src/share/vm/runtime/os.cpp

Fri, 25 Jan 2013 16:50:33 -0800

author
morris
date
Fri, 25 Jan 2013 16:50:33 -0800
changeset 4535
9fae07c31641
parent 4299
f34d701e952e
child 4802
eca90b8a06eb
permissions
-rw-r--r--

6518907: cleanup IA64 specific code in Hotspot
Summary: removed unused IA64 specific code
Reviewed-by: twisti, kvn, dholmes

     1 /*
     2  * Copyright (c) 1997, 2012, 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 #include "oops/oop.inline.hpp"
    36 #include "prims/jvm.h"
    37 #include "prims/jvm_misc.hpp"
    38 #include "prims/privilegedStack.hpp"
    39 #include "runtime/arguments.hpp"
    40 #include "runtime/frame.inline.hpp"
    41 #include "runtime/interfaceSupport.hpp"
    42 #include "runtime/java.hpp"
    43 #include "runtime/javaCalls.hpp"
    44 #include "runtime/mutexLocker.hpp"
    45 #include "runtime/os.hpp"
    46 #include "runtime/stubRoutines.hpp"
    47 #include "runtime/thread.inline.hpp"
    48 #include "services/attachListener.hpp"
    49 #include "services/memTracker.hpp"
    50 #include "services/threadService.hpp"
    51 #include "utilities/defaultStream.hpp"
    52 #include "utilities/events.hpp"
    53 #ifdef TARGET_OS_FAMILY_linux
    54 # include "os_linux.inline.hpp"
    55 #endif
    56 #ifdef TARGET_OS_FAMILY_solaris
    57 # include "os_solaris.inline.hpp"
    58 #endif
    59 #ifdef TARGET_OS_FAMILY_windows
    60 # include "os_windows.inline.hpp"
    61 #endif
    62 #ifdef TARGET_OS_FAMILY_bsd
    63 # include "os_bsd.inline.hpp"
    64 #endif
    66 # include <signal.h>
    68 OSThread*         os::_starting_thread    = NULL;
    69 address           os::_polling_page       = NULL;
    70 volatile int32_t* os::_mem_serialize_page = NULL;
    71 uintptr_t         os::_serialize_page_mask = 0;
    72 long              os::_rand_seed          = 1;
    73 int               os::_processor_count    = 0;
    74 size_t            os::_page_sizes[os::page_sizes_max];
    76 #ifndef PRODUCT
    77 julong os::num_mallocs = 0;         // # of calls to malloc/realloc
    78 julong os::alloc_bytes = 0;         // # of bytes allocated
    79 julong os::num_frees = 0;           // # of calls to free
    80 julong os::free_bytes = 0;          // # of bytes freed
    81 #endif
    83 void os_init_globals() {
    84   // Called from init_globals().
    85   // See Threads::create_vm() in thread.cpp, and init.cpp.
    86   os::init_globals();
    87 }
    89 // Fill in buffer with current local time as an ISO-8601 string.
    90 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
    91 // Returns buffer, or NULL if it failed.
    92 // This would mostly be a call to
    93 //     strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
    94 // except that on Windows the %z behaves badly, so we do it ourselves.
    95 // Also, people wanted milliseconds on there,
    96 // and strftime doesn't do milliseconds.
    97 char* os::iso8601_time(char* buffer, size_t buffer_length) {
    98   // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
    99   //                                      1         2
   100   //                             12345678901234567890123456789
   101   static const char* iso8601_format =
   102     "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
   103   static const size_t needed_buffer = 29;
   105   // Sanity check the arguments
   106   if (buffer == NULL) {
   107     assert(false, "NULL buffer");
   108     return NULL;
   109   }
   110   if (buffer_length < needed_buffer) {
   111     assert(false, "buffer_length too small");
   112     return NULL;
   113   }
   114   // Get the current time
   115   jlong milliseconds_since_19700101 = javaTimeMillis();
   116   const int milliseconds_per_microsecond = 1000;
   117   const time_t seconds_since_19700101 =
   118     milliseconds_since_19700101 / milliseconds_per_microsecond;
   119   const int milliseconds_after_second =
   120     milliseconds_since_19700101 % milliseconds_per_microsecond;
   121   // Convert the time value to a tm and timezone variable
   122   struct tm time_struct;
   123   if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
   124     assert(false, "Failed localtime_pd");
   125     return NULL;
   126   }
   127 #if defined(_ALLBSD_SOURCE)
   128   const time_t zone = (time_t) time_struct.tm_gmtoff;
   129 #else
   130   const time_t zone = timezone;
   131 #endif
   133   // If daylight savings time is in effect,
   134   // we are 1 hour East of our time zone
   135   const time_t seconds_per_minute = 60;
   136   const time_t minutes_per_hour = 60;
   137   const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
   138   time_t UTC_to_local = zone;
   139   if (time_struct.tm_isdst > 0) {
   140     UTC_to_local = UTC_to_local - seconds_per_hour;
   141   }
   142   // Compute the time zone offset.
   143   //    localtime_pd() sets timezone to the difference (in seconds)
   144   //    between UTC and and local time.
   145   //    ISO 8601 says we need the difference between local time and UTC,
   146   //    we change the sign of the localtime_pd() result.
   147   const time_t local_to_UTC = -(UTC_to_local);
   148   // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
   149   char sign_local_to_UTC = '+';
   150   time_t abs_local_to_UTC = local_to_UTC;
   151   if (local_to_UTC < 0) {
   152     sign_local_to_UTC = '-';
   153     abs_local_to_UTC = -(abs_local_to_UTC);
   154   }
   155   // Convert time zone offset seconds to hours and minutes.
