  1152         case '/':
  1153             *q++ = fileSep;
  1154             break;
  1155         case ':':
  1156             *q++ = pathSep;
  1157             break;
  1158         default:
  1159             *q++ = *p;
  1162     *q = '\0';
  1164     assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
  1165     return formatted_path;
  1169 bool os::set_boot_path(char fileSep, char pathSep) {
  1170     const char* home = Arguments::get_java_home();
  1171     int home_len = (int)strlen(home);
  1173     static const char* meta_index_dir_format = "%/lib/";
  1174     static const char* meta_index_format = "%/lib/meta-index";
  1175     char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
  1176     if (meta_index == NULL) return false;
  1177     char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
  1178     if (meta_index_dir == NULL) return false;
  1179     Arguments::set_meta_index_path(meta_index, meta_index_dir);
  1181     // Any modification to the JAR-file list, for the boot classpath must be
  1182     // aligned with install/install/make/common/Pack.gmk. Note: boot class
  1183     // path class JARs, are stripped for StackMapTable to reduce download size.
  1184     static const char classpath_format[] =
  1185         "%/lib/resources.jar:"
  1186         "%/lib/rt.jar:"
  1187         "%/lib/sunrsasign.jar:"
  1188         "%/lib/jsse.jar:"
  1189         "%/lib/jce.jar:"
  1190         "%/lib/charsets.jar:"
  1191         "%/lib/jfr.jar:"
  1192         "%/classes";
  1193     char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
  1194     if (sysclasspath == NULL) return false;
  1195     Arguments::set_sysclasspath(sysclasspath);
  1197     return true;
  1200 /*
  1201  * Splits a path, based on its separator, the number of
  1202  * elements is returned back in n.
  1203  * It is the callers responsibility to:
  1204  *   a> check the value of n, and n may be 0.
  1205  *   b> ignore any empty path elements
  1206  *   c> free up the data.
  1207  */
  1208 char** os::split_path(const char* path, int* n) {
  1209   *n = 0;
  1210   if (path == NULL || strlen(path) == 0) {
  1211     return NULL;
  1213   const char psepchar = *os::path_separator();
  1214   char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
  1215   if (inpath == NULL) {
  1216     return NULL;
  1218   strcpy(inpath, path);
  1219   int count = 1;
  1220   char* p = strchr(inpath, psepchar);
  1221   // Get a count of elements to allocate memory
  1222   while (p != NULL) {
  1223     count++;
  1224     p++;
  1225     p = strchr(p, psepchar);
  1227   char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
  1228   if (opath == NULL) {
  1229     return NULL;
  1232   // do the actual splitting
  1233   p = inpath;
  1234   for (int i = 0 ; i < count ; i++) {
  1235     size_t len = strcspn(p, os::path_separator());
  1236     if (len > JVM_MAXPATHLEN) {
  1237       return NULL;
  1239     // allocate the string and add terminator storage
  1240     char* s  = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
  1241     if (s == NULL) {
  1242       return NULL;
  1244     strncpy(s, p, len);
  1245     s[len] = '\0';
  1246     opath[i] = s;
  1247     p += len + 1;
  1249   FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
  1250   *n = count;
  1251   return opath;
  1254 void os::set_memory_serialize_page(address page) {
  1255   int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
  1256   _mem_serialize_page = (volatile int32_t *)page;
  1257   // We initialize the serialization page shift count here
  1258   // We assume a cache line size of 64 bytes
  1259   assert(SerializePageShiftCount == count,
  1260          "thread size changed, fix SerializePageShiftCount constant");
  1261   set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
  1264 static volatile intptr_t SerializePageLock = 0;
  1266 // This method is called from signal handler when SIGSEGV occurs while the current
  1267 // thread tries to store to the "read-only" memory serialize page during state
  1268 // transition.
  1269 void os::block_on_serialize_page_trap() {
  1270   if (TraceSafepoint) {
  1271     tty->print_cr("Block until the serialize page permission restored");
  1273   // When VMThread is holding the SerializePageLock during modifying the
  1274   // access permission of the memory serialize page, the following call
  1275   // will block until the permission of that page is restored to rw.
  1276   // Generally, it is unsafe to manipulate locks in signal handlers, but in
  1277   // this case, it's OK as the signal is synchronous and we know precisely when
  1278   // it can occur.
