The Tor Browser / file comparison
comparison: content/media/SharedThreadPool.h
content/media/SharedThreadPool.h
- branch
- TOR_BUG_9701
- changeset 13
- 44a2da4a2ab2
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| -1:000000000000 | 0:462fa82891d4 |
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| 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ | |
| 2 /* vim:set ts=2 sw=2 sts=2 et cindent: */ | |
| 3 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #ifndef SharedThreadPool_h_ | |
| 8 #define SharedThreadPool_h_ | |
| 9 | |
| 10 #include <queue> | |
| 11 #include "mozilla/RefPtr.h" | |
| 12 #include "nsThreadUtils.h" | |
| 13 #include "nsIThreadPool.h" | |
| 14 #include "nsISupports.h" | |
| 15 #include "nsISupportsImpl.h" | |
| 16 #include "nsCOMPtr.h" | |
| 17 | |
| 18 namespace mozilla { | |
| 19 | |
| 20 // Wrapper that makes an nsIThreadPool a singleton, and provides a | |
| 21 // consistent threadsafe interface to get instances. Callers simply get a | |
| 22 // SharedThreadPool by the name of its nsIThreadPool. All get requests of | |
| 23 // the same name get the same SharedThreadPool. Users must store a reference | |
| 24 // to the pool, and when the last reference to a SharedThreadPool is dropped | |
| 25 // the pool is shutdown and deleted. Users aren't required to manually | |
| 26 // shutdown the pool, and can release references on any thread. On Windows | |
| 27 // all threads in the pool have MSCOM initialized with COINIT_MULTITHREADED. | |
| 28 class SharedThreadPool : public nsIThreadPool | |
| 29 { | |
| 30 public: | |
| 31 | |
| 32 // Gets (possibly creating) the shared thread pool singleton instance with | |
| 33 // thread pool named aName. | |
| 34 // *Must* be called on the main thread. | |
| 35 static TemporaryRef<SharedThreadPool> Get(const nsCString& aName, | |
| 36 uint32_t aThreadLimit = 4); | |
| 37 | |
| 38 // Spins the event loop until all thread pools are shutdown. | |
| 39 // *Must* be called on the main thread. | |
| 40 static void SpinUntilShutdown(); | |
| 41 | |
| 42 // We implement custom threadsafe AddRef/Release pair, that destroys the | |
| 43 // the shared pool singleton when the refcount drops to 0. The addref/release | |
| 44 // are implemented using locking, so it's not recommended that you use them | |
| 45 // in a tight loop. | |
| 46 NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr); | |
| 47 NS_IMETHOD_(MozExternalRefCountType) AddRef(void); | |
| 48 NS_IMETHOD_(MozExternalRefCountType) Release(void); | |
| 49 | |
| 50 // Forward behaviour to wrapped thread pool implementation. | |
| 51 NS_FORWARD_SAFE_NSITHREADPOOL(mPool); | |
| 52 NS_FORWARD_SAFE_NSIEVENTTARGET(GetEventTarget()); | |
| 53 | |
| 54 nsIEventTarget* GetEventTarget() { | |
| 55 return mEventTarget; | |
| 56 } | |
| 57 | |
| 58 private: | |
| 59 | |
| 60 // Creates necessary statics. | |
| 61 // Main thread only. | |
| 62 static void EnsureInitialized(); | |
| 63 | |
| 64 // Creates a singleton SharedThreadPool wrapper around aPool. | |
| 65 // aName is the name of the aPool, and is used to lookup the | |
| 66 // SharedThreadPool in the hash table of all created pools. | |
| 67 SharedThreadPool(const nsCString& aName, | |
| 68 nsIThreadPool* aPool); | |
| 69 virtual ~SharedThreadPool(); | |
| 70 | |
| 71 nsresult EnsureThreadLimitIsAtLeast(uint32_t aThreadLimit); | |
| 72 | |
| 73 // Name of mPool. | |
| 74 const nsCString mName; | |
| 75 | |
| 76 // Thread pool being wrapped. | |
| 77 nsCOMPtr<nsIThreadPool> mPool; | |
| 78 | |
| 79 // Refcount. We implement custom ref counting so that the thread pool is | |
| 80 // shutdown in a threadsafe manner and singletonness is preserved. | |
| 81 nsrefcnt mRefCnt; | |
| 82 | |
| 83 // mPool QI'd to nsIEventTarget. We cache this, so that we can use | |
| 84 // NS_FORWARD_SAFE_NSIEVENTTARGET above. | |
| 85 nsCOMPtr<nsIEventTarget> mEventTarget; | |
| 86 }; | |
| 87 | |
| 88 } // namespace mozilla | |
| 89 | |
| 90 #endif // SharedThreadPool_h_ |
