jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/shared/concurrentGCThread.cpp@55a0da3d420b (annotated)

src/share/vm/gc_implementation/shared/concurrentGCThread.cpp@55a0da3d420b (annotated)

src/share/vm/gc_implementation/shared/concurrentGCThread.cpp

Tue, 26 Nov 2013 14:35:38 +0100

author: sjohanss
date: Tue, 26 Nov 2013 14:35:38 +0100
changeset 6148: 55a0da3d420b
parent 4047: aed758eda82a
child 6876: 710a3c8b516e
child 6906: 581e70386ec9
permissions: -rw-r--r--

8027675: Full collections with Serial slower in JDK 8 compared to 7u40
Summary: Reduced the number of calls to follow_class_loader and instead marked and pushed the klass holder directly. Also removed unneeded calls to adjust_klass.
Reviewed-by: coleenp, jmasa, mgerdin, tschatzl

 /*
  * Copyright (c) 2001, 2012, 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/systemDictionary.hpp"
 #include "gc_implementation/shared/concurrentGCThread.hpp"
 #include "oops/instanceRefKlass.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/init.hpp"
 #include "runtime/interfaceSupport.hpp"
 #include "runtime/java.hpp"
 #include "runtime/javaCalls.hpp"
 // CopyrightVersion 1.2
 int  ConcurrentGCThread::_CGC_flag            = CGC_nil;
 SuspendibleThreadSet ConcurrentGCThread::_sts;
 ConcurrentGCThread::ConcurrentGCThread() :
   _should_terminate(false), _has_terminated(false) {
   _sts.initialize();
 };
 void ConcurrentGCThread::safepoint_synchronize() {
   _sts.suspend_all();
 }
 void ConcurrentGCThread::safepoint_desynchronize() {
   _sts.resume_all();
 }
 void ConcurrentGCThread::create_and_start() {
   if (os::create_thread(this, os::cgc_thread)) {
     // XXX: need to set this to low priority
     // unless "agressive mode" set; priority
     // should be just less than that of VMThread.
     os::set_priority(this, NearMaxPriority);
     if (!_should_terminate && !DisableStartThread) {
       os::start_thread(this);
     }
   }
 }
 void ConcurrentGCThread::initialize_in_thread() {
   this->record_stack_base_and_size();
   this->initialize_thread_local_storage();
   this->set_active_handles(JNIHandleBlock::allocate_block());
   // From this time Thread::current() should be working.
   assert(this == Thread::current(), "just checking");
 }
 void ConcurrentGCThread::wait_for_universe_init() {
   MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
   while (!is_init_completed() && !_should_terminate) {
     CGC_lock->wait(Mutex::_no_safepoint_check_flag, 200);
   }
 }
 void ConcurrentGCThread::terminate() {
   // Signal that it is terminated
   {
     MutexLockerEx mu(Terminator_lock,
                      Mutex::_no_safepoint_check_flag);
     _has_terminated = true;
     Terminator_lock->notify();
   }
   // Thread destructor usually does this..
   ThreadLocalStorage::set_thread(NULL);
 }
 void SuspendibleThreadSet::initialize_work() {
   MutexLocker x(STS_init_lock);
   if (!_initialized) {
     _m             = new Monitor(Mutex::leaf,
                                  "SuspendibleThreadSetLock", true);
     _async         = 0;
     _async_stop    = false;
     _async_stopped = 0;
     _initialized   = true;
   }
 }
 void SuspendibleThreadSet::join() {
   initialize();
   MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   while (_async_stop) _m->wait(Mutex::_no_safepoint_check_flag);
   _async++;
   assert(_async > 0, "Huh.");
 }
 void SuspendibleThreadSet::leave() {
   assert(_initialized, "Must be initialized.");
   MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   _async--;
   assert(_async >= 0, "Huh.");
   if (_async_stop) _m->notify_all();
 }
 void SuspendibleThreadSet::yield(const char* id) {
   assert(_initialized, "Must be initialized.");
   if (_async_stop) {
     MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
     if (_async_stop) {
       _async_stopped++;
       assert(_async_stopped > 0, "Huh.");
       if (_async_stopped == _async) {
         if (ConcGCYieldTimeout > 0) {
           double now = os::elapsedTime();
           guarantee((now - _suspend_all_start) * 1000.0 <
                     (double)ConcGCYieldTimeout,
                     "Long delay; whodunit?");
         }
       }
       _m->notify_all();
       while (_async_stop) _m->wait(Mutex::_no_safepoint_check_flag);
       _async_stopped--;
       assert(_async >= 0, "Huh");
       _m->notify_all();
     }
   }
 }
 void SuspendibleThreadSet::suspend_all() {
   initialize();  // If necessary.
   if (ConcGCYieldTimeout > 0) {
     _suspend_all_start = os::elapsedTime();
   }
   MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   assert(!_async_stop, "Only one at a time.");
   _async_stop = true;
   while (_async_stopped < _async) _m->wait(Mutex::_no_safepoint_check_flag);
 }
 void SuspendibleThreadSet::resume_all() {
   assert(_initialized, "Must be initialized.");
   MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   assert(_async_stopped == _async, "Huh.");
   _async_stop = false;
   _m->notify_all();
