Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "classfile/symbolTable.hpp"

 #include "classfile/vmSymbols.hpp"

 #include "compiler/compileBroker.hpp"

 #include "compiler/compilerOracle.hpp"

 #include "gc_implementation/shared/isGCActiveMark.hpp"

 #include "memory/resourceArea.hpp"

 #include "oops/symbol.hpp"

 #include "runtime/arguments.hpp"

 #include "runtime/deoptimization.hpp"

 #include "runtime/interfaceSupport.hpp"

 #include "runtime/sweeper.hpp"

 #include "runtime/thread.inline.hpp"

 #include "runtime/vm_operations.hpp"

 #include "services/threadService.hpp"

 #include "trace/tracing.hpp"

 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

 #define VM_OP_NAME_INITIALIZE(name) #name,

 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \

   { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };

 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {

   _calling_thread = thread;

   assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");

   _priority = priority;

 }

 void VM_Operation::evaluate() {

   ResourceMark rm;

   if (TraceVMOperation) {

     tty->print("[");

     NOT_PRODUCT(print();)

   }

   doit();

   if (TraceVMOperation) {

     tty->print_cr("]");

   }

 }

 const char* VM_Operation::mode_to_string(Mode mode) {

   switch(mode) {

     case _safepoint      : return "safepoint";

     case _no_safepoint   : return "no safepoint";

     case _concurrent     : return "concurrent";

     case _async_safepoint: return "async safepoint";

     default              : return "unknown";

   }

 }

 // Called by fatal error handler.

 void VM_Operation::print_on_error(outputStream* st) const {

   st->print("VM_Operation (" PTR_FORMAT "): ", this);

   st->print("%s", name());

   const char* mode = mode_to_string(evaluation_mode());

   st->print(", mode: %s", mode);

   if (calling_thread()) {

     st->print(", requested by thread " PTR_FORMAT, calling_thread());

   }

 }

 void VM_ThreadStop::doit() {

   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");

   JavaThread* target = java_lang_Thread::thread(target_thread());

   // Note that this now allows multiple ThreadDeath exceptions to be

   // thrown at a thread.

   if (target != NULL) {

     // the thread has run and is not already in the process of exiting

     target->send_thread_stop(throwable());

   }

 }

 void VM_Deoptimize::doit() {

   // We do not want any GCs to happen while we are in the middle of this VM operation

   ResourceMark rm;

   DeoptimizationMarker dm;

   // Deoptimize all activations depending on marked nmethods

   Deoptimization::deoptimize_dependents();

   // Make the dependent methods not entrant

   CodeCache::make_marked_nmethods_not_entrant();

 }

 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) {

   _thread = thread;

   _id     = id;

 }

 void VM_DeoptimizeFrame::doit() {

   Deoptimization::deoptimize_frame_internal(_thread, _id);

 }

 #ifndef PRODUCT

 void VM_DeoptimizeAll::doit() {

   DeoptimizationMarker dm;

   // deoptimize all java threads in the system

   if (DeoptimizeALot) {

     for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {

       if (thread->has_last_Java_frame()) {

         thread->deoptimize();

       }

     }

   } else if (DeoptimizeRandom) {

     // Deoptimize some selected threads and frames

     int tnum = os::random() & 0x3;

     int fnum =  os::random() & 0x3;

     int tcount = 0;

     for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {

       if (thread->has_last_Java_frame()) {

         if (tcount++ == tnum)  {

         tcount = 0;

           int fcount = 0;

           // Deoptimize some selected frames.

           // Biased llocking wants a updated register map

           for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {

             if (fst.current()->can_be_deoptimized()) {

               if (fcount++ == fnum) {

                 fcount = 0;

                 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());

               }

             }

           }

         }

       }

     }

   }

 }

 void VM_ZombieAll::doit() {

   JavaThread *thread = (JavaThread *)calling_thread();

   assert(thread->is_Java_thread(), "must be a Java thread");

   thread->make_zombies();

 }

 #endif // !PRODUCT

 void VM_UnlinkSymbols::doit() {

   JavaThread *thread = (JavaThread *)calling_thread();

   assert(thread->is_Java_thread(), "must be a Java thread");

   SymbolTable::unlink();

 }

 void VM_Verify::doit() {

   Universe::heap()->prepare_for_verify();

