blob: e8d12df5925d0edf4bea06c98cc29128aaeff408 [file] [log] [blame]
* Copyright (c) 2021 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.
#include <memory>
#include <utility>
#include "api/task_queue/task_queue_base.h"
#include "net/dcsctp/public/timeout.h"
#include "rtc_base/task_utils/pending_task_safety_flag.h"
namespace dcsctp {
// The TaskQueueTimeoutFactory creates `Timeout` instances, which schedules
// itself to be triggered on the provided `task_queue`, which may be a thread,
// an actual TaskQueue or something else which supports posting a delayed task.
// Note that each `DcSctpSocket` must have its own `TaskQueueTimeoutFactory`,
// as the `TimeoutID` are not unique among sockets.
// This class must outlive any created Timeout that it has created. Note that
// the `DcSctpSocket` will ensure that all Timeouts are deleted when the socket
// is destructed, so this means that this class must outlive the `DcSctpSocket`.
// This class, and the timeouts created it, are not thread safe.
class TaskQueueTimeoutFactory {
// The `get_time` function must return the current time, relative to any
// epoch. Whenever a timeout expires, the `on_expired` callback will be
// triggered, and then the client should provided `timeout_id` to
// `DcSctpSocketInterface::HandleTimeout`.
TaskQueueTimeoutFactory(webrtc::TaskQueueBase& task_queue,
std::function<TimeMs()> get_time,
std::function<void(TimeoutID timeout_id)> on_expired)
: task_queue_(task_queue),
on_expired_(std::move(on_expired)) {}
// Creates an implementation of `Timeout`.
std::unique_ptr<Timeout> CreateTimeout() {
return std::make_unique<TaskQueueTimeout>(*this);
class TaskQueueTimeout : public Timeout {
explicit TaskQueueTimeout(TaskQueueTimeoutFactory& parent);
void Start(DurationMs duration_ms, TimeoutID timeout_id) override;
void Stop() override;
TaskQueueTimeoutFactory& parent_;
// A safety flag to ensure that posted tasks to the task queue don't
// reference these object when they go out of scope. Note that this safety
// flag will be re-created if the scheduled-but-not-yet-expired task is not
// to be run. This happens when there is a posted delayed task with an
// expiration time _further away_ than what is now the expected expiration
// time. In this scenario, a new delayed task has to be posted with a
// shorter duration and the old task has to be forgotten.
rtc::scoped_refptr<webrtc::PendingTaskSafetyFlag> pending_task_safety_flag_;
// The time when the posted delayed task is set to expire. Will be set to
// the infinite future if there is no such task running.
TimeMs posted_task_expiration_ = TimeMs::InfiniteFuture();
// The time when the timeout expires. It will be set to the infinite future
// if the timeout is not running/not started.
TimeMs timeout_expiration_ = TimeMs::InfiniteFuture();
// The current timeout ID that will be reported when expired.
TimeoutID timeout_id_ = TimeoutID(0);
RTC_NO_UNIQUE_ADDRESS webrtc::SequenceChecker thread_checker_;
webrtc::TaskQueueBase& task_queue_;
const std::function<TimeMs()> get_time_;
const std::function<void(TimeoutID)> on_expired_;
} // namespace dcsctp