chrome_frame/task_marshaller.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_FRAME_TASK_MARSHALLER_H_
   6 #define CHROME_FRAME_TASK_MARSHALLER_H_
   7 #pragma once
   8
   9 #include <windows.h>
  10 #include <deque>
  11 #include <queue>
  12
  13 #include "base/callback.h"
  14 #include "base/pending_task.h"
  15 #include "base/synchronization/lock.h"
  16 #include "base/threading/non_thread_safe.h"
  17 #include "base/time.h"
  18
  19 class Task;
  20
  21 namespace tracked_objects {
  22 class Location;
  23 }
  24
  25 // TaskMarshallerThroughMessageQueue is similar to base::MessageLoopForUI
  26 // in cases where we do not control the thread lifetime and message retrieval
  27 // and dispatching. It uses a HWND to ::PostMessage to it as a signal that
  28 // the task queue is not empty.
  29 class TaskMarshallerThroughMessageQueue : public base::NonThreadSafe {
  30  public:
  31   TaskMarshallerThroughMessageQueue();
  32   virtual ~TaskMarshallerThroughMessageQueue();
  33
  34   void SetWindow(HWND wnd, UINT msg) {
  35     wnd_ = wnd;
  36     msg_ = msg;
  37   }
  38
  39   virtual void PostTask(const tracked_objects::Location& from_here,
  40                         const base::Closure& task);
  41   virtual void PostDelayedTask(const tracked_objects::Location& source,
  42                                const base::Closure& task,
  43                                base::TimeDelta& delay);
  44
  45   // Called by the owner of the HWND.
  46   BOOL ProcessWindowMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
  47                             LRESULT& lResult, DWORD dwMsgMapID = 0);
  48  private:
  49   void ClearTasks();
  50   inline base::Closure PopTask();
  51   inline void ExecuteQueuedTasks();
  52   void ExecuteDelayedTasks();
  53
  54   // Shortest delays ordered at the top of the queue.
  55   base::DelayedTaskQueue delayed_tasks_;
  56
  57   // A list of tasks that need to be processed by this instance.
  58   std::queue<base::Closure> pending_tasks_;
  59
  60   // Lock accesses to |pending_tasks_|.
  61   base::Lock lock_;
  62
  63   // ::PostMessage parameters.
  64   HWND wnd_;
  65   UINT msg_;
  66 };
  67
  68 #endif  // CHROME_FRAME_TASK_MARSHALLER_H_