   Universe::verify(_silent);

 }

 bool VM_PrintThreads::doit_prologue() {

   assert(Thread::current()->is_Java_thread(), "just checking");

   // Make sure AbstractOwnableSynchronizer is loaded

   if (JDK_Version::is_gte_jdk16x_version()) {

     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());

   }

   // Get Heap_lock if concurrent locks will be dumped

   if (_print_concurrent_locks) {

     Heap_lock->lock();

   }

   return true;

 }

 void VM_PrintThreads::doit() {

   Threads::print_on(_out, true, false, _print_concurrent_locks);

 }

 void VM_PrintThreads::doit_epilogue() {

   if (_print_concurrent_locks) {

     // Release Heap_lock

     Heap_lock->unlock();

   }

 }

 void VM_PrintJNI::doit() {

   JNIHandles::print_on(_out);

 }

 VM_FindDeadlocks::~VM_FindDeadlocks() {

   if (_deadlocks != NULL) {

     DeadlockCycle* cycle = _deadlocks;

     while (cycle != NULL) {

       DeadlockCycle* d = cycle;

       cycle = cycle->next();

       delete d;

     }

   }

 }

 bool VM_FindDeadlocks::doit_prologue() {

   assert(Thread::current()->is_Java_thread(), "just checking");

   // Load AbstractOwnableSynchronizer class

   if (_concurrent_locks && JDK_Version::is_gte_jdk16x_version()) {

     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());

   }

   return true;

 }

 void VM_FindDeadlocks::doit() {

   _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);

   if (_out != NULL) {

     int num_deadlocks = 0;

     for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {

       num_deadlocks++;

       cycle->print_on(_out);

     }

     if (num_deadlocks == 1) {

       _out->print_cr("\nFound 1 deadlock.\n");

       _out->flush();

     } else if (num_deadlocks > 1) {

       _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);

       _out->flush();

     }

   }

 }

 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,

                              int max_depth,

                              bool with_locked_monitors,

                              bool with_locked_synchronizers) {

   _result = result;

   _num_threads = 0; // 0 indicates all threads

   _threads = NULL;

   _result = result;

   _max_depth = max_depth;

   _with_locked_monitors = with_locked_monitors;

   _with_locked_synchronizers = with_locked_synchronizers;

 }

 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,

                              GrowableArray<instanceHandle>* threads,

                              int num_threads,

                              int max_depth,

                              bool with_locked_monitors,

                              bool with_locked_synchronizers) {

   _result = result;

   _num_threads = num_threads;

   _threads = threads;

   _result = result;

   _max_depth = max_depth;

   _with_locked_monitors = with_locked_monitors;

   _with_locked_synchronizers = with_locked_synchronizers;

 }

 bool VM_ThreadDump::doit_prologue() {

   assert(Thread::current()->is_Java_thread(), "just checking");

   // Load AbstractOwnableSynchronizer class before taking thread snapshots

   if (JDK_Version::is_gte_jdk16x_version()) {

     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());

   }

   if (_with_locked_synchronizers) {

     // Acquire Heap_lock to dump concurrent locks

     Heap_lock->lock();

   }

   return true;

 }

 void VM_ThreadDump::doit_epilogue() {

   if (_with_locked_synchronizers) {

     // Release Heap_lock

     Heap_lock->unlock();

   }

 }

 void VM_ThreadDump::doit() {

   ResourceMark rm;

   ConcurrentLocksDump concurrent_locks(true);

   if (_with_locked_synchronizers) {

     concurrent_locks.dump_at_safepoint();

   }

   if (_num_threads == 0) {

     // Snapshot all live threads

     for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {

       if (jt->is_exiting() ||

           jt->is_hidden_from_external_view())  {

         // skip terminating threads and hidden threads

         continue;

       }

       ThreadConcurrentLocks* tcl = NULL;

       if (_with_locked_synchronizers) {

         tcl = concurrent_locks.thread_concurrent_locks(jt);

       }

       ThreadSnapshot* ts = snapshot_thread(jt, tcl);

       _result->add_thread_snapshot(ts);

     }

   } else {

     // Snapshot threads in the given _threads array

     // A dummy snapshot is created if a thread doesn't exist

     for (int i = 0; i < _num_threads; i++) {

       instanceHandle th = _threads->at(i);

       if (th() == NULL) {

         // skip if the thread doesn't exist

         // Add a dummy snapshot

         _result->add_thread_snapshot(new ThreadSnapshot());

         continue;

       }

       // Dump thread stack only if the thread is alive and not exiting

       // and not VM internal thread.

