src/chrome_frame/task_marshaller.cc

   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 #include "chrome_frame/task_marshaller.h"
   6
   7 #include "base/callback.h"
   8 #include "base/logging.h"
   9
  10 TaskMarshallerThroughMessageQueue::TaskMarshallerThroughMessageQueue()
  11     : wnd_(NULL),
  12       msg_(0xFFFF) {
  13 }
  14
  15 TaskMarshallerThroughMessageQueue::~TaskMarshallerThroughMessageQueue() {
  16   ClearTasks();
  17 }
  18
  19 void TaskMarshallerThroughMessageQueue::PostTask(
  20     const tracked_objects::Location& from_here, const base::Closure& task) {
  21   DCHECK(wnd_ != NULL);
  22
  23   lock_.Acquire();
  24   bool has_work = !pending_tasks_.empty();
  25   pending_tasks_.push(task);
  26   lock_.Release();
  27
  28   // Don't post message if there is already one.
  29   if (has_work)
  30     return;
  31
  32   if (!::PostMessage(wnd_, msg_, 0, 0)) {
  33     DVLOG(1) << "Dropping MSG_EXECUTE_TASK message for destroyed window.";
  34     ClearTasks();
  35   }
  36 }
  37
  38 void TaskMarshallerThroughMessageQueue::PostDelayedTask(
  39     const tracked_objects::Location& source,
  40     const base::Closure& task,
  41     base::TimeDelta& delay) {
  42   DCHECK(wnd_);
  43
  44   base::AutoLock lock(lock_);
  45   base::PendingTask delayed_task(source, task, base::TimeTicks::Now() + delay,
  46                                  true);
  47   base::TimeTicks top_run_time = delayed_tasks_.top().delayed_run_time;
  48   delayed_tasks_.push(delayed_task);
  49
  50   // Reschedule the timer if |delayed_task| will be the next delayed task to
  51   // run.
  52   if (delayed_task.delayed_run_time < top_run_time) {
  53     ::SetTimer(wnd_, reinterpret_cast<UINT_PTR>(this),
  54                static_cast<DWORD>(delay.InMilliseconds()), NULL);
  55   }
  56 }
  57
  58 BOOL TaskMarshallerThroughMessageQueue::ProcessWindowMessage(HWND hWnd,
  59                                                              UINT uMsg,
  60                                                              WPARAM wParam,
  61                                                              LPARAM lParam,
  62                                                              LRESULT& lResult,
  63                                                              DWORD dwMsgMapID) {
  64   if (hWnd == wnd_ && uMsg == msg_) {
  65     ExecuteQueuedTasks();
  66     lResult = 0;
  67     return TRUE;
  68   }
  69
  70   if (hWnd == wnd_ && uMsg == WM_TIMER) {
  71     ExecuteDelayedTasks();
  72     lResult = 0;
  73     return TRUE;
  74   }
  75
  76   return FALSE;
  77 }
  78
  79 base::Closure TaskMarshallerThroughMessageQueue::PopTask() {
  80   base::AutoLock lock(lock_);
  81   if (pending_tasks_.empty())
  82     return base::Closure();
  83
  84   base::Closure task = pending_tasks_.front();
  85   pending_tasks_.pop();
  86   return task;
  87 }
  88
  89 void TaskMarshallerThroughMessageQueue::ExecuteQueuedTasks() {
  90   DCHECK(CalledOnValidThread());
  91   base::Closure task;
  92   while (!(task = PopTask()).is_null())
  93     task.Run();
  94 }
  95
  96 void TaskMarshallerThroughMessageQueue::ExecuteDelayedTasks() {
  97   DCHECK(CalledOnValidThread());
  98   ::KillTimer(wnd_, reinterpret_cast<UINT_PTR>(this));
  99   while (true) {
 100     lock_.Acquire();
 101
 102     if (delayed_tasks_.empty()) {
 103       lock_.Release();
 104       return;
 105     }
 106
 107     base::PendingTask next_task = delayed_tasks_.top();
 108     base::TimeTicks now = base::TimeTicks::Now();
 109     base::TimeTicks next_run = next_task.delayed_run_time;
 110     if (next_run > now) {
 111       int64 delay = (next_run - now).InMillisecondsRoundedUp();
 112       ::SetTimer(wnd_, reinterpret_cast<UINT_PTR>(this),
 113                  static_cast<DWORD>(delay), NULL);
 114       lock_.Release();
 115       return;
 116     }
 117
 118     delayed_tasks_.pop();
 119     lock_.Release();
 120
 121     // Run the task outside the lock.
 122     next_task.task.Run();
 123   }
 124 }
 125
 126 void TaskMarshallerThroughMessageQueue::ClearTasks() {
 127   base::AutoLock lock(lock_);
 128   DVLOG_IF(1, !pending_tasks_.empty()) << "Destroying "
 129                                        << pending_tasks_.size()
 130                                        << " pending tasks.";
 131   while (!pending_tasks_.empty())
 132     pending_tasks_.pop();
 133
 134   while (!delayed_tasks_.empty())
 135     delayed_tasks_.pop();
 136 }