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// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/message_loop_proxy_impl.h"
#include "base/thread_restrictions.h"
namespace base {
MessageLoopProxyImpl::MessageLoopProxyImpl()
: target_message_loop_(MessageLoop::current()) {
target_message_loop_->AddDestructionObserver(this);
}
MessageLoopProxyImpl::~MessageLoopProxyImpl() {
AutoLock lock(message_loop_lock_);
// If the target message loop still exists, the d'tor WILL execute on the
// target loop.
if (target_message_loop_) {
DCHECK(MessageLoop::current() == target_message_loop_);
MessageLoop::current()->RemoveDestructionObserver(this);
}
}
// MessageLoopProxy implementation
bool MessageLoopProxyImpl::PostTask(const tracked_objects::Location& from_here,
Task* task) {
return PostTaskHelper(from_here, task, 0, true);
}
bool MessageLoopProxyImpl::PostDelayedTask(
const tracked_objects::Location& from_here, Task* task, int64 delay_ms) {
return PostTaskHelper(from_here, task, delay_ms, true);
}
bool MessageLoopProxyImpl::PostNonNestableTask(
const tracked_objects::Location& from_here, Task* task) {
return PostTaskHelper(from_here, task, 0, false);
}
bool MessageLoopProxyImpl::PostNonNestableDelayedTask(
const tracked_objects::Location& from_here,
Task* task,
int64 delay_ms) {
return PostTaskHelper(from_here, task, delay_ms, false);
}
bool MessageLoopProxyImpl::BelongsToCurrentThread() {
// We shouldn't use MessageLoop::current() since it uses LazyInstance which
// may be deleted by ~AtExitManager when a WorkerPool thread calls this
// function.
// http://crbug.com/63678
base::ThreadRestrictions::ScopedAllowSingleton allow_singleton;
AutoLock lock(message_loop_lock_);
return (target_message_loop_ &&
(MessageLoop::current() == target_message_loop_));
}
bool MessageLoopProxyImpl::PostTaskHelper(
const tracked_objects::Location& from_here, Task* task, int64 delay_ms,
bool nestable) {
bool ret = false;
{
AutoLock lock(message_loop_lock_);
if (target_message_loop_) {
if (nestable) {
target_message_loop_->PostDelayedTask(from_here, task, delay_ms);
} else {
target_message_loop_->PostNonNestableDelayedTask(from_here, task,
delay_ms);
}
ret = true;
}
}
if (!ret)
delete task;
return ret;
}
void MessageLoopProxyImpl::OnDestruct() const {
// We shouldn't use MessageLoop::current() since it uses LazyInstance which
// may be deleted by ~AtExitManager when a WorkerPool thread calls this
// function.
// http://crbug.com/63678
base::ThreadRestrictions::ScopedAllowSingleton allow_singleton;
bool delete_later = false;
{
AutoLock lock(message_loop_lock_);
if (target_message_loop_ &&
(MessageLoop::current() != target_message_loop_)) {
target_message_loop_->DeleteSoon(FROM_HERE, this);
delete_later = true;
}
}
if (!delete_later)
delete this;
}
// MessageLoop::DestructionObserver implementation
void MessageLoopProxyImpl::WillDestroyCurrentMessageLoop() {
AutoLock lock(message_loop_lock_);
target_message_loop_ = NULL;
}
scoped_refptr<MessageLoopProxy>
MessageLoopProxy::CreateForCurrentThread() {
scoped_refptr<MessageLoopProxy> ret(new MessageLoopProxyImpl());
return ret;
}
} // namespace base