1 /* 2 * Copyright (C) 2013 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef AsyncMethodRunner_h 32 #define AsyncMethodRunner_h 33 34 #include "platform/Timer.h" 35 #include "wtf/FastAllocBase.h" 36 #include "wtf/Noncopyable.h" 37 38 namespace WebCore { 39 40 template <typename TargetClass> 41 class AsyncMethodRunner FINAL { 42 WTF_MAKE_NONCOPYABLE(AsyncMethodRunner); 43 WTF_MAKE_FAST_ALLOCATED; 44 public: 45 typedef void (TargetClass::*TargetMethod)(); 46 AsyncMethodRunner(TargetClass * object,TargetMethod method)47 AsyncMethodRunner(TargetClass* object, TargetMethod method) 48 : m_timer(this, &AsyncMethodRunner<TargetClass>::fired) 49 , m_object(object) 50 , m_method(method) 51 , m_suspended(false) 52 , m_runWhenResumed(false) 53 { 54 } 55 56 // Schedules to run the method asynchronously. Do nothing if it's already 57 // scheduled. If it's suspended, remember to schedule to run the method when 58 // resume() is called. runAsync()59 void runAsync() 60 { 61 if (m_suspended) { 62 ASSERT(!m_timer.isActive()); 63 m_runWhenResumed = true; 64 return; 65 } 66 67 // FIXME: runAsync should take a TraceLocation and pass it to timer here. 68 if (!m_timer.isActive()) 69 m_timer.startOneShot(0, FROM_HERE); 70 } 71 72 // If it's scheduled to run the method, cancel it and remember to schedule 73 // it again when resume() is called. Mainly for implementing 74 // ActiveDOMObject::suspend(). suspend()75 void suspend() 76 { 77 ASSERT(!m_suspended); 78 m_suspended = true; 79 80 if (!m_timer.isActive()) 81 return; 82 83 m_timer.stop(); 84 m_runWhenResumed = true; 85 } 86 87 // Resumes pending method run. resume()88 void resume() 89 { 90 ASSERT(m_suspended); 91 m_suspended = false; 92 93 if (!m_runWhenResumed) 94 return; 95 96 m_runWhenResumed = false; 97 // FIXME: resume should take a TraceLocation and pass it to timer here. 98 m_timer.startOneShot(0, FROM_HERE); 99 } 100 stop()101 void stop() 102 { 103 if (m_suspended) { 104 ASSERT(!m_timer.isActive()); 105 m_runWhenResumed = false; 106 m_suspended = false; 107 return; 108 } 109 110 ASSERT(!m_runWhenResumed); 111 if (m_timer.isActive()) 112 m_timer.stop(); 113 } 114 isActive()115 bool isActive() const 116 { 117 return m_timer.isActive(); 118 } 119 120 private: fired(Timer<AsyncMethodRunner<TargetClass>> *)121 void fired(Timer<AsyncMethodRunner<TargetClass> >*) { (m_object->*m_method)(); } 122 123 Timer<AsyncMethodRunner<TargetClass> > m_timer; 124 125 // FIXME: oilpan: AsyncMethodRunner should be moved to the heap and m_object should be traced. 126 // This raw pointer is safe as long as AsyncMethodRunner<X> is held by the X itself 127 // (That's the case in the current code base). 128 GC_PLUGIN_IGNORE("363031") 129 TargetClass* m_object; 130 TargetMethod m_method; 131 132 bool m_suspended; 133 bool m_runWhenResumed; 134 }; 135 136 } 137 138 #endif 139