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comparison: gfx/skia/trunk/src/core/SkMessageBus.h
gfx/skia/trunk/src/core/SkMessageBus.h
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:3f3bcb493a57 |
|---|---|
| 1 /* | |
| 2 * Copyright 2013 Google Inc. | |
| 3 * | |
| 4 * Use of this source code is governed by a BSD-style license that can be | |
| 5 * found in the LICENSE file. | |
| 6 */ | |
| 7 | |
| 8 #ifndef SkMessageBus_DEFINED | |
| 9 #define SkMessageBus_DEFINED | |
| 10 | |
| 11 #include "SkOnce.h" | |
| 12 #include "SkTDArray.h" | |
| 13 #include "SkThread.h" | |
| 14 #include "SkTypes.h" | |
| 15 | |
| 16 template <typename Message> | |
| 17 class SkMessageBus : SkNoncopyable { | |
| 18 public: | |
| 19 // Post a message to be received by all Inboxes for this Message type. Threadsafe. | |
| 20 static void Post(const Message& m); | |
| 21 | |
| 22 class Inbox { | |
| 23 public: | |
| 24 Inbox(); | |
| 25 ~Inbox(); | |
| 26 | |
| 27 // Overwrite out with all the messages we've received since the last call. Threadsafe. | |
| 28 void poll(SkTDArray<Message>* out); | |
| 29 | |
| 30 private: | |
| 31 SkTDArray<Message> fMessages; | |
| 32 SkMutex fMessagesMutex; | |
| 33 | |
| 34 friend class SkMessageBus; | |
| 35 void receive(const Message& m); // SkMessageBus is a friend only to call this. | |
| 36 }; | |
| 37 | |
| 38 private: | |
| 39 SkMessageBus(); | |
| 40 static SkMessageBus* Get(); | |
| 41 static void New(SkMessageBus**); | |
| 42 | |
| 43 SkTDArray<Inbox*> fInboxes; | |
| 44 SkMutex fInboxesMutex; | |
| 45 }; | |
| 46 | |
| 47 // This must go in a single .cpp file, not some .h, or we risk creating more than one global | |
| 48 // SkMessageBus per type when using shared libraries. | |
| 49 #define DECLARE_SKMESSAGEBUS_MESSAGE(Message) \ | |
| 50 template <> \ | |
| 51 SkMessageBus<Message>* SkMessageBus<Message>::Get() { \ | |
| 52 static SkMessageBus<Message>* bus = NULL; \ | |
| 53 SK_DECLARE_STATIC_ONCE(once); \ | |
| 54 SkOnce(&once, &New, &bus); \ | |
| 55 SkASSERT(bus != NULL); \ | |
| 56 return bus; \ | |
| 57 } | |
| 58 | |
| 59 // ----------------------- Implementation of SkMessageBus::Inbox ----------------------- | |
| 60 | |
| 61 template<typename Message> | |
| 62 SkMessageBus<Message>::Inbox::Inbox() { | |
| 63 // Register ourselves with the corresponding message bus. | |
| 64 SkMessageBus<Message>* bus = SkMessageBus<Message>::Get(); | |
| 65 SkAutoMutexAcquire lock(bus->fInboxesMutex); | |
| 66 bus->fInboxes.push(this); | |
| 67 } | |
| 68 | |
| 69 template<typename Message> | |
| 70 SkMessageBus<Message>::Inbox::~Inbox() { | |
| 71 // Remove ourselves from the corresponding message bus. | |
| 72 SkMessageBus<Message>* bus = SkMessageBus<Message>::Get(); | |
| 73 SkAutoMutexAcquire lock(bus->fInboxesMutex); | |
| 74 // This is a cheaper fInboxes.remove(fInboxes.find(this)) when order doesn't matter. | |
| 75 for (int i = 0; i < bus->fInboxes.count(); i++) { | |
| 76 if (this == bus->fInboxes[i]) { | |
| 77 bus->fInboxes.removeShuffle(i); | |
| 78 break; | |
| 79 } | |
| 80 } | |
| 81 } | |
| 82 | |
| 83 template<typename Message> | |
| 84 void SkMessageBus<Message>::Inbox::receive(const Message& m) { | |
| 85 SkAutoMutexAcquire lock(fMessagesMutex); | |
| 86 fMessages.push(m); | |
| 87 } | |
| 88 | |
| 89 template<typename Message> | |
| 90 void SkMessageBus<Message>::Inbox::poll(SkTDArray<Message>* messages) { | |
| 91 SkASSERT(NULL != messages); | |
| 92 messages->reset(); | |
| 93 SkAutoMutexAcquire lock(fMessagesMutex); | |
| 94 messages->swap(fMessages); | |
| 95 } | |
| 96 | |
| 97 // ----------------------- Implementation of SkMessageBus ----------------------- | |
| 98 | |
| 99 template <typename Message> | |
| 100 SkMessageBus<Message>::SkMessageBus() {} | |
| 101 | |
| 102 template <typename Message> | |
| 103 /*static*/ void SkMessageBus<Message>::New(SkMessageBus<Message>** bus) { | |
| 104 *bus = new SkMessageBus<Message>(); | |
| 105 } | |
| 106 | |
| 107 template <typename Message> | |
| 108 /*static*/ void SkMessageBus<Message>::Post(const Message& m) { | |
| 109 SkMessageBus<Message>* bus = SkMessageBus<Message>::Get(); | |
| 110 SkAutoMutexAcquire lock(bus->fInboxesMutex); | |
| 111 for (int i = 0; i < bus->fInboxes.count(); i++) { | |
| 112 bus->fInboxes[i]->receive(m); | |
| 113 } | |
| 114 } | |
| 115 | |
| 116 #endif // SkMessageBus_DEFINED |
