chrome_frame/task_marshaller.h

   1 // Copyright (c) 2010 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/synchronization/lock.h"
  14 #include "base/threading/non_thread_safe.h"
  15 #include "base/time.h"
  16
  17 class Task;
  18 namespace tracked_objects {
  19   class Location;
  20 }
  21
  22 // TaskMarshallerThroughMessageQueue is similar to base::MessageLoopForUI
  23 // in cases where we do not control the thread lifetime and message retrieval
  24 // and dispatching. It uses a HWND to ::PostMessage to it as a signal that
  25 // the task queue is not empty.
  26 class TaskMarshallerThroughMessageQueue : public base::NonThreadSafe {
  27  public:
  28   TaskMarshallerThroughMessageQueue();
  29   ~TaskMarshallerThroughMessageQueue();
  30
  31   void SetWindow(HWND wnd, UINT msg) {
  32     wnd_ = wnd;
  33     msg_ = msg;
  34   }
  35
  36   virtual void PostTask(const tracked_objects::Location& from_here,
  37                         Task* task);
  38   virtual void PostDelayedTask(const tracked_objects::Location& source,
  39                                Task* task,
  40                                base::TimeDelta& delay);
  41   // Called by the owner of the HWND.
  42   BOOL ProcessWindowMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
  43                             LRESULT& lResult, DWORD dwMsgMapID = 0);
  44  private:
  45   void DeleteAll();
  46   inline Task* PopTask();
  47   inline void ExecuteQueuedTasks();
  48   void ExecuteDelayedTasks();
  49   void RunTask(Task* task);
  50
  51   struct DelayedTask {
  52     DelayedTask(Task* task, base::Time at) : run_at(at), task(task), seq(0) {}
  53     base::Time run_at;
  54     Task* task;
  55     int seq;
  56     // To support sorting based on time in priority_queue.
  57     bool operator<(const DelayedTask& other) const;
  58   };
  59
  60   std::priority_queue<DelayedTask> delayed_tasks_;
  61   std::queue<Task*> pending_tasks_;
  62   base::Lock lock_;
  63   HWND wnd_;
  64   UINT msg_;
  65   int invoke_task_;
  66 };
  67
  68 #endif  // CHROME_FRAME_TASK_MARSHALLER_H_