hotspot/src/share/vm/runtime/thread.cpp
changeset 1 489c9b5090e2
child 234 4da9c1bbc810
child 222 3d1795325749
child 191 314312979e7a
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0:fd16c54261b3 1:489c9b5090e2
       
     1 /*
       
     2  * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
       
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
       
    21  * have any questions.
       
    22  *
       
    23  */
       
    24 
       
    25 # include "incls/_precompiled.incl"
       
    26 # include "incls/_thread.cpp.incl"
       
    27 
       
    28 #ifdef DTRACE_ENABLED
       
    29 
       
    30 // Only bother with this argument setup if dtrace is available
       
    31 
       
    32 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
       
    33 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
       
    34 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
       
    35   intptr_t, intptr_t, bool);
       
    36 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
       
    37   intptr_t, intptr_t, bool);
       
    38 
       
    39 #define DTRACE_THREAD_PROBE(probe, javathread)                             \
       
    40   {                                                                        \
       
    41     ResourceMark rm(this);                                                 \
       
    42     int len = 0;                                                           \
       
    43     const char* name = (javathread)->get_thread_name();                    \
       
    44     len = strlen(name);                                                    \
       
    45     HS_DTRACE_PROBE5(hotspot, thread__##probe,                             \
       
    46       name, len,                                                           \
       
    47       java_lang_Thread::thread_id((javathread)->threadObj()),              \
       
    48       (javathread)->osthread()->thread_id(),                               \
       
    49       java_lang_Thread::is_daemon((javathread)->threadObj()));             \
       
    50   }
       
    51 
       
    52 #else //  ndef DTRACE_ENABLED
       
    53 
       
    54 #define DTRACE_THREAD_PROBE(probe, javathread)
       
    55 
       
    56 #endif // ndef DTRACE_ENABLED
       
    57 
       
    58 // Class hierarchy
       
    59 // - Thread
       
    60 //   - VMThread
       
    61 //   - WatcherThread
       
    62 //   - ConcurrentMarkSweepThread
       
    63 //   - JavaThread
       
    64 //     - CompilerThread
       
    65 
       
    66 // ======= Thread ========
       
    67 
       
    68 // Support for forcing alignment of thread objects for biased locking
       
    69 void* Thread::operator new(size_t size) {
       
    70   if (UseBiasedLocking) {
       
    71     const int alignment = markOopDesc::biased_lock_alignment;
       
    72     size_t aligned_size = size + (alignment - sizeof(intptr_t));
       
    73     void* real_malloc_addr = CHeapObj::operator new(aligned_size);
       
    74     void* aligned_addr     = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
       
    75     assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
       
    76            ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
       
    77            "JavaThread alignment code overflowed allocated storage");
       
    78     if (TraceBiasedLocking) {
       
    79       if (aligned_addr != real_malloc_addr)
       
    80         tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
       
    81                       real_malloc_addr, aligned_addr);
       
    82     }
       
    83     ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
       
    84     return aligned_addr;
       
    85   } else {
       
    86     return CHeapObj::operator new(size);
       
    87   }
       
    88 }
       
    89 
       
    90 void Thread::operator delete(void* p) {
       
    91   if (UseBiasedLocking) {
       
    92     void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
       
    93     CHeapObj::operator delete(real_malloc_addr);
       
    94   } else {
       
    95     CHeapObj::operator delete(p);
       
    96   }
       
    97 }
       
    98 
       
    99 
       
   100 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
       
   101 // JavaThread
       
   102 
       
   103 
       
   104 Thread::Thread() {
       
   105   // stack
       
   106   _stack_base   = NULL;
       
   107   _stack_size   = 0;
       
   108   _self_raw_id  = 0;
       
   109   _lgrp_id      = -1;
       
   110   _osthread     = NULL;
       
   111 
       
   112   // allocated data structures
       
   113   set_resource_area(new ResourceArea());
       
   114   set_handle_area(new HandleArea(NULL));
       
   115   set_active_handles(NULL);
       
   116   set_free_handle_block(NULL);
       
   117   set_last_handle_mark(NULL);
       
   118   set_osthread(NULL);
       
   119 
       
   120   // This initial value ==> never claimed.
       
   121   _oops_do_parity = 0;
       
   122 
       
   123   // the handle mark links itself to last_handle_mark
       
   124   new HandleMark(this);
       
   125 
       
   126   // plain initialization
       
   127   debug_only(_owned_locks = NULL;)
       
   128   debug_only(_allow_allocation_count = 0;)
       
   129   NOT_PRODUCT(_allow_safepoint_count = 0;)
       
   130   CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
       
   131   _highest_lock = NULL;
       
   132   _jvmti_env_iteration_count = 0;
       
   133   _vm_operation_started_count = 0;
       
   134   _vm_operation_completed_count = 0;
       
   135   _current_pending_monitor = NULL;
       
   136   _current_pending_monitor_is_from_java = true;
       
   137   _current_waiting_monitor = NULL;
       
   138   _num_nested_signal = 0;
       
   139   omFreeList = NULL ;
       
   140   omFreeCount = 0 ;
       
   141   omFreeProvision = 32 ;
       
   142 
       
   143   _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
       
   144   _suspend_flags = 0;
       
   145 
       
   146   // thread-specific hashCode stream generator state - Marsaglia shift-xor form
       
   147   _hashStateX = os::random() ;
       
   148   _hashStateY = 842502087 ;
       
   149   _hashStateZ = 0x8767 ;    // (int)(3579807591LL & 0xffff) ;
       
   150   _hashStateW = 273326509 ;
       
   151 
       
   152   _OnTrap   = 0 ;
       
   153   _schedctl = NULL ;
       
   154   _Stalled  = 0 ;
       
   155   _TypeTag  = 0x2BAD ;
       
   156 
       
   157   // Many of the following fields are effectively final - immutable
       
   158   // Note that nascent threads can't use the Native Monitor-Mutex
       
   159   // construct until the _MutexEvent is initialized ...
       
   160   // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
       
   161   // we might instead use a stack of ParkEvents that we could provision on-demand.
       
   162   // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
       
   163   // and ::Release()
       
   164   _ParkEvent   = ParkEvent::Allocate (this) ;
       
   165   _SleepEvent  = ParkEvent::Allocate (this) ;
       
   166   _MutexEvent  = ParkEvent::Allocate (this) ;
       
   167   _MuxEvent    = ParkEvent::Allocate (this) ;
       
   168 
       
   169 #ifdef CHECK_UNHANDLED_OOPS
       
   170   if (CheckUnhandledOops) {
       
   171     _unhandled_oops = new UnhandledOops(this);
       
   172   }
       
   173 #endif // CHECK_UNHANDLED_OOPS
       
   174 #ifdef ASSERT
       
   175   if (UseBiasedLocking) {
       
   176     assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
       
   177     assert(this == _real_malloc_address ||
       
   178            this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
       
   179            "bug in forced alignment of thread objects");
       
   180   }
       
   181 #endif /* ASSERT */
       
   182 }
       
   183 
       
   184 void Thread::initialize_thread_local_storage() {
       
   185   // Note: Make sure this method only calls
       
   186   // non-blocking operations. Otherwise, it might not work
       
   187   // with the thread-startup/safepoint interaction.
       
   188 
       
   189   // During Java thread startup, safepoint code should allow this
       
   190   // method to complete because it may need to allocate memory to
       
   191   // store information for the new thread.
       
   192 
       
   193   // initialize structure dependent on thread local storage
       
   194   ThreadLocalStorage::set_thread(this);
       
   195 
       
   196   // set up any platform-specific state.
       
   197   os::initialize_thread();
       
   198 
       
   199 }
       
   200 
       
   201 void Thread::record_stack_base_and_size() {
       
   202   set_stack_base(os::current_stack_base());
       
   203   set_stack_size(os::current_stack_size());
       
   204 }
       
   205 
       
   206 
       
   207 Thread::~Thread() {
       
   208   // Reclaim the objectmonitors from the omFreeList of the moribund thread.
       
   209   ObjectSynchronizer::omFlush (this) ;
       
   210 
       
   211   // deallocate data structures
       
   212   delete resource_area();
       
   213   // since the handle marks are using the handle area, we have to deallocated the root
       
   214   // handle mark before deallocating the thread's handle area,
       
   215   assert(last_handle_mark() != NULL, "check we have an element");
       
   216   delete last_handle_mark();
       
   217   assert(last_handle_mark() == NULL, "check we have reached the end");
       
   218 
       
   219   // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
       
   220   // We NULL out the fields for good hygiene.
       
   221   ParkEvent::Release (_ParkEvent)   ; _ParkEvent   = NULL ;
       
   222   ParkEvent::Release (_SleepEvent)  ; _SleepEvent  = NULL ;
       
   223   ParkEvent::Release (_MutexEvent)  ; _MutexEvent  = NULL ;
       
   224   ParkEvent::Release (_MuxEvent)    ; _MuxEvent    = NULL ;
       
   225 
       
   226   delete handle_area();
       
   227 
       
   228   // osthread() can be NULL, if creation of thread failed.
       
   229   if (osthread() != NULL) os::free_thread(osthread());
       
   230 
       
   231   delete _SR_lock;
       
   232 
       
   233   // clear thread local storage if the Thread is deleting itself
       
   234   if (this == Thread::current()) {
       
   235     ThreadLocalStorage::set_thread(NULL);
       
   236   } else {
       
   237     // In the case where we're not the current thread, invalidate all the
       
   238     // caches in case some code tries to get the current thread or the
       
   239     // thread that was destroyed, and gets stale information.
       
   240     ThreadLocalStorage::invalidate_all();
       
   241   }
       
   242   CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
       
   243 }
       
   244 
       
   245 // NOTE: dummy function for assertion purpose.
       
   246 void Thread::run() {
       
   247   ShouldNotReachHere();
       
   248 }
       
   249 
       
   250 #ifdef ASSERT
       
   251 // Private method to check for dangling thread pointer
       
   252 void check_for_dangling_thread_pointer(Thread *thread) {
       
   253  assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
       
   254          "possibility of dangling Thread pointer");
       
   255 }
       
   256 #endif
       
   257 
       
   258 
       
   259 #ifndef PRODUCT
       
   260 // Tracing method for basic thread operations
       
   261 void Thread::trace(const char* msg, const Thread* const thread) {
       
   262   if (!TraceThreadEvents) return;
       
   263   ResourceMark rm;
       
   264   ThreadCritical tc;
       
   265   const char *name = "non-Java thread";
       
   266   int prio = -1;
       
   267   if (thread->is_Java_thread()
       
   268       && !thread->is_Compiler_thread()) {
       
   269     // The Threads_lock must be held to get information about
       
   270     // this thread but may not be in some situations when
       
   271     // tracing  thread events.
       
   272     bool release_Threads_lock = false;
       
   273     if (!Threads_lock->owned_by_self()) {
       
   274       Threads_lock->lock();
       
   275       release_Threads_lock = true;
       
   276     }
       
   277     JavaThread* jt = (JavaThread *)thread;
       
   278     name = (char *)jt->get_thread_name();
       
   279     oop thread_oop = jt->threadObj();
       
   280     if (thread_oop != NULL) {
       
   281       prio = java_lang_Thread::priority(thread_oop);
       
   282     }
       
   283     if (release_Threads_lock) {
       
   284       Threads_lock->unlock();
       
   285     }
       
   286   }
       
   287   tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
       
   288 }
       
   289 #endif
       
   290 
       
   291 
       
   292 ThreadPriority Thread::get_priority(const Thread* const thread) {
       
   293   trace("get priority", thread);
       
   294   ThreadPriority priority;
       
   295   // Can return an error!
       
   296   (void)os::get_priority(thread, priority);
       
   297   assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
       
   298   return priority;
       
   299 }
       
   300 
       
   301 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
       
   302   trace("set priority", thread);
       
   303   debug_only(check_for_dangling_thread_pointer(thread);)
       
   304   // Can return an error!
       
   305   (void)os::set_priority(thread, priority);
       
   306 }
       
   307 
       
   308 
       
   309 void Thread::start(Thread* thread) {
       
   310   trace("start", thread);
       
   311   // Start is different from resume in that its safety is guaranteed by context or
       
   312   // being called from a Java method synchronized on the Thread object.
       
   313   if (!DisableStartThread) {
       
   314     if (thread->is_Java_thread()) {
       
   315       // Initialize the thread state to RUNNABLE before starting this thread.
       
   316       // Can not set it after the thread started because we do not know the
       
   317       // exact thread state at that time. It could be in MONITOR_WAIT or
       
   318       // in SLEEPING or some other state.
       
   319       java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
       
   320                                           java_lang_Thread::RUNNABLE);
       
   321     }
       
   322     os::start_thread(thread);
       
   323   }
       
   324 }
       
   325 
       
   326 // Enqueue a VM_Operation to do the job for us - sometime later
       
   327 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
       
   328   VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
       
   329   VMThread::execute(vm_stop);
       
   330 }
       
   331 
       
   332 
       
   333 //
       
   334 // Check if an external suspend request has completed (or has been
       
   335 // cancelled). Returns true if the thread is externally suspended and
       
   336 // false otherwise.
       
   337 //
       
   338 // The bits parameter returns information about the code path through
       
   339 // the routine. Useful for debugging:
       
   340 //
       
   341 // set in is_ext_suspend_completed():
       
   342 // 0x00000001 - routine was entered
       
   343 // 0x00000010 - routine return false at end
       
   344 // 0x00000100 - thread exited (return false)
       
   345 // 0x00000200 - suspend request cancelled (return false)
       
   346 // 0x00000400 - thread suspended (return true)
       
   347 // 0x00001000 - thread is in a suspend equivalent state (return true)
       
   348 // 0x00002000 - thread is native and walkable (return true)
       
   349 // 0x00004000 - thread is native_trans and walkable (needed retry)
       
   350 //
       
   351 // set in wait_for_ext_suspend_completion():
       
   352 // 0x00010000 - routine was entered
       
   353 // 0x00020000 - suspend request cancelled before loop (return false)
       
   354 // 0x00040000 - thread suspended before loop (return true)
       
   355 // 0x00080000 - suspend request cancelled in loop (return false)
       
   356 // 0x00100000 - thread suspended in loop (return true)
       
   357 // 0x00200000 - suspend not completed during retry loop (return false)
       
   358 //
       
   359 
       
   360 // Helper class for tracing suspend wait debug bits.
       
   361 //
       
   362 // 0x00000100 indicates that the target thread exited before it could
       
   363 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
       
   364 // 0x00080000 each indicate a cancelled suspend request so they don't
       
   365 // count as wait failures either.
       
   366 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
       
   367 
       
   368 class TraceSuspendDebugBits : public StackObj {
       
   369  private:
       
   370   JavaThread * jt;
       
   371   bool         is_wait;
       
   372   bool         called_by_wait;  // meaningful when !is_wait
       
   373   uint32_t *   bits;
       
   374 
       
   375  public:
       
   376   TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
       
   377                         uint32_t *_bits) {
       
   378     jt             = _jt;
       
   379     is_wait        = _is_wait;
       
   380     called_by_wait = _called_by_wait;
       
   381     bits           = _bits;
       
   382   }
       
   383 
       
   384   ~TraceSuspendDebugBits() {
       
   385     if (!is_wait) {
       
   386 #if 1
       
   387       // By default, don't trace bits for is_ext_suspend_completed() calls.
       
   388       // That trace is very chatty.
       
   389       return;
       
   390 #else
       
   391       if (!called_by_wait) {
       
   392         // If tracing for is_ext_suspend_completed() is enabled, then only
       
   393         // trace calls to it from wait_for_ext_suspend_completion()
       
   394         return;
       
   395       }
       
   396 #endif
       
   397     }
       
   398 
       
   399     if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
       
   400       if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
       
   401         MutexLocker ml(Threads_lock);  // needed for get_thread_name()
       
   402         ResourceMark rm;
       
   403 
       
   404         tty->print_cr(
       
   405             "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
       
   406             jt->get_thread_name(), *bits);
       
   407 
       
   408         guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
       
   409       }
       
   410     }
       
   411   }
       
   412 };
       
   413 #undef DEBUG_FALSE_BITS
       
   414 
       
   415 
       
   416 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
       
   417   TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
       
   418 
       
   419   bool did_trans_retry = false;  // only do thread_in_native_trans retry once
       
   420   bool do_trans_retry;           // flag to force the retry
       
   421 
       
   422   *bits |= 0x00000001;
       
   423 
       
   424   do {
       
   425     do_trans_retry = false;
       
   426 
       
   427     if (is_exiting()) {
       
   428       // Thread is in the process of exiting. This is always checked
       
   429       // first to reduce the risk of dereferencing a freed JavaThread.
       
   430       *bits |= 0x00000100;
       
   431       return false;
       
   432     }
       
   433 
       
   434     if (!is_external_suspend()) {
       
   435       // Suspend request is cancelled. This is always checked before
       
   436       // is_ext_suspended() to reduce the risk of a rogue resume
       
   437       // confusing the thread that made the suspend request.
       
   438       *bits |= 0x00000200;
       
   439       return false;
       
   440     }
       
   441 
       
   442     if (is_ext_suspended()) {
       
   443       // thread is suspended
       
   444       *bits |= 0x00000400;
       
   445       return true;
       
   446     }
       
   447 
       
   448     // Now that we no longer do hard suspends of threads running
       
   449     // native code, the target thread can be changing thread state
       
   450     // while we are in this routine:
       
   451     //
       
   452     //   _thread_in_native -> _thread_in_native_trans -> _thread_blocked
       
   453     //
       
   454     // We save a copy of the thread state as observed at this moment
       
   455     // and make our decision about suspend completeness based on the
       
   456     // copy. This closes the race where the thread state is seen as
       
   457     // _thread_in_native_trans in the if-thread_blocked check, but is
       
   458     // seen as _thread_blocked in if-thread_in_native_trans check.
       
   459     JavaThreadState save_state = thread_state();
       
   460 
       
   461     if (save_state == _thread_blocked && is_suspend_equivalent()) {
       
   462       // If the thread's state is _thread_blocked and this blocking
       
   463       // condition is known to be equivalent to a suspend, then we can
       
   464       // consider the thread to be externally suspended. This means that
       
   465       // the code that sets _thread_blocked has been modified to do
       
   466       // self-suspension if the blocking condition releases. We also
       
   467       // used to check for CONDVAR_WAIT here, but that is now covered by
       
   468       // the _thread_blocked with self-suspension check.
       
   469       //
       
   470       // Return true since we wouldn't be here unless there was still an
       
   471       // external suspend request.
       
   472       *bits |= 0x00001000;
       
   473       return true;
       
   474     } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
       
   475       // Threads running native code will self-suspend on native==>VM/Java
       
   476       // transitions. If its stack is walkable (should always be the case
       
   477       // unless this function is called before the actual java_suspend()
       
   478       // call), then the wait is done.
       
   479       *bits |= 0x00002000;
       
   480       return true;
       
   481     } else if (!called_by_wait && !did_trans_retry &&
       
   482                save_state == _thread_in_native_trans &&
       
   483                frame_anchor()->walkable()) {
       
   484       // The thread is transitioning from thread_in_native to another
       
   485       // thread state. check_safepoint_and_suspend_for_native_trans()
       
   486       // will force the thread to self-suspend. If it hasn't gotten
       
   487       // there yet we may have caught the thread in-between the native
       
   488       // code check above and the self-suspend. Lucky us. If we were
       
   489       // called by wait_for_ext_suspend_completion(), then it
       
   490       // will be doing the retries so we don't have to.
       
   491       //
       
   492       // Since we use the saved thread state in the if-statement above,
       
   493       // there is a chance that the thread has already transitioned to
       
   494       // _thread_blocked by the time we get here. In that case, we will
       
   495       // make a single unnecessary pass through the logic below. This
       
   496       // doesn't hurt anything since we still do the trans retry.
       
   497 
       
   498       *bits |= 0x00004000;
       
   499 
       
   500       // Once the thread leaves thread_in_native_trans for another
       
   501       // thread state, we break out of this retry loop. We shouldn't
       
   502       // need this flag to prevent us from getting back here, but
       
   503       // sometimes paranoia is good.
       
   504       did_trans_retry = true;
       
   505 
       
   506       // We wait for the thread to transition to a more usable state.
       
   507       for (int i = 1; i <= SuspendRetryCount; i++) {
       
   508         // We used to do an "os::yield_all(i)" call here with the intention
       
   509         // that yielding would increase on each retry. However, the parameter
       
   510         // is ignored on Linux which means the yield didn't scale up. Waiting
       
   511         // on the SR_lock below provides a much more predictable scale up for
       
   512         // the delay. It also provides a simple/direct point to check for any
       
   513         // safepoint requests from the VMThread
       
   514 
       
   515         // temporarily drops SR_lock while doing wait with safepoint check
       
   516         // (if we're a JavaThread - the WatcherThread can also call this)
       
   517         // and increase delay with each retry
       
   518         SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
       
   519 
       
   520         // check the actual thread state instead of what we saved above
       
   521         if (thread_state() != _thread_in_native_trans) {
       
   522           // the thread has transitioned to another thread state so
       
   523           // try all the checks (except this one) one more time.
       
