Index: Source/platform/ThreadTimers.cpp |
diff --git a/Source/platform/ThreadTimers.cpp b/Source/platform/ThreadTimers.cpp |
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+/* |
+ * Copyright (C) 2006, 2008 Apple Inc. All rights reserved. |
+ * Copyright (C) 2009 Google Inc. All rights reserved. |
+ * |
+ * Redistribution and use in source and binary forms, with or without |
+ * modification, are permitted provided that the following conditions |
+ * are met: |
+ * 1. Redistributions of source code must retain the above copyright |
+ * notice, this list of conditions and the following disclaimer. |
+ * 2. Redistributions in binary form must reproduce the above copyright |
+ * notice, this list of conditions and the following disclaimer in the |
+ * documentation and/or other materials provided with the distribution. |
+ * |
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY |
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR |
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
+ */ |
+ |
+#include "config.h" |
+#include "platform/ThreadTimers.h" |
+ |
+#include "platform/PlatformThreadData.h" |
+#include "platform/SharedTimer.h" |
+#include "platform/Timer.h" |
+#include "platform/TraceEvent.h" |
+#include "public/platform/Platform.h" |
+#include "public/platform/WebScheduler.h" |
+#include "wtf/AddressSanitizer.h" |
+#include "wtf/CurrentTime.h" |
+#include "wtf/MainThread.h" |
+ |
+namespace blink { |
+ |
+// Fire timers for this length of time, and then quit to let the run loop process user input events. |
+// 100ms is about a perceptable delay in UI, so use a half of that as a threshold. |
+// This is to prevent UI freeze when there are too many timers or machine performance is low. |
+static const double maxDurationOfFiringTimers = 0.050; |
+ |
+// Timers are created, started and fired on the same thread, and each thread has its own ThreadTimers |
+// copy to keep the heap and a set of currently firing timers. |
+ |
+static PassOwnPtr<MainThreadSharedTimer> mainThreadSharedTimer() |
+{ |
+ return adoptPtr(new MainThreadSharedTimer); |
+} |
+ |
+ThreadTimers::ThreadTimers() |
+ : m_sharedTimer(0) |
+ , m_firingTimers(false) |
+ , m_pendingSharedTimerFireTime(0) |
+{ |
+ if (isMainThread()) |
+ setSharedTimer(mainThreadSharedTimer()); |
+} |
+ |
+// A worker thread may initialize SharedTimer after some timers are created. |
+// Also, SharedTimer can be replaced with 0 before all timers are destroyed. |
+void ThreadTimers::setSharedTimer(PassOwnPtr<SharedTimer> sharedTimer) |
+{ |
+ if (m_sharedTimer) { |
+ m_sharedTimer->setFiredFunction(0); |
+ m_sharedTimer->stop(); |
+ m_pendingSharedTimerFireTime = 0; |
+ } |
+ |
+ m_sharedTimer = sharedTimer; |
+ |
+ if (m_sharedTimer) { |
+ m_sharedTimer->setFiredFunction(ThreadTimers::sharedTimerFired); |
+ updateSharedTimer(); |
+ } |
+} |
+ |
+NO_LAZY_SWEEP_SANITIZE_ADDRESS |
+void ThreadTimers::updateSharedTimer() |
+{ |
+ if (!m_sharedTimer) |
+ return; |
+ |
+ if (m_firingTimers || m_timerHeap.isEmpty()) { |
+ m_pendingSharedTimerFireTime = 0; |
+ m_sharedTimer->stop(); |
+ } else { |
+ double nextFireTime = m_timerHeap.first()->m_nextFireTime; |
+ double currentMonotonicTime = monotonicallyIncreasingTime(); |
+ if (m_pendingSharedTimerFireTime) { |
+ // No need to restart the timer if both the pending fire time and the new fire time are in the past. |
+ if (m_pendingSharedTimerFireTime <= currentMonotonicTime && nextFireTime <= currentMonotonicTime) |
+ return; |
+ } |
+ m_pendingSharedTimerFireTime = nextFireTime; |
+ m_sharedTimer->setFireInterval(std::max(nextFireTime - currentMonotonicTime, 0.0)); |
+ } |
+} |
+ |
+void ThreadTimers::sharedTimerFired() |
+{ |
+ TRACE_EVENT_SET_SAMPLING_STATE("blink", "BlinkInternal"); |
+ |
+ // Redirect to non-static method. |
+ PlatformThreadData::current().threadTimers().sharedTimerFiredInternal(); |
+ |
+ TRACE_EVENT_SET_SAMPLING_STATE("blink", "Sleeping"); |
+} |
+ |
+NO_LAZY_SWEEP_SANITIZE_ADDRESS |
+void ThreadTimers::sharedTimerFiredInternal() |
+{ |
+ // Do a re-entrancy check. |
+ if (m_firingTimers) |
+ return; |
+ m_firingTimers = true; |
+ m_pendingSharedTimerFireTime = 0; |
+ |
+ double fireTime = monotonicallyIncreasingTime(); |
+ double timeToQuit = fireTime + maxDurationOfFiringTimers; |
+ |
+ while (!m_timerHeap.isEmpty() && m_timerHeap.first()->m_nextFireTime <= fireTime) { |
+ TimerBase& timer = *m_timerHeap.first(); |
+ timer.m_nextFireTime = 0; |
+ timer.m_unalignedNextFireTime = 0; |
+ timer.heapDeleteMin(); |
+ |
+ double interval = timer.repeatInterval(); |
+ timer.setNextFireTime(interval ? fireTime + interval : 0); |
+ |
+ TRACE_EVENT2("blink", "ThreadTimers::sharedTimerFiredInternal", |
+ "src_file", timer.location().fileName(), |
+ "src_func", timer.location().functionName()); |
+ |
+ // Once the timer has been fired, it may be deleted, so do nothing else with it after this point. |
+ timer.fired(); |
+ |
+ // Catch the case where the timer asked timers to fire in a nested event loop, or we are over time limit. |
+ if (!m_firingTimers || timeToQuit < monotonicallyIncreasingTime() |
+ || (isMainThread() && Platform::current()->currentThread()->scheduler()->shouldYieldForHighPriorityWork())) |
+ break; |
+ } |
+ |
+ m_firingTimers = false; |
+ |
+ updateSharedTimer(); |
+} |
+ |
+} // namespace blink |