message_pump_win.h revision 5e3f23d412006dc4db4e659864679f29341e113f
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 BASE_MESSAGE_PUMP_WIN_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define BASE_MESSAGE_PUMP_WIN_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <windows.h> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <list> 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/base_export.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/scoped_ptr.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/message_pump.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/message_pump_dispatcher.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/message_pump_observer.h" 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/observer_list.h" 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/time.h" 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/win/scoped_handle.h" 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base { 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MessagePumpWin serves as the base for specialized versions of the MessagePump 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// for Windows. It provides basic functionality like handling of observers and 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// controlling the lifetime of the message pump. 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class BASE_EXPORT MessagePumpWin : public MessagePump { 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MessagePumpWin() : have_work_(0), state_(NULL) {} 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~MessagePumpWin() {} 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Add an Observer, which will start receiving notifications immediately. 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void AddObserver(MessagePumpObserver* observer); 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Remove an Observer. It is safe to call this method while an Observer is 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // receiving a notification callback. 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void RemoveObserver(MessagePumpObserver* observer); 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Give a chance to code processing additional messages to notify the 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // message loop observers that another message has been processed. 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void WillProcessMessage(const MSG& msg); 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void DidProcessMessage(const MSG& msg); 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Like MessagePump::Run, but MSG objects are routed through dispatcher. 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void RunWithDispatcher(Delegate* delegate, MessagePumpDispatcher* dispatcher); 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // MessagePump methods: 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void Run(Delegate* delegate) { RunWithDispatcher(delegate, NULL); } 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void Quit(); 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) protected: 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct RunState { 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Delegate* delegate; 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MessagePumpDispatcher* dispatcher; 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Used to flag that the current Run() invocation should return ASAP. 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool should_quit; 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Used to count how many Run() invocations are on the stack. 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int run_depth; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void DoRunLoop() = 0; 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int GetCurrentDelay() const; 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ObserverList<MessagePumpObserver> observers_; 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The time at which delayed work should run. 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) TimeTicks delayed_work_time_; 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A boolean value used to indicate if there is a kMsgDoWork message pending 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // in the Windows Message queue. There is at most one such message, and it 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // can drive execution of tasks when a native message pump is running. 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) LONG have_work_; 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // State for the current invocation of Run. 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) RunState* state_; 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//----------------------------------------------------------------------------- 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MessagePumpForUI extends MessagePumpWin with methods that are particular to a 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MessageLoop instantiated with TYPE_UI. 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MessagePumpForUI implements a "traditional" Windows message pump. It contains 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// a nearly infinite loop that peeks out messages, and then dispatches them. 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Intermixed with those peeks are callouts to DoWork for pending tasks, and 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DoDelayedWork for pending timers. When there are no events to be serviced, 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// this pump goes into a wait state. In most cases, this message pump handles 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// all processing. 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// However, when a task, or windows event, invokes on the stack a native dialog 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// box or such, that window typically provides a bare bones (native?) message 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// pump. That bare-bones message pump generally supports little more than a 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// peek of the Windows message queue, followed by a dispatch of the peeked 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// message. MessageLoop extends that bare-bones message pump to also service 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Tasks, at the cost of some complexity. 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The basic structure of the extension (refered to as a sub-pump) is that a 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// special message, kMsgHaveWork, is repeatedly injected into the Windows 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Message queue. Each time the kMsgHaveWork message is peeked, checks are 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// made for an extended set of events, including the availability of Tasks to 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// run. 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// After running a task, the special message kMsgHaveWork is again posted to 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the Windows Message queue, ensuring a future time slice for processing a 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// future event. To prevent flooding the Windows Message queue, care is taken 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// to be sure that at most one kMsgHaveWork message is EVER pending in the 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Window's Message queue. 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// There are a few additional complexities in this system where, when there are 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// no Tasks to run, this otherwise infinite stream of messages which drives the 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// sub-pump is halted. The pump is automatically re-started when Tasks are 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// queued. 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A second complexity is that the presence of this stream of posted tasks may 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// prevent a bare-bones message pump from ever peeking a WM_PAINT or WM_TIMER. 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Such paint and timer events always give priority to a posted message, such as 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// kMsgHaveWork messages. As a result, care is taken to do some peeking in 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// between the posting of each kMsgHaveWork message (i.e., after kMsgHaveWork 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// is peeked, and before a replacement kMsgHaveWork is posted). 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// NOTE: Although it may seem odd that messages are used to start and stop this 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// flow (as opposed to signaling objects, etc.), it should be understood that 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the native message pump will *only* respond to messages. As a result, it is 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// an excellent choice. It is also helpful that the starter messages that are 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// placed in the queue when new task arrive also awakens DoRunLoop. 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class BASE_EXPORT MessagePumpForUI : public MessagePumpWin { 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A MessageFilter implements the common Peek/Translate/Dispatch code to deal 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // with windows messages. 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This abstraction is used to inject TSF message peeking. See 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // TextServicesMessageFilter. 