       JavaThread* jt = java_lang_Thread::thread(th());

       if (jt == NULL || /* thread not alive */

           jt->is_exiting() ||

           jt->is_hidden_from_external_view())  {

         // add a NULL snapshot if skipped

         _result->add_thread_snapshot(new ThreadSnapshot());

         continue;

       }

       ThreadConcurrentLocks* tcl = NULL;

       if (_with_locked_synchronizers) {

         tcl = concurrent_locks.thread_concurrent_locks(jt);

       }

       ThreadSnapshot* ts = snapshot_thread(jt, tcl);

       _result->add_thread_snapshot(ts);

     }

   }

 }

 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {

   ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);

   snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);

   snapshot->set_concurrent_locks(tcl);

   return snapshot;

 }

 volatile bool VM_Exit::_vm_exited = false;

 Thread * VM_Exit::_shutdown_thread = NULL;

 int VM_Exit::set_vm_exited() {

   Thread * thr_cur = ThreadLocalStorage::get_thread_slow();

   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");

   int num_active = 0;

   _shutdown_thread = thr_cur;

   _vm_exited = true;                                // global flag

   for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())

     if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {

       ++num_active;

       thr->set_terminated(JavaThread::_vm_exited);  // per-thread flag

     }

   return num_active;

 }

 int VM_Exit::wait_for_threads_in_native_to_block() {

   // VM exits at safepoint. This function must be called at the final safepoint

   // to wait for threads in _thread_in_native state to be quiescent.

   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");

   Thread * thr_cur = ThreadLocalStorage::get_thread_slow();

   Monitor timer(Mutex::leaf, "VM_Exit timer", true);

   // Compiler threads need longer wait because they can access VM data directly

   // while in native. If they are active and some structures being used are

   // deleted by the shutdown sequence, they will crash. On the other hand, user

   // threads must go through native=>Java/VM transitions first to access VM

   // data, and they will be stopped during state transition. In theory, we

   // don't have to wait for user threads to be quiescent, but it's always

   // better to terminate VM when current thread is the only active thread, so

   // wait for user threads too. Numbers are in 10 milliseconds.

   int max_wait_user_thread = 30;                  // at least 300 milliseconds

   int max_wait_compiler_thread = 1000;            // at least 10 seconds

   int max_wait = max_wait_compiler_thread;

   int attempts = 0;

   while (true) {

     int num_active = 0;

     int num_active_compiler_thread = 0;

     for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {

       if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {

         num_active++;

         if (thr->is_Compiler_thread()) {

           num_active_compiler_thread++;

         }

       }

     }

     if (num_active == 0) {

        return 0;

     } else if (attempts > max_wait) {

        return num_active;

     } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {

        return num_active;

     }

     attempts++;

     MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);

     timer.wait(Mutex::_no_safepoint_check_flag, 10);

   }

 }

 void VM_Exit::doit() {

   CompileBroker::set_should_block();

   // Wait for a short period for threads in native to block. Any thread

   // still executing native code after the wait will be stopped at

   // native==>Java/VM barriers.

   // Among 16276 JCK tests, 94% of them come here without any threads still

   // running in native; the other 6% are quiescent within 250ms (Ultra 80).

   wait_for_threads_in_native_to_block();

   set_vm_exited();

   // cleanup globals resources before exiting. exit_globals() currently

   // cleans up outputStream resources and PerfMemory resources.

   exit_globals();

   // Check for exit hook

   exit_hook_t exit_hook = Arguments::exit_hook();

   if (exit_hook != NULL) {

     // exit hook should exit.

     exit_hook(_exit_code);

     // ... but if it didn't, we must do it here

     vm_direct_exit(_exit_code);

   } else {

     vm_direct_exit(_exit_code);

   }

 }

 void VM_Exit::wait_if_vm_exited() {

   if (_vm_exited &&

       ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {

     // _vm_exited is set at safepoint, and the Threads_lock is never released

     // we will block here until the process dies

     Threads_lock->lock_without_safepoint_check();

     ShouldNotReachHere();

   }

 }