   524           do_trans_retry = true;
       
   525           break;
       
   526         }
       
   527       } // end retry loop
       
   528 
       
   529 
       
   530     }
       
   531   } while (do_trans_retry);
       
   532 
       
   533   *bits |= 0x00000010;
       
   534   return false;
       
   535 }
       
   536 
       
   537 //
       
   538 // Wait for an external suspend request to complete (or be cancelled).
       
   539 // Returns true if the thread is externally suspended and false otherwise.
       
   540 //
       
   541 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
       
   542        uint32_t *bits) {
       
   543   TraceSuspendDebugBits tsdb(this, true /* is_wait */,
       
   544                              false /* !called_by_wait */, bits);
       
   545 
       
   546   // local flag copies to minimize SR_lock hold time
       
   547   bool is_suspended;
       
   548   bool pending;
       
   549   uint32_t reset_bits;
       
   550 
       
   551   // set a marker so is_ext_suspend_completed() knows we are the caller
       
   552   *bits |= 0x00010000;
       
   553 
       
   554   // We use reset_bits to reinitialize the bits value at the top of
       
   555   // each retry loop. This allows the caller to make use of any
       
   556   // unused bits for their own marking purposes.
       
   557   reset_bits = *bits;
       
   558 
       
   559   {
       
   560     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
       
   561     is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
       
   562                                             delay, bits);
       
   563     pending = is_external_suspend();
       
   564   }
       
   565   // must release SR_lock to allow suspension to complete
       
   566 
       
   567   if (!pending) {
       
   568     // A cancelled suspend request is the only false return from
       
   569     // is_ext_suspend_completed() that keeps us from entering the
       
   570     // retry loop.
       
   571     *bits |= 0x00020000;
       
   572     return false;
       
   573   }
       
   574 
       
   575   if (is_suspended) {
       
   576     *bits |= 0x00040000;
       
   577     return true;
       
   578   }
       
   579 
       
   580   for (int i = 1; i <= retries; i++) {
       
   581     *bits = reset_bits;  // reinit to only track last retry
       
   582 
       
   583     // We used to do an "os::yield_all(i)" call here with the intention
       
   584     // that yielding would increase on each retry. However, the parameter
       
   585     // is ignored on Linux which means the yield didn't scale up. Waiting
       
   586     // on the SR_lock below provides a much more predictable scale up for
       
   587     // the delay. It also provides a simple/direct point to check for any
       
   588     // safepoint requests from the VMThread
       
   589 
       
   590     {
       
   591       MutexLocker ml(SR_lock());
       
   592       // wait with safepoint check (if we're a JavaThread - the WatcherThread
       
   593       // can also call this)  and increase delay with each retry
       
   594       SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
       
   595 
       
   596       is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
       
   597                                               delay, bits);
       
   598 
       
   599       // It is possible for the external suspend request to be cancelled
       
   600       // (by a resume) before the actual suspend operation is completed.
       
   601       // Refresh our local copy to see if we still need to wait.
       
   602       pending = is_external_suspend();
       
   603     }
       
   604 
       
   605     if (!pending) {
       
   606       // A cancelled suspend request is the only false return from
       
   607       // is_ext_suspend_completed() that keeps us from staying in the
       
   608       // retry loop.
       
   609       *bits |= 0x00080000;
       
   610       return false;
       
   611     }
       
   612 
       
   613     if (is_suspended) {
       
   614       *bits |= 0x00100000;
       
   615       return true;
       
   616     }
       
   617   } // end retry loop
       
   618 
       
   619   // thread did not suspend after all our retries
       
   620   *bits |= 0x00200000;
       
   621   return false;
       
   622 }
       
   623 
       
   624 #ifndef PRODUCT
       
   625 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
       
   626 
       
   627   // This should not need to be atomic as the only way for simultaneous
       
   628   // updates is via interrupts. Even then this should be rare or non-existant
       
   629   // and we don't care that much anyway.
       
   630 
       
   631   int index = _jmp_ring_index;
       
   632   _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
       
   633   _jmp_ring[index]._target = (intptr_t) target;
       
   634   _jmp_ring[index]._instruction = (intptr_t) instr;
       
   635   _jmp_ring[index]._file = file;
       
   636   _jmp_ring[index]._line = line;
       
   637 }
       
   638 #endif /* PRODUCT */
       
   639 
       
   640 // Called by flat profiler
       
   641 // Callers have already called wait_for_ext_suspend_completion
       
   642 // The assertion for that is currently too complex to put here:
       
   643 bool JavaThread::profile_last_Java_frame(frame* _fr) {
       
   644   bool gotframe = false;
       
   645   // self suspension saves needed state.
       
   646   if (has_last_Java_frame() && _anchor.walkable()) {
       
   647      *_fr = pd_last_frame();
       
   648      gotframe = true;
       
   649   }
       
   650   return gotframe;
       
   651 }
       
   652 
       
   653 void Thread::interrupt(Thread* thread) {
       
   654   trace("interrupt", thread);
       
   655   debug_only(check_for_dangling_thread_pointer(thread);)
       
   656   os::interrupt(thread);
       
   657 }
       
   658 
       
   659 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
       
   660   trace("is_interrupted", thread);
       
   661   debug_only(check_for_dangling_thread_pointer(thread);)
       
   662   // Note:  If clear_interrupted==false, this simply fetches and
       
   663   // returns the value of the field osthread()->interrupted().
       
   664   return os::is_interrupted(thread, clear_interrupted);
       
   665 }
       
   666 
       
   667 
       
   668 // GC Support
       
   669 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
       
   670   jint thread_parity = _oops_do_parity;
       
   671   if (thread_parity != strong_roots_parity) {
       
   672     jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
       
   673     if (res == thread_parity) return true;
       
   674     else {
       
   675       guarantee(res == strong_roots_parity, "Or else what?");
       
   676       assert(SharedHeap::heap()->n_par_threads() > 0,
       
   677              "Should only fail when parallel.");
       
   678       return false;
       
   679     }
       
   680   }
       
   681   assert(SharedHeap::heap()->n_par_threads() > 0,
       
   682          "Should only fail when parallel.");
       
   683   return false;
       
   684 }
       
   685 
       
   686 void Thread::oops_do(OopClosure* f) {
       
   687   active_handles()->oops_do(f);
       
   688   // Do oop for ThreadShadow
       
   689   f->do_oop((oop*)&_pending_exception);
       
   690   handle_area()->oops_do(f);
       
   691 }
       
   692 
       
   693 void Thread::nmethods_do() {
       
   694 }
       
   695 
       
   696 void Thread::print_on(outputStream* st) const {
       
   697   // get_priority assumes osthread initialized
       
   698   if (osthread() != NULL) {
       
   699     st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
       
   700     osthread()->print_on(st);
       
   701   }
       
   702   debug_only(if (WizardMode) print_owned_locks_on(st);)
       
   703 }
       
   704 
       
   705 // Thread::print_on_error() is called by fatal error handler. Don't use
       
   706 // any lock or allocate memory.
       
   707 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
       
   708   if      (is_VM_thread())                  st->print("VMThread");
       
   709   else if (is_Compiler_thread())            st->print("CompilerThread");
       
   710   else if (is_Java_thread())                st->print("JavaThread");
       
   711   else if (is_GC_task_thread())             st->print("GCTaskThread");
       
   712   else if (is_Watcher_thread())             st->print("WatcherThread");
       
   713   else if (is_ConcurrentGC_thread())        st->print("ConcurrentGCThread");
       
   714   else st->print("Thread");
       
   715 
       
   716   st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
       
   717             _stack_base - _stack_size, _stack_base);
       
   718 
       
   719   if (osthread()) {
       
   720     st->print(" [id=%d]", osthread()->thread_id());
       
   721   }
       
   722 }
       
   723 
       
   724 #ifdef ASSERT
       
   725 void Thread::print_owned_locks_on(outputStream* st) const {
       
   726   Monitor *cur = _owned_locks;
       
   727   if (cur == NULL) {
       
   728     st->print(" (no locks) ");
       
   729   } else {
       
   730     st->print_cr(" Locks owned:");
       
   731     while(cur) {
       
   732       cur->print_on(st);
       
   733       cur = cur->next();
       
   734     }
       
   735   }
       
   736 }
       
   737 
       
   738 static int ref_use_count  = 0;
       
   739 
       
   740 bool Thread::owns_locks_but_compiled_lock() const {
       
   741   for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
       
   742     if (cur != Compile_lock) return true;
       
   743   }
       
   744   return false;
       
   745 }
       
   746 
       
   747 
       
   748 #endif
       
   749 
       
   750 #ifndef PRODUCT
       
   751 
       
   752 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
       
   753 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
       
   754 // no threads which allow_vm_block's are held
       
   755 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
       
   756     // Check if current thread is allowed to block at a safepoint
       
   757     if (!(_allow_safepoint_count == 0))
       
   758       fatal("Possible safepoint reached by thread that does not allow it");
       
   759     if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
       
   760       fatal("LEAF method calling lock?");
       
   761     }
       
   762 
       
   763 #ifdef ASSERT
       
   764     if (potential_vm_operation && is_Java_thread()
       
   765         && !Universe::is_bootstrapping()) {
       
   766       // Make sure we do not hold any locks that the VM thread also uses.
       
   767       // This could potentially lead to deadlocks
       
   768       for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
       
   769         // Threads_lock is special, since the safepoint synchronization will not start before this is
       
   770         // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
       
   771         // since it is used to transfer control between JavaThreads and the VMThread
       
   772         // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
       
   773         if ( (cur->allow_vm_block() &&
       
   774               cur != Threads_lock &&
       
   775               cur != Compile_lock &&               // Temporary: should not be necessary when we get spearate compilation
       
   776               cur != VMOperationRequest_lock &&
       
   777               cur != VMOperationQueue_lock) ||
       
   778               cur->rank() == Mutex::special) {
       
   779           warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
       
   780         }
       
   781       }
       
   782     }
       
   783 
       
   784     if (GCALotAtAllSafepoints) {
       
   785       // We could enter a safepoint here and thus have a gc
       
   786       InterfaceSupport::check_gc_alot();
       
   787     }
       
   788 
       
   789 #endif
       
   790 }
       
   791 #endif
       
   792 
       
   793 bool Thread::lock_is_in_stack(address adr) const {
       
   794   assert(Thread::current() == this, "lock_is_in_stack can only be called from current thread");
       
   795   // High limit: highest_lock is set during thread execution
       
   796   // Low  limit: address of the local variable dummy, rounded to 4K boundary.
       
   797   // (The rounding helps finding threads in unsafe mode, even if the particular stack
       
   798   // frame has been popped already.  Correct as long as stacks are at least 4K long and aligned.)
       
   799   address end = os::current_stack_pointer();
       
   800   if (_highest_lock >= adr && adr >= end) return true;
       
   801 
       
   802   return false;
       
   803 }
       
   804 
       
   805 
       
   806 bool Thread::is_in_stack(address adr) const {
       
   807   assert(Thread::current() == this, "is_in_stack can only be called from current thread");
       
   808   address end = os::current_stack_pointer();
       
   809   if (stack_base() >= adr && adr >= end) return true;
       
   810 
       
   811   return false;
       
   812 }
       
   813 
       
   814 
       
   815 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
       
   816 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
       
   817 // used for compilation in the future. If that change is made, the need for these methods
       
   818 // should be revisited, and they should be removed if possible.
       
   819 
       
   820 bool Thread::is_lock_owned(address adr) const {
       
   821   if (lock_is_in_stack(adr) ) return true;
       
   822   return false;
       
   823 }
       
   824 
       
   825 bool Thread::set_as_starting_thread() {
       
   826  // NOTE: this must be called inside the main thread.
       
   827   return os::create_main_thread((JavaThread*)this);
       
   828 }
       
   829 
       
   830 static void initialize_class(symbolHandle class_name, TRAPS) {
       
   831   klassOop klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
       
   832   instanceKlass::cast(klass)->initialize(CHECK);
       
   833 }
       
   834 
       
   835 
       
   836 // Creates the initial ThreadGroup
       
   837 static Handle create_initial_thread_group(TRAPS) {
       
   838   klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH);
       
   839   instanceKlassHandle klass (THREAD, k);
       
   840 
       
   841   Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
       
   842   {
       
   843     JavaValue result(T_VOID);
       
   844     JavaCalls::call_special(&result,
       
   845                             system_instance,
       
   846                             klass,
       
   847                             vmSymbolHandles::object_initializer_name(),
       
   848                             vmSymbolHandles::void_method_signature(),
       
   849                             CHECK_NH);
       
   850   }
       
   851   Universe::set_system_thread_group(system_instance());
       
   852 
       
   853   Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
       
   854   {
       
   855     JavaValue result(T_VOID);
       
   856     Handle string = java_lang_String::create_from_str("main", CHECK_NH);
       
   857     JavaCalls::call_special(&result,
       
   858                             main_instance,
       
   859                             klass,
       
   860                             vmSymbolHandles::object_initializer_name(),
       
   861                             vmSymbolHandles::threadgroup_string_void_signature(),
       
   862                             system_instance,
       
   863                             string,
       
   864                             CHECK_NH);
       
   865   }
       
   866   return main_instance;
       
   867 }
       
   868 
       
   869 // Creates the initial Thread
       
   870 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
       
   871   klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL);
       
   872   instanceKlassHandle klass (THREAD, k);
       
   873   instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
       
   874 
       
   875   java_lang_Thread::set_thread(thread_oop(), thread);
       
   876   java_lang_Thread::set_priority(thread_oop(), NormPriority);
       
   877   thread->set_threadObj(thread_oop());
       
   878 
       
   879   Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
       
   880 
       
   881   JavaValue result(T_VOID);
       
   882   JavaCalls::call_special(&result, thread_oop,
       
   883                                    klass,
       
   884                                    vmSymbolHandles::object_initializer_name(),
       
   885                                    vmSymbolHandles::threadgroup_string_void_signature(),
       
   886                                    thread_group,
       
   887                                    string,
       
   888                                    CHECK_NULL);
       
   889   return thread_oop();
       
   890 }
       
   891 
       
   892 static void call_initializeSystemClass(TRAPS) {
       
   893   klassOop k =  SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
       
   894   instanceKlassHandle klass (THREAD, k);
       
   895 
       
   896   JavaValue result(T_VOID);
       
   897   JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(),
       
   898                                          vmSymbolHandles::void_method_signature(), CHECK);
       
   899 }
       
   900 
       
   901 static void reset_vm_info_property(TRAPS) {
       
   902   // the vm info string
       
   903   ResourceMark rm(THREAD);
       
   904   const char *vm_info = VM_Version::vm_info_string();
       
   905 
       
   906   // java.lang.System class
       
   907   klassOop k =  SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
       
   908   instanceKlassHandle klass (THREAD, k);
       
   909 
       
   910   // setProperty arguments
       
   911   Handle key_str    = java_lang_String::create_from_str("java.vm.info", CHECK);
       
   912   Handle value_str  = java_lang_String::create_from_str(vm_info, CHECK);
       
   913 
       
   914   // return value
       
   915   JavaValue r(T_OBJECT);
       
   916 
       
   917   // public static String setProperty(String key, String value);
       
   918   JavaCalls::call_static(&r,
       
   919                          klass,
       
   920                          vmSymbolHandles::setProperty_name(),
       
   921                          vmSymbolHandles::string_string_string_signature(),
       
   922                          key_str,
       
   923                          value_str,
       
   924                          CHECK);
       
   925 }
       
   926 
       
   927 
       
   928 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
       
   929   assert(thread_group.not_null(), "thread group should be specified");
       
   930   assert(threadObj() == NULL, "should only create Java thread object once");
       
   931 
       
   932   klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
       
   933   instanceKlassHandle klass (THREAD, k);
       
   934   instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
       
   935 
       
   936   java_lang_Thread::set_thread(thread_oop(), this);
       
   937   java_lang_Thread::set_priority(thread_oop(), NormPriority);
       
   938   set_threadObj(thread_oop());
       
   939 
       
   940   JavaValue result(T_VOID);
       
   941   if (thread_name != NULL) {
       
   942     Handle name = java_lang_String::create_from_str(thread_name, CHECK);
       
   943     // Thread gets assigned specified name and null target
       
   944     JavaCalls::call_special(&result,
       
   945                             thread_oop,
       
   946                             klass,
       
   947                             vmSymbolHandles::object_initializer_name(),
       
   948                             vmSymbolHandles::threadgroup_string_void_signature(),
       
   949                             thread_group, // Argument 1
       
   950                             name,         // Argument 2
       
   951                             THREAD);
       
   952   } else {
       
   953     // Thread gets assigned name "Thread-nnn" and null target
       
   954     // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
       
   955     JavaCalls::call_special(&result,
       
   956                             thread_oop,
       
   957                             klass,
       
   958                             vmSymbolHandles::object_initializer_name(),
       
   959                             vmSymbolHandles::threadgroup_runnable_void_signature(),
       
   960                             thread_group, // Argument 1
       
   961                             Handle(),     // Argument 2
       
   962                             THREAD);
       
   963   }
       
   964 
       
   965 
       
   966   if (daemon) {
       
   967       java_lang_Thread::set_daemon(thread_oop());
       
   968   }
       
   969 
       
   970   if (HAS_PENDING_EXCEPTION) {
       
   971     return;
       
   972   }
       
   973 
       
   974   KlassHandle group(this, SystemDictionary::threadGroup_klass());
       
   975   Handle threadObj(this, this->threadObj());
       
   976 
       
   977   JavaCalls::call_special(&result,
       
   978                          thread_group,
       
   979                          group,
       
   980                          vmSymbolHandles::add_method_name(),
       
   981                          vmSymbolHandles::thread_void_signature(),
       
   982                          threadObj,          // Arg 1
       
   983                          THREAD);
       
   984 
       
   985 
       
   986 }
       
   987 
       
   988 // NamedThread --  non-JavaThread subclasses with multiple
       
   989 // uniquely named instances should derive from this.
       
   990 NamedThread::NamedThread() : Thread() {
       
   991   _name = NULL;
       
   992 }
       
   993 
       
   994 NamedThread::~NamedThread() {
       
   995   if (_name != NULL) {
       
   996     FREE_C_HEAP_ARRAY(char, _name);
       
   997     _name = NULL;
       
   998   }
       
   999 }
       
  1000 
       
  1001 void NamedThread::set_name(const char* format, ...) {
       
  1002   guarantee(_name == NULL, "Only get to set name once.");
       
  1003   _name = NEW_C_HEAP_ARRAY(char, max_name_len);
       
  1004   guarantee(_name != NULL, "alloc failure");
       
  1005   va_list ap;
       
  1006   va_start(ap, format);
       
  1007   jio_vsnprintf(_name, max_name_len, format, ap);
       
  1008   va_end(ap);
       
  1009 }
       
  1010 
       
  1011 // ======= WatcherThread ========
       
  1012 
       
  1013 // The watcher thread exists to simulate timer interrupts.  It should
       
  1014 // be replaced by an abstraction over whatever native support for
       
  1015 // timer interrupts exists on the platform.
       
  1016 
       
  1017 WatcherThread* WatcherThread::_watcher_thread   = NULL;
       
  1018 bool           WatcherThread::_should_terminate = false;
       
  1019 
       
  1020 WatcherThread::WatcherThread() : Thread() {
       
  1021   assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
       
  1022   if (os::create_thread(this, os::watcher_thread)) {
       
  1023     _watcher_thread = this;
       
  1024 
       
  1025     // Set the watcher thread to the highest OS priority which should not be
       
  1026     // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
       
  1027     // is created. The only normal thread using this priority is the reference
       
  1028     // handler thread, which runs for very short intervals only.
       
  1029     // If the VMThread's priority is not lower than the WatcherThread profiling
       
  1030     // will be inaccurate.
       
  1031     os::set_priority(this, MaxPriority);
       
  1032     if (!DisableStartThread) {
       
  1033       os::start_thread(this);
       
  1034     }
       
  1035   }
       
  1036 }
       
  1037 
       
  1038 void WatcherThread::run() {
       
  1039   assert(this == watcher_thread(), "just checking");
       
  1040 
       
  1041   this->record_stack_base_and_size();
       
  1042   this->initialize_thread_local_storage();
       
  1043   this->set_active_handles(JNIHandleBlock::allocate_block());
       
  1044   while(!_should_terminate) {
       
  1045     assert(watcher_thread() == Thread::current(),  "thread consistency check");
       
  1046     assert(watcher_thread() == this,  "thread consistency check");
       
  1047 
       
  1048     // Calculate how long it'll be until the next PeriodicTask work
       
  1049     // should be done, and sleep that amount of time.
       
  1050     const size_t time_to_wait = PeriodicTask::time_to_wait();
       
  1051     os::sleep(this, time_to_wait, false);
       
  1052 
       
  1053     if (is_error_reported()) {
       
  1054       // A fatal error has happened, the error handler(VMError::report_and_die)
       
  1055       // should abort JVM after creating an error log file. However in some
       
  1056       // rare cases, the error handler itself might deadlock. Here we try to
       
  1057       // kill JVM if the fatal error handler fails to abort in 2 minutes.
       
