1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/message_loop_proxy_impl.h"
6 #include "base/threading/thread_restrictions.h"
7
8 namespace base {
9
~MessageLoopProxyImpl()10 MessageLoopProxyImpl::~MessageLoopProxyImpl() {
11 AutoLock lock(message_loop_lock_);
12 // If the target message loop still exists, the d'tor WILL execute on the
13 // target loop.
14 if (target_message_loop_) {
15 DCHECK(MessageLoop::current() == target_message_loop_);
16 MessageLoop::current()->RemoveDestructionObserver(this);
17 }
18 }
19
20 // MessageLoopProxy implementation
PostTask(const tracked_objects::Location & from_here,Task * task)21 bool MessageLoopProxyImpl::PostTask(const tracked_objects::Location& from_here,
22 Task* task) {
23 return PostTaskHelper(from_here, task, 0, true);
24 }
25
PostDelayedTask(const tracked_objects::Location & from_here,Task * task,int64 delay_ms)26 bool MessageLoopProxyImpl::PostDelayedTask(
27 const tracked_objects::Location& from_here, Task* task, int64 delay_ms) {
28 return PostTaskHelper(from_here, task, delay_ms, true);
29 }
30
PostNonNestableTask(const tracked_objects::Location & from_here,Task * task)31 bool MessageLoopProxyImpl::PostNonNestableTask(
32 const tracked_objects::Location& from_here, Task* task) {
33 return PostTaskHelper(from_here, task, 0, false);
34 }
35
PostNonNestableDelayedTask(const tracked_objects::Location & from_here,Task * task,int64 delay_ms)36 bool MessageLoopProxyImpl::PostNonNestableDelayedTask(
37 const tracked_objects::Location& from_here,
38 Task* task,
39 int64 delay_ms) {
40 return PostTaskHelper(from_here, task, delay_ms, false);
41 }
42
BelongsToCurrentThread()43 bool MessageLoopProxyImpl::BelongsToCurrentThread() {
44 // We shouldn't use MessageLoop::current() since it uses LazyInstance which
45 // may be deleted by ~AtExitManager when a WorkerPool thread calls this
46 // function.
47 // http://crbug.com/63678
48 base::ThreadRestrictions::ScopedAllowSingleton allow_singleton;
49 AutoLock lock(message_loop_lock_);
50 return (target_message_loop_ &&
51 (MessageLoop::current() == target_message_loop_));
52 }
53
54 // MessageLoop::DestructionObserver implementation
WillDestroyCurrentMessageLoop()55 void MessageLoopProxyImpl::WillDestroyCurrentMessageLoop() {
56 AutoLock lock(message_loop_lock_);
57 target_message_loop_ = NULL;
58 }
59
OnDestruct() const60 void MessageLoopProxyImpl::OnDestruct() const {
61 // We shouldn't use MessageLoop::current() since it uses LazyInstance which
62 // may be deleted by ~AtExitManager when a WorkerPool thread calls this
63 // function.
64 // http://crbug.com/63678
65 base::ThreadRestrictions::ScopedAllowSingleton allow_singleton;
66 bool delete_later = false;
67 {
68 AutoLock lock(message_loop_lock_);
69 if (target_message_loop_ &&
70 (MessageLoop::current() != target_message_loop_)) {
71 target_message_loop_->DeleteSoon(FROM_HERE, this);
72 delete_later = true;
73 }
74 }
75 if (!delete_later)
76 delete this;
77 }
78
MessageLoopProxyImpl()79 MessageLoopProxyImpl::MessageLoopProxyImpl()
80 : target_message_loop_(MessageLoop::current()) {
81 target_message_loop_->AddDestructionObserver(this);
82 }
83
PostTaskHelper(const tracked_objects::Location & from_here,Task * task,int64 delay_ms,bool nestable)84 bool MessageLoopProxyImpl::PostTaskHelper(
85 const tracked_objects::Location& from_here, Task* task, int64 delay_ms,
86 bool nestable) {
87 bool ret = false;
88 {
89 AutoLock lock(message_loop_lock_);
90 if (target_message_loop_) {
91 if (nestable) {
92 target_message_loop_->PostDelayedTask(from_here, task, delay_ms);
93 } else {
94 target_message_loop_->PostNonNestableDelayedTask(from_here, task,
95 delay_ms);
96 }
97 ret = true;
98 }
99 }
100 if (!ret)
101 delete task;
102 return ret;
103 }
104
105 scoped_refptr<MessageLoopProxy>
CreateForCurrentThread()106 MessageLoopProxy::CreateForCurrentThread() {
107 scoped_refptr<MessageLoopProxy> ret(new MessageLoopProxyImpl());
108 return ret;
109 }
110
111 } // namespace base
112