   156   const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
   157   const time_t zone_min =
   158     ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
   160   // Print an ISO 8601 date and time stamp into the buffer
   161   const int year = 1900 + time_struct.tm_year;
   162   const int month = 1 + time_struct.tm_mon;
   163   const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
   164                                    year,
   165                                    month,
   166                                    time_struct.tm_mday,
   167                                    time_struct.tm_hour,
   168                                    time_struct.tm_min,
   169                                    time_struct.tm_sec,
   170                                    milliseconds_after_second,
   171                                    sign_local_to_UTC,
   172                                    zone_hours,
   173                                    zone_min);
   174   if (printed == 0) {
   175     assert(false, "Failed jio_printf");
   176     return NULL;
   177   }
   178   return buffer;
   179 }
   181 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
   182 #ifdef ASSERT
   183   if (!(!thread->is_Java_thread() ||
   184          Thread::current() == thread  ||
   185          Threads_lock->owned_by_self()
   186          || thread->is_Compiler_thread()
   187         )) {
   188     assert(false, "possibility of dangling Thread pointer");
   189   }
   190 #endif
   192   if (p >= MinPriority && p <= MaxPriority) {
   193     int priority = java_to_os_priority[p];
   194     return set_native_priority(thread, priority);
   195   } else {
   196     assert(false, "Should not happen");
   197     return OS_ERR;
   198   }
   199 }
   201 // The mapping from OS priority back to Java priority may be inexact because
   202 // Java priorities can map M:1 with native priorities. If you want the definite
   203 // Java priority then use JavaThread::java_priority()
   204 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
   205   int p;
   206   int os_prio;
   207   OSReturn ret = get_native_priority(thread, &os_prio);
   208   if (ret != OS_OK) return ret;
   210   if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
   211     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
   212   } else {
   213     // niceness values are in reverse order
   214     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
   215   }
   216   priority = (ThreadPriority)p;
   217   return OS_OK;
   218 }
   221 // --------------------- sun.misc.Signal (optional) ---------------------
   224 // SIGBREAK is sent by the keyboard to query the VM state
   225 #ifndef SIGBREAK
   226 #define SIGBREAK SIGQUIT
   227 #endif
   229 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
   232 static void signal_thread_entry(JavaThread* thread, TRAPS) {
   233   os::set_priority(thread, NearMaxPriority);
   234   while (true) {
   235     int sig;
   236     {
   237       // FIXME : Currently we have not decieded what should be the status
   238       //         for this java thread blocked here. Once we decide about
   239       //         that we should fix this.
   240       sig = os::signal_wait();
   241     }
   242     if (sig == os::sigexitnum_pd()) {
   243        // Terminate the signal thread
   244        return;
   245     }
   247     switch (sig) {
   248       case SIGBREAK: {
   249         // Check if the signal is a trigger to start the Attach Listener - in that
   250         // case don't print stack traces.
   251         if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
   252           continue;
   253         }
   254         // Print stack traces
   255         // Any SIGBREAK operations added here should make sure to flush
   256         // the output stream (e.g. tty->flush()) after output.  See 4803766.
   257         // Each module also prints an extra carriage return after its output.
   258         VM_PrintThreads op;
   259         VMThread::execute(&op);
   260         VM_PrintJNI jni_op;
   261         VMThread::execute(&jni_op);
   262         VM_FindDeadlocks op1(tty);
   263         VMThread::execute(&op1);
   264         Universe::print_heap_at_SIGBREAK();
   265         if (PrintClassHistogram) {
   266           VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */,
   267                                    true /* need_prologue */);
   268           VMThread::execute(&op1);
   269         }
   270         if (JvmtiExport::should_post_data_dump()) {
   271           JvmtiExport::post_data_dump();
   272         }
   273         break;
   274       }
   275       default: {
   276         // Dispatch the signal to java
   277         HandleMark hm(THREAD);
   278         Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
   279         KlassHandle klass (THREAD, k);
   280         if (klass.not_null()) {
   281           JavaValue result(T_VOID);
   282           JavaCallArguments args;
   283           args.push_int(sig);
   284           JavaCalls::call_static(
   285             &result,
   286             klass,
   287             vmSymbols::dispatch_name(),
   288             vmSymbols::int_void_signature(),
   289             &args,
   290             THREAD
   291           );
   292         }
   293         if (HAS_PENDING_EXCEPTION) {
   294           // tty is initialized early so we don't expect it to be null, but
   295           // if it is we can't risk doing an initialization that might
   296           // trigger additional out-of-memory conditions
   297           if (tty != NULL) {
   298             char klass_name[256];
   299             char tmp_sig_name[16];
   300             const char* sig_name = "UNKNOWN";
   301             InstanceKlass::cast(PENDING_EXCEPTION->klass())->
   302               name()->as_klass_external_name(klass_name, 256);
   303             if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
   304               sig_name = tmp_sig_name;
   305             warning("Exception %s occurred dispatching signal %s to handler"
   306                     "- the VM may need to be forcibly terminated",
   307                     klass_name, sig_name );
   308           }
   309           CLEAR_PENDING_EXCEPTION;
   310         }
   311       }
   312     }
   313   }
   314 }
   317 void os::signal_init() {
   318   if (!ReduceSignalUsage) {
   319     // Setup JavaThread for processing signals
   320     EXCEPTION_MARK;
   321     Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
   322     instanceKlassHandle klass (THREAD, k);
   323     instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
   325     const char thread_name[] = "Signal Dispatcher";
   326     Handle string = java_lang_String::create_from_str(thread_name, CHECK);
   328     // Initialize thread_oop to put it into the system threadGroup
   329     Handle thread_group (THREAD, Universe::system_thread_group());
   330     JavaValue result(T_VOID);
   331     JavaCalls::call_special(&result, thread_oop,
   332                            klass,
   333                            vmSymbols::object_initializer_name(),
   334                            vmSymbols::threadgroup_string_void_signature(),
   335                            thread_group,
   336                            string,
   337                            CHECK);
   339     KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
   340     JavaCalls::call_special(&result,
   341                             thread_group,
   342                             group,
   343                             vmSymbols::add_method_name(),
   344                             vmSymbols::thread_void_signature(),
   345                             thread_oop,         // ARG 1
   346                             CHECK);
   348     os::signal_init_pd();
   350     { MutexLocker mu(Threads_lock);
   351       JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
   353       // At this point it may be possible that no osthread was created for the
   354       // JavaThread due to lack of memory. We would have to throw an exception
   355       // in that case. However, since this must work and we do not allow
   356       // exceptions anyway, check and abort if this fails.
