commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 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 | |
mtklein | 1b24933 | 2015-07-07 12:21:21 -0700 | [diff] [blame] | 11 | #include "SkMutex.h" |
mtklein | ffa4a92 | 2016-05-05 16:05:56 -0700 | [diff] [blame] | 12 | #include "SkOnce.h" |
bsalomon | 23e619c | 2015-02-06 11:54:28 -0800 | [diff] [blame] | 13 | #include "SkTArray.h" |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 14 | #include "SkTDArray.h" |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 15 | #include "SkTypes.h" |
| 16 | |
Brian Salomon | 238069b | 2018-07-11 15:58:57 -0400 | [diff] [blame^] | 17 | /** |
| 18 | * Message must implement bool Message::shouldSend(uint32_t inboxID) const. Perhaps someday we |
| 19 | * can use std::experimental::is_detected to avoid this requirement by sending to all inboxes when |
| 20 | * the method is not detected on Message. |
| 21 | */ |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 22 | template <typename Message> |
| 23 | class SkMessageBus : SkNoncopyable { |
| 24 | public: |
Brian Salomon | 238069b | 2018-07-11 15:58:57 -0400 | [diff] [blame^] | 25 | // Post a message to be received by Inboxes for this Message type. Checks |
| 26 | // Message::shouldSend() for each inbox. Threadsafe. |
| 27 | static void Post(const Message& m); |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 28 | |
| 29 | class Inbox { |
| 30 | public: |
Jim Van Verth | 474d687 | 2017-12-14 13:00:05 -0500 | [diff] [blame] | 31 | Inbox(uint32_t uniqueID = SK_InvalidUniqueID); |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 32 | ~Inbox(); |
| 33 | |
| 34 | // Overwrite out with all the messages we've received since the last call. Threadsafe. |
bsalomon | 23e619c | 2015-02-06 11:54:28 -0800 | [diff] [blame] | 35 | void poll(SkTArray<Message>* out); |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 36 | |
| 37 | private: |
bsalomon | 23e619c | 2015-02-06 11:54:28 -0800 | [diff] [blame] | 38 | SkTArray<Message> fMessages; |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 39 | SkMutex fMessagesMutex; |
Jim Van Verth | 474d687 | 2017-12-14 13:00:05 -0500 | [diff] [blame] | 40 | uint32_t fUniqueID; |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 41 | |
| 42 | friend class SkMessageBus; |
| 43 | void receive(const Message& m); // SkMessageBus is a friend only to call this. |
| 44 | }; |
| 45 | |
| 46 | private: |
| 47 | SkMessageBus(); |
| 48 | static SkMessageBus* Get(); |
mtklein | 148ec59 | 2014-10-13 13:17:56 -0700 | [diff] [blame] | 49 | |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 50 | SkTDArray<Inbox*> fInboxes; |
| 51 | SkMutex fInboxesMutex; |
| 52 | }; |
| 53 | |
commit-bot@chromium.org | c665804 | 2014-01-15 23:09:01 +0000 | [diff] [blame] | 54 | // This must go in a single .cpp file, not some .h, or we risk creating more than one global |
mtklein | 148ec59 | 2014-10-13 13:17:56 -0700 | [diff] [blame] | 55 | // SkMessageBus per type when using shared libraries. NOTE: at most one per file will compile. |
mtklein | 6c59d80 | 2015-09-09 09:09:53 -0700 | [diff] [blame] | 56 | #define DECLARE_SKMESSAGEBUS_MESSAGE(Message) \ |
mtklein | 6c59d80 | 2015-09-09 09:09:53 -0700 | [diff] [blame] | 57 | template <> \ |
| 58 | SkMessageBus<Message>* SkMessageBus<Message>::Get() { \ |
mtklein | ffa4a92 | 2016-05-05 16:05:56 -0700 | [diff] [blame] | 59 | static SkOnce once; \ |