  1058       //
       
  1059       // This code is in WatcherThread because WatcherThread wakes up
       
  1060       // periodically so the fatal error handler doesn't need to do anything;
       
  1061       // also because the WatcherThread is less likely to crash than other
       
  1062       // threads.
       
  1063 
       
  1064       for (;;) {
       
  1065         if (!ShowMessageBoxOnError
       
  1066          && (OnError == NULL || OnError[0] == '\0')
       
  1067          && Arguments::abort_hook() == NULL) {
       
  1068              os::sleep(this, 2 * 60 * 1000, false);
       
  1069              fdStream err(defaultStream::output_fd());
       
  1070              err.print_raw_cr("# [ timer expired, abort... ]");
       
  1071              // skip atexit/vm_exit/vm_abort hooks
       
  1072              os::die();
       
  1073         }
       
  1074 
       
  1075         // Wake up 5 seconds later, the fatal handler may reset OnError or
       
  1076         // ShowMessageBoxOnError when it is ready to abort.
       
  1077         os::sleep(this, 5 * 1000, false);
       
  1078       }
       
  1079     }
       
  1080 
       
  1081     PeriodicTask::real_time_tick(time_to_wait);
       
  1082 
       
  1083     // If we have no more tasks left due to dynamic disenrollment,
       
  1084     // shut down the thread since we don't currently support dynamic enrollment
       
  1085     if (PeriodicTask::num_tasks() == 0) {
       
  1086       _should_terminate = true;
       
  1087     }
       
  1088   }
       
  1089 
       
  1090   // Signal that it is terminated
       
  1091   {
       
  1092     MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
       
  1093     _watcher_thread = NULL;
       
  1094     Terminator_lock->notify();
       
  1095   }
       
  1096 
       
  1097   // Thread destructor usually does this..
       
  1098   ThreadLocalStorage::set_thread(NULL);
       
  1099 }
       
  1100 
       
  1101 void WatcherThread::start() {
       
  1102   if (watcher_thread() == NULL) {
       
  1103     _should_terminate = false;
       
  1104     // Create the single instance of WatcherThread
       
  1105     new WatcherThread();
       
  1106   }
       
  1107 }
       
  1108 
       
  1109 void WatcherThread::stop() {
       
  1110   // it is ok to take late safepoints here, if needed
       
  1111   MutexLocker mu(Terminator_lock);
       
  1112   _should_terminate = true;
       
  1113   while(watcher_thread() != NULL) {
       
  1114     // This wait should make safepoint checks, wait without a timeout,
       
  1115     // and wait as a suspend-equivalent condition.
       
  1116     //
       
  1117     // Note: If the FlatProfiler is running, then this thread is waiting
       
  1118     // for the WatcherThread to terminate and the WatcherThread, via the
       
  1119     // FlatProfiler task, is waiting for the external suspend request on
       
  1120     // this thread to complete. wait_for_ext_suspend_completion() will
       
  1121     // eventually timeout, but that takes time. Making this wait a
       
  1122     // suspend-equivalent condition solves that timeout problem.
       
  1123     //
       
  1124     Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
       
  1125                           Mutex::_as_suspend_equivalent_flag);
       
  1126   }
       
  1127 }
       
  1128 
       
  1129 void WatcherThread::print_on(outputStream* st) const {
       
  1130   st->print("\"%s\" ", name());
       
  1131   Thread::print_on(st);
       
  1132   st->cr();
       
  1133 }
       
  1134 
       
  1135 // ======= JavaThread ========
       
  1136 
       
  1137 // A JavaThread is a normal Java thread
       
  1138 
       
  1139 void JavaThread::initialize() {
       
  1140   // Initialize fields
       
  1141   set_saved_exception_pc(NULL);
       
  1142   set_threadObj(NULL);
       
  1143   _anchor.clear();
       
  1144   set_entry_point(NULL);
       
  1145   set_jni_functions(jni_functions());
       
  1146   set_callee_target(NULL);
       
  1147   set_vm_result(NULL);
       
  1148   set_vm_result_2(NULL);
       
  1149   set_vframe_array_head(NULL);
       
  1150   set_vframe_array_last(NULL);
       
  1151   set_deferred_locals(NULL);
       
  1152   set_deopt_mark(NULL);
       
  1153   clear_must_deopt_id();
       
  1154   set_monitor_chunks(NULL);
       
  1155   set_next(NULL);
       
  1156   set_thread_state(_thread_new);
       
  1157   _terminated = _not_terminated;
       
  1158   _privileged_stack_top = NULL;
       
  1159   _array_for_gc = NULL;
       
  1160   _suspend_equivalent = false;
       
  1161   _in_deopt_handler = 0;
       
  1162   _doing_unsafe_access = false;
       
  1163   _stack_guard_state = stack_guard_unused;
       
  1164   _exception_oop = NULL;
       
  1165   _exception_pc  = 0;
       
  1166   _exception_handler_pc = 0;
       
  1167   _exception_stack_size = 0;
       
  1168   _jvmti_thread_state= NULL;
       
  1169   _jvmti_get_loaded_classes_closure = NULL;
       
  1170   _interp_only_mode    = 0;
       
  1171   _special_runtime_exit_condition = _no_async_condition;
       
  1172   _pending_async_exception = NULL;
       
  1173   _is_compiling = false;
       
  1174   _thread_stat = NULL;
       
  1175   _thread_stat = new ThreadStatistics();
       
  1176   _blocked_on_compilation = false;
       
  1177   _jni_active_critical = 0;
       
  1178   _do_not_unlock_if_synchronized = false;
       
  1179   _cached_monitor_info = NULL;
       
  1180   _parker = Parker::Allocate(this) ;
       
  1181 
       
  1182 #ifndef PRODUCT
       
  1183   _jmp_ring_index = 0;
       
  1184   for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
       
  1185     record_jump(NULL, NULL, NULL, 0);
       
  1186   }
       
  1187 #endif /* PRODUCT */
       
  1188 
       
  1189   set_thread_profiler(NULL);
       
  1190   if (FlatProfiler::is_active()) {
       
  1191     // This is where we would decide to either give each thread it's own profiler
       
  1192     // or use one global one from FlatProfiler,
       
  1193     // or up to some count of the number of profiled threads, etc.
       
  1194     ThreadProfiler* pp = new ThreadProfiler();
       
  1195     pp->engage();
       
  1196     set_thread_profiler(pp);
       
  1197   }
       
  1198 
       
  1199   // Setup safepoint state info for this thread
       
  1200   ThreadSafepointState::create(this);
       
  1201 
       
  1202   debug_only(_java_call_counter = 0);
       
  1203 
       
  1204   // JVMTI PopFrame support
       
  1205   _popframe_condition = popframe_inactive;
       
  1206   _popframe_preserved_args = NULL;
       
  1207   _popframe_preserved_args_size = 0;
       
  1208 
       
  1209   pd_initialize();
       
  1210 }
       
  1211 
       
  1212 JavaThread::JavaThread(bool is_attaching) : Thread() {
       
  1213   initialize();
       
  1214   _is_attaching = is_attaching;
       
  1215 }
       
  1216 
       
  1217 bool JavaThread::reguard_stack(address cur_sp) {
       
  1218   if (_stack_guard_state != stack_guard_yellow_disabled) {
       
  1219     return true; // Stack already guarded or guard pages not needed.
       
  1220   }
       
  1221 
       
  1222   if (register_stack_overflow()) {
       
  1223     // For those architectures which have separate register and
       
  1224     // memory stacks, we must check the register stack to see if
       
  1225     // it has overflowed.
       
  1226     return false;
       
  1227   }
       
  1228 
       
  1229   // Java code never executes within the yellow zone: the latter is only
       
  1230   // there to provoke an exception during stack banging.  If java code
       
  1231   // is executing there, either StackShadowPages should be larger, or
       
  1232   // some exception code in c1, c2 or the interpreter isn't unwinding
       
  1233   // when it should.
       
  1234   guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
       
  1235 
       
  1236   enable_stack_yellow_zone();
       
  1237   return true;
       
  1238 }
       
  1239 
       
  1240 bool JavaThread::reguard_stack(void) {
       
  1241   return reguard_stack(os::current_stack_pointer());
       
  1242 }
       
  1243 
       
  1244 
       
  1245 void JavaThread::block_if_vm_exited() {
       
  1246   if (_terminated == _vm_exited) {
       
  1247     // _vm_exited is set at safepoint, and Threads_lock is never released
       
  1248     // we will block here forever
       
  1249     Threads_lock->lock_without_safepoint_check();
       
  1250     ShouldNotReachHere();
       
  1251   }
       
  1252 }
       
  1253 
       
  1254 
       
  1255 // Remove this ifdef when C1 is ported to the compiler interface.
       
  1256 static void compiler_thread_entry(JavaThread* thread, TRAPS);
       
  1257 
       
  1258 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : Thread() {
       
  1259   if (TraceThreadEvents) {
       
  1260     tty->print_cr("creating thread %p", this);
       
  1261   }
       
  1262   initialize();
       
  1263   _is_attaching = false;
       
  1264   set_entry_point(entry_point);
       
  1265   // Create the native thread itself.
       
  1266   // %note runtime_23
       
  1267   os::ThreadType thr_type = os::java_thread;
       
  1268   thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
       
  1269                                                      os::java_thread;
       
  1270   os::create_thread(this, thr_type, stack_sz);
       
  1271 
       
  1272   // The _osthread may be NULL here because we ran out of memory (too many threads active).
       
  1273   // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
       
  1274   // may hold a lock and all locks must be unlocked before throwing the exception (throwing
       
  1275   // the exception consists of creating the exception object & initializing it, initialization
       
  1276   // will leave the VM via a JavaCall and then all locks must be unlocked).
       
  1277   //
       
  1278   // The thread is still suspended when we reach here. Thread must be explicit started
       
  1279   // by creator! Furthermore, the thread must also explicitly be added to the Threads list
       
  1280   // by calling Threads:add. The reason why this is not done here, is because the thread
       
  1281   // object must be fully initialized (take a look at JVM_Start)
       
  1282 }
       
  1283 
       
  1284 JavaThread::~JavaThread() {
       
  1285   if (TraceThreadEvents) {
       
  1286       tty->print_cr("terminate thread %p", this);
       
  1287   }
       
  1288 
       
  1289   // JSR166 -- return the parker to the free list
       
  1290   Parker::Release(_parker);
       
  1291   _parker = NULL ;
       
  1292 
       
  1293   // Free any remaining  previous UnrollBlock
       
  1294   vframeArray* old_array = vframe_array_last();
       
  1295 
       
  1296   if (old_array != NULL) {
       
  1297     Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
       
  1298     old_array->set_unroll_block(NULL);
       
  1299     delete old_info;
       
  1300     delete old_array;
       
  1301   }
       
  1302 
       
  1303   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
       
  1304   if (deferred != NULL) {
       
  1305     // This can only happen if thread is destroyed before deoptimization occurs.
       
  1306     assert(deferred->length() != 0, "empty array!");
       
  1307     do {
       
  1308       jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
       
  1309       deferred->remove_at(0);
       
  1310       // individual jvmtiDeferredLocalVariableSet are CHeapObj's
       
  1311       delete dlv;
       
  1312     } while (deferred->length() != 0);
       
  1313     delete deferred;
       
  1314   }
       
  1315 
       
  1316   // All Java related clean up happens in exit
       
  1317   ThreadSafepointState::destroy(this);
       
  1318   if (_thread_profiler != NULL) delete _thread_profiler;
       
  1319   if (_thread_stat != NULL) delete _thread_stat;
       
  1320 
       
  1321   if (jvmti_thread_state() != NULL) {
       
  1322     JvmtiExport::cleanup_thread(this);
       
  1323   }
       
  1324 }
       
  1325 
       
  1326 
       
  1327 // The first routine called by a new Java thread
       
  1328 void JavaThread::run() {
       
  1329   // initialize thread-local alloc buffer related fields
       
  1330   this->initialize_tlab();
       
  1331 
       
  1332   // used to test validitity of stack trace backs
       
  1333   this->record_base_of_stack_pointer();
       
  1334 
       
  1335   // Record real stack base and size.
       
  1336   this->record_stack_base_and_size();
       
  1337 
       
  1338   // Initialize thread local storage; set before calling MutexLocker
       
  1339   this->initialize_thread_local_storage();
       
  1340 
       
  1341   this->create_stack_guard_pages();
       
  1342 
       
  1343   // Thread is now sufficient initialized to be handled by the safepoint code as being
       
  1344   // in the VM. Change thread state from _thread_new to _thread_in_vm
       
  1345   ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
       
  1346 
       
  1347   assert(JavaThread::current() == this, "sanity check");
       
  1348   assert(!Thread::current()->owns_locks(), "sanity check");
       
  1349 
       
  1350   DTRACE_THREAD_PROBE(start, this);
       
  1351 
       
  1352   // This operation might block. We call that after all safepoint checks for a new thread has
       
  1353   // been completed.
       
  1354   this->set_active_handles(JNIHandleBlock::allocate_block());
       
  1355 
       
  1356   if (JvmtiExport::should_post_thread_life()) {
       
  1357     JvmtiExport::post_thread_start(this);
       
  1358   }
       
  1359 
       
  1360   // We call another function to do the rest so we are sure that the stack addresses used
       
  1361   // from there will be lower than the stack base just computed
       
  1362   thread_main_inner();
       
  1363 
       
  1364   // Note, thread is no longer valid at this point!
       
  1365 }
       
  1366 
       
  1367 
       
  1368 void JavaThread::thread_main_inner() {
       
  1369   assert(JavaThread::current() == this, "sanity check");
       
  1370   assert(this->threadObj() != NULL, "just checking");
       
  1371 
       
  1372   // Execute thread entry point. If this thread is being asked to restart,
       
  1373   // or has been stopped before starting, do not reexecute entry point.
       
  1374   // Note: Due to JVM_StopThread we can have pending exceptions already!
       
  1375   if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
       
  1376     // enter the thread's entry point only if we have no pending exceptions
       
  1377     HandleMark hm(this);
       
  1378     this->entry_point()(this, this);
       
  1379   }
       
  1380 
       
  1381   DTRACE_THREAD_PROBE(stop, this);
       
  1382 
       
  1383   this->exit(false);
       
  1384   delete this;
       
  1385 }
       
  1386 
       
  1387 
       
  1388 static void ensure_join(JavaThread* thread) {
       
  1389   // We do not need to grap the Threads_lock, since we are operating on ourself.
       
  1390   Handle threadObj(thread, thread->threadObj());
       
  1391   assert(threadObj.not_null(), "java thread object must exist");
       
  1392   ObjectLocker lock(threadObj, thread);
       
  1393   // Ignore pending exception (ThreadDeath), since we are exiting anyway
       
  1394   thread->clear_pending_exception();
       
  1395   // It is of profound importance that we set the stillborn bit and reset the thread object,
       
  1396   // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
       
  1397   // false. So in case another thread is doing a join on this thread , it will detect that the thread
       
  1398   // is dead when it gets notified.
       
  1399   java_lang_Thread::set_stillborn(threadObj());
       
  1400   // Thread is exiting. So set thread_status field in  java.lang.Thread class to TERMINATED.
       
  1401   java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
       
  1402   java_lang_Thread::set_thread(threadObj(), NULL);
       
  1403   lock.notify_all(thread);
       
  1404   // Ignore pending exception (ThreadDeath), since we are exiting anyway
       
  1405   thread->clear_pending_exception();
       
  1406 }
       
  1407 
       
  1408 // For any new cleanup additions, please check to see if they need to be applied to
       
  1409 // cleanup_failed_attach_current_thread as well.
       
  1410 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
       
  1411   assert(this == JavaThread::current(),  "thread consistency check");
       
  1412   if (!InitializeJavaLangSystem) return;
       
  1413 
       
  1414   HandleMark hm(this);
       
  1415   Handle uncaught_exception(this, this->pending_exception());
       
  1416   this->clear_pending_exception();
       
  1417   Handle threadObj(this, this->threadObj());
       
  1418   assert(threadObj.not_null(), "Java thread object should be created");
       
  1419 
       
  1420   if (get_thread_profiler() != NULL) {
       
  1421     get_thread_profiler()->disengage();
       
  1422     ResourceMark rm;
       
  1423     get_thread_profiler()->print(get_thread_name());
       
  1424   }
       
  1425 
       
  1426 
       
  1427   // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
       
  1428   {
       
  1429     EXCEPTION_MARK;
       
  1430 
       
  1431     CLEAR_PENDING_EXCEPTION;
       
  1432   }
       
  1433   // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
       
  1434   // has to be fixed by a runtime query method
       
  1435   if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
       
  1436     // JSR-166: change call from from ThreadGroup.uncaughtException to
       
  1437     // java.lang.Thread.dispatchUncaughtException
       
  1438     if (uncaught_exception.not_null()) {
       
  1439       Handle group(this, java_lang_Thread::threadGroup(threadObj()));
       
  1440       Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
       
  1441         (address)uncaught_exception(), (address)threadObj(), (address)group());
       
  1442       {
       
  1443         EXCEPTION_MARK;
       
  1444         // Check if the method Thread.dispatchUncaughtException() exists. If so
       
  1445         // call it.  Otherwise we have an older library without the JSR-166 changes,
       
  1446         // so call ThreadGroup.uncaughtException()
       
  1447         KlassHandle recvrKlass(THREAD, threadObj->klass());
       
  1448         CallInfo callinfo;
       
  1449         KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass());
       
  1450         LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
       
  1451                                            vmSymbolHandles::dispatchUncaughtException_name(),
       
  1452                                            vmSymbolHandles::throwable_void_signature(),
       
  1453                                            KlassHandle(), false, false, THREAD);
       
  1454         CLEAR_PENDING_EXCEPTION;
       
  1455         methodHandle method = callinfo.selected_method();
       
  1456         if (method.not_null()) {
       
  1457           JavaValue result(T_VOID);
       
  1458           JavaCalls::call_virtual(&result,
       
  1459                                   threadObj, thread_klass,
       
  1460                                   vmSymbolHandles::dispatchUncaughtException_name(),
       
  1461                                   vmSymbolHandles::throwable_void_signature(),
       
  1462                                   uncaught_exception,
       
  1463                                   THREAD);
       
  1464         } else {
       
  1465           KlassHandle thread_group(THREAD, SystemDictionary::threadGroup_klass());
       
  1466           JavaValue result(T_VOID);
       
  1467           JavaCalls::call_virtual(&result,
       
  1468                                   group, thread_group,
       
  1469                                   vmSymbolHandles::uncaughtException_name(),
       
  1470                                   vmSymbolHandles::thread_throwable_void_signature(),
       
  1471                                   threadObj,           // Arg 1
       
  1472                                   uncaught_exception,  // Arg 2
       
  1473                                   THREAD);
       
  1474         }
       
  1475         CLEAR_PENDING_EXCEPTION;
       
  1476       }
       
  1477     }
       
  1478 
       
  1479     // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
       
  1480     // the execution of the method. If that is not enough, then we don't really care. Thread.stop
       
  1481     // is deprecated anyhow.
       
  1482     { int count = 3;
       
  1483       while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
       
  1484         EXCEPTION_MARK;
       
  1485         JavaValue result(T_VOID);
       
  1486         KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass());
       
  1487         JavaCalls::call_virtual(&result,
       
  1488                               threadObj, thread_klass,
       
  1489                               vmSymbolHandles::exit_method_name(),
       
  1490                               vmSymbolHandles::void_method_signature(),
       
  1491                               THREAD);
       
  1492         CLEAR_PENDING_EXCEPTION;
       
  1493       }
       
  1494     }
       
  1495 
       
  1496     // notify JVMTI
       
  1497     if (JvmtiExport::should_post_thread_life()) {
       
  1498       JvmtiExport::post_thread_end(this);
       
  1499     }
       
  1500 
       
  1501     // We have notified the agents that we are exiting, before we go on,
       
  1502     // we must check for a pending external suspend request and honor it
       
  1503     // in order to not surprise the thread that made the suspend request.
       
  1504     while (true) {
       
  1505       {
       
  1506         MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
       
  1507         if (!is_external_suspend()) {
       
  1508           set_terminated(_thread_exiting);
       
  1509           ThreadService::current_thread_exiting(this);
       
  1510           break;
       
  1511         }
       
  1512         // Implied else:
       
  1513         // Things get a little tricky here. We have a pending external
       
  1514         // suspend request, but we are holding the SR_lock so we
       
  1515         // can't just self-suspend. So we temporarily drop the lock
       
  1516         // and then self-suspend.
       
  1517       }
       
  1518 
       
  1519       ThreadBlockInVM tbivm(this);
       
  1520       java_suspend_self();
       
  1521 
       
  1522       // We're done with this suspend request, but we have to loop around
       
  1523       // and check again. Eventually we will get SR_lock without a pending
       
  1524       // external suspend request and will be able to mark ourselves as
       
  1525       // exiting.
       