   357       if (signal_thread == NULL || signal_thread->osthread() == NULL) {
   358         vm_exit_during_initialization("java.lang.OutOfMemoryError",
   359                                       "unable to create new native thread");
   360       }
   362       java_lang_Thread::set_thread(thread_oop(), signal_thread);
   363       java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
   364       java_lang_Thread::set_daemon(thread_oop());
   366       signal_thread->set_threadObj(thread_oop());
   367       Threads::add(signal_thread);
   368       Thread::start(signal_thread);
   369     }
   370     // Handle ^BREAK
   371     os::signal(SIGBREAK, os::user_handler());
   372   }
   373 }
   376 void os::terminate_signal_thread() {
   377   if (!ReduceSignalUsage)
   378     signal_notify(sigexitnum_pd());
   379 }
   382 // --------------------- loading libraries ---------------------
   384 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
   385 extern struct JavaVM_ main_vm;
   387 static void* _native_java_library = NULL;
   389 void* os::native_java_library() {
   390   if (_native_java_library == NULL) {
   391     char buffer[JVM_MAXPATHLEN];
   392     char ebuf[1024];
   394     // Try to load verify dll first. In 1.3 java dll depends on it and is not
   395     // always able to find it when the loading executable is outside the JDK.
   396     // In order to keep working with 1.2 we ignore any loading errors.
   397     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
   398                        "verify")) {
   399       dll_load(buffer, ebuf, sizeof(ebuf));
   400     }
   402     // Load java dll
   403     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
   404                        "java")) {
   405       _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
   406     }
   407     if (_native_java_library == NULL) {
   408       vm_exit_during_initialization("Unable to load native library", ebuf);
   409     }
   411 #if defined(__OpenBSD__)
   412     // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
   413     // ignore errors
   414     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
   415                        "net")) {
   416       dll_load(buffer, ebuf, sizeof(ebuf));
   417     }
   418 #endif
   419   }
   420   static jboolean onLoaded = JNI_FALSE;
   421   if (onLoaded) {
   422     // We may have to wait to fire OnLoad until TLS is initialized.
   423     if (ThreadLocalStorage::is_initialized()) {
   424       // The JNI_OnLoad handling is normally done by method load in
   425       // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
   426       // explicitly so we have to check for JNI_OnLoad as well
   427       const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
   428       JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
   429           JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
   430       if (JNI_OnLoad != NULL) {
   431         JavaThread* thread = JavaThread::current();
   432         ThreadToNativeFromVM ttn(thread);
   433         HandleMark hm(thread);
   434         jint ver = (*JNI_OnLoad)(&main_vm, NULL);
   435         onLoaded = JNI_TRUE;
   436         if (!Threads::is_supported_jni_version_including_1_1(ver)) {
   437           vm_exit_during_initialization("Unsupported JNI version");
   438         }
   439       }
   440     }
   441   }
   442   return _native_java_library;
   443 }
   445 // --------------------- heap allocation utilities ---------------------
   447 char *os::strdup(const char *str, MEMFLAGS flags) {
   448   size_t size = strlen(str);
   449   char *dup_str = (char *)malloc(size + 1, flags);
   450   if (dup_str == NULL) return NULL;
   451   strcpy(dup_str, str);
   452   return dup_str;
   453 }
   457 #ifdef ASSERT
   458 #define space_before             (MallocCushion + sizeof(double))
   459 #define space_after              MallocCushion
   460 #define size_addr_from_base(p)   (size_t*)(p + space_before - sizeof(size_t))
   461 #define size_addr_from_obj(p)    ((size_t*)p - 1)
   462 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
   463 // NB: cannot be debug variable, because these aren't set from the command line until
   464 // *after* the first few allocs already happened
   465 #define MallocCushion            16
   466 #else
   467 #define space_before             0
   468 #define space_after              0
   469 #define size_addr_from_base(p)   should not use w/o ASSERT
   470 #define size_addr_from_obj(p)    should not use w/o ASSERT
   471 #define MallocCushion            0
   472 #endif
   473 #define paranoid                 0  /* only set to 1 if you suspect checking code has bug */
   475 #ifdef ASSERT
   476 inline size_t get_size(void* obj) {
   477   size_t size = *size_addr_from_obj(obj);
   478   if (size < 0) {
   479     fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
   480                   SIZE_FORMAT ")", obj, size));
   481   }
   482   return size;
   483 }
   485 u_char* find_cushion_backwards(u_char* start) {
   486   u_char* p = start;
   487   while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
   488          p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
   489   // ok, we have four consecutive marker bytes; find start
   490   u_char* q = p - 4;
   491   while (*q == badResourceValue) q--;
   492   return q + 1;
   493 }
   495 u_char* find_cushion_forwards(u_char* start) {
   496   u_char* p = start;
   497   while (p[0] != badResourceValue || p[1] != badResourceValue ||
   498          p[2] != badResourceValue || p[3] != badResourceValue) p++;
   499   // ok, we have four consecutive marker bytes; find end of cushion
   500   u_char* q = p + 4;
   501   while (*q == badResourceValue) q++;
   502   return q - MallocCushion;
   503 }
   505 void print_neighbor_blocks(void* ptr) {
   506   // find block allocated before ptr (not entirely crash-proof)
   507   if (MallocCushion < 4) {
   508     tty->print_cr("### cannot find previous block (MallocCushion < 4)");
   509     return;
   510   }
   511   u_char* start_of_this_block = (u_char*)ptr - space_before;
   512   u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
   513   // look for cushion in front of prev. block
   514   u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
   515   ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
   516   u_char* obj = start_of_prev_block + space_before;
   517   if (size <= 0 ) {
   518     // start is bad; mayhave been confused by OS data inbetween objects
   519     // search one more backwards
   520     start_of_prev_block = find_cushion_backwards(start_of_prev_block);
   521     size = *size_addr_from_base(start_of_prev_block);
   522     obj = start_of_prev_block + space_before;
   523   }
   525   if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
   526     tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
   527   } else {
   528     tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
   529   }
   531   // now find successor block
   532   u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
   533   start_of_next_block = find_cushion_forwards(start_of_next_block);
   534   u_char* next_obj = start_of_next_block + space_before;
   535   ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
   536   if (start_of_next_block[0] == badResourceValue &&
   537       start_of_next_block[1] == badResourceValue &&
   538       start_of_next_block[2] == badResourceValue &&
   539       start_of_next_block[3] == badResourceValue) {
   540     tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
   541   } else {
   542     tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
   543   }
   544 }
   547 void report_heap_error(void* memblock, void* bad, const char* where) {
   548   tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
   549   tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
   550   print_neighbor_blocks(memblock);
   551   fatal("memory stomping error");
   552 }
   554 void verify_block(void* memblock) {
   555   size_t size = get_size(memblock);
   556   if (MallocCushion) {
   557     u_char* ptr = (u_char*)memblock - space_before;
   558     for (int i = 0; i < MallocCushion; i++) {
   559       if (ptr[i] != badResourceValue) {
   560         report_heap_error(memblock, ptr+i, "in front of");
   561       }
   562     }
   563     u_char* end = (u_char*)memblock + size + space_after;
   564     for (int j = -MallocCushion; j < 0; j++) {
   565       if (end[j] != badResourceValue) {
   566         report_heap_error(memblock, end+j, "after");
   567       }
   568     }
   569   }
   570 }
   571 #endif
   573 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
   574   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
   575   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
   577   if (size == 0) {
   578     // return a valid pointer if size is zero
   579     // if NULL is returned the calling functions assume out of memory.