  1279   Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
  1280   Thread::muxRelease(&SerializePageLock);
  1283 // Serialize all thread state variables
  1284 void os::serialize_thread_states() {
  1285   // On some platforms such as Solaris & Linux, the time duration of the page
  1286   // permission restoration is observed to be much longer than expected  due to
  1287   // scheduler starvation problem etc. To avoid the long synchronization
  1288   // time and expensive page trap spinning, 'SerializePageLock' is used to block
  1289   // the mutator thread if such case is encountered. See bug 6546278 for details.
  1290   Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
  1291   os::protect_memory((char *)os::get_memory_serialize_page(),
  1292                      os::vm_page_size(), MEM_PROT_READ);
  1293   os::protect_memory((char *)os::get_memory_serialize_page(),
  1294                      os::vm_page_size(), MEM_PROT_RW);
  1295   Thread::muxRelease(&SerializePageLock);
  1298 // Returns true if the current stack pointer is above the stack shadow
  1299 // pages, false otherwise.
  1301 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
  1302   assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
  1303   address sp = current_stack_pointer();
  1304   // Check if we have StackShadowPages above the yellow zone.  This parameter
  1305   // is dependent on the depth of the maximum VM call stack possible from
  1306   // the handler for stack overflow.  'instanceof' in the stack overflow
  1307   // handler or a println uses at least 8k stack of VM and native code
  1308   // respectively.
  1309   const int framesize_in_bytes =
  1310     Interpreter::size_top_interpreter_activation(method()) * wordSize;
  1311   int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
  1312                       * vm_page_size()) + framesize_in_bytes;
  1313   // The very lower end of the stack
  1314   address stack_limit = thread->stack_base() - thread->stack_size();
  1315   return (sp > (stack_limit + reserved_area));
  1318 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
  1319                                 uint min_pages)
  1321   assert(min_pages > 0, "sanity");
  1322   if (UseLargePages) {
  1323     const size_t max_page_size = region_max_size / min_pages;
  1325     for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
  1326       const size_t sz = _page_sizes[i];
  1327       const size_t mask = sz - 1;
  1328       if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
  1329         // The largest page size with no fragmentation.
  1330         return sz;
  1333       if (sz <= max_page_size) {
  1334         // The largest page size that satisfies the min_pages requirement.
  1335         return sz;
  1340   return vm_page_size();
  1343 #ifndef PRODUCT
  1344 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
  1346   if (TracePageSizes) {
  1347     tty->print("%s: ", str);
  1348     for (int i = 0; i < count; ++i) {
  1349       tty->print(" " SIZE_FORMAT, page_sizes[i]);
  1351     tty->cr();
  1355 void os::trace_page_sizes(const char* str, const size_t region_min_size,
  1356                           const size_t region_max_size, const size_t page_size,
  1357                           const char* base, const size_t size)
  1359   if (TracePageSizes) {
  1360     tty->print_cr("%s:  min=" SIZE_FORMAT " max=" SIZE_FORMAT
  1361                   " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
  1362                   " size=" SIZE_FORMAT,
  1363                   str, region_min_size, region_max_size,
  1364                   page_size, base, size);
  1367 #endif  // #ifndef PRODUCT
  1369 // This is the working definition of a server class machine:
  1370 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
  1371 // because the graphics memory (?) sometimes masks physical memory.
  1372 // If you want to change the definition of a server class machine
  1373 // on some OS or platform, e.g., >=4GB on Windohs platforms,
  1374 // then you'll have to parameterize this method based on that state,
  1375 // as was done for logical processors here, or replicate and
  1376 // specialize this method for each platform.  (Or fix os to have
  1377 // some inheritance structure and use subclassing.  Sigh.)
  1378 // If you want some platform to always or never behave as a server
  1379 // class machine, change the setting of AlwaysActAsServerClassMachine
  1380 // and NeverActAsServerClassMachine in globals*.hpp.
  1381 bool os::is_server_class_machine() {
  1382   // First check for the early returns
  1383   if (NeverActAsServerClassMachine) {
  1384     return false;
  1386   if (AlwaysActAsServerClassMachine) {
  1387     return true;
  1389   // Then actually look at the machine
  1390   bool         result            = false;
  1391   const unsigned int    server_processors = 2;
  1392   const julong server_memory     = 2UL * G;
  1393   // We seem not to get our full complement of memory.
