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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/threading/platform_thread.h" | |
10 #include "cc/thread_task.h" | |
11 #include <wtf/OwnPtr.h> | |
12 #include <wtf/PassOwnPtr.h> | |
13 #include <wtf/ThreadSafeRefCounted.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 ThreadSafeRefCounted<ScopedThreadProxy> { | 26 class ScopedThreadProxy : public base::RefCounted<ScopedThreadProxy> { |
enne (OOO)
2012/10/29 17:40:42
Sanity checking: this doesn't need to be thread-sa
| |
28 public: | 27 public: |
29 static PassRefPtr<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 adoptRef(new ScopedThreadProxy(targetThread)); | 31 return make_scoped_refptr(new ScopedThreadProxy(targetThread)); |
33 } | 32 } |
34 | 33 |
35 ~ScopedThreadProxy(); | |
36 | |
37 // 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 |
38 // shutdown() is called before it runs. | 35 // shutdown() is called before it runs. |
39 void postTask(PassOwnPtr<Thread::Task> task) | 36 void postTask(const tracked_objects::Location& location, base::Closure cb); |
40 { | |
41 ref(); | |
42 m_targetThread->postTask(createThreadTask(this, &ScopedThreadProxy::runT askIfNotShutdown, task)); | |
43 } | |
44 | 37 |
45 void shutdown() | 38 void shutdown(); |
46 { | |
47 DCHECK(base::PlatformThread::CurrentId() == m_targetThread->threadID()); | |
48 DCHECK(!m_shutdown); | |
49 m_shutdown = true; | |
50 } | |
51 | 39 |
52 private: | 40 private: |
53 explicit ScopedThreadProxy(Thread* targetThread); | 41 explicit ScopedThreadProxy(cc::Thread* targetThread); |
42 friend class base::RefCounted<ScopedThreadProxy>; | |
43 ~ScopedThreadProxy(); | |
54 | 44 |
55 void runTaskIfNotShutdown(PassOwnPtr<Thread::Task> popTask) | 45 void runTaskIfNotShutdown(base::Closure cb); |
56 { | |
57 OwnPtr<Thread::Task> task = popTask; | |
58 // If our shutdown flag is set, it's possible that m_targetThread has al ready been destroyed so don't | |
59 // touch it. | |
60 if (m_shutdown) { | |
61 deref(); | |
62 return; | |
63 } | |
64 DCHECK(base::PlatformThread::CurrentId() == m_targetThread->threadID()); | |
65 task->performTask(); | |
66 deref(); | |
67 } | |
68 | 46 |
69 Thread* m_targetThread; | 47 cc::Thread* m_targetThread; |
70 bool m_shutdown; // Only accessed on the target thread | 48 bool m_shutdown; // Only accessed on the target thread |
71 }; | 49 }; |
72 | 50 |
73 } | 51 } |
74 | 52 |
75 #endif | 53 #endif |
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