  1526     }
       
  1527     // no more external suspends are allowed at this point
       
  1528   } else {
       
  1529     // before_exit() has already posted JVMTI THREAD_END events
       
  1530   }
       
  1531 
       
  1532   // Notify waiters on thread object. This has to be done after exit() is called
       
  1533   // on the thread (if the thread is the last thread in a daemon ThreadGroup the
       
  1534   // group should have the destroyed bit set before waiters are notified).
       
  1535   ensure_join(this);
       
  1536   assert(!this->has_pending_exception(), "ensure_join should have cleared");
       
  1537 
       
  1538   // 6282335 JNI DetachCurrentThread spec states that all Java monitors
       
  1539   // held by this thread must be released.  A detach operation must only
       
  1540   // get here if there are no Java frames on the stack.  Therefore, any
       
  1541   // owned monitors at this point MUST be JNI-acquired monitors which are
       
  1542   // pre-inflated and in the monitor cache.
       
  1543   //
       
  1544   // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
       
  1545   if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
       
  1546     assert(!this->has_last_Java_frame(), "detaching with Java frames?");
       
  1547     ObjectSynchronizer::release_monitors_owned_by_thread(this);
       
  1548     assert(!this->has_pending_exception(), "release_monitors should have cleared");
       
  1549   }
       
  1550 
       
  1551   // These things needs to be done while we are still a Java Thread. Make sure that thread
       
  1552   // is in a consistent state, in case GC happens
       
  1553   assert(_privileged_stack_top == NULL, "must be NULL when we get here");
       
  1554 
       
  1555   if (active_handles() != NULL) {
       
  1556     JNIHandleBlock* block = active_handles();
       
  1557     set_active_handles(NULL);
       
  1558     JNIHandleBlock::release_block(block);
       
  1559   }
       
  1560 
       
  1561   if (free_handle_block() != NULL) {
       
  1562     JNIHandleBlock* block = free_handle_block();
       
  1563     set_free_handle_block(NULL);
       
  1564     JNIHandleBlock::release_block(block);
       
  1565   }
       
  1566 
       
  1567   // These have to be removed while this is still a valid thread.
       
  1568   remove_stack_guard_pages();
       
  1569 
       
  1570   if (UseTLAB) {
       
  1571     tlab().make_parsable(true);  // retire TLAB
       
  1572   }
       
  1573 
       
  1574   // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
       
  1575   Threads::remove(this);
       
  1576 }
       
  1577 
       
  1578 void JavaThread::cleanup_failed_attach_current_thread() {
       
  1579 
       
  1580      if (get_thread_profiler() != NULL) {
       
  1581        get_thread_profiler()->disengage();
       
  1582        ResourceMark rm;
       
  1583        get_thread_profiler()->print(get_thread_name());
       
  1584      }
       
  1585 
       
  1586      if (active_handles() != NULL) {
       
  1587       JNIHandleBlock* block = active_handles();
       
  1588       set_active_handles(NULL);
       
  1589       JNIHandleBlock::release_block(block);
       
  1590      }
       
  1591 
       
  1592      if (free_handle_block() != NULL) {
       
  1593        JNIHandleBlock* block = free_handle_block();
       
  1594        set_free_handle_block(NULL);
       
  1595        JNIHandleBlock::release_block(block);
       
  1596      }
       
  1597 
       
  1598      if (UseTLAB) {
       
  1599        tlab().make_parsable(true);  // retire TLAB, if any
       
  1600      }
       
  1601 
       
  1602      Threads::remove(this);
       
  1603      delete this;
       
  1604 }
       
  1605 
       
  1606 
       
  1607 JavaThread* JavaThread::active() {
       
  1608   Thread* thread = ThreadLocalStorage::thread();
       
  1609   assert(thread != NULL, "just checking");
       
  1610   if (thread->is_Java_thread()) {
       
  1611     return (JavaThread*) thread;
       
  1612   } else {
       
  1613     assert(thread->is_VM_thread(), "this must be a vm thread");
       
  1614     VM_Operation* op = ((VMThread*) thread)->vm_operation();
       
  1615     JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
       
  1616     assert(ret->is_Java_thread(), "must be a Java thread");
       
  1617     return ret;
       
  1618   }
       
  1619 }
       
  1620 
       
  1621 bool JavaThread::is_lock_owned(address adr) const {
       
  1622   if (lock_is_in_stack(adr)) return true;
       
  1623 
       
  1624   for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
       
  1625     if (chunk->contains(adr)) return true;
       
  1626   }
       
  1627 
       
  1628   return false;
       
  1629 }
       
  1630 
       
  1631 
       
  1632 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
       
  1633   chunk->set_next(monitor_chunks());
       
  1634   set_monitor_chunks(chunk);
       
  1635 }
       
  1636 
       
  1637 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
       
  1638   guarantee(monitor_chunks() != NULL, "must be non empty");
       
  1639   if (monitor_chunks() == chunk) {
       
  1640     set_monitor_chunks(chunk->next());
       
  1641   } else {
       
  1642     MonitorChunk* prev = monitor_chunks();
       
  1643     while (prev->next() != chunk) prev = prev->next();
       
  1644     prev->set_next(chunk->next());
       
  1645   }
       
  1646 }
       
  1647 
       
  1648 // JVM support.
       
  1649 
       
  1650 // Note: this function shouldn't block if it's called in
       
  1651 // _thread_in_native_trans state (such as from
       
  1652 // check_special_condition_for_native_trans()).
       
  1653 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
       
  1654 
       
  1655   if (has_last_Java_frame() && has_async_condition()) {
       
  1656     // If we are at a polling page safepoint (not a poll return)
       
  1657     // then we must defer async exception because live registers
       
  1658     // will be clobbered by the exception path. Poll return is
       
  1659     // ok because the call we a returning from already collides
       
  1660     // with exception handling registers and so there is no issue.
       
  1661     // (The exception handling path kills call result registers but
       
  1662     //  this is ok since the exception kills the result anyway).
       
  1663 
       
  1664     if (is_at_poll_safepoint()) {
       
  1665       // if the code we are returning to has deoptimized we must defer
       
  1666       // the exception otherwise live registers get clobbered on the
       
  1667       // exception path before deoptimization is able to retrieve them.
       
  1668       //
       
  1669       RegisterMap map(this, false);
       
  1670       frame caller_fr = last_frame().sender(&map);
       
  1671       assert(caller_fr.is_compiled_frame(), "what?");
       
  1672       if (caller_fr.is_deoptimized_frame()) {
       
  1673         if (TraceExceptions) {
       
  1674           ResourceMark rm;
       
  1675           tty->print_cr("deferred async exception at compiled safepoint");
       
  1676         }
       
  1677         return;
       
  1678       }
       
  1679     }
       
  1680   }
       
  1681 
       
  1682   JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
       
  1683   if (condition == _no_async_condition) {
       
  1684     // Conditions have changed since has_special_runtime_exit_condition()
       
  1685     // was called:
       
  1686     // - if we were here only because of an external suspend request,
       
  1687     //   then that was taken care of above (or cancelled) so we are done
       
  1688     // - if we were here because of another async request, then it has
       
  1689     //   been cleared between the has_special_runtime_exit_condition()
       
  1690     //   and now so again we are done
       
  1691     return;
       
  1692   }
       
  1693 
       
  1694   // Check for pending async. exception
       
  1695   if (_pending_async_exception != NULL) {
       
  1696     // Only overwrite an already pending exception, if it is not a threadDeath.
       
  1697     if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::threaddeath_klass())) {
       
  1698 
       
  1699       // We cannot call Exceptions::_throw(...) here because we cannot block
       
  1700       set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
       
  1701 
       
  1702       if (TraceExceptions) {
       
  1703         ResourceMark rm;
       
  1704         tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
       
  1705         if (has_last_Java_frame() ) {
       
  1706           frame f = last_frame();
       
  1707           tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
       
  1708         }
       
  1709         tty->print_cr(" of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
       
  1710       }
       
  1711       _pending_async_exception = NULL;
       
  1712       clear_has_async_exception();
       
  1713     }
       
  1714   }
       
  1715 
       
  1716   if (check_unsafe_error &&
       
  1717       condition == _async_unsafe_access_error && !has_pending_exception()) {
       
  1718     condition = _no_async_condition;  // done
       
  1719     switch (thread_state()) {
       
  1720     case _thread_in_vm:
       
  1721       {
       
  1722         JavaThread* THREAD = this;
       
  1723         THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
       
  1724       }
       
  1725     case _thread_in_native:
       
  1726       {
       
  1727         ThreadInVMfromNative tiv(this);
       
  1728         JavaThread* THREAD = this;
       
  1729         THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
       
  1730       }
       
  1731     case _thread_in_Java:
       
  1732       {
       
  1733         ThreadInVMfromJava tiv(this);
       
  1734         JavaThread* THREAD = this;
       
  1735         THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
       
  1736       }
       
  1737     default:
       
  1738       ShouldNotReachHere();
       
  1739     }
       
  1740   }
       
  1741 
       
  1742   assert(condition == _no_async_condition || has_pending_exception() ||
       
  1743          (!check_unsafe_error && condition == _async_unsafe_access_error),
       
  1744          "must have handled the async condition, if no exception");
       
  1745 }
       
  1746 
       
  1747 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
       
  1748   //
       
  1749   // Check for pending external suspend. Internal suspend requests do
       
  1750   // not use handle_special_runtime_exit_condition().
       
  1751   // If JNIEnv proxies are allowed, don't self-suspend if the target
       
  1752   // thread is not the current thread. In older versions of jdbx, jdbx
       
  1753   // threads could call into the VM with another thread's JNIEnv so we
       
  1754   // can be here operating on behalf of a suspended thread (4432884).
       
  1755   bool do_self_suspend = is_external_suspend_with_lock();
       
  1756   if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
       
  1757     //
       
  1758     // Because thread is external suspended the safepoint code will count
       
  1759     // thread as at a safepoint. This can be odd because we can be here
       
  1760     // as _thread_in_Java which would normally transition to _thread_blocked
       
  1761     // at a safepoint. We would like to mark the thread as _thread_blocked
       
  1762     // before calling java_suspend_self like all other callers of it but
       
  1763     // we must then observe proper safepoint protocol. (We can't leave
       
  1764     // _thread_blocked with a safepoint in progress). However we can be
       
  1765     // here as _thread_in_native_trans so we can't use a normal transition
       
  1766     // constructor/destructor pair because they assert on that type of
       
  1767     // transition. We could do something like:
       
  1768     //
       
  1769     // JavaThreadState state = thread_state();
       
  1770     // set_thread_state(_thread_in_vm);
       
  1771     // {
       
  1772     //   ThreadBlockInVM tbivm(this);
       
  1773     //   java_suspend_self()
       
  1774     // }
       
  1775     // set_thread_state(_thread_in_vm_trans);
       
  1776     // if (safepoint) block;
       
  1777     // set_thread_state(state);
       
  1778     //
       
  1779     // but that is pretty messy. Instead we just go with the way the
       
  1780     // code has worked before and note that this is the only path to
       
  1781     // java_suspend_self that doesn't put the thread in _thread_blocked
       
  1782     // mode.
       
  1783 
       
  1784     frame_anchor()->make_walkable(this);
       
  1785     java_suspend_self();
       
  1786 
       
  1787     // We might be here for reasons in addition to the self-suspend request
       
  1788     // so check for other async requests.
       
  1789   }
       
  1790 
       
  1791   if (check_asyncs) {
       
  1792     check_and_handle_async_exceptions();
       
  1793   }
       
  1794 }
       
  1795 
       
  1796 void JavaThread::send_thread_stop(oop java_throwable)  {
       
  1797   assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
       
  1798   assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
       
  1799   assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
       
  1800 
       
  1801   // Do not throw asynchronous exceptions against the compiler thread
       
  1802   // (the compiler thread should not be a Java thread -- fix in 1.4.2)
       
  1803   if (is_Compiler_thread()) return;
       
  1804 
       
  1805   // This is a change from JDK 1.1, but JDK 1.2 will also do it:
       
  1806   if (java_throwable->is_a(SystemDictionary::threaddeath_klass())) {
       
  1807     java_lang_Thread::set_stillborn(threadObj());
       
  1808   }
       
  1809 
       
  1810   {
       
  1811     // Actually throw the Throwable against the target Thread - however
       
  1812     // only if there is no thread death exception installed already.
       
  1813     if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::threaddeath_klass())) {
       
  1814       // If the topmost frame is a runtime stub, then we are calling into
       
  1815       // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
       
  1816       // must deoptimize the caller before continuing, as the compiled  exception handler table
       
  1817       // may not be valid
       
  1818       if (has_last_Java_frame()) {
       
  1819         frame f = last_frame();
       
  1820         if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
       
  1821           // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
       
  1822           RegisterMap reg_map(this, UseBiasedLocking);
       
  1823           frame compiled_frame = f.sender(&reg_map);
       
  1824           if (compiled_frame.can_be_deoptimized()) {
       
  1825             Deoptimization::deoptimize(this, compiled_frame, &reg_map);
       
  1826           }
       
  1827         }
       
  1828       }
       
  1829 
       
  1830       // Set async. pending exception in thread.
       
  1831       set_pending_async_exception(java_throwable);
       
  1832 
       
  1833       if (TraceExceptions) {
       
  1834        ResourceMark rm;
       
  1835        tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
       
  1836       }
       
  1837       // for AbortVMOnException flag
       
  1838       NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_pending_async_exception->klass())->external_name()));
       
  1839     }
       
  1840   }
       
  1841 
       
  1842 
       
  1843   // Interrupt thread so it will wake up from a potential wait()
       
  1844   Thread::interrupt(this);
       
  1845 }
       
  1846 
       
  1847 // External suspension mechanism.
       
  1848 //
       
  1849 // Tell the VM to suspend a thread when ever it knows that it does not hold on
       
  1850 // to any VM_locks and it is at a transition
       
  1851 // Self-suspension will happen on the transition out of the vm.
       
  1852 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
       
  1853 //
       
  1854 // Guarantees on return:
       
  1855 //   + Target thread will not execute any new bytecode (that's why we need to
       
  1856 //     force a safepoint)
       
  1857 //   + Target thread will not enter any new monitors
       
  1858 //
       
  1859 void JavaThread::java_suspend() {
       
  1860   { MutexLocker mu(Threads_lock);
       
  1861     if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
       
  1862        return;
       
  1863     }
       
  1864   }
       
  1865 
       
  1866   { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
       
  1867     if (!is_external_suspend()) {
       
  1868       // a racing resume has cancelled us; bail out now
       
  1869       return;
       
  1870     }
       
  1871 
       
  1872     // suspend is done
       
  1873     uint32_t debug_bits = 0;
       
  1874     // Warning: is_ext_suspend_completed() may temporarily drop the
       
  1875     // SR_lock to allow the thread to reach a stable thread state if
       
  1876     // it is currently in a transient thread state.
       
  1877     if (is_ext_suspend_completed(false /* !called_by_wait */,
       
  1878                                  SuspendRetryDelay, &debug_bits) ) {
       
  1879       return;
       
  1880     }
       
  1881   }
       
  1882 
       
  1883   VM_ForceSafepoint vm_suspend;
       
  1884   VMThread::execute(&vm_suspend);
       
  1885 }
       
  1886 
       
  1887 // Part II of external suspension.
       
  1888 // A JavaThread self suspends when it detects a pending external suspend
       
  1889 // request. This is usually on transitions. It is also done in places
       
  1890 // where continuing to the next transition would surprise the caller,
       
  1891 // e.g., monitor entry.
       
  1892 //
       
  1893 // Returns the number of times that the thread self-suspended.
       
  1894 //
       
  1895 // Note: DO NOT call java_suspend_self() when you just want to block current
       
  1896 //       thread. java_suspend_self() is the second stage of cooperative
       
  1897 //       suspension for external suspend requests and should only be used
       
  1898 //       to complete an external suspend request.
       
  1899 //
       
  1900 int JavaThread::java_suspend_self() {
       
  1901   int ret = 0;
       
  1902 
       
  1903   // we are in the process of exiting so don't suspend
       
  1904   if (is_exiting()) {
       
  1905      clear_external_suspend();
       
  1906      return ret;
       
  1907   }
       
  1908 
       
  1909   assert(_anchor.walkable() ||
       
  1910     (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
       
  1911     "must have walkable stack");
       
  1912 
       
  1913   MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
       
  1914 
       
  1915   assert(!this->is_any_suspended(),
       
  1916     "a thread trying to self-suspend should not already be suspended");
       
  1917 
       
  1918   if (this->is_suspend_equivalent()) {
       
  1919     // If we are self-suspending as a result of the lifting of a
       
  1920     // suspend equivalent condition, then the suspend_equivalent
       
  1921     // flag is not cleared until we set the ext_suspended flag so
       
  1922     // that wait_for_ext_suspend_completion() returns consistent
       
  1923     // results.
       
  1924     this->clear_suspend_equivalent();
       
  1925   }
       
  1926 
       
  1927   // A racing resume may have cancelled us before we grabbed SR_lock
       
  1928   // above. Or another external suspend request could be waiting for us
       
  1929   // by the time we return from SR_lock()->wait(). The thread
       
  1930   // that requested the suspension may already be trying to walk our
       
  1931   // stack and if we return now, we can change the stack out from under
       
  1932   // it. This would be a "bad thing (TM)" and cause the stack walker
       
  1933   // to crash. We stay self-suspended until there are no more pending
       
  1934   // external suspend requests.
       
  1935   while (is_external_suspend()) {
       
  1936     ret++;
       
  1937     this->set_ext_suspended();
       
  1938 
       
  1939     // _ext_suspended flag is cleared by java_resume()
       
  1940     while (is_ext_suspended()) {
       
  1941       this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
       
  1942     }
       
  1943   }
       
  1944 
       
  1945   return ret;
       
  1946 }
       
  1947 
       
  1948 #ifdef ASSERT
       
  1949 // verify the JavaThread has not yet been published in the Threads::list, and
       
  1950 // hence doesn't need protection from concurrent access at this stage
       
  1951 void JavaThread::verify_not_published() {
       
  1952   if (!Threads_lock->owned_by_self()) {
       
  1953    MutexLockerEx ml(Threads_lock,  Mutex::_no_safepoint_check_flag);
       
  1954    assert( !Threads::includes(this),
       
  1955            "java thread shouldn't have been published yet!");
       
  1956   }
       
  1957   else {
       
  1958    assert( !Threads::includes(this),
       
  1959            "java thread shouldn't have been published yet!");
       
  1960   }
       
  1961 }
       
  1962 #endif
       
  1963 
       
  1964 // Slow path when the native==>VM/Java barriers detect a safepoint is in
       
  1965 // progress or when _suspend_flags is non-zero.
       
  1966 // Current thread needs to self-suspend if there is a suspend request and/or
       
  1967 // block if a safepoint is in progress.
       
  1968 // Async exception ISN'T checked.
       
  1969 // Note only the ThreadInVMfromNative transition can call this function
       
  1970 // directly and when thread state is _thread_in_native_trans
       
  1971 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
       
  1972   assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
       
  1973 
       
  1974   JavaThread *curJT = JavaThread::current();
       
  1975   bool do_self_suspend = thread->is_external_suspend();
       
  1976 
       
  1977   assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
       
  1978 
       
  1979   // If JNIEnv proxies are allowed, don't self-suspend if the target
       
  1980   // thread is not the current thread. In older versions of jdbx, jdbx
       
  1981   // threads could call into the VM with another thread's JNIEnv so we
       
  1982   // can be here operating on behalf of a suspended thread (4432884).
       
  1983   if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
       
  1984     JavaThreadState state = thread->thread_state();
       
  1985 
       
  1986     // We mark this thread_blocked state as a suspend-equivalent so
       
  1987     // that a caller to is_ext_suspend_completed() won't be confused.
       
  1988     // The suspend-equivalent state is cleared by java_suspend_self().
       
  1989     thread->set_suspend_equivalent();
       
  1990 
       
  1991     // If the safepoint code sees the _thread_in_native_trans state, it will
       
  1992     // wait until the thread changes to other thread state. There is no
       
  1993     // guarantee on how soon we can obtain the SR_lock and complete the
       
  1994     // self-suspend request. It would be a bad idea to let safepoint wait for
       
  1995     // too long. Temporarily change the state to _thread_blocked to
       
  1996     // let the VM thread know that this thread is ready for GC. The problem
       
  1997     // of changing thread state is that safepoint could happen just after
       
  1998     // java_suspend_self() returns after being resumed, and VM thread will
       
  1999     // see the _thread_blocked state. We must check for safepoint
       
  2000     // after restoring the state and make sure we won't leave while a safepoint
       
  2001     // is in progress.
       
