1 /* 2 * Copyright (C) 2011 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 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 #ifndef WebThread_h 26 #define WebThread_h 27 28 #include "WebCommon.h" 29 #include <stdint.h> 30 31 namespace blink { 32 33 // Always an integer value. 34 typedef uintptr_t PlatformThreadId; 35 36 // Provides an interface to an embedder-defined thread implementation. 37 // 38 // Deleting the thread blocks until all pending, non-delayed tasks have been 39 // run. 40 class BLINK_PLATFORM_EXPORT WebThread { 41 public: 42 class Task { 43 public: ~Task()44 virtual ~Task() { } 45 virtual void run() = 0; 46 }; 47 48 class BLINK_PLATFORM_EXPORT TaskObserver { 49 public: ~TaskObserver()50 virtual ~TaskObserver() { } 51 virtual void willProcessTask() = 0; 52 virtual void didProcessTask() = 0; 53 }; 54 55 // postTask() and postDelayedTask() take ownership of the passed Task 56 // object. It is safe to invoke postTask() and postDelayedTask() from any 57 // thread. 58 virtual void postTask(Task*) = 0; 59 virtual void postDelayedTask(Task*, long long delayMs) = 0; 60 61 virtual bool isCurrentThread() const = 0; threadId()62 virtual PlatformThreadId threadId() const { return 0; } 63 addTaskObserver(TaskObserver *)64 virtual void addTaskObserver(TaskObserver*) { } removeTaskObserver(TaskObserver *)65 virtual void removeTaskObserver(TaskObserver*) { } 66 67 // enterRunLoop() processes tasks posted to this WebThread. This call does not return until some task calls exitRunLoop(). 68 // WebThread does not support nesting, meaning that once the run loop is entered for a given WebThread it is not valid to 69 // call enterRunLoop() again. 70 virtual void enterRunLoop() = 0; 71 72 // exitRunLoop() runs tasks until there are no tasks available to run, then returns control to the caller of enterRunLoop(). 73 // Must be called when the WebThread is running. 74 virtual void exitRunLoop() = 0; 75 ~WebThread()76 virtual ~WebThread() { } 77 }; 78 79 } // namespace blink 80 81 #endif 82