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 if (!m_timer.isActive()) 68 m_timer.startOneShot(0); 69 } 70 71 // If it's scheduled to run the method, cancel it and remember to schedule 72 // it again when resume() is called. Mainly for implementing 73 // ActiveDOMObject::suspend(). suspend()74 void suspend() 75 { 76 ASSERT(!m_suspended); 77 m_suspended = true; 78 79 if (!m_timer.isActive()) 80 return; 81 82 m_timer.stop(); 83 m_runWhenResumed = true; 84 } 85 86 // Resumes pending method run. resume()87 void resume() 88 { 89 ASSERT(m_suspended); 90 m_suspended = false; 91 92 if (!m_runWhenResumed) 93 return; 94 95 m_runWhenResumed = false; 96 m_timer.startOneShot(0); 97 } 98 stop()99 void stop() 100 { 101 if (m_suspended) { 102 ASSERT(!m_timer.isActive()); 103 m_runWhenResumed = false; 104 m_suspended = false; 105 return; 106 } 107 108 ASSERT(!m_runWhenResumed); 109 if (m_timer.isActive()) 110 m_timer.stop(); 111 } 112 isActive()113 bool isActive() const 114 { 115 return m_timer.isActive(); 116 } 117 118 private: fired(Timer<AsyncMethodRunner<TargetClass>> *)119 void fired(Timer<AsyncMethodRunner<TargetClass> >*) { (m_object->*m_method)(); } 120 121 Timer<AsyncMethodRunner<TargetClass> > m_timer; 122 123 TargetClass* m_object; 124 TargetMethod m_method; 125 126 bool m_suspended; 127 bool m_runWhenResumed; 128 }; 129 130 } 131 132 #endif 133