blob: e0cf17513a6fd0d4376a235d6d93c0943e61100f [file] [log] [blame]
/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_BASE_TASKRUNNER_H__
#define WEBRTC_BASE_TASKRUNNER_H__
#include <vector>
#include "webrtc/base/basictypes.h"
#include "webrtc/base/sigslot.h"
#include "webrtc/base/taskparent.h"
namespace rtc {
class Task;
const int64_t kSecToMsec = 1000;
const int64_t kMsecTo100ns = 10000;
const int64_t kSecTo100ns = kSecToMsec * kMsecTo100ns;
class TaskRunner : public TaskParent, public sigslot::has_slots<> {
public:
TaskRunner();
~TaskRunner() override;
virtual void WakeTasks() = 0;
// Returns the current time in 100ns units. It is used for
// determining timeouts. The origin is not important, only
// the units and that rollover while the computer is running.
//
// On Windows, GetSystemTimeAsFileTime is the typical implementation.
virtual int64_t CurrentTime() = 0;
void StartTask(Task *task);
void RunTasks();
void PollTasks();
void UpdateTaskTimeout(Task* task, int64_t previous_task_timeout_time);
#if !defined(NDEBUG)
bool is_ok_to_delete(Task* task) {
return task == deleting_task_;
}
void IncrementAbortCount() {
++abort_count_;
}
void DecrementAbortCount() {
--abort_count_;
}
#endif
// Returns the next absolute time when a task times out
// OR "0" if there is no next timeout.
int64_t next_task_timeout() const;
protected:
// The primary usage of this method is to know if
// a callback timer needs to be set-up or adjusted.
// This method will be called
// * when the next_task_timeout() becomes a smaller value OR
// * when next_task_timeout() has changed values and the previous
// value is in the past.
//
// If the next_task_timeout moves to the future, this method will *not*
// get called (because it subclass should check next_task_timeout()
// when its timer goes off up to see if it needs to set-up a new timer).
//
// Note that this maybe called conservatively. In that it may be
// called when no time change has happened.
virtual void OnTimeoutChange() {
// by default, do nothing.
}
private:
void InternalRunTasks(bool in_destructor);
void CheckForTimeoutChange(int64_t previous_timeout_time);
std::vector<Task *> tasks_;
Task *next_timeout_task_;
bool tasks_running_;
#if !defined(NDEBUG)
int abort_count_;
Task* deleting_task_;
#endif
void RecalcNextTimeout(Task *exclude_task);
};
} // namespace rtc
#endif // TASK_BASE_TASKRUNNER_H__