  2002     thread->set_thread_state(_thread_blocked);
       
  2003     thread->java_suspend_self();
       
  2004     thread->set_thread_state(state);
       
  2005     // Make sure new state is seen by VM thread
       
  2006     if (os::is_MP()) {
       
  2007       if (UseMembar) {
       
  2008         // Force a fence between the write above and read below
       
  2009         OrderAccess::fence();
       
  2010       } else {
       
  2011         // Must use this rather than serialization page in particular on Windows
       
  2012         InterfaceSupport::serialize_memory(thread);
       
  2013       }
       
  2014     }
       
  2015   }
       
  2016 
       
  2017   if (SafepointSynchronize::do_call_back()) {
       
  2018     // If we are safepointing, then block the caller which may not be
       
  2019     // the same as the target thread (see above).
       
  2020     SafepointSynchronize::block(curJT);
       
  2021   }
       
  2022 
       
  2023   if (thread->is_deopt_suspend()) {
       
  2024     thread->clear_deopt_suspend();
       
  2025     RegisterMap map(thread, false);
       
  2026     frame f = thread->last_frame();
       
  2027     while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
       
  2028       f = f.sender(&map);
       
  2029     }
       
  2030     if (f.id() == thread->must_deopt_id()) {
       
  2031       thread->clear_must_deopt_id();
       
  2032       // Since we know we're safe to deopt the current state is a safe state
       
  2033       f.deoptimize(thread, true);
       
  2034     } else {
       
  2035       fatal("missed deoptimization!");
       
  2036     }
       
  2037   }
       
  2038 }
       
  2039 
       
  2040 // Slow path when the native==>VM/Java barriers detect a safepoint is in
       
  2041 // progress or when _suspend_flags is non-zero.
       
  2042 // Current thread needs to self-suspend if there is a suspend request and/or
       
  2043 // block if a safepoint is in progress.
       
  2044 // Also check for pending async exception (not including unsafe access error).
       
  2045 // Note only the native==>VM/Java barriers can call this function and when
       
  2046 // thread state is _thread_in_native_trans.
       
  2047 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
       
  2048   check_safepoint_and_suspend_for_native_trans(thread);
       
  2049 
       
  2050   if (thread->has_async_exception()) {
       
  2051     // We are in _thread_in_native_trans state, don't handle unsafe
       
  2052     // access error since that may block.
       
  2053     thread->check_and_handle_async_exceptions(false);
       
  2054   }
       
  2055 }
       
  2056 
       
  2057 // We need to guarantee the Threads_lock here, since resumes are not
       
  2058 // allowed during safepoint synchronization
       
  2059 // Can only resume from an external suspension
       
  2060 void JavaThread::java_resume() {
       
  2061   assert_locked_or_safepoint(Threads_lock);
       
  2062 
       
  2063   // Sanity check: thread is gone, has started exiting or the thread
       
  2064   // was not externally suspended.
       
  2065   if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
       
  2066     return;
       
  2067   }
       
  2068 
       
  2069   MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
       
  2070 
       
  2071   clear_external_suspend();
       
  2072 
       
  2073   if (is_ext_suspended()) {
       
  2074     clear_ext_suspended();
       
  2075     SR_lock()->notify_all();
       
  2076   }
       
  2077 }
       
  2078 
       
  2079 void JavaThread::create_stack_guard_pages() {
       
  2080   if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
       
  2081   address low_addr = stack_base() - stack_size();
       
  2082   size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
       
  2083 
       
  2084   int allocate = os::allocate_stack_guard_pages();
       
  2085   // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
       
  2086 
       
  2087   if (allocate && !os::commit_memory((char *) low_addr, len)) {
       
  2088     warning("Attempt to allocate stack guard pages failed.");
       
  2089     return;
       
  2090   }
       
  2091 
       
  2092   if (os::guard_memory((char *) low_addr, len)) {
       
  2093     _stack_guard_state = stack_guard_enabled;
       
  2094   } else {
       
  2095     warning("Attempt to protect stack guard pages failed.");
       
  2096     if (os::uncommit_memory((char *) low_addr, len)) {
       
  2097       warning("Attempt to deallocate stack guard pages failed.");
       
  2098     }
       
  2099   }
       
  2100 }
       
  2101 
       
  2102 void JavaThread::remove_stack_guard_pages() {
       
  2103   if (_stack_guard_state == stack_guard_unused) return;
       
  2104   address low_addr = stack_base() - stack_size();
       
  2105   size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
       
  2106 
       
  2107   if (os::allocate_stack_guard_pages()) {
       
  2108     if (os::uncommit_memory((char *) low_addr, len)) {
       
  2109       _stack_guard_state = stack_guard_unused;
       
  2110     } else {
       
  2111       warning("Attempt to deallocate stack guard pages failed.");
       
  2112     }
       
  2113   } else {
       
  2114     if (_stack_guard_state == stack_guard_unused) return;
       
  2115     if (os::unguard_memory((char *) low_addr, len)) {
       
  2116       _stack_guard_state = stack_guard_unused;
       
  2117     } else {
       
  2118         warning("Attempt to unprotect stack guard pages failed.");
       
  2119     }
       
  2120   }
       
  2121 }
       
  2122 
       
  2123 void JavaThread::enable_stack_yellow_zone() {
       
  2124   assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
       
  2125   assert(_stack_guard_state != stack_guard_enabled, "already enabled");
       
  2126 
       
  2127   // The base notation is from the stacks point of view, growing downward.
       
  2128   // We need to adjust it to work correctly with guard_memory()
       
  2129   address base = stack_yellow_zone_base() - stack_yellow_zone_size();
       
  2130 
       
  2131   guarantee(base < stack_base(),"Error calculating stack yellow zone");
       
  2132   guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
       
  2133 
       
  2134   if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
       
  2135     _stack_guard_state = stack_guard_enabled;
       
  2136   } else {
       
  2137     warning("Attempt to guard stack yellow zone failed.");
       
  2138   }
       
  2139   enable_register_stack_guard();
       
  2140 }
       
  2141 
       
  2142 void JavaThread::disable_stack_yellow_zone() {
       
  2143   assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
       
  2144   assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
       
  2145 
       
  2146   // Simply return if called for a thread that does not use guard pages.
       
  2147   if (_stack_guard_state == stack_guard_unused) return;
       
  2148 
       
  2149   // The base notation is from the stacks point of view, growing downward.
       
  2150   // We need to adjust it to work correctly with guard_memory()
       
  2151   address base = stack_yellow_zone_base() - stack_yellow_zone_size();
       
  2152 
       
  2153   if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
       
  2154     _stack_guard_state = stack_guard_yellow_disabled;
       
  2155   } else {
       
  2156     warning("Attempt to unguard stack yellow zone failed.");
       
  2157   }
       
  2158   disable_register_stack_guard();
       
  2159 }
       
  2160 
       
  2161 void JavaThread::enable_stack_red_zone() {
       
  2162   // The base notation is from the stacks point of view, growing downward.
       
  2163   // We need to adjust it to work correctly with guard_memory()
       
  2164   assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
       
  2165   address base = stack_red_zone_base() - stack_red_zone_size();
       
  2166 
       
  2167   guarantee(base < stack_base(),"Error calculating stack red zone");
       
  2168   guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
       
  2169 
       
  2170   if(!os::guard_memory((char *) base, stack_red_zone_size())) {
       
  2171     warning("Attempt to guard stack red zone failed.");
       
  2172   }
       
  2173 }
       
  2174 
       
  2175 void JavaThread::disable_stack_red_zone() {
       
  2176   // The base notation is from the stacks point of view, growing downward.
       
  2177   // We need to adjust it to work correctly with guard_memory()
       
  2178   assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
       
  2179   address base = stack_red_zone_base() - stack_red_zone_size();
       
  2180   if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
       
  2181     warning("Attempt to unguard stack red zone failed.");
       
  2182   }
       
  2183 }
       
  2184 
       
  2185 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
       
  2186   // ignore is there is no stack
       
  2187   if (!has_last_Java_frame()) return;
       
  2188   // traverse the stack frames. Starts from top frame.
       
  2189   for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
       
  2190     frame* fr = fst.current();
       
  2191     f(fr, fst.register_map());
       
  2192   }
       
  2193 }
       
  2194 
       
  2195 
       
  2196 #ifndef PRODUCT
       
  2197 // Deoptimization
       
  2198 // Function for testing deoptimization
       
  2199 void JavaThread::deoptimize() {
       
  2200   // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
       
  2201   StackFrameStream fst(this, UseBiasedLocking);
       
  2202   bool deopt = false;           // Dump stack only if a deopt actually happens.
       
  2203   bool only_at = strlen(DeoptimizeOnlyAt) > 0;
       
  2204   // Iterate over all frames in the thread and deoptimize
       
  2205   for(; !fst.is_done(); fst.next()) {
       
  2206     if(fst.current()->can_be_deoptimized()) {
       
  2207 
       
  2208       if (only_at) {
       
  2209         // Deoptimize only at particular bcis.  DeoptimizeOnlyAt
       
  2210         // consists of comma or carriage return separated numbers so
       
  2211         // search for the current bci in that string.
       
  2212         address pc = fst.current()->pc();
       
  2213         nmethod* nm =  (nmethod*) fst.current()->cb();
       
  2214         ScopeDesc* sd = nm->scope_desc_at( pc);
       
  2215         char buffer[8];
       
  2216         jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
       
  2217         size_t len = strlen(buffer);
       
  2218         const char * found = strstr(DeoptimizeOnlyAt, buffer);
       
  2219         while (found != NULL) {
       
  2220           if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
       
  2221               (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
       
  2222             // Check that the bci found is bracketed by terminators.
       
  2223             break;
       
  2224           }
       
  2225           found = strstr(found + 1, buffer);
       
  2226         }
       
  2227         if (!found) {
       
  2228           continue;
       
  2229         }
       
  2230       }
       
  2231 
       
  2232       if (DebugDeoptimization && !deopt) {
       
  2233         deopt = true; // One-time only print before deopt
       
  2234         tty->print_cr("[BEFORE Deoptimization]");
       
  2235         trace_frames();
       
  2236         trace_stack();
       
  2237       }
       
  2238       Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
       
  2239     }
       
  2240   }
       
  2241 
       
  2242   if (DebugDeoptimization && deopt) {
       
  2243     tty->print_cr("[AFTER Deoptimization]");
       
  2244     trace_frames();
       
  2245   }
       
  2246 }
       
  2247 
       
  2248 
       
  2249 // Make zombies
       
  2250 void JavaThread::make_zombies() {
       
  2251   for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
       
  2252     if (fst.current()->can_be_deoptimized()) {
       
  2253       // it is a Java nmethod
       
  2254       nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
       
  2255       nm->make_not_entrant();
       
  2256     }
       
  2257   }
       
  2258 }
       
  2259 #endif // PRODUCT
       
  2260 
       
  2261 
       
  2262 void JavaThread::deoptimized_wrt_marked_nmethods() {
       
  2263   if (!has_last_Java_frame()) return;
       
  2264   // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
       
  2265   StackFrameStream fst(this, UseBiasedLocking);
       
  2266   for(; !fst.is_done(); fst.next()) {
       
  2267     if (fst.current()->should_be_deoptimized()) {
       
  2268       Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
       
  2269     }
       
  2270   }
       
  2271 }
       
  2272 
       
  2273 
       
  2274 // GC support
       
  2275 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
       
  2276 
       
  2277 void JavaThread::gc_epilogue() {
       
  2278   frames_do(frame_gc_epilogue);
       
  2279 }
       
  2280 
       
  2281 
       
  2282 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
       
  2283 
       
  2284 void JavaThread::gc_prologue() {
       
  2285   frames_do(frame_gc_prologue);
       
  2286 }
       
  2287 
       
  2288 
       
  2289 void JavaThread::oops_do(OopClosure* f) {
       
  2290   // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
       
  2291   // since there may be more than one thread using each ThreadProfiler.
       
  2292 
       
  2293   // Traverse the GCHandles
       
  2294   Thread::oops_do(f);
       
  2295 
       
  2296   assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
       
  2297           (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
       
  2298 
       
  2299   if (has_last_Java_frame()) {
       
  2300 
       
  2301     // Traverse the privileged stack
       
  2302     if (_privileged_stack_top != NULL) {
       
  2303       _privileged_stack_top->oops_do(f);
       
  2304     }
       
  2305 
       
  2306     // traverse the registered growable array
       
  2307     if (_array_for_gc != NULL) {
       
  2308       for (int index = 0; index < _array_for_gc->length(); index++) {
       
  2309         f->do_oop(_array_for_gc->adr_at(index));
       
  2310       }
       
  2311     }
       
  2312 
       
  2313     // Traverse the monitor chunks
       
  2314     for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
       
  2315       chunk->oops_do(f);
       
  2316     }
       
  2317 
       
  2318     // Traverse the execution stack
       
  2319     for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
       
  2320       fst.current()->oops_do(f, fst.register_map());
       
  2321     }
       
  2322   }
       
  2323 
       
  2324   // callee_target is never live across a gc point so NULL it here should
       
  2325   // it still contain a methdOop.
       
  2326 
       
  2327   set_callee_target(NULL);
       
  2328 
       
  2329   assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
       
  2330   // If we have deferred set_locals there might be oops waiting to be
       
  2331   // written
       
  2332   GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
       
  2333   if (list != NULL) {
       
  2334     for (int i = 0; i < list->length(); i++) {
       
  2335       list->at(i)->oops_do(f);
       
  2336     }
       
  2337   }
       
  2338 
       
  2339   // Traverse instance variables at the end since the GC may be moving things
       
  2340   // around using this function
       
  2341   f->do_oop((oop*) &_threadObj);
       
  2342   f->do_oop((oop*) &_vm_result);
       
  2343   f->do_oop((oop*) &_vm_result_2);
       
  2344   f->do_oop((oop*) &_exception_oop);
       
  2345   f->do_oop((oop*) &_pending_async_exception);
       
  2346 
       
  2347   if (jvmti_thread_state() != NULL) {
       
  2348     jvmti_thread_state()->oops_do(f);
       
  2349   }
       
  2350 }
       
  2351 
       
  2352 void JavaThread::nmethods_do() {
       
  2353   // Traverse the GCHandles
       
  2354   Thread::nmethods_do();
       
  2355 
       
  2356   assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
       
  2357           (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
       
  2358 
       
  2359   if (has_last_Java_frame()) {
       
  2360     // Traverse the execution stack
       
  2361     for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
       
  2362       fst.current()->nmethods_do();
       
  2363     }
       
  2364   }
       
  2365 }
       
  2366 
       
  2367 // Printing
       
  2368 const char* _get_thread_state_name(JavaThreadState _thread_state) {
       
  2369   switch (_thread_state) {
       
  2370   case _thread_uninitialized:     return "_thread_uninitialized";
       
  2371   case _thread_new:               return "_thread_new";
       
  2372   case _thread_new_trans:         return "_thread_new_trans";
       
  2373   case _thread_in_native:         return "_thread_in_native";
       
  2374   case _thread_in_native_trans:   return "_thread_in_native_trans";
       
  2375   case _thread_in_vm:             return "_thread_in_vm";
       
  2376   case _thread_in_vm_trans:       return "_thread_in_vm_trans";
       
  2377   case _thread_in_Java:           return "_thread_in_Java";
       
  2378   case _thread_in_Java_trans:     return "_thread_in_Java_trans";
       
  2379   case _thread_blocked:           return "_thread_blocked";
       
  2380   case _thread_blocked_trans:     return "_thread_blocked_trans";
       
  2381   default:                        return "unknown thread state";
       
  2382   }
       
  2383 }
       
  2384 
       
  2385 #ifndef PRODUCT
       
  2386 void JavaThread::print_thread_state_on(outputStream *st) const {
       
  2387   st->print_cr("   JavaThread state: %s", _get_thread_state_name(_thread_state));
       
  2388 };
       
  2389 void JavaThread::print_thread_state() const {
       
  2390   print_thread_state_on(tty);
       
  2391 };
       
  2392 #endif // PRODUCT
       
  2393 
       
  2394 // Called by Threads::print() for VM_PrintThreads operation
       
  2395 void JavaThread::print_on(outputStream *st) const {
       
  2396   st->print("\"%s\" ", get_thread_name());
       
  2397   oop thread_oop = threadObj();
       
  2398   if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop))  st->print("daemon ");
       
  2399   Thread::print_on(st);
       
  2400   // print guess for valid stack memory region (assume 4K pages); helps lock debugging
       
  2401   st->print_cr("[" INTPTR_FORMAT ".." INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12), highest_lock());
       
  2402   if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
       
  2403     st->print_cr("   java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
       
  2404   }
       
  2405 #ifndef PRODUCT
       
  2406   print_thread_state_on(st);
       
  2407   _safepoint_state->print_on(st);
       
  2408 #endif // PRODUCT
       
  2409 }
       
  2410 
       
  2411 // Called by fatal error handler. The difference between this and
       
  2412 // JavaThread::print() is that we can't grab lock or allocate memory.
       
  2413 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
       
  2414   st->print("JavaThread \"%s\"",  get_thread_name_string(buf, buflen));
       
  2415   oop thread_obj = threadObj();
       
  2416   if (thread_obj != NULL) {
       
  2417      if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
       
  2418   }
       
  2419   st->print(" [");
       
  2420   st->print("%s", _get_thread_state_name(_thread_state));
       
  2421   if (osthread()) {
       
  2422     st->print(", id=%d", osthread()->thread_id());
       
  2423   }
       
  2424   st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
       
  2425             _stack_base - _stack_size, _stack_base);
       
  2426   st->print("]");
       
  2427   return;
       
  2428 }
       
  2429 
       
  2430 // Verification
       
  2431 
       
  2432 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
       
  2433 
       
  2434 void JavaThread::verify() {
       
  2435   // Verify oops in the thread.
       
  2436   oops_do(&VerifyOopClosure::verify_oop);
       
  2437 
       
  2438   // Verify the stack frames.
       
  2439   frames_do(frame_verify);
       
  2440 }
       
  2441 
       
  2442 // CR 6300358 (sub-CR 2137150)
       
  2443 // Most callers of this method assume that it can't return NULL but a
       
  2444 // thread may not have a name whilst it is in the process of attaching to
       
  2445 // the VM - see CR 6412693, and there are places where a JavaThread can be
       
  2446 // seen prior to having it's threadObj set (eg JNI attaching threads and
       
  2447 // if vm exit occurs during initialization). These cases can all be accounted
       
  2448 // for such that this method never returns NULL.
       
  2449 const char* JavaThread::get_thread_name() const {
       
  2450 #ifdef ASSERT
       
  2451   // early safepoints can hit while current thread does not yet have TLS
       
  2452   if (!SafepointSynchronize::is_at_safepoint()) {
       
  2453     Thread *cur = Thread::current();
       
  2454     if (!(cur->is_Java_thread() && cur == this)) {
       
  2455       // Current JavaThreads are allowed to get their own name without
       
  2456       // the Threads_lock.
       
  2457       assert_locked_or_safepoint(Threads_lock);
       
  2458     }
       
  2459   }
       
  2460 #endif // ASSERT
       
  2461     return get_thread_name_string();
       
  2462 }
       
  2463 
       
  2464 // Returns a non-NULL representation of this thread's name, or a suitable
       
  2465 // descriptive string if there is no set name
       
  2466 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
       
  2467   const char* name_str;
       
  2468   oop thread_obj = threadObj();
       
  2469   if (thread_obj != NULL) {
       
  2470     typeArrayOop name = java_lang_Thread::name(thread_obj);
       
  2471     if (name != NULL) {
       
  2472       if (buf == NULL) {
       
  2473         name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
       
  2474       }
       
  2475       else {
       
  2476         name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
       
  2477       }
       
  2478     }
       
  2479     else if (is_attaching()) { // workaround for 6412693 - see 6404306
       
  2480       name_str = "<no-name - thread is attaching>";
       
  2481     }
       
  2482     else {
       
  2483       name_str = Thread::name();
       
  2484     }
       
  2485   }
       
  2486   else {
       
  2487     name_str = Thread::name();
       
  2488   }
       
  2489   assert(name_str != NULL, "unexpected NULL thread name");
       
  2490   return name_str;
       
  2491 }
       
  2492 
       
  2493 
       
  2494 const char* JavaThread::get_threadgroup_name() const {
       
  2495   debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
       
  2496   oop thread_obj = threadObj();
       
  2497   if (thread_obj != NULL) {
       
  2498     oop thread_group = java_lang_Thread::threadGroup(thread_obj);
       
  2499     if (thread_group != NULL) {
       
  2500       typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
       
  2501       // ThreadGroup.name can be null
       
  2502       if (name != NULL) {
       
  2503         const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
       
  2504         return str;
       
  2505       }
       
  2506     }
       
  2507   }
       
  2508   return NULL;
       
  2509 }
       
  2510 
       
  2511 const char* JavaThread::get_parent_name() const {
       
  2512   debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
       
  2513   oop thread_obj = threadObj();
       
  2514   if (thread_obj != NULL) {
       
  2515     oop thread_group = java_lang_Thread::threadGroup(thread_obj);
       
  2516     if (thread_group != NULL) {
       
  2517       oop parent = java_lang_ThreadGroup::parent(thread_group);
       
  2518       if (parent != NULL) {
       
  2519         typeArrayOop name = java_lang_ThreadGroup::name(parent);
       
  2520         // ThreadGroup.name can be null
       
  2521         if (name != NULL) {
       
  2522           const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
       
  2523           return str;
       
  2524         }
       
  2525       }
       
  2526     }
       
  2527   }
       
  2528   return NULL;
       
  2529 }
       
  2530 
       
  2531 ThreadPriority JavaThread::java_priority() const {
       
  2532   oop thr_oop = threadObj();
       
  2533   if (thr_oop == NULL) return NormPriority; // Bootstrapping
       
  2534   ThreadPriority priority = java_lang_Thread::priority(thr_oop);
       
  2535   assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
       
  2536   return priority;
       
  2537 }
       
  2538 
       
  2539 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
       
  2540 
       
  2541   assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
       
  2542   // Link Java Thread object <-> C++ Thread
       
  2543 
       
  2544   // Get the C++ thread object (an oop) from the JNI handle (a jthread)
       
  2545   // and put it into a new Handle.  The Handle "thread_oop" can then
       
  2546   // be used to pass the C++ thread object to other methods.
       
