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7119584: UseParallelGC barrier task can be overwritten

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Provoke a GC for a metadata allocation failure.

Reviewed-by: johnc, iveresov
This commit is contained in:
Jon Masamitsu 2011-12-09 19:28:34 -08:00
parent bb40d3f9f4
commit 714e978aac
2 changed files with 22 additions and 3 deletions
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15
hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.cpp
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2002, 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
@ -53,6 +53,9 @@ const char* GCTask::Kind::to_string(kind value) {
case noop_task:
result = "noop task";
break;
case idle_task:
result = "idle task";
break;
}
return result;
};
@ -782,6 +785,12 @@ void GCTaskManager::note_release(uint which) {
void GCTaskManager::execute_and_wait(GCTaskQueue* list) {
WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
list->enqueue(fin);
// The barrier task will be read by one of the GC
// workers once it is added to the list of tasks.
// Be sure that is globally visible before the
// GC worker reads it (which is after the task is added
// to the list of tasks below).
OrderAccess::storestore();
add_list(list);
fin->wait_for(true /* reset */);
// We have to release the barrier tasks!
@ -833,11 +842,15 @@ void NoopGCTask::destruct() {
IdleGCTask* IdleGCTask::create() {
IdleGCTask* result = new IdleGCTask(false);
assert(UseDynamicNumberOfGCThreads,
"Should only be used with dynamic GC thread");
return result;
}
IdleGCTask* IdleGCTask::create_on_c_heap() {
IdleGCTask* result = new(ResourceObj::C_HEAP) IdleGCTask(true);
assert(UseDynamicNumberOfGCThreads,
"Should only be used with dynamic GC thread");
return result;
}

10
hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.cpp
View file

@ -1,6 +1,6 @@
/*
* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2002, 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
@ -129,6 +129,8 @@ void GCTaskThread::run() {
for (; /* break */; ) {
// This will block until there is a task to be gotten.
GCTask* task = manager()->get_task(which());
// Record if this is an idle task for later use.
bool is_idle_task = task->is_idle_task();
// In case the update is costly
if (PrintGCTaskTimeStamps) {
timer.update();
@ -137,9 +139,13 @@ void GCTaskThread::run() {
jlong entry_time = timer.ticks();
char* name = task->name();
// If this is the barrier task, it can be destroyed
// by the GC task manager once the do_it() executes.
task->do_it(manager(), which());
if (!task->is_idle_task()) {
// Use the saved value of is_idle_task because references
// using "task" are not reliable for the barrier task.
if (!is_idle_task) {
manager()->note_completion(which());
if (PrintGCTaskTimeStamps) {