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 36 namespace 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 // 57 class WebScopedMicrotaskSuppression { 58 public: WebScopedMicrotaskSuppression()59 WebScopedMicrotaskSuppression() { initialize(); } ~WebScopedMicrotaskSuppression()60 ~WebScopedMicrotaskSuppression() { reset(); } 61 62 private: 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