jdk8-mips64-public/hotspot: src/share/vm/runtime/serviceThread.cpp@216d916d5c12 (annotated)

src/share/vm/runtime/serviceThread.cpp@216d916d5c12 (annotated)

src/share/vm/runtime/serviceThread.cpp

Tue, 15 Mar 2011 06:35:10 -0700

author: dcubed
date: Tue, 15 Mar 2011 06:35:10 -0700
changeset 2623: 216d916d5c12
parent 2511: bf8517f4e4d0
child 2888: 78542e2b5e35
permissions: -rw-r--r--

7024234: 2/3 jvmti tests fail assert(!_oops_are_stale) failed: oops are stale on Win-AMD64
Summary: Move initialization of the '_instance' field to avoid race with ServiceThread start.
Reviewed-by: dholmes, kamg, never, dsamersoff, ysr, coleenp, acorn

 /*
  * Copyright (c) 2011, 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 "runtime/interfaceSupport.hpp"
 #include "runtime/javaCalls.hpp"
 #include "runtime/serviceThread.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "prims/jvmtiImpl.hpp"
 ServiceThread* ServiceThread::_instance = NULL;
 void ServiceThread::initialize() {
   EXCEPTION_MARK;
   instanceKlassHandle klass (THREAD,  SystemDictionary::Thread_klass());
   instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
   const char* name = JDK_Version::is_gte_jdk17x_version() ?
       "Service Thread" : "Low Memory Detector";
   Handle string = java_lang_String::create_from_str(name, CHECK);
   // 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);
   {
     MutexLocker mu(Threads_lock);
     ServiceThread* thread =  new ServiceThread(&service_thread_entry);
     // 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 (thread == NULL || thread->osthread() == NULL) {
       vm_exit_during_initialization("java.lang.OutOfMemoryError",
                                     "unable to create new native thread");
     }
     java_lang_Thread::set_thread(thread_oop(), thread);
     java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
     java_lang_Thread::set_daemon(thread_oop());
     thread->set_threadObj(thread_oop());
     _instance = thread;
     Threads::add(thread);
     Thread::start(thread);
   }
 }
 void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) {
   while (true) {
     bool sensors_changed = false;
     bool has_jvmti_events = false;
     JvmtiDeferredEvent jvmti_event;
     {
       // Need state transition ThreadBlockInVM so that this thread
       // will be handled by safepoint correctly when this thread is
       // notified at a safepoint.
       // This ThreadBlockInVM object is not also considered to be
       // suspend-equivalent because ServiceThread is not visible to
       // external suspension.
       ThreadBlockInVM tbivm(jt);
       MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
       while (!(sensors_changed = LowMemoryDetector::has_pending_requests()) &&
              !(has_jvmti_events = JvmtiDeferredEventQueue::has_events())) {
         // wait until one of the sensors has pending requests, or there is a
         // pending JVMTI event to post
         Service_lock->wait(Mutex::_no_safepoint_check_flag);
       }
       if (has_jvmti_events) {
         jvmti_event = JvmtiDeferredEventQueue::dequeue();
       }
     }
     if (has_jvmti_events) {
       jvmti_event.post();
     }
     if (sensors_changed) {
       LowMemoryDetector::process_sensor_changes(jt);
     }
   }
 }
 bool ServiceThread::is_service_thread(Thread* thread) {
   return thread == _instance;
 }

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src/share/vm/runtime/serviceThread.cpp@216d916d5c12 (annotated)

src/share/vm/runtime/serviceThread.cpp