auto_thread.h revision 5821806d5e7f356e8fa4b058a389a808ea183019
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef REMOTING_BASE_AUTO_THREAD_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define REMOTING_BASE_AUTO_THREAD_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <string> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/message_loop.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/threading/platform_thread.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "remoting/base/auto_thread_task_runner.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace remoting { 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Thread implementation that runs a MessageLoop on a new thread, and manages 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the lifetime of the MessageLoop and thread by tracking references to the 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// thread's TaskRunner. The caller passes the thread's TaskRunner to each 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// object that needs to run code on the thread, and when no references to the 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// TaskRunner remain, the thread will exit. When the caller destroys this 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// object they will be blocked until the thread exits. 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// All pending tasks queued on the thread's message loop will run to completion 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// before the thread is terminated. 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// After the thread is stopped, the destruction sequence is: 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (1) Thread::CleanUp() 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (2) MessageLoop::~MessageLoop 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (3.b) MessageLoop::DestructionObserver::WillDestroyCurrentMessageLoop 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class AutoThread : base::PlatformThread::Delegate { 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Create an AutoThread with the specified message-loop |type| and |name|. 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The supplied AutoThreadTaskRunner will be used to join and delete the 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // new thread when no references to it remain. 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static scoped_refptr<AutoThreadTaskRunner> CreateWithType( 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const char* name, 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AutoThreadTaskRunner> joiner, 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MessageLoop::Type type); 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static scoped_refptr<AutoThreadTaskRunner> Create( 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const char* name, 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AutoThreadTaskRunner> joiner); 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Construct the AutoThread. |name| identifies the thread for debugging. 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) explicit AutoThread(const char* name); 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Waits for the thread to exit, and then destroys it. 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~AutoThread(); 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Starts a the thread, running the specified type of MessageLoop. Returns 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // an AutoThreadTaskRunner through which tasks may be posted to the thread 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // if successful, or NULL on failure. 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Note: This function can't be called on Windows with the loader lock held; 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // i.e. during a DllMain, global object construction or destruction, atexit() 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // callback. 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // NOTE: You must not call this MessageLoop's Quit method directly. The 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // thread will exit when no references to the TaskRunner remain. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AutoThreadTaskRunner> StartWithType(MessageLoop::Type type); 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Shorthand for StartWithType(MessageLoop::TYPE_DEFAULT). 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AutoThreadTaskRunner> Start(); 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AutoThread(const char* name, AutoThreadTaskRunner* joiner); 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void QuitThread(scoped_refptr<base::SingleThreadTaskRunner> task_runner); 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void JoinAndDeleteThread(); 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // base::PlatformThread::Delegate methods: 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void ThreadMain() OVERRIDE; 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Used to pass data to ThreadMain. 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct StartupData; 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) StartupData* startup_data_; 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The thread's handle. 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::PlatformThreadHandle thread_; 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The name of the thread. Used for debugging purposes. 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::string name_; 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Flag used to indicate whether MessageLoop was quit properly. 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This allows us to detect premature exit via MessageLoop::Quit(). 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool was_quit_properly_; 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // AutoThreadTaskRunner to post a task to to join & delete this thread. 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AutoThreadTaskRunner> joiner_; 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(AutoThread); 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace remoting 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // REMOTING_AUTO_THREAD_H_ 96