   580     size = 1;
   581   }
   582   if (size > size + space_before + space_after) { // Check for rollover.
   583     return NULL;
   584   }
   585   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   586   u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
   588 #ifdef ASSERT
   589   if (ptr == NULL) return NULL;
   590   if (MallocCushion) {
   591     for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
   592     u_char* end = ptr + space_before + size;
   593     for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
   594     for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
   595   }
   596   // put size just before data
   597   *size_addr_from_base(ptr) = size;
   598 #endif
   599   u_char* memblock = ptr + space_before;
   600   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
   601     tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
   602     breakpoint();
   603   }
   604   debug_only(if (paranoid) verify_block(memblock));
   605   if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
   607   // we do not track MallocCushion memory
   608     MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
   610   return memblock;
   611 }
   614 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
   615 #ifndef ASSERT
   616   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
   617   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
   618   void* ptr = ::realloc(memblock, size);
   619   if (ptr != NULL) {
   620     MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags,
   621      caller == 0 ? CALLER_PC : caller);
   622   }
   623   return ptr;
   624 #else
   625   if (memblock == NULL) {
   626     return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
   627   }
   628   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
   629     tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
   630     breakpoint();
   631   }
   632   verify_block(memblock);
   633   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   634   if (size == 0) return NULL;
   635   // always move the block
   636   void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
   637   if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
   638   // Copy to new memory if malloc didn't fail
   639   if ( ptr != NULL ) {
   640     memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
   641     if (paranoid) verify_block(ptr);
   642     if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
   643       tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
   644       breakpoint();
   645     }
   646     free(memblock);
   647   }
   648   return ptr;
   649 #endif
   650 }
   653 void  os::free(void *memblock, MEMFLAGS memflags) {
   654   NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
   655 #ifdef ASSERT
   656   if (memblock == NULL) return;
   657   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
   658     if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
   659     breakpoint();
   660   }
   661   verify_block(memblock);
   662   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   663   // Added by detlefs.
   664   if (MallocCushion) {
   665     u_char* ptr = (u_char*)memblock - space_before;
   666     for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
   667       guarantee(*p == badResourceValue,
   668                 "Thing freed should be malloc result.");
   669       *p = (u_char)freeBlockPad;
   670     }
   671     size_t size = get_size(memblock);
   672     inc_stat_counter(&free_bytes, size);
   673     u_char* end = ptr + space_before + size;
   674     for (u_char* q = end; q < end + MallocCushion; q++) {
   675       guarantee(*q == badResourceValue,
   676                 "Thing freed should be malloc result.");
   677       *q = (u_char)freeBlockPad;
   678     }
   679     if (PrintMalloc && tty != NULL)
   680       fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
   681   } else if (PrintMalloc && tty != NULL) {
   682     // tty->print_cr("os::free %p", memblock);
   683     fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
   684   }
   685 #endif
   686   MemTracker::record_free((address)memblock, memflags);
   688   ::free((char*)memblock - space_before);
   689 }
   691 void os::init_random(long initval) {
   692   _rand_seed = initval;
   693 }
   696 long os::random() {
   697   /* standard, well-known linear congruential random generator with
   698    * next_rand = (16807*seed) mod (2**31-1)
   699    * see
   700    * (1) "Random Number Generators: Good Ones Are Hard to Find",
   701    *      S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
   702    * (2) "Two Fast Implementations of the 'Minimal Standard' Random
   703    *     Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
   704   */
   705   const long a = 16807;
   706   const unsigned long m = 2147483647;
   707   const long q = m / a;        assert(q == 127773, "weird math");
   708   const long r = m % a;        assert(r == 2836, "weird math");
   710   // compute az=2^31p+q
   711   unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
   712   unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
   713   lo += (hi & 0x7FFF) << 16;
   715   // if q overflowed, ignore the overflow and increment q
   716   if (lo > m) {
   717     lo &= m;
   718     ++lo;
   719   }
   720   lo += hi >> 15;
   722   // if (p+q) overflowed, ignore the overflow and increment (p+q)
   723   if (lo > m) {
   724     lo &= m;
   725     ++lo;
   726   }
   727   return (_rand_seed = lo);
   728 }
   730 // The INITIALIZED state is distinguished from the SUSPENDED state because the
   731 // conditions in which a thread is first started are different from those in which
   732 // a suspension is resumed.  These differences make it hard for us to apply the
   733 // tougher checks when starting threads that we want to do when resuming them.
   734 // However, when start_thread is called as a result of Thread.start, on a Java
   735 // thread, the operation is synchronized on the Java Thread object.  So there
   736 // cannot be a race to start the thread and hence for the thread to exit while
   737 // we are working on it.  Non-Java threads that start Java threads either have
   738 // to do so in a context in which races are impossible, or should do appropriate
   739 // locking.