  2547 
       
  2548   // Set the Java level thread object (jthread) field of the
       
  2549   // new thread (a JavaThread *) to C++ thread object using the
       
  2550   // "thread_oop" handle.
       
  2551 
       
  2552   // Set the thread field (a JavaThread *) of the
       
  2553   // oop representing the java_lang_Thread to the new thread (a JavaThread *).
       
  2554 
       
  2555   Handle thread_oop(Thread::current(),
       
  2556                     JNIHandles::resolve_non_null(jni_thread));
       
  2557   assert(instanceKlass::cast(thread_oop->klass())->is_linked(),
       
  2558     "must be initialized");
       
  2559   set_threadObj(thread_oop());
       
  2560   java_lang_Thread::set_thread(thread_oop(), this);
       
  2561 
       
  2562   if (prio == NoPriority) {
       
  2563     prio = java_lang_Thread::priority(thread_oop());
       
  2564     assert(prio != NoPriority, "A valid priority should be present");
       
  2565   }
       
  2566 
       
  2567   // Push the Java priority down to the native thread; needs Threads_lock
       
  2568   Thread::set_priority(this, prio);
       
  2569 
       
  2570   // Add the new thread to the Threads list and set it in motion.
       
  2571   // We must have threads lock in order to call Threads::add.
       
  2572   // It is crucial that we do not block before the thread is
       
  2573   // added to the Threads list for if a GC happens, then the java_thread oop
       
  2574   // will not be visited by GC.
       
  2575   Threads::add(this);
       
  2576 }
       
  2577 
       
  2578 oop JavaThread::current_park_blocker() {
       
  2579   // Support for JSR-166 locks
       
  2580   oop thread_oop = threadObj();
       
  2581   if (thread_oop != NULL && JDK_Version::supports_thread_park_blocker()) {
       
  2582     return java_lang_Thread::park_blocker(thread_oop);
       
  2583   }
       
  2584   return NULL;
       
  2585 }
       
  2586 
       
  2587 
       
  2588 void JavaThread::print_stack_on(outputStream* st) {
       
  2589   if (!has_last_Java_frame()) return;
       
  2590   ResourceMark rm;
       
  2591   HandleMark   hm;
       
  2592 
       
  2593   RegisterMap reg_map(this);
       
  2594   vframe* start_vf = last_java_vframe(&reg_map);
       
  2595   int count = 0;
       
  2596   for (vframe* f = start_vf; f; f = f->sender() ) {
       
  2597     if (f->is_java_frame()) {
       
  2598       javaVFrame* jvf = javaVFrame::cast(f);
       
  2599       java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
       
  2600 
       
  2601       // Print out lock information
       
  2602       if (JavaMonitorsInStackTrace) {
       
  2603         jvf->print_lock_info_on(st, count);
       
  2604       }
       
  2605     } else {
       
  2606       // Ignore non-Java frames
       
  2607     }
       
  2608 
       
  2609     // Bail-out case for too deep stacks
       
  2610     count++;
       
  2611     if (MaxJavaStackTraceDepth == count) return;
       
  2612   }
       
  2613 }
       
  2614 
       
  2615 
       
  2616 // JVMTI PopFrame support
       
  2617 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
       
  2618   assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
       
  2619   if (in_bytes(size_in_bytes) != 0) {
       
  2620     _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes));
       
  2621     _popframe_preserved_args_size = in_bytes(size_in_bytes);
       
  2622     Copy::conjoint_bytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
       
  2623   }
       
  2624 }
       
  2625 
       
  2626 void* JavaThread::popframe_preserved_args() {
       
  2627   return _popframe_preserved_args;
       
  2628 }
       
  2629 
       
  2630 ByteSize JavaThread::popframe_preserved_args_size() {
       
  2631   return in_ByteSize(_popframe_preserved_args_size);
       
  2632 }
       
  2633 
       
  2634 WordSize JavaThread::popframe_preserved_args_size_in_words() {
       
  2635   int sz = in_bytes(popframe_preserved_args_size());
       
  2636   assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
       
  2637   return in_WordSize(sz / wordSize);
       
  2638 }
       
  2639 
       
  2640 void JavaThread::popframe_free_preserved_args() {
       
  2641   assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
       
  2642   FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
       
  2643   _popframe_preserved_args = NULL;
       
  2644   _popframe_preserved_args_size = 0;
       
  2645 }
       
  2646 
       
  2647 #ifndef PRODUCT
       
  2648 
       
  2649 void JavaThread::trace_frames() {
       
  2650   tty->print_cr("[Describe stack]");
       
  2651   int frame_no = 1;
       
  2652   for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
       
  2653     tty->print("  %d. ", frame_no++);
       
  2654     fst.current()->print_value_on(tty,this);
       
  2655     tty->cr();
       
  2656   }
       
  2657 }
       
  2658 
       
  2659 
       
  2660 void JavaThread::trace_stack_from(vframe* start_vf) {
       
  2661   ResourceMark rm;
       
  2662   int vframe_no = 1;
       
  2663   for (vframe* f = start_vf; f; f = f->sender() ) {
       
  2664     if (f->is_java_frame()) {
       
  2665       javaVFrame::cast(f)->print_activation(vframe_no++);
       
  2666     } else {
       
  2667       f->print();
       
  2668     }
       
  2669     if (vframe_no > StackPrintLimit) {
       
  2670       tty->print_cr("...<more frames>...");
       
  2671       return;
       
  2672     }
       
  2673   }
       
  2674 }
       
  2675 
       
  2676 
       
  2677 void JavaThread::trace_stack() {
       
  2678   if (!has_last_Java_frame()) return;
       
  2679   ResourceMark rm;
       
  2680   HandleMark   hm;
       
  2681   RegisterMap reg_map(this);
       
  2682   trace_stack_from(last_java_vframe(&reg_map));
       
  2683 }
       
  2684 
       
  2685 
       
  2686 #endif // PRODUCT
       
  2687 
       
  2688 
       
  2689 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
       
  2690   assert(reg_map != NULL, "a map must be given");
       
  2691   frame f = last_frame();
       
  2692   for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
       
  2693     if (vf->is_java_frame()) return javaVFrame::cast(vf);
       
  2694   }
       
  2695   return NULL;
       
  2696 }
       
  2697 
       
  2698 
       
  2699 klassOop JavaThread::security_get_caller_class(int depth) {
       
  2700   vframeStream vfst(this);
       
  2701   vfst.security_get_caller_frame(depth);
       
  2702   if (!vfst.at_end()) {
       
  2703     return vfst.method()->method_holder();
       
  2704   }
       
  2705   return NULL;
       
  2706 }
       
  2707 
       
  2708 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
       
  2709   assert(thread->is_Compiler_thread(), "must be compiler thread");
       
  2710   CompileBroker::compiler_thread_loop();
       
  2711 }
       
  2712 
       
  2713 // Create a CompilerThread
       
  2714 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
       
  2715 : JavaThread(&compiler_thread_entry) {
       
  2716   _env   = NULL;
       
  2717   _log   = NULL;
       
  2718   _task  = NULL;
       
  2719   _queue = queue;
       
  2720   _counters = counters;
       
  2721 
       
  2722 #ifndef PRODUCT
       
  2723   _ideal_graph_printer = NULL;
       
  2724 #endif
       
  2725 }
       
  2726 
       
  2727 
       
  2728 // ======= Threads ========
       
  2729 
       
  2730 // The Threads class links together all active threads, and provides
       
  2731 // operations over all threads.  It is protected by its own Mutex
       
  2732 // lock, which is also used in other contexts to protect thread
       
  2733 // operations from having the thread being operated on from exiting
       
  2734 // and going away unexpectedly (e.g., safepoint synchronization)
       
  2735 
       
  2736 JavaThread* Threads::_thread_list = NULL;
       
  2737 int         Threads::_number_of_threads = 0;
       
  2738 int         Threads::_number_of_non_daemon_threads = 0;
       
  2739 int         Threads::_return_code = 0;
       
  2740 size_t      JavaThread::_stack_size_at_create = 0;
       
  2741 
       
  2742 // All JavaThreads
       
  2743 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
       
  2744 
       
  2745 void os_stream();
       
  2746 
       
  2747 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
       
  2748 void Threads::threads_do(ThreadClosure* tc) {
       
  2749   assert_locked_or_safepoint(Threads_lock);
       
  2750   // ALL_JAVA_THREADS iterates through all JavaThreads
       
  2751   ALL_JAVA_THREADS(p) {
       
  2752     tc->do_thread(p);
       
  2753   }
       
  2754   // Someday we could have a table or list of all non-JavaThreads.
       
  2755   // For now, just manually iterate through them.
       
  2756   tc->do_thread(VMThread::vm_thread());
       
  2757   Universe::heap()->gc_threads_do(tc);
       
  2758   tc->do_thread(WatcherThread::watcher_thread());
       
  2759   // If CompilerThreads ever become non-JavaThreads, add them here
       
  2760 }
       
  2761 
       
  2762 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
       
  2763 
       
  2764   // Check version
       
  2765   if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
       
  2766 
       
  2767   // Initialize the output stream module
       
  2768   ostream_init();
       
  2769 
       
  2770   // Process java launcher properties.
       
  2771   Arguments::process_sun_java_launcher_properties(args);
       
  2772 
       
  2773   // Initialize the os module before using TLS
       
  2774   os::init();
       
  2775 
       
  2776   // Initialize system properties.
       
  2777   Arguments::init_system_properties();
       
  2778 
       
  2779   // Parse arguments
       
  2780   jint parse_result = Arguments::parse(args);
       
  2781   if (parse_result != JNI_OK) return parse_result;
       
  2782 
       
  2783   if (PauseAtStartup) {
       
  2784     os::pause();
       
  2785   }
       
  2786 
       
  2787   HS_DTRACE_PROBE(hotspot, vm__init__begin);
       
  2788 
       
  2789   // Record VM creation timing statistics
       
  2790   TraceVmCreationTime create_vm_timer;
       
  2791   create_vm_timer.start();
       
  2792 
       
  2793   // Timing (must come after argument parsing)
       
  2794   TraceTime timer("Create VM", TraceStartupTime);
       
  2795 
       
  2796   // Initialize the os module after parsing the args
       
  2797   jint os_init_2_result = os::init_2();
       
  2798   if (os_init_2_result != JNI_OK) return os_init_2_result;
       
  2799 
       
  2800   // Initialize output stream logging
       
  2801   ostream_init_log();
       
  2802 
       
  2803   // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
       
  2804   // Must be before create_vm_init_agents()
       
  2805   if (Arguments::init_libraries_at_startup()) {
       
  2806     convert_vm_init_libraries_to_agents();
       
  2807   }
       
  2808 
       
  2809   // Launch -agentlib/-agentpath and converted -Xrun agents
       
  2810   if (Arguments::init_agents_at_startup()) {
       
  2811     create_vm_init_agents();
       
  2812   }
       
  2813 
       
  2814   // Initialize Threads state
       
  2815   _thread_list = NULL;
       
  2816   _number_of_threads = 0;
       
  2817   _number_of_non_daemon_threads = 0;
       
  2818 
       
  2819   // Initialize TLS
       
  2820   ThreadLocalStorage::init();
       
  2821 
       
  2822   // Initialize global data structures and create system classes in heap
       
  2823   vm_init_globals();
       
  2824 
       
  2825   // Attach the main thread to this os thread
       
  2826   JavaThread* main_thread = new JavaThread();
       
  2827   main_thread->set_thread_state(_thread_in_vm);
       
  2828   // must do this before set_active_handles and initialize_thread_local_storage
       
  2829   // Note: on solaris initialize_thread_local_storage() will (indirectly)
       
  2830   // change the stack size recorded here to one based on the java thread
       
  2831   // stacksize. This adjusted size is what is used to figure the placement
       
  2832   // of the guard pages.
       
  2833   main_thread->record_stack_base_and_size();
       
  2834   main_thread->initialize_thread_local_storage();
       
  2835 
       
  2836   main_thread->set_active_handles(JNIHandleBlock::allocate_block());
       
  2837 
       
  2838   if (!main_thread->set_as_starting_thread()) {
       
  2839     vm_shutdown_during_initialization(
       
  2840       "Failed necessary internal allocation. Out of swap space");
       
  2841     delete main_thread;
       
  2842     *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
       
  2843     return JNI_ENOMEM;
       
  2844   }
       
  2845 
       
  2846   // Enable guard page *after* os::create_main_thread(), otherwise it would
       
  2847   // crash Linux VM, see notes in os_linux.cpp.
       
  2848   main_thread->create_stack_guard_pages();
       
  2849 
       
  2850   // Initialize Java-Leve synchronization subsystem
       
  2851   ObjectSynchronizer::Initialize() ;
       
  2852 
       
  2853   // Initialize global modules
       
  2854   jint status = init_globals();
       
  2855   if (status != JNI_OK) {
       
  2856     delete main_thread;
       
  2857     *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
       
  2858     return status;
       
  2859   }
       
  2860 
       
  2861   HandleMark hm;
       
  2862 
       
  2863   { MutexLocker mu(Threads_lock);
       
  2864     Threads::add(main_thread);
       
  2865   }
       
  2866 
       
  2867   // Any JVMTI raw monitors entered in onload will transition into
       
  2868   // real raw monitor. VM is setup enough here for raw monitor enter.
       
  2869   JvmtiExport::transition_pending_onload_raw_monitors();
       
  2870 
       
  2871   if (VerifyBeforeGC &&
       
  2872       Universe::heap()->total_collections() >= VerifyGCStartAt) {
       
  2873     Universe::heap()->prepare_for_verify();
       
  2874     Universe::verify();   // make sure we're starting with a clean slate
       
  2875   }
       
  2876 
       
  2877   // Create the VMThread
       
  2878   { TraceTime timer("Start VMThread", TraceStartupTime);
       
  2879     VMThread::create();
       
  2880     Thread* vmthread = VMThread::vm_thread();
       
  2881 
       
  2882     if (!os::create_thread(vmthread, os::vm_thread))
       
  2883       vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
       
  2884 
       
  2885     // Wait for the VM thread to become ready, and VMThread::run to initialize
       
  2886     // Monitors can have spurious returns, must always check another state flag
       
  2887     {
       
  2888       MutexLocker ml(Notify_lock);
       
  2889       os::start_thread(vmthread);
       
  2890       while (vmthread->active_handles() == NULL) {
       
  2891         Notify_lock->wait();
       
  2892       }
       
  2893     }
       
  2894   }
       
  2895 
       
  2896   assert (Universe::is_fully_initialized(), "not initialized");
       
  2897   EXCEPTION_MARK;
       
  2898 
       
  2899   // At this point, the Universe is initialized, but we have not executed
       
  2900   // any byte code.  Now is a good time (the only time) to dump out the
       
  2901   // internal state of the JVM for sharing.
       
  2902 
       
  2903   if (DumpSharedSpaces) {
       
  2904     Universe::heap()->preload_and_dump(CHECK_0);
       
  2905     ShouldNotReachHere();
       
  2906   }
       
  2907 
       
  2908   // Always call even when there are not JVMTI environments yet, since environments
       
  2909   // may be attached late and JVMTI must track phases of VM execution
       
  2910   JvmtiExport::enter_start_phase();
       
  2911 
       
  2912   // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
       
  2913   JvmtiExport::post_vm_start();
       
  2914 
       
  2915   {
       
  2916     TraceTime timer("Initialize java.lang classes", TraceStartupTime);
       
  2917 
       
  2918     if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
       
  2919       create_vm_init_libraries();
       
  2920     }
       
  2921 
       
  2922     if (InitializeJavaLangString) {
       
  2923       initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
       
  2924     } else {
       
  2925       warning("java.lang.String not initialized");
       
  2926     }
       
  2927 
       
  2928     // Initialize java_lang.System (needed before creating the thread)
       
  2929     if (InitializeJavaLangSystem) {
       
  2930       initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
       
  2931       initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
       
  2932       Handle thread_group = create_initial_thread_group(CHECK_0);
       
  2933       Universe::set_main_thread_group(thread_group());
       
  2934       initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
       
  2935       oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
       
  2936       main_thread->set_threadObj(thread_object);
       
  2937       // Set thread status to running since main thread has
       
  2938       // been started and running.
       
  2939       java_lang_Thread::set_thread_status(thread_object,
       
  2940                                           java_lang_Thread::RUNNABLE);
       
  2941 
       
  2942       // The VM preresolve methods to these classes. Make sure that get initialized
       
  2943       initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
       
  2944       initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(),  CHECK_0);
       
  2945       // The VM creates & returns objects of this class. Make sure it's initialized.
       
  2946       initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
       
  2947       call_initializeSystemClass(CHECK_0);
       
  2948     } else {
       
  2949       warning("java.lang.System not initialized");
       
  2950     }
       
  2951 
       
  2952     // an instance of OutOfMemory exception has been allocated earlier
       
  2953     if (InitializeJavaLangExceptionsErrors) {
       
  2954       initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
       
  2955       initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
       
  2956       initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
       
  2957       initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
       
  2958       initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
       
  2959       initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
       
  2960       initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
       
  2961     } else {
       
  2962       warning("java.lang.OutOfMemoryError has not been initialized");
       
  2963       warning("java.lang.NullPointerException has not been initialized");
       
  2964       warning("java.lang.ClassCastException has not been initialized");
       
  2965       warning("java.lang.ArrayStoreException has not been initialized");
       
  2966       warning("java.lang.ArithmeticException has not been initialized");
       
  2967       warning("java.lang.StackOverflowError has not been initialized");
       
  2968     }
       
  2969   }
       
  2970 
       
  2971   // See        : bugid 4211085.
       
  2972   // Background : the static initializer of java.lang.Compiler tries to read
       
  2973   //              property"java.compiler" and read & write property "java.vm.info".
       
  2974   //              When a security manager is installed through the command line
       
  2975   //              option "-Djava.security.manager", the above properties are not
       
  2976   //              readable and the static initializer for java.lang.Compiler fails
       
  2977   //              resulting in a NoClassDefFoundError.  This can happen in any
       
  2978   //              user code which calls methods in java.lang.Compiler.
       
  2979   // Hack :       the hack is to pre-load and initialize this class, so that only
       
  2980   //              system domains are on the stack when the properties are read.
       
  2981   //              Currently even the AWT code has calls to methods in java.lang.Compiler.
       
  2982   //              On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
       
  2983   // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
       
  2984   //              read and write"java.vm.info" in the default policy file. See bugid 4211383
       
  2985   //              Once that is done, we should remove this hack.
       
  2986   initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
       
  2987 
       
  2988   // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
       
  2989   // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
       
  2990   // compiler does not get loaded through java.lang.Compiler).  "java -version" with the
       
  2991   // hotspot vm says "nojit" all the time which is confusing.  So, we reset it here.
       
  2992   // This should also be taken out as soon as 4211383 gets fixed.
       
  2993   reset_vm_info_property(CHECK_0);
       
  2994 
       
  2995   quicken_jni_functions();
       
  2996 
       
  2997   // Set flag that basic initialization has completed. Used by exceptions and various
       
  2998   // debug stuff, that does not work until all basic classes have been initialized.
       
  2999   set_init_completed();
       
  3000 
       
  3001   HS_DTRACE_PROBE(hotspot, vm__init__end);
       
  3002 
       
  3003   // record VM initialization completion time
       
  3004   Management::record_vm_init_completed();
       
  3005 
       
  3006   // Compute system loader. Note that this has to occur after set_init_completed, since
       
  3007   // valid exceptions may be thrown in the process.
       
  3008   // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
       
  3009   // set_init_completed has just been called, causing exceptions not to be shortcut
       
  3010   // anymore. We call vm_exit_during_initialization directly instead.
       