 }
 static void _sltLoop(JavaThread* thread, TRAPS) {
   SurrogateLockerThread* slt = (SurrogateLockerThread*)thread;
   slt->loop();
 }
 SurrogateLockerThread::SurrogateLockerThread() :
   JavaThread(&_sltLoop),
   _monitor(Mutex::nonleaf, "SLTMonitor"),
   _buffer(empty)
 {}
 SurrogateLockerThread* SurrogateLockerThread::make(TRAPS) {
   Klass* k =
     SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(),
                                       true, CHECK_NULL);
   instanceKlassHandle klass (THREAD, k);
   instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
   const char thread_name[] = "Surrogate Locker Thread (Concurrent GC)";
   Handle string = java_lang_String::create_from_str(thread_name, CHECK_NULL);
   // Initialize thread_oop to put it into the system threadGroup
   Handle thread_group (THREAD, Universe::system_thread_group());
   JavaValue result(T_VOID);
   JavaCalls::call_special(&result, thread_oop,
                           klass,
                           vmSymbols::object_initializer_name(),
                           vmSymbols::threadgroup_string_void_signature(),
                           thread_group,
                           string,
                           CHECK_NULL);
   SurrogateLockerThread* res;
   {
     MutexLocker mu(Threads_lock);
     res = new SurrogateLockerThread();
     // At this point it may be possible that no osthread was created for the
     // JavaThread due to lack of memory. We would have to throw an exception
     // in that case. However, since this must work and we do not allow
     // exceptions anyway, check and abort if this fails.
     if (res == NULL || res->osthread() == NULL) {
       vm_exit_during_initialization("java.lang.OutOfMemoryError",
                                     "unable to create new native thread");
     }
     java_lang_Thread::set_thread(thread_oop(), res);
     java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
     java_lang_Thread::set_daemon(thread_oop());
     res->set_threadObj(thread_oop());
     Threads::add(res);
     Thread::start(res);
   }
   os::yield(); // This seems to help with initial start-up of SLT
   return res;
 }
 void SurrogateLockerThread::manipulatePLL(SLT_msg_type msg) {
   MutexLockerEx x(&_monitor, Mutex::_no_safepoint_check_flag);
   assert(_buffer == empty, "Should be empty");
   assert(msg != empty, "empty message");
   assert(!Heap_lock->owned_by_self(), "Heap_lock owned by requesting thread");
   _buffer = msg;
   while (_buffer != empty) {
     _monitor.notify();
     _monitor.wait(Mutex::_no_safepoint_check_flag);
   }
 }
 // ======= Surrogate Locker Thread =============
 void SurrogateLockerThread::loop() {
   BasicLock pll_basic_lock;
   SLT_msg_type msg;
   debug_only(unsigned int owned = 0;)
   while (/* !isTerminated() */ 1) {
     {
       MutexLocker x(&_monitor);
       // Since we are a JavaThread, we can't be here at a safepoint.
       assert(!SafepointSynchronize::is_at_safepoint(),
              "SLT is a JavaThread");
       // wait for msg buffer to become non-empty
       while (_buffer == empty) {
         _monitor.notify();
         _monitor.wait();
       }
       msg = _buffer;
     }
     switch(msg) {
       case acquirePLL: {
         InstanceRefKlass::acquire_pending_list_lock(&pll_basic_lock);
         debug_only(owned++;)
         break;
       }
       case releaseAndNotifyPLL: {
         assert(owned > 0, "Don't have PLL");
         InstanceRefKlass::release_and_notify_pending_list_lock(&pll_basic_lock);
         debug_only(owned--;)
         break;
       }
       case empty:
       default: {
         guarantee(false,"Unexpected message in _buffer");
         break;
       }
     }
     {
       MutexLocker x(&_monitor);
       // Since we are a JavaThread, we can't be here at a safepoint.
       assert(!SafepointSynchronize::is_at_safepoint(),
              "SLT is a JavaThread");
       _buffer = empty;
       _monitor.notify();
     }
   }
   assert(!_monitor.owned_by_self(), "Should unlock before exit.");
 }
 // ===== STS Access From Outside CGCT =====
 void ConcurrentGCThread::stsYield(const char* id) {
   assert( Thread::current()->is_ConcurrentGC_thread(),
           "only a conc GC thread can call this" );
   _sts.yield(id);
 }
 bool ConcurrentGCThread::stsShouldYield() {
   assert( Thread::current()->is_ConcurrentGC_thread(),
           "only a conc GC thread can call this" );
   return _sts.should_yield();
 }
 void ConcurrentGCThread::stsJoin() {
   assert( Thread::current()->is_ConcurrentGC_thread(),
           "only a conc GC thread can call this" );
   _sts.join();
 }
 void ConcurrentGCThread::stsLeave() {
   assert( Thread::current()->is_ConcurrentGC_thread(),
           "only a conc GC thread can call this" );
   _sts.leave();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/shared/concurrentGCThread.cpp@55a0da3d420b (annotated)

src/share/vm/gc_implementation/shared/concurrentGCThread.cpp