   741 void os::start_thread(Thread* thread) {
   742   // guard suspend/resume
   743   MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
   744   OSThread* osthread = thread->osthread();
   745   osthread->set_state(RUNNABLE);
   746   pd_start_thread(thread);
   747 }
   749 //---------------------------------------------------------------------------
   750 // Helper functions for fatal error handler
   752 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
   753   assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
   755   int cols = 0;
   756   int cols_per_line = 0;
   757   switch (unitsize) {
   758     case 1: cols_per_line = 16; break;
   759     case 2: cols_per_line = 8;  break;
   760     case 4: cols_per_line = 4;  break;
   761     case 8: cols_per_line = 2;  break;
   762     default: return;
   763   }
   765   address p = start;
   766   st->print(PTR_FORMAT ":   ", start);
   767   while (p < end) {
   768     switch (unitsize) {
   769       case 1: st->print("%02x", *(u1*)p); break;
   770       case 2: st->print("%04x", *(u2*)p); break;
   771       case 4: st->print("%08x", *(u4*)p); break;
   772       case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
   773     }
   774     p += unitsize;
   775     cols++;
   776     if (cols >= cols_per_line && p < end) {
   777        cols = 0;
   778        st->cr();
   779        st->print(PTR_FORMAT ":   ", p);
   780     } else {
   781        st->print(" ");
   782     }
   783   }
   784   st->cr();
   785 }
   787 void os::print_environment_variables(outputStream* st, const char** env_list,
   788                                      char* buffer, int len) {
   789   if (env_list) {
   790     st->print_cr("Environment Variables:");
   792     for (int i = 0; env_list[i] != NULL; i++) {
   793       if (getenv(env_list[i], buffer, len)) {
   794         st->print(env_list[i]);
   795         st->print("=");
   796         st->print_cr(buffer);
   797       }
   798     }
   799   }
   800 }
   802 void os::print_cpu_info(outputStream* st) {
   803   // cpu
   804   st->print("CPU:");
   805   st->print("total %d", os::processor_count());
   806   // It's not safe to query number of active processors after crash
   807   // st->print("(active %d)", os::active_processor_count());
   808   st->print(" %s", VM_Version::cpu_features());
   809   st->cr();
   810   pd_print_cpu_info(st);
   811 }
   813 void os::print_date_and_time(outputStream *st) {
   814   time_t tloc;
   815   (void)time(&tloc);
   816   st->print("time: %s", ctime(&tloc));  // ctime adds newline.
   818   double t = os::elapsedTime();
   819   // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
   820   //       Linux. Must be a bug in glibc ? Workaround is to round "t" to int
   821   //       before printf. We lost some precision, but who cares?
   822   st->print_cr("elapsed time: %d seconds", (int)t);
   823 }
   825 // moved from debug.cpp (used to be find()) but still called from there
   826 // The verbose parameter is only set by the debug code in one case
   827 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
   828   address addr = (address)x;
   829   CodeBlob* b = CodeCache::find_blob_unsafe(addr);
   830   if (b != NULL) {
   831     if (b->is_buffer_blob()) {
   832       // the interpreter is generated into a buffer blob
   833       InterpreterCodelet* i = Interpreter::codelet_containing(addr);
   834       if (i != NULL) {
   835         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
   836         i->print_on(st);
   837         return;
   838       }
   839       if (Interpreter::contains(addr)) {
   840         st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
   841                      " (not bytecode specific)", addr);
   842         return;
   843       }
   844       //
   845       if (AdapterHandlerLibrary::contains(b)) {
   846         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
   847         AdapterHandlerLibrary::print_handler_on(st, b);
   848       }
   849       // the stubroutines are generated into a buffer blob
   850       StubCodeDesc* d = StubCodeDesc::desc_for(addr);
   851       if (d != NULL) {
   852         st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
   853         d->print_on(st);
   854         st->cr();
   855         return;
   856       }
   857       if (StubRoutines::contains(addr)) {
   858         st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
   859                      "stub routine", addr);
   860         return;
   861       }
   862       // the InlineCacheBuffer is using stubs generated into a buffer blob
   863       if (InlineCacheBuffer::contains(addr)) {
   864         st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
   865         return;
   866       }
   867       VtableStub* v = VtableStubs::stub_containing(addr);
   868       if (v != NULL) {
   869         st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
   870         v->print_on(st);
   871         st->cr();
   872         return;
   873       }
   874     }
   875     nmethod* nm = b->as_nmethod_or_null();
   876     if (nm != NULL) {
   877       ResourceMark rm;
   878       st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
   879                 addr, (int)(addr - nm->entry_point()), nm);
   880       if (verbose) {
   881         st->print(" for ");
   882         nm->method()->print_value_on(st);
   883       }
   884       st->cr();
   885       nm->print_nmethod(verbose);
   886       return;
   887     }
   888     st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
   889     b->print_on(st);
   890     return;
   891   }
   893   if (Universe::heap()->is_in(addr)) {
   894     HeapWord* p = Universe::heap()->block_start(addr);
   895     bool print = false;
   896     // If we couldn't find it it just may mean that heap wasn't parseable
   897     // See if we were just given an oop directly
   898     if (p != NULL && Universe::heap()->block_is_obj(p)) {
   899       print = true;
   900     } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
   901       p = (HeapWord*) addr;
   902       print = true;
   903     }
   904     if (print) {
   905       if (p == (HeapWord*) addr) {
   906         st->print_cr(INTPTR_FORMAT " is an oop", addr);
   907       } else {
   908         st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
   909       }
   910       oop(p)->print_on(st);
   911       return;
   912     }
   913   } else {
   914     if (Universe::heap()->is_in_reserved(addr)) {
   915       st->print_cr(INTPTR_FORMAT " is an unallocated location "
   916                    "in the heap", addr);
   917       return;
   918     }
   919   }
   920   if (JNIHandles::is_global_handle((jobject) addr)) {
   921     st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
   922     return;
   923   }
   924   if (JNIHandles::is_weak_global_handle((jobject) addr)) {
   925     st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
   926     return;
   927   }
   928 #ifndef PRODUCT
   929   // we don't keep the block list in product mode
   930   if (JNIHandleBlock::any_contains((jobject) addr)) {
   931     st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
   932     return;
   933   }
   934 #endif
   936   for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
   937     // Check for privilege stack
   938     if (thread->privileged_stack_top() != NULL &&
   939         thread->privileged_stack_top()->contains(addr)) {
   940       st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
   941                    "for thread: " INTPTR_FORMAT, addr, thread);
   942       if (verbose) thread->print_on(st);
   943       return;
   944     }
   945     // If the addr is a java thread print information about that.