  3011   SystemDictionary::compute_java_system_loader(THREAD);
       
  3012   if (HAS_PENDING_EXCEPTION) {
       
  3013     vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
       
  3014   }
       
  3015 
       
  3016 #ifndef SERIALGC
       
  3017   // Support for ConcurrentMarkSweep. This should be cleaned up
       
  3018   // and better encapsulated. XXX YSR
       
  3019   if (UseConcMarkSweepGC) {
       
  3020     ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
       
  3021     if (HAS_PENDING_EXCEPTION) {
       
  3022       vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
       
  3023     }
       
  3024   }
       
  3025 #endif // SERIALGC
       
  3026 
       
  3027   // Always call even when there are not JVMTI environments yet, since environments
       
  3028   // may be attached late and JVMTI must track phases of VM execution
       
  3029   JvmtiExport::enter_live_phase();
       
  3030 
       
  3031   // Signal Dispatcher needs to be started before VMInit event is posted
       
  3032   os::signal_init();
       
  3033 
       
  3034   // Start Attach Listener if +StartAttachListener or it can't be started lazily
       
  3035   if (!DisableAttachMechanism) {
       
  3036     if (StartAttachListener || AttachListener::init_at_startup()) {
       
  3037       AttachListener::init();
       
  3038     }
       
  3039   }
       
  3040 
       
  3041   // Launch -Xrun agents
       
  3042   // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
       
  3043   // back-end can launch with -Xdebug -Xrunjdwp.
       
  3044   if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
       
  3045     create_vm_init_libraries();
       
  3046   }
       
  3047 
       
  3048   // Notify JVMTI agents that VM initialization is complete - nop if no agents.
       
  3049   JvmtiExport::post_vm_initialized();
       
  3050 
       
  3051   Chunk::start_chunk_pool_cleaner_task();
       
  3052 
       
  3053   // initialize compiler(s)
       
  3054   CompileBroker::compilation_init();
       
  3055 
       
  3056   Management::initialize(THREAD);
       
  3057   if (HAS_PENDING_EXCEPTION) {
       
  3058     // management agent fails to start possibly due to
       
  3059     // configuration problem and is responsible for printing
       
  3060     // stack trace if appropriate. Simply exit VM.
       
  3061     vm_exit(1);
       
  3062   }
       
  3063 
       
  3064   if (Arguments::has_profile())       FlatProfiler::engage(main_thread, true);
       
  3065   if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
       
  3066   if (MemProfiling)                   MemProfiler::engage();
       
  3067   StatSampler::engage();
       
  3068   if (CheckJNICalls)                  JniPeriodicChecker::engage();
       
  3069   if (CacheTimeMillis)                TimeMillisUpdateTask::engage();
       
  3070 
       
  3071   BiasedLocking::init();
       
  3072 
       
  3073 
       
  3074   // Start up the WatcherThread if there are any periodic tasks
       
  3075   // NOTE:  All PeriodicTasks should be registered by now. If they
       
  3076   //   aren't, late joiners might appear to start slowly (we might
       
  3077   //   take a while to process their first tick).
       
  3078   if (PeriodicTask::num_tasks() > 0) {
       
  3079     WatcherThread::start();
       
  3080   }
       
  3081 
       
  3082   create_vm_timer.end();
       
  3083   return JNI_OK;
       
  3084 }
       
  3085 
       
  3086 // type for the Agent_OnLoad and JVM_OnLoad entry points
       
  3087 extern "C" {
       
  3088   typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
       
  3089 }
       
  3090 // Find a command line agent library and return its entry point for
       
  3091 //         -agentlib:  -agentpath:   -Xrun
       
  3092 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
       
  3093 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
       
  3094   OnLoadEntry_t on_load_entry = NULL;
       
  3095   void *library = agent->os_lib();  // check if we have looked it up before
       
  3096 
       
  3097   if (library == NULL) {
       
  3098     char buffer[JVM_MAXPATHLEN];
       
  3099     char ebuf[1024];
       
  3100     const char *name = agent->name();
       
  3101 
       
  3102     if (agent->is_absolute_path()) {
       
  3103       library = hpi::dll_load(name, ebuf, sizeof ebuf);
       
  3104       if (library == NULL) {
       
  3105         // If we can't find the agent, exit.
       
  3106         vm_exit_during_initialization("Could not find agent library in absolute path", name);
       
  3107       }
       
  3108     } else {
       
  3109       // Try to load the agent from the standard dll directory
       
  3110       hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
       
  3111       library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
       
  3112 #ifdef KERNEL
       
  3113       // Download instrument dll
       
  3114       if (library == NULL && strcmp(name, "instrument") == 0) {
       
  3115         char *props = Arguments::get_kernel_properties();
       
  3116         char *home  = Arguments::get_java_home();
       
  3117         const char *fmt   = "%s/bin/java %s -Dkernel.background.download=false"
       
  3118                       " sun.jkernel.DownloadManager -download client_jvm";
       
  3119         int length = strlen(props) + strlen(home) + strlen(fmt) + 1;
       
  3120         char *cmd = AllocateHeap(length);
       
  3121         jio_snprintf(cmd, length, fmt, home, props);
       
  3122         int status = os::fork_and_exec(cmd);
       
  3123         FreeHeap(props);
       
  3124         FreeHeap(cmd);
       
  3125         if (status == -1) {
       
  3126           warning(cmd);
       
  3127           vm_exit_during_initialization("fork_and_exec failed: %s",
       
  3128                                          strerror(errno));
       
  3129         }
       
  3130         // when this comes back the instrument.dll should be where it belongs.
       
  3131         library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
       
  3132       }
       
  3133 #endif // KERNEL
       
  3134       if (library == NULL) { // Try the local directory
       
  3135         char ns[1] = {0};
       
  3136         hpi::dll_build_name(buffer, sizeof(buffer), ns, name);
       
  3137         library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
       
  3138         if (library == NULL) {
       
  3139           // If we can't find the agent, exit.
       
  3140           vm_exit_during_initialization("Could not find agent library on the library path or in the local directory", name);
       
  3141         }
       
  3142       }
       
  3143     }
       
  3144     agent->set_os_lib(library);
       
  3145   }
       
  3146 
       
  3147   // Find the OnLoad function.
       
  3148   for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
       
  3149     on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index]));
       
  3150     if (on_load_entry != NULL) break;
       
  3151   }
       
  3152   return on_load_entry;
       
  3153 }
       
  3154 
       
  3155 // Find the JVM_OnLoad entry point
       
  3156 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
       
  3157   const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
       
  3158   return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
       
  3159 }
       
  3160 
       
  3161 // Find the Agent_OnLoad entry point
       
  3162 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
       
  3163   const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
       
  3164   return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
       
  3165 }
       
  3166 
       
  3167 // For backwards compatibility with -Xrun
       
  3168 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
       
  3169 // treated like -agentpath:
       
  3170 // Must be called before agent libraries are created
       
  3171 void Threads::convert_vm_init_libraries_to_agents() {
       
  3172   AgentLibrary* agent;
       
  3173   AgentLibrary* next;
       
  3174 
       
  3175   for (agent = Arguments::libraries(); agent != NULL; agent = next) {
       
  3176     next = agent->next();  // cache the next agent now as this agent may get moved off this list
       
  3177     OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
       
  3178 
       
  3179     // If there is an JVM_OnLoad function it will get called later,
       
  3180     // otherwise see if there is an Agent_OnLoad
       
  3181     if (on_load_entry == NULL) {
       
  3182       on_load_entry = lookup_agent_on_load(agent);
       
  3183       if (on_load_entry != NULL) {
       
  3184         // switch it to the agent list -- so that Agent_OnLoad will be called,
       
  3185         // JVM_OnLoad won't be attempted and Agent_OnUnload will
       
  3186         Arguments::convert_library_to_agent(agent);
       
  3187       } else {
       
  3188         vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
       
  3189       }
       
  3190     }
       
  3191   }
       
  3192 }
       
  3193 
       
  3194 // Create agents for -agentlib:  -agentpath:  and converted -Xrun
       
  3195 // Invokes Agent_OnLoad
       
  3196 // Called very early -- before JavaThreads exist
       
  3197 void Threads::create_vm_init_agents() {
       
  3198   extern struct JavaVM_ main_vm;
       
  3199   AgentLibrary* agent;
       
  3200 
       
  3201   JvmtiExport::enter_onload_phase();
       
  3202   for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
       
  3203     OnLoadEntry_t  on_load_entry = lookup_agent_on_load(agent);
       
  3204 
       
  3205     if (on_load_entry != NULL) {
       
  3206       // Invoke the Agent_OnLoad function
       
  3207       jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
       
  3208       if (err != JNI_OK) {
       
  3209         vm_exit_during_initialization("agent library failed to init", agent->name());
       
  3210       }
       
  3211     } else {
       
  3212       vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
       
  3213     }
       
  3214   }
       
  3215   JvmtiExport::enter_primordial_phase();
       
  3216 }
       
  3217 
       
  3218 extern "C" {
       
  3219   typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
       
  3220 }
       
  3221 
       
  3222 void Threads::shutdown_vm_agents() {
       
  3223   // Send any Agent_OnUnload notifications
       
  3224   const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
       
  3225   extern struct JavaVM_ main_vm;
       
  3226   for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
       
  3227 
       
  3228     // Find the Agent_OnUnload function.
       
  3229     for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
       
  3230       Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
       
  3231                hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
       
  3232 
       
  3233       // Invoke the Agent_OnUnload function
       
  3234       if (unload_entry != NULL) {
       
  3235         JavaThread* thread = JavaThread::current();
       
  3236         ThreadToNativeFromVM ttn(thread);
       
  3237         HandleMark hm(thread);
       
  3238         (*unload_entry)(&main_vm);
       
  3239         break;
       
  3240       }
       
  3241     }
       
  3242   }
       
  3243 }
       
  3244 
       
  3245 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
       
  3246 // Invokes JVM_OnLoad
       
  3247 void Threads::create_vm_init_libraries() {
       
  3248   extern struct JavaVM_ main_vm;
       
  3249   AgentLibrary* agent;
       
  3250 
       
  3251   for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
       
  3252     OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
       
  3253 
       
  3254     if (on_load_entry != NULL) {
       
  3255       // Invoke the JVM_OnLoad function
       
  3256       JavaThread* thread = JavaThread::current();
       
  3257       ThreadToNativeFromVM ttn(thread);
       
  3258       HandleMark hm(thread);
       
  3259       jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
       
  3260       if (err != JNI_OK) {
       
  3261         vm_exit_during_initialization("-Xrun library failed to init", agent->name());
       
  3262       }
       
  3263     } else {
       
  3264       vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
       
  3265     }
       
  3266   }
       
  3267 }
       
  3268 
       
  3269 // Last thread running calls java.lang.Shutdown.shutdown()
       
  3270 void JavaThread::invoke_shutdown_hooks() {
       
  3271   HandleMark hm(this);
       
  3272 
       
  3273   // We could get here with a pending exception, if so clear it now.
       
  3274   if (this->has_pending_exception()) {
       
  3275     this->clear_pending_exception();
       
  3276   }
       
  3277 
       
  3278   EXCEPTION_MARK;
       
  3279   klassOop k =
       
  3280     SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(),
       
  3281                                       THREAD);
       
  3282   if (k != NULL) {
       
  3283     // SystemDictionary::resolve_or_null will return null if there was
       
  3284     // an exception.  If we cannot load the Shutdown class, just don't
       
  3285     // call Shutdown.shutdown() at all.  This will mean the shutdown hooks
       
  3286     // and finalizers (if runFinalizersOnExit is set) won't be run.
       
  3287     // Note that if a shutdown hook was registered or runFinalizersOnExit
       
  3288     // was called, the Shutdown class would have already been loaded
       
  3289     // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
       
  3290     instanceKlassHandle shutdown_klass (THREAD, k);
       
  3291     JavaValue result(T_VOID);
       
  3292     JavaCalls::call_static(&result,
       
  3293                            shutdown_klass,
       
  3294                            vmSymbolHandles::shutdown_method_name(),
       
  3295                            vmSymbolHandles::void_method_signature(),
       
  3296                            THREAD);
       
  3297   }
       
  3298   CLEAR_PENDING_EXCEPTION;
       
  3299 }
       
  3300 
       
  3301 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
       
  3302 // the program falls off the end of main(). Another VM exit path is through
       
  3303 // vm_exit() when the program calls System.exit() to return a value or when
       
  3304 // there is a serious error in VM. The two shutdown paths are not exactly
       
  3305 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
       
  3306 // and VM_Exit op at VM level.
       
  3307 //
       
  3308 // Shutdown sequence:
       
  3309 //   + Wait until we are the last non-daemon thread to execute
       
  3310 //     <-- every thing is still working at this moment -->
       
  3311 //   + Call java.lang.Shutdown.shutdown(), which will invoke Java level
       
  3312 //        shutdown hooks, run finalizers if finalization-on-exit
       
  3313 //   + Call before_exit(), prepare for VM exit
       
  3314 //      > run VM level shutdown hooks (they are registered through JVM_OnExit(),
       
  3315 //        currently the only user of this mechanism is File.deleteOnExit())
       
  3316 //      > stop flat profiler, StatSampler, watcher thread, CMS threads,
       
  3317 //        post thread end and vm death events to JVMTI,
       
  3318 //        stop signal thread
       
  3319 //   + Call JavaThread::exit(), it will:
       
  3320 //      > release JNI handle blocks, remove stack guard pages
       
  3321 //      > remove this thread from Threads list
       
  3322 //     <-- no more Java code from this thread after this point -->
       
  3323 //   + Stop VM thread, it will bring the remaining VM to a safepoint and stop
       
  3324 //     the compiler threads at safepoint
       
  3325 //     <-- do not use anything that could get blocked by Safepoint -->
       
  3326 //   + Disable tracing at JNI/JVM barriers
       
  3327 //   + Set _vm_exited flag for threads that are still running native code
       
  3328 //   + Delete this thread
       
  3329 //   + Call exit_globals()
       
  3330 //      > deletes tty
       
  3331 //      > deletes PerfMemory resources
       
  3332 //   + Return to caller
       
  3333 
       
  3334 bool Threads::destroy_vm() {
       
  3335   JavaThread* thread = JavaThread::current();
       
  3336 
       
  3337   // Wait until we are the last non-daemon thread to execute
       
  3338   { MutexLocker nu(Threads_lock);
       
  3339     while (Threads::number_of_non_daemon_threads() > 1 )
       
  3340       // This wait should make safepoint checks, wait without a timeout,
       
  3341       // and wait as a suspend-equivalent condition.
       
  3342       //
       
  3343       // Note: If the FlatProfiler is running and this thread is waiting
       
  3344       // for another non-daemon thread to finish, then the FlatProfiler
       
  3345       // is waiting for the external suspend request on this thread to
       
  3346       // complete. wait_for_ext_suspend_completion() will eventually
       
  3347       // timeout, but that takes time. Making this wait a suspend-
       
  3348       // equivalent condition solves that timeout problem.
       
  3349       //
       
  3350       Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
       
  3351                          Mutex::_as_suspend_equivalent_flag);
       
  3352   }
       
  3353 
       
  3354   // Hang forever on exit if we are reporting an error.
       
  3355   if (ShowMessageBoxOnError && is_error_reported()) {
       
  3356     os::infinite_sleep();
       
  3357   }
       
  3358 
       
  3359   if (JDK_Version::is_jdk12x_version()) {
       
  3360     // We are the last thread running, so check if finalizers should be run.
       
  3361     // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
       
  3362     HandleMark rm(thread);
       
  3363     Universe::run_finalizers_on_exit();
       
  3364   } else {
       
  3365     // run Java level shutdown hooks
       
  3366     thread->invoke_shutdown_hooks();
       
  3367   }
       
  3368 
       
  3369   before_exit(thread);
       
  3370 
       
  3371   thread->exit(true);
       
  3372 
       
  3373   // Stop VM thread.
       
  3374   {
       
  3375     // 4945125 The vm thread comes to a safepoint during exit.
       
  3376     // GC vm_operations can get caught at the safepoint, and the
       
  3377     // heap is unparseable if they are caught. Grab the Heap_lock
       
  3378     // to prevent this. The GC vm_operations will not be able to
       
  3379     // queue until after the vm thread is dead.
       
  3380     MutexLocker ml(Heap_lock);
       
  3381 
       
  3382     VMThread::wait_for_vm_thread_exit();
       
  3383     assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
       
  3384     VMThread::destroy();
       
  3385   }
       
  3386 
       
  3387   // clean up ideal graph printers
       
  3388 #if defined(COMPILER2) && !defined(PRODUCT)
       
  3389   IdealGraphPrinter::clean_up();
       
  3390 #endif
       
  3391 
       
  3392   // Now, all Java threads are gone except daemon threads. Daemon threads
       
  3393   // running Java code or in VM are stopped by the Safepoint. However,
       
  3394   // daemon threads executing native code are still running.  But they
       
  3395   // will be stopped at native=>Java/VM barriers. Note that we can't
       
  3396   // simply kill or suspend them, as it is inherently deadlock-prone.
       
  3397 
       
  3398 #ifndef PRODUCT
       
  3399   // disable function tracing at JNI/JVM barriers
       
  3400   TraceHPI = false;
       
  3401   TraceJNICalls = false;
       
  3402   TraceJVMCalls = false;
       
  3403   TraceRuntimeCalls = false;
       
  3404 #endif
       
  3405 
       
  3406   VM_Exit::set_vm_exited();
       
  3407 
       
  3408   notify_vm_shutdown();
       
  3409 
       
  3410   delete thread;
       
  3411 
       
  3412   // exit_globals() will delete tty
       
  3413   exit_globals();
       
  3414 
       
  3415   return true;
       
  3416 }
       
  3417 
       
  3418 
       
  3419 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
       
  3420   if (version == JNI_VERSION_1_1) return JNI_TRUE;
       
  3421   return is_supported_jni_version(version);
       
  3422 }
       
  3423 
       
  3424 
       
  3425 jboolean Threads::is_supported_jni_version(jint version) {
       
  3426   if (version == JNI_VERSION_1_2) return JNI_TRUE;
       
  3427   if (version == JNI_VERSION_1_4) return JNI_TRUE;
       
  3428   if (version == JNI_VERSION_1_6) return JNI_TRUE;
       
  3429   return JNI_FALSE;
       
  3430 }
       
  3431 
       
  3432 
       
  3433 void Threads::add(JavaThread* p, bool force_daemon) {
       
  3434   // The threads lock must be owned at this point
       
  3435   assert_locked_or_safepoint(Threads_lock);
       
  3436   p->set_next(_thread_list);
       
  3437   _thread_list = p;
       
  3438   _number_of_threads++;
       
  3439   oop threadObj = p->threadObj();
       
  3440   bool daemon = true;
       
  3441   // Bootstrapping problem: threadObj can be null for initial
       
  3442   // JavaThread (or for threads attached via JNI)
       
  3443   if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
       
  3444     _number_of_non_daemon_threads++;
       
  3445     daemon = false;
       
  3446   }
       
  3447 
       
  3448   ThreadService::add_thread(p, daemon);
       
  3449 
       
  3450   // Possible GC point.
       
  3451   Events::log("Thread added: " INTPTR_FORMAT, p);
       
  3452 }
       
  3453 
       
  3454 void Threads::remove(JavaThread* p) {
       
  3455   // Extra scope needed for Thread_lock, so we can check
       
  3456   // that we do not remove thread without safepoint code notice
       
  3457   { MutexLocker ml(Threads_lock);
       
  3458 
       
  3459     assert(includes(p), "p must be present");
       
  3460 
       
  3461     JavaThread* current = _thread_list;
       
  3462     JavaThread* prev    = NULL;
       
  3463 
       
  3464     while (current != p) {
       
  3465       prev    = current;
       
  3466       current = current->next();
       
  3467     }
       
  3468 
       
  3469     if (prev) {
       
  3470       prev->set_next(current->next());
       
  3471     } else {
       
  3472       _thread_list = p->next();
       
  3473     }
       
  3474     _number_of_threads--;
       
  3475     oop threadObj = p->threadObj();
       
  3476     bool daemon = true;
       
  3477     if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
       
  3478       _number_of_non_daemon_threads--;
       
  3479       daemon = false;
       
  3480 
       
  3481       // Only one thread left, do a notify on the Threads_lock so a thread waiting
       
  3482       // on destroy_vm will wake up.
       
  3483       if (number_of_non_daemon_threads() == 1)
       
  3484         Threads_lock->notify_all();
       
  3485     }
       
  3486     ThreadService::remove_thread(p, daemon);
       
  3487 
       
  3488     // Make sure that safepoint code disregard this thread. This is needed since
       
  3489     // the thread might mess around with locks after this point. This can cause it
       
  3490     // to do callbacks into the safepoint code. However, the safepoint code is not aware
       
  3491     // of this thread since it is removed from the queue.
       
