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 PendingGCRunner_h 32 #define PendingGCRunner_h 33 34 #include "platform/heap/ThreadState.h" 35 #include "public/platform/WebThread.h" 36 37 namespace blink { 38 39 class PendingGCRunner : public blink::WebThread::TaskObserver { 40 public: PendingGCRunner()41 PendingGCRunner() : m_nesting(0) { } 42 ~PendingGCRunner()43 ~PendingGCRunner() 44 { 45 // m_nesting can be 1 if this was unregistered in a task and 46 // didProcessTask was not called. 47 ASSERT(!m_nesting || m_nesting == 1); 48 } 49 willProcessTask()50 virtual void willProcessTask() 51 { 52 m_nesting++; 53 } 54 didProcessTask()55 virtual void didProcessTask() 56 { 57 // In the production code WebKit::initialize is called from inside the 58 // message loop so we can get didProcessTask() without corresponding 59 // willProcessTask once. This is benign. 60 if (m_nesting) 61 m_nesting--; 62 63 blink::ThreadState* state = blink::ThreadState::current(); 64 state->safePoint(m_nesting ? blink::ThreadState::HeapPointersOnStack : blink::ThreadState::NoHeapPointersOnStack); 65 } 66 67 private: 68 int m_nesting; 69 }; 70 71 } 72 73 #endif 74