   946     if (addr == (address)thread) {
   947       if (verbose) {
   948         thread->print_on(st);
   949       } else {
   950         st->print_cr(INTPTR_FORMAT " is a thread", addr);
   951       }
   952       return;
   953     }
   954     // If the addr is in the stack region for this thread then report that
   955     // and print thread info
   956     if (thread->stack_base() >= addr &&
   957         addr > (thread->stack_base() - thread->stack_size())) {
   958       st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
   959                    INTPTR_FORMAT, addr, thread);
   960       if (verbose) thread->print_on(st);
   961       return;
   962     }
   964   }
   966 #ifndef PRODUCT
   967   // Check if in metaspace.
   968   if (ClassLoaderDataGraph::contains((address)addr)) {
   969     // Use addr->print() from the debugger instead (not here)
   970     st->print_cr(INTPTR_FORMAT
   971                  " is pointing into metadata", addr);
   972     return;
   973   }
   974 #endif
   976   // Try an OS specific find
   977   if (os::find(addr, st)) {
   978     return;
   979   }
   981   st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
   982 }
   984 // Looks like all platforms except IA64 can use the same function to check
   985 // if C stack is walkable beyond current frame. The check for fp() is not
   986 // necessary on Sparc, but it's harmless.
   987 bool os::is_first_C_frame(frame* fr) {
   988 #if defined(IA64) && !defined(_WIN32)
   989   // On IA64 we have to check if the callers bsp is still valid
   990   // (i.e. within the register stack bounds).
   991   // Notice: this only works for threads created by the VM and only if
   992   // we walk the current stack!!! If we want to be able to walk
   993   // arbitrary other threads, we'll have to somehow store the thread
   994   // object in the frame.
   995   Thread *thread = Thread::current();
   996   if ((address)fr->fp() <=
   997       thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
   998     // This check is a little hacky, because on Linux the first C
   999     // frame's ('start_thread') register stack frame starts at
  1000     // "register_stack_base + 0x48" while on HPUX, the first C frame's
  1001     // ('__pthread_bound_body') register stack frame seems to really
  1002     // start at "register_stack_base".
  1003     return true;
  1004   } else {
  1005     return false;
  1007 #elif defined(IA64) && defined(_WIN32)
  1008   return true;
  1009 #else
  1010   // Load up sp, fp, sender sp and sender fp, check for reasonable values.
  1011   // Check usp first, because if that's bad the other accessors may fault
  1012   // on some architectures.  Ditto ufp second, etc.
  1013   uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
  1014   // sp on amd can be 32 bit aligned.
  1015   uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
  1017   uintptr_t usp    = (uintptr_t)fr->sp();
  1018   if ((usp & sp_align_mask) != 0) return true;
  1020   uintptr_t ufp    = (uintptr_t)fr->fp();
  1021   if ((ufp & fp_align_mask) != 0) return true;
  1023   uintptr_t old_sp = (uintptr_t)fr->sender_sp();
  1024   if ((old_sp & sp_align_mask) != 0) return true;
  1025   if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
  1027   uintptr_t old_fp = (uintptr_t)fr->link();
  1028   if ((old_fp & fp_align_mask) != 0) return true;
  1029   if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
  1031   // stack grows downwards; if old_fp is below current fp or if the stack
  1032   // frame is too large, either the stack is corrupted or fp is not saved
  1033   // on stack (i.e. on x86, ebp may be used as general register). The stack
  1034   // is not walkable beyond current frame.
  1035   if (old_fp < ufp) return true;
  1036   if (old_fp - ufp > 64 * K) return true;
  1038   return false;
  1039 #endif
  1042 #ifdef ASSERT
  1043 extern "C" void test_random() {
  1044   const double m = 2147483647;
  1045   double mean = 0.0, variance = 0.0, t;
  1046   long reps = 10000;
  1047   unsigned long seed = 1;
  1049   tty->print_cr("seed %ld for %ld repeats...", seed, reps);
  1050   os::init_random(seed);
  1051   long num;
  1052   for (int k = 0; k < reps; k++) {
  1053     num = os::random();
  1054     double u = (double)num / m;
  1055     assert(u >= 0.0 && u <= 1.0, "bad random number!");
  1057     // calculate mean and variance of the random sequence
  1058     mean += u;
  1059     variance += (u*u);
  1061   mean /= reps;
  1062   variance /= (reps - 1);
  1064   assert(num == 1043618065, "bad seed");
  1065   tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
  1066   tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
  1067   const double eps = 0.0001;
  1068   t = fabsd(mean - 0.5018);
  1069   assert(t < eps, "bad mean");
  1070   t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
  1071   assert(t < eps, "bad variance");
  1073 #endif
  1076 // Set up the boot classpath.
  1078 char* os::format_boot_path(const char* format_string,
  1079                            const char* home,
  1080                            int home_len,
  1081                            char fileSep,
  1082                            char pathSep) {
  1083     assert((fileSep == '/' && pathSep == ':') ||
  1084            (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
  1086     // Scan the format string to determine the length of the actual
  1087     // boot classpath, and handle platform dependencies as well.
  1088     int formatted_path_len = 0;
  1089     const char* p;
  1090     for (p = format_string; *p != 0; ++p) {
  1091         if (*p == '%') formatted_path_len += home_len - 1;
  1092         ++formatted_path_len;
  1095     char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
  1096     if (formatted_path == NULL) {
  1097         return NULL;
  1100     // Create boot classpath from format, substituting separator chars and
  1101     // java home directory.
