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| 1 /* | |
| 2 * Copyright (C) 2006, 2008 Apple Inc. All rights reserved. | |
| 3 * Copyright (C) 2009 Google Inc. All rights reserved. | |
| 4 * | |
| 5 * Redistribution and use in source and binary forms, with or without | |
| 6 * modification, are permitted provided that the following conditions | |
| 7 * are met: | |
| 8 * 1. Redistributions of source code must retain the above copyright | |
| 9 * notice, this list of conditions and the following disclaimer. | |
| 10 * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 * notice, this list of conditions and the following disclaimer in the | |
| 12 * documentation and/or other materials provided with the distribution. | |
| 13 * | |
| 14 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY | |
| 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR | |
| 18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
| 19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
| 20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | |
| 21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY | |
| 22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 25 */ | |
| 26 | |
| 27 #include "config.h" | |
| 28 #include "platform/ThreadTimers.h" | |
| 29 | |
| 30 #include "platform/PlatformThreadData.h" | |
| 31 #include "platform/SharedTimer.h" | |
| 32 #include "platform/Timer.h" | |
| 33 #include "platform/TraceEvent.h" | |
| 34 #include "public/platform/Platform.h" | |
| 35 #include "public/platform/WebScheduler.h" | |
| 36 #include "wtf/CurrentTime.h" | |
| 37 #include "wtf/MainThread.h" | |
| 38 | |
| 39 namespace blink { | |
| 40 | |
| 41 // Fire timers for this length of time, and then quit to let the run loop proces
s user input events. | |
| 42 // 100ms is about a perceptable delay in UI, so use a half of that as a threshol
d. | |
| 43 // This is to prevent UI freeze when there are too many timers or machine perfor
mance is low. | |
| 44 static const double maxDurationOfFiringTimers = 0.050; | |
| 45 | |
| 46 // Timers are created, started and fired on the same thread, and each thread has
its own ThreadTimers | |
| 47 // copy to keep the heap and a set of currently firing timers. | |
| 48 | |
| 49 static PassOwnPtr<MainThreadSharedTimer> mainThreadSharedTimer() | |
| 50 { | |
| 51 return adoptPtr(new MainThreadSharedTimer); | |
| 52 } | |
| 53 | |
| 54 ThreadTimers::ThreadTimers() | |
| 55 : m_sharedTimer(0) | |
| 56 , m_firingTimers(false) | |
| 57 , m_pendingSharedTimerFireTime(0) | |
| 58 { | |
| 59 if (isMainThread()) | |
| 60 setSharedTimer(mainThreadSharedTimer()); | |
| 61 } | |
| 62 | |
| 63 // A worker thread may initialize SharedTimer after some timers are created. | |
| 64 // Also, SharedTimer can be replaced with 0 before all timers are destroyed. | |
| 65 void ThreadTimers::setSharedTimer(PassOwnPtr<SharedTimer> sharedTimer) | |
| 66 { | |
| 67 if (m_sharedTimer) { | |
| 68 m_sharedTimer->setFiredFunction(0); | |
| 69 m_sharedTimer->stop(); | |
| 70 m_pendingSharedTimerFireTime = 0; | |
| 71 } | |
| 72 | |
| 73 m_sharedTimer = sharedTimer; | |
| 74 | |
| 75 if (m_sharedTimer) { | |
| 76 m_sharedTimer->setFiredFunction(ThreadTimers::sharedTimerFired); | |
| 77 updateSharedTimer(); | |
| 78 } | |
| 79 } | |
| 80 | |
| 81 void ThreadTimers::updateSharedTimer() | |
| 82 { | |
| 83 if (!m_sharedTimer) | |
| 84 return; | |
| 85 | |
| 86 if (m_firingTimers || m_timerHeap.isEmpty()) { | |
| 87 m_pendingSharedTimerFireTime = 0; | |
| 88 m_sharedTimer->stop(); | |
| 89 } else { | |
| 90 double nextFireTime = m_timerHeap.first()->m_nextFireTime; | |
| 91 double currentMonotonicTime = monotonicallyIncreasingTime(); | |
| 92 if (m_pendingSharedTimerFireTime) { | |
| 93 // No need to restart the timer if both the pending fire time and th
e new fire time are in the past. | |
| 94 if (m_pendingSharedTimerFireTime <= currentMonotonicTime && nextFire
Time <= currentMonotonicTime) | |
| 95 return; | |
| 96 } | |
| 97 m_pendingSharedTimerFireTime = nextFireTime; | |
| 98 m_sharedTimer->setFireInterval(std::max(nextFireTime - currentMonotonicT
ime, 0.0)); | |
| 99 } | |
| 100 } | |
| 101 | |
| 102 void ThreadTimers::sharedTimerFired() | |
| 103 { | |
| 104 TRACE_EVENT_SET_SAMPLING_STATE("blink", "BlinkInternal"); | |
| 105 | |
| 106 // Redirect to non-static method. | |
| 107 PlatformThreadData::current().threadTimers().sharedTimerFiredInternal(); | |
| 108 | |
| 109 TRACE_EVENT_SET_SAMPLING_STATE("blink", "Sleeping"); | |
| 110 } | |
| 111 | |
| 112 void ThreadTimers::sharedTimerFiredInternal() | |
| 113 { | |
| 114 // Do a re-entrancy check. | |
| 115 if (m_firingTimers) | |
| 116 return; | |
| 117 m_firingTimers = true; | |
| 118 m_pendingSharedTimerFireTime = 0; | |
| 119 | |
| 120 double fireTime = monotonicallyIncreasingTime(); | |
| 121 double timeToQuit = fireTime + maxDurationOfFiringTimers; | |
| 122 | |
| 123 while (!m_timerHeap.isEmpty() && m_timerHeap.first()->m_nextFireTime <= fire
Time) { | |
| 124 TimerBase& timer = *m_timerHeap.first(); | |
| 125 timer.m_nextFireTime = 0; | |
| 126 timer.m_unalignedNextFireTime = 0; | |
| 127 timer.heapDeleteMin(); | |
| 128 | |
| 129 double interval = timer.repeatInterval(); | |
| 130 timer.setNextFireTime(interval ? fireTime + interval : 0); | |
| 131 | |
| 132 TRACE_EVENT2("blink", "ThreadTimers::sharedTimerFiredInternal", | |
| 133 "src_file", timer.location().fileName(), | |
| 134 "src_func", timer.location().functionName()); | |
| 135 | |
| 136 // Once the timer has been fired, it may be deleted, so do nothing else
with it after this point. | |
| 137 timer.fired(); | |
| 138 | |
| 139 // Catch the case where the timer asked timers to fire in a nested event
loop, or we are over time limit. | |
| 140 if (!m_firingTimers || timeToQuit < monotonicallyIncreasingTime() | |
| 141 || (isMainThread() && Platform::current()->currentThread()->schedule
r()->shouldYieldForHighPriorityWork())) | |
| 142 break; | |
| 143 } | |
| 144 | |
| 145 m_firingTimers = false; | |
| 146 | |
| 147 updateSharedTimer(); | |
| 148 } | |
| 149 | |
| 150 } // namespace blink | |
| 151 | |
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Chromium Code Reviews
Issue 1134523002:
Implement timers by posting delayed tasks (Closed)
Base URL: svn://svn.chromium.org/blink/trunk