| 60 | static SkMessageBus<Message>* bus; \ |
| 61 | once([] { bus = new SkMessageBus<Message>(); }); \ |
| 62 | return bus; \ |
commit-bot@chromium.org | c665804 | 2014-01-15 23:09:01 +0000 | [diff] [blame] | 63 | } |
| 64 | |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 65 | // ----------------------- Implementation of SkMessageBus::Inbox ----------------------- |
| 66 | |
| 67 | template<typename Message> |
Jim Van Verth | 474d687 | 2017-12-14 13:00:05 -0500 | [diff] [blame] | 68 | SkMessageBus<Message>::Inbox::Inbox(uint32_t uniqueID) : fUniqueID(uniqueID) { |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 69 | // Register ourselves with the corresponding message bus. |
| 70 | SkMessageBus<Message>* bus = SkMessageBus<Message>::Get(); |
| 71 | SkAutoMutexAcquire lock(bus->fInboxesMutex); |
| 72 | bus->fInboxes.push(this); |
| 73 | } |
| 74 | |
| 75 | template<typename Message> |
| 76 | SkMessageBus<Message>::Inbox::~Inbox() { |
| 77 | // Remove ourselves from the corresponding message bus. |
| 78 | SkMessageBus<Message>* bus = SkMessageBus<Message>::Get(); |
| 79 | SkAutoMutexAcquire lock(bus->fInboxesMutex); |
| 80 | // This is a cheaper fInboxes.remove(fInboxes.find(this)) when order doesn't matter. |
| 81 | for (int i = 0; i < bus->fInboxes.count(); i++) { |
| 82 | if (this == bus->fInboxes[i]) { |
| 83 | bus->fInboxes.removeShuffle(i); |
| 84 | break; |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | template<typename Message> |
| 90 | void SkMessageBus<Message>::Inbox::receive(const Message& m) { |
| 91 | SkAutoMutexAcquire lock(fMessagesMutex); |
bsalomon | 23e619c | 2015-02-06 11:54:28 -0800 | [diff] [blame] | 92 | fMessages.push_back(m); |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 93 | } |
| 94 | |
| 95 | template<typename Message> |
bsalomon | 23e619c | 2015-02-06 11:54:28 -0800 | [diff] [blame] | 96 | void SkMessageBus<Message>::Inbox::poll(SkTArray<Message>* messages) { |
bsalomon | 49f085d | 2014-09-05 13:34:00 -0700 | [diff] [blame] | 97 | SkASSERT(messages); |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 98 | messages->reset(); |
| 99 | SkAutoMutexAcquire lock(fMessagesMutex); |
Ben Wagner | f08d1d0 | 2018-06-18 15:11:00 -0400 | [diff] [blame] | 100 | fMessages.swap(*messages); |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 101 | } |
| 102 | |
| 103 | // ----------------------- Implementation of SkMessageBus ----------------------- |
| 104 | |
| 105 | template <typename Message> |
| 106 | SkMessageBus<Message>::SkMessageBus() {} |
| 107 | |
| 108 | template <typename Message> |
Brian Salomon | 238069b | 2018-07-11 15:58:57 -0400 | [diff] [blame^] | 109 | /*static*/ void SkMessageBus<Message>::Post(const Message& m) { |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 110 | SkMessageBus<Message>* bus = SkMessageBus<Message>::Get(); |
| 111 | SkAutoMutexAcquire lock(bus->fInboxesMutex); |
| 112 | for (int i = 0; i < bus->fInboxes.count(); i++) { |
Brian Salomon | 238069b | 2018-07-11 15:58:57 -0400 | [diff] [blame^] | 113 | if (m.shouldSend(bus->fInboxes[i]->fUniqueID)) { |
Jim Van Verth | 474d687 | 2017-12-14 13:00:05 -0500 | [diff] [blame] | 114 | bus->fInboxes[i]->receive(m); |
| 115 | } |
commit-bot@chromium.org | 50a3043 | 2013-10-24 17:44:27 +0000 | [diff] [blame] | 116 | } |
| 117 | } |
| 118 | |
| 119 | #endif // SkMessageBus_DEFINED |