  1102     char* q = formatted_path;
  1103     for (p = format_string; *p != 0; ++p) {
  1104         switch (*p) {
  1105         case '%':
  1106             strcpy(q, home);
  1107             q += home_len;
  1108             break;
  1109         case '/':
  1110             *q++ = fileSep;
  1111             break;
  1112         case ':':
  1113             *q++ = pathSep;
  1114             break;
  1115         default:
  1116             *q++ = *p;
  1119     *q = '\0';
  1121     assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
  1122     return formatted_path;
  1126 bool os::set_boot_path(char fileSep, char pathSep) {
  1127     const char* home = Arguments::get_java_home();
  1128     int home_len = (int)strlen(home);
  1130     static const char* meta_index_dir_format = "%/lib/";
  1131     static const char* meta_index_format = "%/lib/meta-index";
  1132     char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
  1133     if (meta_index == NULL) return false;
  1134     char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
  1135     if (meta_index_dir == NULL) return false;
  1136     Arguments::set_meta_index_path(meta_index, meta_index_dir);
  1138     // Any modification to the JAR-file list, for the boot classpath must be
  1139     // aligned with install/install/make/common/Pack.gmk. Note: boot class
  1140     // path class JARs, are stripped for StackMapTable to reduce download size.
  1141     static const char classpath_format[] =
  1142         "%/lib/resources.jar:"
  1143         "%/lib/rt.jar:"
  1144         "%/lib/sunrsasign.jar:"
  1145         "%/lib/jsse.jar:"
  1146         "%/lib/jce.jar:"
  1147         "%/lib/charsets.jar:"
  1148         "%/lib/jfr.jar:"
  1149 #ifdef __APPLE__
  1150         "%/lib/JObjC.jar:"
  1151 #endif
  1152         "%/classes";
  1153     char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
  1154     if (sysclasspath == NULL) return false;
  1155     Arguments::set_sysclasspath(sysclasspath);
  1157     return true;
  1160 /*
  1161  * Splits a path, based on its separator, the number of
  1162  * elements is returned back in n.
  1163  * It is the callers responsibility to:
  1164  *   a> check the value of n, and n may be 0.
  1165  *   b> ignore any empty path elements
  1166  *   c> free up the data.
  1167  */
  1168 char** os::split_path(const char* path, int* n) {
  1169   *n = 0;
  1170   if (path == NULL || strlen(path) == 0) {
  1171     return NULL;
  1173   const char psepchar = *os::path_separator();
  1174   char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
  1175   if (inpath == NULL) {
  1176     return NULL;
  1178   strcpy(inpath, path);
  1179   int count = 1;
  1180   char* p = strchr(inpath, psepchar);
  1181   // Get a count of elements to allocate memory
  1182   while (p != NULL) {
  1183     count++;
  1184     p++;
  1185     p = strchr(p, psepchar);
  1187   char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
  1188   if (opath == NULL) {
  1189     return NULL;
  1192   // do the actual splitting
  1193   p = inpath;
  1194   for (int i = 0 ; i < count ; i++) {
  1195     size_t len = strcspn(p, os::path_separator());
  1196     if (len > JVM_MAXPATHLEN) {
  1197       return NULL;
  1199     // allocate the string and add terminator storage
  1200     char* s  = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
  1201     if (s == NULL) {
  1202       return NULL;
  1204     strncpy(s, p, len);
  1205     s[len] = '\0';
  1206     opath[i] = s;
  1207     p += len + 1;
  1209   FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
  1210   *n = count;
  1211   return opath;
  1214 void os::set_memory_serialize_page(address page) {
  1215   int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
  1216   _mem_serialize_page = (volatile int32_t *)page;
  1217   // We initialize the serialization page shift count here
  1218   // We assume a cache line size of 64 bytes
  1219   assert(SerializePageShiftCount == count,
  1220          "thread size changed, fix SerializePageShiftCount constant");
  1221   set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
  1224 static volatile intptr_t SerializePageLock = 0;
  1226 // This method is called from signal handler when SIGSEGV occurs while the current
  1227 // thread tries to store to the "read-only" memory serialize page during state
  1228 // transition.
  1229 void os::block_on_serialize_page_trap() {
  1230   if (TraceSafepoint) {
  1231     tty->print_cr("Block until the serialize page permission restored");
  1233   // When VMThread is holding the SerializePageLock during modifying the
  1234   // access permission of the memory serialize page, the following call
  1235   // will block until the permission of that page is restored to rw.
  1236   // Generally, it is unsafe to manipulate locks in signal handlers, but in
  1237   // this case, it's OK as the signal is synchronous and we know precisely when
  1238   // it can occur.
  1239   Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
  1240   Thread::muxRelease(&SerializePageLock);
  1243 // Serialize all thread state variables
  1244 void os::serialize_thread_states() {
  1245   // On some platforms such as Solaris & Linux, the time duration of the page
  1246   // permission restoration is observed to be much longer than expected  due to
  1247   // scheduler starvation problem etc. To avoid the long synchronization
  1248   // time and expensive page trap spinning, 'SerializePageLock' is used to block
  1249   // the mutator thread if such case is encountered. See bug 6546278 for details.
  1250   Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
  1251   os::protect_memory((char *)os::get_memory_serialize_page(),
  1252                      os::vm_page_size(), MEM_PROT_READ);
  1253   os::protect_memory((char *)os::get_memory_serialize_page(),
  1254                      os::vm_page_size(), MEM_PROT_RW);
  1255   Thread::muxRelease(&SerializePageLock);
  1258 // Returns true if the current stack pointer is above the stack shadow
  1259 // pages, false otherwise.
  1261 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
  1262   assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
  1263   address sp = current_stack_pointer();
  1264   // Check if we have StackShadowPages above the yellow zone.  This parameter
  1265   // is dependent on the depth of the maximum VM call stack possible from
  1266   // the handler for stack overflow.  'instanceof' in the stack overflow
  1267   // handler or a println uses at least 8k stack of VM and native code
  1268   // respectively.
  1269   const int framesize_in_bytes =
  1270     Interpreter::size_top_interpreter_activation(method()) * wordSize;
  1271   int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
  1272                       * vm_page_size()) + framesize_in_bytes;
  1273   // The very lower end of the stack
  1274   address stack_limit = thread->stack_base() - thread->stack_size();
  1275   return (sp > (stack_limit + reserved_area));
  1278 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
  1279                                 uint min_pages)
  1281   assert(min_pages > 0, "sanity");
  1282   if (UseLargePages) {
  1283     const size_t max_page_size = region_max_size / min_pages;
  1285     for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
  1286       const size_t sz = _page_sizes[i];
  1287       const size_t mask = sz - 1;
  1288       if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
  1289         // The largest page size with no fragmentation.