  1394   //     We allow some part (1/8?) of the memory to be "missing",
  1395   //     based on the sizes of DIMMs, and maybe graphics cards.
  1396   const julong missing_memory   = 256UL * M;
  1398   /* Is this a server class machine? */
  1399   if ((os::active_processor_count() >= (int)server_processors) &&
  1400       (os::physical_memory() >= (server_memory - missing_memory))) {
  1401     const unsigned int logical_processors =
  1402       VM_Version::logical_processors_per_package();
  1403     if (logical_processors > 1) {
  1404       const unsigned int physical_packages =
  1405         os::active_processor_count() / logical_processors;
  1406       if (physical_packages > server_processors) {
  1407         result = true;
  1409     } else {
  1410       result = true;
  1413   return result;
  1416 void os::SuspendedThreadTask::run() {
  1417   assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
  1418   internal_do_task();
  1419   _done = true;
  1422 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
  1423   return os::pd_create_stack_guard_pages(addr, bytes);
  1426 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
  1427   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
  1428   if (result != NULL) {
  1429     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
  1432   return result;
  1435 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
  1436    MEMFLAGS flags) {
  1437   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
  1438   if (result != NULL) {
  1439     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
  1440     MemTracker::record_virtual_memory_type((address)result, flags);
  1443   return result;
  1446 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
  1447   char* result = pd_attempt_reserve_memory_at(bytes, addr);
  1448   if (result != NULL) {
  1449     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
  1451   return result;
  1454 void os::split_reserved_memory(char *base, size_t size,
  1455                                  size_t split, bool realloc) {
  1456   pd_split_reserved_memory(base, size, split, realloc);
  1459 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
  1460   bool res = pd_commit_memory(addr, bytes, executable);
  1461   if (res) {
  1462     MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
  1464   return res;
  1467 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
  1468                               bool executable) {
  1469   bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
  1470   if (res) {
  1471     MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
  1473   return res;
  1476 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
  1477                                const char* mesg) {
  1478   pd_commit_memory_or_exit(addr, bytes, executable, mesg);
  1479   MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
  1482 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
  1483                                bool executable, const char* mesg) {
  1484   os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
  1485   MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
  1488 bool os::uncommit_memory(char* addr, size_t bytes) {
  1489   bool res;
  1490   if (MemTracker::tracking_level() > NMT_minimal) {
  1491     Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
  1492     res = pd_uncommit_memory(addr, bytes);
  1493     if (res) {
  1494       tkr.record((address)addr, bytes);
  1496   } else {
  1497     res = pd_uncommit_memory(addr, bytes);
  1499   return res;
  1502 bool os::release_memory(char* addr, size_t bytes) {
  1503   bool res;
  1504   if (MemTracker::tracking_level() > NMT_minimal) {
  1505     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
  1506     res = pd_release_memory(addr, bytes);
  1507     if (res) {
  1508       tkr.record((address)addr, bytes);
  1510   } else {
  1511     res = pd_release_memory(addr, bytes);
  1513   return res;
  1517 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
  1518                            char *addr, size_t bytes, bool read_only,
  1519                            bool allow_exec) {
  1520   char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
  1521   if (result != NULL) {
  1522     MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
  1524   return result;
  1527 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
  1528                              char *addr, size_t bytes, bool read_only,
  1529                              bool allow_exec) {
  1530   return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
  1531                     read_only, allow_exec);
  1534 bool os::unmap_memory(char *addr, size_t bytes) {
  1535   bool result;
  1536   if (MemTracker::tracking_level() > NMT_minimal) {
  1537     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
  1538     result = pd_unmap_memory(addr, bytes);
  1539     if (result) {
  1540       tkr.record((address)addr, bytes);
  1542   } else {
  1543     result = pd_unmap_memory(addr, bytes);
  1545   return result;
  1548 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  1549   pd_free_memory(addr, bytes, alignment_hint);
  1552 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  1553   pd_realign_memory(addr, bytes, alignment_hint);
  1556 #ifndef TARGET_OS_FAMILY_windows
  1557 /* try to switch state from state "from" to state "to"
  1558  * returns the state set after the method is complete
  1559  */
  1560 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
  1561                                                          os::SuspendResume::State to)
  1563   os::SuspendResume::State result =
  1564     (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
  1565   if (result == from) {
  1566     // success
  1567     return to;
  1569   return result;
  1571 #endif

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