1/* 2 * Copyright (C) 2012 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 WebScopedMicrotaskSuppression_h 32#define WebScopedMicrotaskSuppression_h 33 34#include "../platform/WebPrivateOwnPtr.h" 35 36namespace blink { 37 38// This class wraps V8RecursionScope::BypassMicrotaskCheckpoint. Please 39// see V8RecursionScope.h for full usage. Short story: Embedder calls into 40// script contexts which also host page script must do one of two things: 41// 42// 1. If the call may cause any page/author script to run, it must be 43// captured for pre/post work (e.g. inspector instrumentation/microtask 44// delivery) and thus be invoked through WebFrame (e.g. executeScript*, 45// callFunction*). 46// 2. If the call will not cause any page/author script to run, the call 47// should be made directly via the v8 context, but the callsite must be 48// accompanied by a stack allocated WebScopedMicrotaskSuppression, e.g.: 49// 50// ... 51// { 52// blink::WebScopedMicrotaskSuppression suppression; 53// func->Call(global, argv, args); 54// } 55// ... 56// 57class WebScopedMicrotaskSuppression { 58public: 59 WebScopedMicrotaskSuppression() { initialize(); } 60 ~WebScopedMicrotaskSuppression() { reset(); } 61 62private: 63 BLINK_EXPORT void initialize(); 64 BLINK_EXPORT void reset(); 65 66 // Always declare this data member. When assertions are on in 67 // Release builds of Blink, this header may be included from 68 // Chromium with different preprocessor options than used when 69 // building Blink itself. 70 class Impl; 71 WebPrivateOwnPtr<Impl> m_impl; 72}; 73 74} // WebKit 75 76#endif 77