  3492     p->set_terminated_value();
       
  3493   } // unlock Threads_lock
       
  3494 
       
  3495   // Since Events::log uses a lock, we grab it outside the Threads_lock
       
  3496   Events::log("Thread exited: " INTPTR_FORMAT, p);
       
  3497 }
       
  3498 
       
  3499 // Threads_lock must be held when this is called (or must be called during a safepoint)
       
  3500 bool Threads::includes(JavaThread* p) {
       
  3501   assert(Threads_lock->is_locked(), "sanity check");
       
  3502   ALL_JAVA_THREADS(q) {
       
  3503     if (q == p ) {
       
  3504       return true;
       
  3505     }
       
  3506   }
       
  3507   return false;
       
  3508 }
       
  3509 
       
  3510 // Operations on the Threads list for GC.  These are not explicitly locked,
       
  3511 // but the garbage collector must provide a safe context for them to run.
       
  3512 // In particular, these things should never be called when the Threads_lock
       
  3513 // is held by some other thread. (Note: the Safepoint abstraction also
       
  3514 // uses the Threads_lock to gurantee this property. It also makes sure that
       
  3515 // all threads gets blocked when exiting or starting).
       
  3516 
       
  3517 void Threads::oops_do(OopClosure* f) {
       
  3518   ALL_JAVA_THREADS(p) {
       
  3519     p->oops_do(f);
       
  3520   }
       
  3521   VMThread::vm_thread()->oops_do(f);
       
  3522 }
       
  3523 
       
  3524 void Threads::possibly_parallel_oops_do(OopClosure* f) {
       
  3525   // Introduce a mechanism allowing parallel threads to claim threads as
       
  3526   // root groups.  Overhead should be small enough to use all the time,
       
  3527   // even in sequential code.
       
  3528   SharedHeap* sh = SharedHeap::heap();
       
  3529   bool is_par = (sh->n_par_threads() > 0);
       
  3530   int cp = SharedHeap::heap()->strong_roots_parity();
       
  3531   ALL_JAVA_THREADS(p) {
       
  3532     if (p->claim_oops_do(is_par, cp)) {
       
  3533       p->oops_do(f);
       
  3534     }
       
  3535   }
       
  3536   VMThread* vmt = VMThread::vm_thread();
       
  3537   if (vmt->claim_oops_do(is_par, cp))
       
  3538     vmt->oops_do(f);
       
  3539 }
       
  3540 
       
  3541 #ifndef SERIALGC
       
  3542 // Used by ParallelScavenge
       
  3543 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
       
  3544   ALL_JAVA_THREADS(p) {
       
  3545     q->enqueue(new ThreadRootsTask(p));
       
  3546   }
       
  3547   q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
       
  3548 }
       
  3549 
       
  3550 // Used by Parallel Old
       
  3551 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
       
  3552   ALL_JAVA_THREADS(p) {
       
  3553     q->enqueue(new ThreadRootsMarkingTask(p));
       
  3554   }
       
  3555   q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
       
  3556 }
       
  3557 #endif // SERIALGC
       
  3558 
       
  3559 void Threads::nmethods_do() {
       
  3560   ALL_JAVA_THREADS(p) {
       
  3561     p->nmethods_do();
       
  3562   }
       
  3563   VMThread::vm_thread()->nmethods_do();
       
  3564 }
       
  3565 
       
  3566 void Threads::gc_epilogue() {
       
  3567   ALL_JAVA_THREADS(p) {
       
  3568     p->gc_epilogue();
       
  3569   }
       
  3570 }
       
  3571 
       
  3572 void Threads::gc_prologue() {
       
  3573   ALL_JAVA_THREADS(p) {
       
  3574     p->gc_prologue();
       
  3575   }
       
  3576 }
       
  3577 
       
  3578 void Threads::deoptimized_wrt_marked_nmethods() {
       
  3579   ALL_JAVA_THREADS(p) {
       
  3580     p->deoptimized_wrt_marked_nmethods();
       
  3581   }
       
  3582 }
       
  3583 
       
  3584 
       
  3585 // Get count Java threads that are waiting to enter the specified monitor.
       
  3586 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
       
  3587   address monitor, bool doLock) {
       
  3588   assert(doLock || SafepointSynchronize::is_at_safepoint(),
       
  3589     "must grab Threads_lock or be at safepoint");
       
  3590   GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
       
  3591 
       
  3592   int i = 0;
       
  3593   {
       
  3594     MutexLockerEx ml(doLock ? Threads_lock : NULL);
       
  3595     ALL_JAVA_THREADS(p) {
       
  3596       if (p->is_Compiler_thread()) continue;
       
  3597 
       
  3598       address pending = (address)p->current_pending_monitor();
       
  3599       if (pending == monitor) {             // found a match
       
  3600         if (i < count) result->append(p);   // save the first count matches
       
  3601         i++;
       
  3602       }
       
  3603     }
       
  3604   }
       
  3605   return result;
       
  3606 }
       
  3607 
       
  3608 
       
  3609 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
       
  3610   assert(doLock ||
       
  3611          Threads_lock->owned_by_self() ||
       
  3612          SafepointSynchronize::is_at_safepoint(),
       
  3613          "must grab Threads_lock or be at safepoint");
       
  3614 
       
  3615   // NULL owner means not locked so we can skip the search
       
  3616   if (owner == NULL) return NULL;
       
  3617 
       
  3618   {
       
  3619     MutexLockerEx ml(doLock ? Threads_lock : NULL);
       
  3620     ALL_JAVA_THREADS(p) {
       
  3621       // first, see if owner is the address of a Java thread
       
  3622       if (owner == (address)p) return p;
       
  3623     }
       
  3624   }
       
  3625   assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
       
  3626   if (UseHeavyMonitors) return NULL;
       
  3627 
       
  3628   //
       
  3629   // If we didn't find a matching Java thread and we didn't force use of
       
  3630   // heavyweight monitors, then the owner is the stack address of the
       
  3631   // Lock Word in the owning Java thread's stack.
       
  3632   //
       
  3633   // We can't use Thread::is_lock_owned() or Thread::lock_is_in_stack() because
       
  3634   // those routines rely on the "current" stack pointer. That would be our
       
  3635   // stack pointer which is not relevant to the question. Instead we use the
       
  3636   // highest lock ever entered by the thread and find the thread that is
       
  3637   // higher than and closest to our target stack address.
       
  3638   //
       
  3639   address    least_diff = 0;
       
  3640   bool       least_diff_initialized = false;
       
  3641   JavaThread* the_owner = NULL;
       
  3642   {
       
  3643     MutexLockerEx ml(doLock ? Threads_lock : NULL);
       
  3644     ALL_JAVA_THREADS(q) {
       
  3645       address addr = q->highest_lock();
       
  3646       if (addr == NULL || addr < owner) continue;  // thread has entered no monitors or is too low
       
  3647       address diff = (address)(addr - owner);
       
  3648       if (!least_diff_initialized || diff < least_diff) {
       
  3649         least_diff_initialized = true;
       
  3650         least_diff = diff;
       
  3651         the_owner = q;
       
  3652       }
       
  3653     }
       
  3654   }
       
  3655   assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
       
  3656   return the_owner;
       
  3657 }
       
  3658 
       
  3659 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
       
  3660 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
       
  3661   char buf[32];
       
  3662   st->print_cr(os::local_time_string(buf, sizeof(buf)));
       
  3663 
       
  3664   st->print_cr("Full thread dump %s (%s %s):",
       
  3665                 Abstract_VM_Version::vm_name(),
       
  3666                 Abstract_VM_Version::vm_release(),
       
  3667                 Abstract_VM_Version::vm_info_string()
       
  3668                );
       
  3669   st->cr();
       
  3670 
       
  3671 #ifndef SERIALGC
       
  3672   // Dump concurrent locks
       
  3673   ConcurrentLocksDump concurrent_locks;
       
  3674   if (print_concurrent_locks) {
       
  3675     concurrent_locks.dump_at_safepoint();
       
  3676   }
       
  3677 #endif // SERIALGC
       
  3678 
       
  3679   ALL_JAVA_THREADS(p) {
       
  3680     ResourceMark rm;
       
  3681     p->print_on(st);
       
  3682     if (print_stacks) {
       
  3683       if (internal_format) {
       
  3684         p->trace_stack();
       
  3685       } else {
       
  3686         p->print_stack_on(st);
       
  3687       }
       
  3688     }
       
  3689     st->cr();
       
  3690 #ifndef SERIALGC
       
  3691     if (print_concurrent_locks) {
       
  3692       concurrent_locks.print_locks_on(p, st);
       
  3693     }
       
  3694 #endif // SERIALGC
       
  3695   }
       
  3696 
       
  3697   VMThread::vm_thread()->print_on(st);
       
  3698   st->cr();
       
  3699   Universe::heap()->print_gc_threads_on(st);
       
  3700   WatcherThread* wt = WatcherThread::watcher_thread();
       
  3701   if (wt != NULL) wt->print_on(st);
       
  3702   st->cr();
       
  3703   CompileBroker::print_compiler_threads_on(st);
       
  3704   st->flush();
       
  3705 }
       
  3706 
       
  3707 // Threads::print_on_error() is called by fatal error handler. It's possible
       
  3708 // that VM is not at safepoint and/or current thread is inside signal handler.
       
  3709 // Don't print stack trace, as the stack may not be walkable. Don't allocate
       
  3710 // memory (even in resource area), it might deadlock the error handler.
       
  3711 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
       
  3712   bool found_current = false;
       
  3713   st->print_cr("Java Threads: ( => current thread )");
       
  3714   ALL_JAVA_THREADS(thread) {
       
  3715     bool is_current = (current == thread);
       
  3716     found_current = found_current || is_current;
       
  3717 
       
  3718     st->print("%s", is_current ? "=>" : "  ");
       
  3719 
       
  3720     st->print(PTR_FORMAT, thread);
       
  3721     st->print(" ");
       
  3722     thread->print_on_error(st, buf, buflen);
       
  3723     st->cr();
       
  3724   }
       
  3725   st->cr();
       
  3726 
       
  3727   st->print_cr("Other Threads:");
       
  3728   if (VMThread::vm_thread()) {
       
  3729     bool is_current = (current == VMThread::vm_thread());
       
  3730     found_current = found_current || is_current;
       
  3731     st->print("%s", current == VMThread::vm_thread() ? "=>" : "  ");
       
  3732 
       
  3733     st->print(PTR_FORMAT, VMThread::vm_thread());
       
  3734     st->print(" ");
       
  3735     VMThread::vm_thread()->print_on_error(st, buf, buflen);
       
  3736     st->cr();
       
  3737   }
       
  3738   WatcherThread* wt = WatcherThread::watcher_thread();
       
  3739   if (wt != NULL) {
       
  3740     bool is_current = (current == wt);
       
  3741     found_current = found_current || is_current;
       
  3742     st->print("%s", is_current ? "=>" : "  ");
       
  3743 
       
  3744     st->print(PTR_FORMAT, wt);
       
  3745     st->print(" ");
       
  3746     wt->print_on_error(st, buf, buflen);
       
  3747     st->cr();
       
  3748   }
       
  3749   if (!found_current) {
       
  3750     st->cr();
       
  3751     st->print("=>" PTR_FORMAT " (exited) ", current);
       
  3752     current->print_on_error(st, buf, buflen);
       
  3753     st->cr();
       
  3754   }
       
  3755 }
       
  3756 
       
  3757 
       
  3758 // Lifecycle management for TSM ParkEvents.
       
  3759 // ParkEvents are type-stable (TSM).
       
  3760 // In our particular implementation they happen to be immortal.
       
  3761 //
       
  3762 // We manage concurrency on the FreeList with a CAS-based
       
  3763 // detach-modify-reattach idiom that avoids the ABA problems
       
  3764 // that would otherwise be present in a simple CAS-based
       
  3765 // push-pop implementation.   (push-one and pop-all)
       
  3766 //
       
  3767 // Caveat: Allocate() and Release() may be called from threads
       
  3768 // other than the thread associated with the Event!
       
  3769 // If we need to call Allocate() when running as the thread in
       
  3770 // question then look for the PD calls to initialize native TLS.
       
  3771 // Native TLS (Win32/Linux/Solaris) can only be initialized or
       
  3772 // accessed by the associated thread.
       
  3773 // See also pd_initialize().
       
  3774 //
       
  3775 // Note that we could defer associating a ParkEvent with a thread
       
  3776 // until the 1st time the thread calls park().  unpark() calls to
       
  3777 // an unprovisioned thread would be ignored.  The first park() call
       
  3778 // for a thread would allocate and associate a ParkEvent and return
       
  3779 // immediately.
       
  3780 
       
  3781 volatile int ParkEvent::ListLock = 0 ;
       
  3782 ParkEvent * volatile ParkEvent::FreeList = NULL ;
       
  3783 
       
  3784 ParkEvent * ParkEvent::Allocate (Thread * t) {
       
  3785   // In rare cases -- JVM_RawMonitor* operations -- we can find t == null.
       
  3786   ParkEvent * ev ;
       
  3787 
       
  3788   // Start by trying to recycle an existing but unassociated
       
  3789   // ParkEvent from the global free list.
       
  3790   for (;;) {
       
  3791     ev = FreeList ;
       
  3792     if (ev == NULL) break ;
       
  3793     // 1: Detach - sequester or privatize the list
       
  3794     // Tantamount to ev = Swap (&FreeList, NULL)
       
  3795     if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) {
       
  3796        continue ;
       
  3797     }
       
  3798 
       
  3799     // We've detached the list.  The list in-hand is now
       
  3800     // local to this thread.   This thread can operate on the
       
  3801     // list without risk of interference from other threads.
       
  3802     // 2: Extract -- pop the 1st element from the list.
       
  3803     ParkEvent * List = ev->FreeNext ;
       
  3804     if (List == NULL) break ;
       
  3805     for (;;) {
       
  3806         // 3: Try to reattach the residual list
       
  3807         guarantee (List != NULL, "invariant") ;
       
  3808         ParkEvent * Arv =  (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
       
  3809         if (Arv == NULL) break ;
       
  3810 
       
  3811         // New nodes arrived.  Try to detach the recent arrivals.
       
  3812         if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
       
  3813             continue ;
       
  3814         }
       
  3815         guarantee (Arv != NULL, "invariant") ;
       
  3816         // 4: Merge Arv into List
       
  3817         ParkEvent * Tail = List ;
       
  3818         while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
       
  3819         Tail->FreeNext = Arv ;
       
  3820     }
       
  3821     break ;
       
  3822   }
       
  3823 
       
  3824   if (ev != NULL) {
       
  3825     guarantee (ev->AssociatedWith == NULL, "invariant") ;
       
  3826   } else {
       
  3827     // Do this the hard way -- materialize a new ParkEvent.
       
  3828     // In rare cases an allocating thread might detach a long list --
       
  3829     // installing null into FreeList -- and then stall or be obstructed.
       
  3830     // A 2nd thread calling Allocate() would see FreeList == null.
       
  3831     // The list held privately by the 1st thread is unavailable to the 2nd thread.
       
  3832     // In that case the 2nd thread would have to materialize a new ParkEvent,
       
  3833     // even though free ParkEvents existed in the system.  In this case we end up
       
  3834     // with more ParkEvents in circulation than we need, but the race is
       
  3835     // rare and the outcome is benign.  Ideally, the # of extant ParkEvents
       
  3836     // is equal to the maximum # of threads that existed at any one time.
       
  3837     // Because of the race mentioned above, segments of the freelist
       
  3838     // can be transiently inaccessible.  At worst we may end up with the
       
  3839     // # of ParkEvents in circulation slightly above the ideal.
       
  3840     // Note that if we didn't have the TSM/immortal constraint, then
       
  3841     // when reattaching, above, we could trim the list.
       
  3842     ev = new ParkEvent () ;
       
  3843     guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ;
       
  3844   }
       
  3845   ev->reset() ;                     // courtesy to caller
       
  3846   ev->AssociatedWith = t ;          // Associate ev with t
       
  3847   ev->FreeNext       = NULL ;
       
  3848   return ev ;
       
  3849 }
       
  3850 
       
  3851 void ParkEvent::Release (ParkEvent * ev) {
       
  3852   if (ev == NULL) return ;
       
  3853   guarantee (ev->FreeNext == NULL      , "invariant") ;
       
  3854   ev->AssociatedWith = NULL ;
       
  3855   for (;;) {
       
  3856     // Push ev onto FreeList
       
  3857     // The mechanism is "half" lock-free.
       
  3858     ParkEvent * List = FreeList ;
       
  3859     ev->FreeNext = List ;
       
  3860     if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ;
       
  3861   }
       
  3862 }
       
  3863 
       
  3864 // Override operator new and delete so we can ensure that the
       
  3865 // least significant byte of ParkEvent addresses is 0.
       
  3866 // Beware that excessive address alignment is undesirable
       
  3867 // as it can result in D$ index usage imbalance as
       
  3868 // well as bank access imbalance on Niagara-like platforms,
       
  3869 // although Niagara's hash function should help.
       
  3870 
       
  3871 void * ParkEvent::operator new (size_t sz) {
       
  3872   return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ;
       
  3873 }
       
  3874 
       
  3875 void ParkEvent::operator delete (void * a) {
       
  3876   // ParkEvents are type-stable and immortal ...
       
  3877   ShouldNotReachHere();
       
  3878 }
       
  3879 
       
  3880 
       
  3881 // 6399321 As a temporary measure we copied & modified the ParkEvent::
       
  3882 // allocate() and release() code for use by Parkers.  The Parker:: forms
       
  3883 // will eventually be removed as we consolide and shift over to ParkEvents
       
  3884 // for both builtin synchronization and JSR166 operations.
       
  3885 
       
  3886 volatile int Parker::ListLock = 0 ;
       
  3887 Parker * volatile Parker::FreeList = NULL ;
       
  3888 
       
  3889 Parker * Parker::Allocate (JavaThread * t) {
       
  3890   guarantee (t != NULL, "invariant") ;
       
  3891   Parker * p ;
       
  3892 
       
  3893   // Start by trying to recycle an existing but unassociated
       
  3894   // Parker from the global free list.
       
  3895   for (;;) {
       
  3896     p = FreeList ;
       
  3897     if (p  == NULL) break ;
       
  3898     // 1: Detach
       
  3899     // Tantamount to p = Swap (&FreeList, NULL)
       
  3900     if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) {
       
  3901        continue ;
       
  3902     }
       
  3903 
       
  3904     // We've detached the list.  The list in-hand is now
       
  3905     // local to this thread.   This thread can operate on the
       
  3906     // list without risk of interference from other threads.
       
  3907     // 2: Extract -- pop the 1st element from the list.
       
  3908     Parker * List = p->FreeNext ;
       
  3909     if (List == NULL) break ;
       
  3910     for (;;) {
       
  3911         // 3: Try to reattach the residual list
       
  3912         guarantee (List != NULL, "invariant") ;
       
  3913         Parker * Arv =  (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
       
  3914         if (Arv == NULL) break ;
       
  3915 
       
  3916         // New nodes arrived.  Try to detach the recent arrivals.
       
  3917         if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
       
  3918             continue ;
       
  3919         }
       
  3920         guarantee (Arv != NULL, "invariant") ;
       
  3921         // 4: Merge Arv into List
       
  3922         Parker * Tail = List ;
       
  3923         while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
       
  3924         Tail->FreeNext = Arv ;
       
  3925     }
       
  3926     break ;
       
  3927   }
       
  3928 
       
  3929   if (p != NULL) {
       
  3930     guarantee (p->AssociatedWith == NULL, "invariant") ;
       
  3931   } else {
       
  3932     // Do this the hard way -- materialize a new Parker..
       
  3933     // In rare cases an allocating thread might detach
       
  3934     // a long list -- installing null into FreeList --and
       
  3935     // then stall.  Another thread calling Allocate() would see
       
  3936     // FreeList == null and then invoke the ctor.  In this case we
       
  3937     // end up with more Parkers in circulation than we need, but
       
  3938     // the race is rare and the outcome is benign.
       
  3939     // Ideally, the # of extant Parkers is equal to the
       
  3940     // maximum # of threads that existed at any one time.
       
  3941     // Because of the race mentioned above, segments of the
       
  3942     // freelist can be transiently inaccessible.  At worst
       
  3943     // we may end up with the # of Parkers in circulation
       
  3944     // slightly above the ideal.
       
  3945     p = new Parker() ;
       
  3946   }
       
  3947   p->AssociatedWith = t ;          // Associate p with t
       
  3948   p->FreeNext       = NULL ;
       
  3949   return p ;
       
  3950 }
       
  3951 
       
  3952 
       
  3953 void Parker::Release (Parker * p) {
       
  3954   if (p == NULL) return ;
       
  3955   guarantee (p->AssociatedWith != NULL, "invariant") ;
       
  3956   guarantee (p->FreeNext == NULL      , "invariant") ;
       
  3957   p->AssociatedWith = NULL ;
       
  3958   for (;;) {
       
  3959     // Push p onto FreeList
       
  3960     Parker * List = FreeList ;
       
  3961     p->FreeNext = List ;
       
  3962     if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ;
       
  3963   }
       
  3964 }
       
  3965 
       
  3966 void Threads::verify() {
       
  3967   ALL_JAVA_THREADS(p) {
       
  3968     p->verify();
       
  3969   }
       
  3970   VMThread* thread = VMThread::vm_thread();
       
  3971   if (thread != NULL) thread->verify();
       
  3972 }