  1290         return sz;
  1293       if (sz <= max_page_size) {
  1294         // The largest page size that satisfies the min_pages requirement.
  1295         return sz;
  1300   return vm_page_size();
  1303 #ifndef PRODUCT
  1304 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
  1306   if (TracePageSizes) {
  1307     tty->print("%s: ", str);
  1308     for (int i = 0; i < count; ++i) {
  1309       tty->print(" " SIZE_FORMAT, page_sizes[i]);
  1311     tty->cr();
  1315 void os::trace_page_sizes(const char* str, const size_t region_min_size,
  1316                           const size_t region_max_size, const size_t page_size,
  1317                           const char* base, const size_t size)
  1319   if (TracePageSizes) {
  1320     tty->print_cr("%s:  min=" SIZE_FORMAT " max=" SIZE_FORMAT
  1321                   " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
  1322                   " size=" SIZE_FORMAT,
  1323                   str, region_min_size, region_max_size,
  1324                   page_size, base, size);
  1327 #endif  // #ifndef PRODUCT
  1329 // This is the working definition of a server class machine:
  1330 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
  1331 // because the graphics memory (?) sometimes masks physical memory.
  1332 // If you want to change the definition of a server class machine
  1333 // on some OS or platform, e.g., >=4GB on Windohs platforms,
  1334 // then you'll have to parameterize this method based on that state,
  1335 // as was done for logical processors here, or replicate and
  1336 // specialize this method for each platform.  (Or fix os to have
  1337 // some inheritance structure and use subclassing.  Sigh.)
  1338 // If you want some platform to always or never behave as a server
  1339 // class machine, change the setting of AlwaysActAsServerClassMachine
  1340 // and NeverActAsServerClassMachine in globals*.hpp.
  1341 bool os::is_server_class_machine() {
  1342   // First check for the early returns
  1343   if (NeverActAsServerClassMachine) {
  1344     return false;
  1346   if (AlwaysActAsServerClassMachine) {
  1347     return true;
  1349   // Then actually look at the machine
  1350   bool         result            = false;
  1351   const unsigned int    server_processors = 2;
  1352   const julong server_memory     = 2UL * G;
  1353   // We seem not to get our full complement of memory.
  1354   //     We allow some part (1/8?) of the memory to be "missing",
  1355   //     based on the sizes of DIMMs, and maybe graphics cards.
  1356   const julong missing_memory   = 256UL * M;
  1358   /* Is this a server class machine? */
  1359   if ((os::active_processor_count() >= (int)server_processors) &&
  1360       (os::physical_memory() >= (server_memory - missing_memory))) {
  1361     const unsigned int logical_processors =
  1362       VM_Version::logical_processors_per_package();
  1363     if (logical_processors > 1) {
  1364       const unsigned int physical_packages =
  1365         os::active_processor_count() / logical_processors;
  1366       if (physical_packages > server_processors) {
  1367         result = true;
  1369     } else {
  1370       result = true;
  1373   return result;
  1376 // Read file line by line, if line is longer than bsize,
  1377 // skip rest of line.
  1378 int os::get_line_chars(int fd, char* buf, const size_t bsize){
  1379   size_t sz, i = 0;
  1381   // read until EOF, EOL or buf is full
  1382   while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
  1383      ++i;
  1386   if (buf[i] == '\n') {
  1387     // EOL reached so ignore EOL character and return
  1389     buf[i] = 0;
  1390     return (int) i;
  1393   buf[i+1] = 0;
  1395   if (sz != 1) {
  1396     // EOF reached. if we read chars before EOF return them and
  1397     // return EOF on next call otherwise return EOF
  1399     return (i == 0) ? -1 : (int) i;
  1402   // line is longer than size of buf, skip to EOL
  1403   char ch;
  1404   while (read(fd, &ch, 1) == 1 && ch != '\n') {
  1405     // Do nothing
  1408   // return initial part of line that fits in buf.
  1409   // If we reached EOF, it will be returned on next call.
  1411   return (int) i;
  1414 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
  1415   return os::pd_create_stack_guard_pages(addr, bytes);
  1419 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
  1420   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
  1421   if (result != NULL) {
  1422     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
  1425   return result;
  1427 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
  1428   char* result = pd_attempt_reserve_memory_at(bytes, addr);
  1429   if (result != NULL) {
  1430     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
  1432   return result;
  1435 void os::split_reserved_memory(char *base, size_t size,
  1436                                  size_t split, bool realloc) {
  1437   pd_split_reserved_memory(base, size, split, realloc);
  1440 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
  1441   bool res = pd_commit_memory(addr, bytes, executable);
  1442   if (res) {
  1443     MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
  1445   return res;
  1448 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
  1449                               bool executable) {
  1450   bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
  1451   if (res) {
  1452     MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
  1454   return res;
  1457 bool os::uncommit_memory(char* addr, size_t bytes) {
  1458   bool res = pd_uncommit_memory(addr, bytes);
  1459   if (res) {
  1460     MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
  1462   return res;
  1465 bool os::release_memory(char* addr, size_t bytes) {
  1466   bool res = pd_release_memory(addr, bytes);
  1467   if (res) {
  1468     MemTracker::record_virtual_memory_release((address)addr, bytes);
  1470   return res;
  1474 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
  1475                            char *addr, size_t bytes, bool read_only,
  1476                            bool allow_exec) {
  1477   char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
  1478   if (result != NULL) {
  1479     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
  1480     MemTracker::record_virtual_memory_commit((address)result, bytes, CALLER_PC);
  1482   return result;
  1485 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
  1486                              char *addr, size_t bytes, bool read_only,
  1487                              bool allow_exec) {
  1488   return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
  1489                     read_only, allow_exec);
  1492 bool os::unmap_memory(char *addr, size_t bytes) {
  1493   bool result = pd_unmap_memory(addr, bytes);
  1494   if (result) {
  1495     MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
  1496     MemTracker::record_virtual_memory_release((address)addr, bytes);
  1498   return result;
  1501 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  1502   pd_free_memory(addr, bytes, alignment_hint);
  1505 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  1506   pd_realign_memory(addr, bytes, alignment_hint);

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