1 /* 2 * Copyright (C) 2014 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 MessageLoopInterruptor_h 32 #define MessageLoopInterruptor_h 33 34 #include "platform/heap/ThreadState.h" 35 #include "public/platform/WebThread.h" 36 37 namespace blink { 38 39 class MessageLoopInterruptor : public ThreadState::Interruptor { 40 public: MessageLoopInterruptor(blink::WebThread * thread)41 explicit MessageLoopInterruptor(blink::WebThread* thread) : m_thread(thread) { } 42 requestInterrupt()43 virtual void requestInterrupt() OVERRIDE 44 { 45 // GCTask has an empty run() method. Its only purpose is to guarantee 46 // that MessageLoop will have a task to process which will result 47 // in PendingGCRunner::didProcessTask being executed. 48 m_thread->postTask(new GCTask); 49 } 50 clearInterrupt()51 virtual void clearInterrupt() OVERRIDE { } 52 53 private: 54 class GCTask : public blink::WebThread::Task { 55 public: ~GCTask()56 virtual ~GCTask() { } 57 run()58 virtual void run() OVERRIDE 59 { 60 // Don't do anything here because we don't know if this is 61 // a nested event loop or not. PendingGCRunner::didProcessTask 62 // will enter correct safepoint for us. 63 // We are not calling onInterrupted() because that always 64 // conservatively enters safepoint with pointers on stack. 65 } 66 }; 67 68 blink::WebThread* m_thread; 69 }; 70 71 } 72 73 #endif 74