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class BASE_EXPORT MessageFilter { 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~MessageFilter() {} 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Implements the functionality exposed by the OS through PeekMessage. 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual BOOL DoPeekMessage(MSG* msg, 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HWND window_handle, 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) UINT msg_filter_min, 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) UINT msg_filter_max, 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) UINT remove_msg) { 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return PeekMessage(msg, window_handle, msg_filter_min, msg_filter_max, 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) remove_msg); 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns true if |message| was consumed by the filter and no extra 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // processing is required. If this method returns false, it is the 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // responsibility of the caller to ensure that normal processing takes 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // place. 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The priority to consume messages is the following: 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // - Native Windows' message filter (CallMsgFilter). 1525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // - MessageFilter::ProcessMessage. 1535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // - MessagePumpDispatcher. 1545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // - TranslateMessage / DispatchMessage. 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual bool ProcessMessage(const MSG& msg) { return false;} 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The application-defined code passed to the hook procedure. 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static const int kMessageFilterCode = 0x5001; 1595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MessagePumpForUI(); 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~MessagePumpForUI(); 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Sets a new MessageFilter. MessagePumpForUI takes ownership of 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |message_filter|. When SetMessageFilter is called, old MessageFilter is 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // deleted. 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void SetMessageFilter(scoped_ptr<MessageFilter> message_filter); 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // MessagePump methods: 1695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void ScheduleWork(); 1705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time); 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Applications can call this to encourage us to process all pending WM_PAINT 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // messages. This method will process all paint messages the Windows Message 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // queue can provide, up to some fixed number (to avoid any infinite loops). 1755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void PumpOutPendingPaintMessages(); 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static LRESULT CALLBACK WndProcThunk(HWND window_handle, 1795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) UINT message, 1805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WPARAM wparam, 1815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) LPARAM lparam); 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void DoRunLoop(); 1835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void InitMessageWnd(); 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void WaitForWork(); 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void HandleWorkMessage(); 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void HandleTimerMessage(); 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool ProcessNextWindowsMessage(); 1885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool ProcessMessageHelper(const MSG& msg); 1895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool ProcessPumpReplacementMessage(); 1905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1915e3f23d412006dc4db4e659864679f29341e113fTorne (Richard Coles) // Atom representing the registered window class. 1925e3f23d412006dc4db4e659864679f29341e113fTorne (Richard Coles) ATOM atom_; 1935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A hidden message-only window. 1955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HWND message_hwnd_; 1965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_ptr<MessageFilter> message_filter_; 1985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//----------------------------------------------------------------------------- 2015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MessagePumpForIO extends MessagePumpWin with methods that are particular to a 2025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MessageLoop instantiated with TYPE_IO. This version of MessagePump does not 2035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// deal with Windows mesagges, and instead has a Run loop based on Completion 2045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Ports so it is better suited for IO operations. 2055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 2065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class BASE_EXPORT MessagePumpForIO : public MessagePumpWin { 2075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 2085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct IOContext; 2095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Clients interested in receiving OS notifications when asynchronous IO 2115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // operations complete should implement this interface and register themselves 2125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // with the message pump. 2135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Typical use #1: 2155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // Use only when there are no user's buffers involved on the actual IO, 2165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // so that all the cleanup can be done by the message pump. 2175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // class MyFile : public IOHandler { 2185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // MyFile() { 2195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ... 2205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // context_ = new IOContext; 2215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // context_->handler = this; 2225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // message_pump->RegisterIOHandler(file_, this); 2235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ~MyFile() { 2255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // if (pending_) { 2265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // By setting the handler to NULL, we're asking for this context 2275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // to be deleted when received, without calling back to us. 2285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // context_->handler = NULL; 2295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } else { 2305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // delete context_; 2315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // virtual void OnIOCompleted(IOContext* context, DWORD bytes_transfered, 2345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // DWORD error) { 2355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // pending_ = false; 2365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // void DoSomeIo() { 2385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ... 2395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // The only buffer required for this operation is the overlapped 2405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // structure. 2415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ConnectNamedPipe(file_, &context_->overlapped); 2425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // pending_ = true; 2435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // bool pending_; 2455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // IOContext* context_; 2465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // HANDLE file_; 2475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // }; 2485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Typical use #2: 2505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // class MyFile : public IOHandler { 2515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // MyFile() { 2525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ... 2535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // message_pump->RegisterIOHandler(file_, this); 2545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // Plus some code to make sure that this destructor is not called 2565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // while there are pending IO operations. 2575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ~MyFile() { 2585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // virtual void OnIOCompleted(IOContext* context, DWORD bytes_transfered, 2605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // DWORD error) { 2615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ... 2625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // delete context; 2635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // void DoSomeIo() { 2655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ... 2665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // IOContext* context = new IOContext; 2675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // This is not used for anything. It just prevents the context from 2685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // // being considered "abandoned". 