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1 // Copyright 2011 The Chromium Authors. All rights reserved. | 1 // Copyright 2011 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef CCScopedThreadProxy_h | 5 #ifndef CCScopedThreadProxy_h |
6 #define CCScopedThreadProxy_h | 6 #define CCScopedThreadProxy_h |
7 | 7 |
| 8 #include "base/memory/ref_counted.h" |
| 9 #include "base/callback.h" |
| 10 #include "cc/thread.h" |
| 11 #include "base/location.h" |
8 #include "base/logging.h" | 12 #include "base/logging.h" |
9 #include "base/memory/ref_counted.h" | |
10 #include "base/threading/platform_thread.h" | |
11 #include "cc/thread_task.h" | |
12 #include <wtf/OwnPtr.h> | |
13 #include <wtf/PassOwnPtr.h> | |
14 | 13 |
15 namespace cc { | 14 namespace cc { |
16 | 15 |
17 // This class is a proxy used to post tasks to an target thread from any other t
hread. The proxy may be shut down at | 16 // This class is a proxy used to post tasks to an target thread from any other t
hread. The proxy may be shut down at |
18 // any point from the target thread after which no more tasks posted to the prox
y will run. In other words, all | 17 // any point from the target thread after which no more tasks posted to the prox
y will run. In other words, all |
19 // tasks posted via a proxy are scoped to the lifecycle of the proxy. Use this w
hen posting tasks to an object that | 18 // tasks posted via a proxy are scoped to the lifecycle of the proxy. Use this w
hen posting tasks to an object that |
20 // might die with tasks in flight. | 19 // might die with tasks in flight. |
21 // | 20 // |
22 // The proxy must be created and shut down from the target thread, tasks may be
posted from any thread. | 21 // The proxy must be created and shut down from the target thread, tasks may be
posted from any thread. |
23 // | 22 // |
24 // Implementation note: Unlike ScopedRunnableMethodFactory in Chromium, pending
tasks are not cancelled by actually | 23 // Implementation note: Unlike ScopedRunnableMethodFactory in Chromium, pending
tasks are not cancelled by actually |
25 // destroying the proxy. Instead each pending task holds a reference to the prox
y to avoid maintaining an explicit | 24 // destroying the proxy. Instead each pending task holds a reference to the prox
y to avoid maintaining an explicit |
26 // list of outstanding tasks. | 25 // list of outstanding tasks. |
27 class ScopedThreadProxy : public base::RefCountedThreadSafe<ScopedThreadProxy> { | 26 class ScopedThreadProxy : public base::RefCountedThreadSafe<ScopedThreadProxy> { |
28 public: | 27 public: |
29 static scoped_refptr<ScopedThreadProxy> create(Thread* targetThread) | 28 static scoped_refptr<ScopedThreadProxy> create(cc::Thread* targetThread) |
30 { | 29 { |
31 DCHECK(base::PlatformThread::CurrentId() == targetThread->threadID()); | 30 DCHECK(targetThread->belongsToCurrentThread()); |
32 return make_scoped_refptr(new ScopedThreadProxy(targetThread)); | 31 return make_scoped_refptr(new ScopedThreadProxy(targetThread)); |
33 } | 32 } |
34 | 33 |
35 | |
36 // Can be called from any thread. Posts a task to the target thread that run
s unless | 34 // Can be called from any thread. Posts a task to the target thread that run
s unless |
37 // shutdown() is called before it runs. | 35 // shutdown() is called before it runs. |
38 void postTask(PassOwnPtr<Thread::Task> task) | 36 void postTask(const tracked_objects::Location& location, base::Closure cb); |
39 { | |
40 AddRef(); | |
41 m_targetThread->postTask(createThreadTask(this, &ScopedThreadProxy::runT
askIfNotShutdown, task)); | |
42 } | |
43 | 37 |
44 void shutdown() | 38 void shutdown(); |
45 { | |
46 DCHECK(base::PlatformThread::CurrentId() == m_targetThread->threadID()); | |
47 DCHECK(!m_shutdown); | |
48 m_shutdown = true; | |
49 } | |
50 | 39 |
51 private: | 40 private: |
| 41 explicit ScopedThreadProxy(cc::Thread* targetThread); |
52 friend class base::RefCountedThreadSafe<ScopedThreadProxy>; | 42 friend class base::RefCountedThreadSafe<ScopedThreadProxy>; |
53 ~ScopedThreadProxy(); | 43 ~ScopedThreadProxy(); |
54 | 44 |
55 explicit ScopedThreadProxy(Thread* targetThread); | 45 void runTaskIfNotShutdown(base::Closure cb); |
56 | 46 |
57 void runTaskIfNotShutdown(PassOwnPtr<Thread::Task> popTask) | 47 cc::Thread* m_targetThread; |
58 { | |
59 OwnPtr<Thread::Task> task = popTask; | |
60 // If our shutdown flag is set, it's possible that m_targetThread has al
ready been destroyed so don't | |
61 // touch it. | |
62 if (m_shutdown) { | |
63 Release(); | |
64 return; | |
65 } | |
66 DCHECK(base::PlatformThread::CurrentId() == m_targetThread->threadID()); | |
67 task->performTask(); | |
68 Release(); | |
69 } | |
70 | |
71 Thread* m_targetThread; | |
72 bool m_shutdown; // Only accessed on the target thread | 48 bool m_shutdown; // Only accessed on the target thread |
73 }; | 49 }; |
74 | 50 |
75 } // namespace cc | 51 } // namespace cc |
76 | 52 |
77 #endif | 53 #endif |
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