2695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // context->handler = this; 2705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ReadFile(file_, buffer, num_bytes, &read, &context->overlapped); 2715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // HANDLE file_; 2735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // }; 2745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Typical use #3: 2765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Same as the previous example, except that in order to deal with the 2775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // requirement stated for the destructor, the class calls WaitForIOCompletion 2785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // from the destructor to block until all IO finishes. 2795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ~MyFile() { 2805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // while(pending_) 2815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // message_pump->WaitForIOCompletion(INFINITE, this); 2825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // } 2835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class IOHandler { 2855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 2865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~IOHandler() {} 2875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This will be called once the pending IO operation associated with 2885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |context| completes. |error| is the Win32 error code of the IO operation 2895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // (ERROR_SUCCESS if there was no error). |bytes_transfered| will be zero 2905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // on error. 2915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void OnIOCompleted(IOContext* context, DWORD bytes_transfered, 2925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DWORD error) = 0; 2935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 2945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // An IOObserver is an object that receives IO notifications from the 2965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // MessagePump. 2975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // NOTE: An IOObserver implementation should be extremely fast! 2995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class IOObserver { 3005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 3015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) IOObserver() {} 3025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void WillProcessIOEvent() = 0; 3045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void DidProcessIOEvent() = 0; 3055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) protected: 3075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~IOObserver() {} 3085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 3095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The extended context that should be used as the base structure on every 3115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // overlapped IO operation. |handler| must be set to the registered IOHandler 3125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // for the given file when the operation is started, and it can be set to NULL 3135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // before the operation completes to indicate that the handler should not be 3145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // called anymore, and instead, the IOContext should be deleted when the OS 3155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // notifies the completion of this operation. Please remember that any buffers 3165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // involved with an IO operation should be around until the callback is 3175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // received, so this technique can only be used for IO that do not involve 3185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // additional buffers (other than the overlapped structure itself). 3195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct IOContext { 3205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OVERLAPPED overlapped; 3215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) IOHandler* handler; 3225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 3235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MessagePumpForIO(); 3255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~MessagePumpForIO() {} 3265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // MessagePump methods: 3285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void ScheduleWork(); 3295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time); 3305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Register the handler to be used when asynchronous IO for the given file 3325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // completes. The registration persists as long as |file_handle| is valid, so 3335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |handler| must be valid as long as there is pending IO for the given file. 3345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void RegisterIOHandler(HANDLE file_handle, IOHandler* handler); 3355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Register the handler to be used to process job events. The registration 3375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // persists as long as the job object is live, so |handler| must be valid 3385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // until the job object is destroyed. Returns true if the registration 3395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // succeeded, and false otherwise. 3405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool RegisterJobObject(HANDLE job_handle, IOHandler* handler); 3415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Waits for the next IO completion that should be processed by |filter|, for 3435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // up to |timeout| milliseconds. Return true if any IO operation completed, 3445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // regardless of the involved handler, and false if the timeout expired. If 3455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // the completion port received any message and the involved IO handler 3465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // matches |filter|, the callback is called before returning from this code; 3475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // if the handler is not the one that we are looking for, the callback will 3485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // be postponed for another time, so reentrancy problems can be avoided. 3495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // External use of this method should be reserved for the rare case when the 3505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // caller is willing to allow pausing regular task dispatching on this thread. 3515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool WaitForIOCompletion(DWORD timeout, IOHandler* filter); 3525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void AddIOObserver(IOObserver* obs); 3545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void RemoveIOObserver(IOObserver* obs); 3555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 3575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct IOItem { 3585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) IOHandler* handler; 3595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) IOContext* context; 3605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DWORD bytes_transfered; 3615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DWORD error; 3625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // In some cases |context| can be a non-pointer value casted to a pointer. 3645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |has_valid_io_context| is true if |context| is a valid IOContext 3655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // pointer, and false otherwise. 3665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool has_valid_io_context; 3675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 3685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void DoRunLoop(); 3705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void WaitForWork(); 3715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool MatchCompletedIOItem(IOHandler* filter, IOItem* item); 3725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool GetIOItem(DWORD timeout, IOItem* item); 3735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool ProcessInternalIOItem(const IOItem& item); 3745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void WillProcessIOEvent(); 3755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void DidProcessIOEvent(); 3765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Converts an IOHandler pointer to a completion port key. 3785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |has_valid_io_context| specifies whether completion packets posted to 3795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |handler| will have valid OVERLAPPED pointers. 3805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static ULONG_PTR HandlerToKey(IOHandler* handler, bool has_valid_io_context); 3815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Converts a completion port key to an IOHandler pointer. 3835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static IOHandler* KeyToHandler(ULONG_PTR key, bool* has_valid_io_context); 3845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The completion port associated with this thread. 3865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) win::ScopedHandle port_; 3875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This list will be empty almost always. It stores IO completions that have 3885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // not been delivered yet because somebody was doing cleanup. 3895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::list<IOItem> completed_io_; 3905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ObserverList<IOObserver> io_observers_; 3925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 3935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace base 3955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // BASE_MESSAGE_PUMP_WIN_H_ 397