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/*
* Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
* Copyright (C) 2009 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "third_party/blink/renderer/platform/timer.h"
#include <algorithm>
#include "base/task/delay_policy.h"
#include "base/task/single_thread_task_runner.h"
#include "base/time/tick_clock.h"
#include "third_party/blink/public/platform/platform.h"
#include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
#include "third_party/blink/renderer/platform/scheduler/public/thread_scheduler.h"
#include "third_party/blink/renderer/platform/wtf/sanitizers.h"
namespace blink {
TimerBase::TimerBase(
scoped_refptr<base::SingleThreadTaskRunner> web_task_runner)
: web_task_runner_(std::move(web_task_runner))
#if DCHECK_IS_ON()
,
thread_(CurrentThread())
#endif
{
}
TimerBase::~TimerBase() {
Stop();
}
void TimerBase::Start(base::TimeDelta next_fire_interval,
std::optional<base::TimeDelta> repeat_interval,
const base::Location& caller,
bool precise) {
#if DCHECK_IS_ON()
DCHECK_EQ(thread_, CurrentThread());
#endif
location_ = caller;
repeat_interval_ = repeat_interval;
delay_policy_ = precise ? base::subtle::DelayPolicy::kPrecise
: base::subtle::DelayPolicy::kFlexibleNoSooner;
SetNextFireTime(next_fire_interval.is_zero()
? base::TimeTicks()
: TimerCurrentTimeTicks() + next_fire_interval);
}
void TimerBase::Stop() {
#if DCHECK_IS_ON()
DCHECK_EQ(thread_, CurrentThread());
#endif
repeat_interval_ = std::nullopt;
next_fire_time_ = base::TimeTicks::Max();
delayed_task_handle_.CancelTask();
}
base::TimeDelta TimerBase::NextFireInterval() const {
DCHECK(IsActive());
if (next_fire_time_.is_null())
return base::TimeDelta();
base::TimeTicks current = TimerCurrentTimeTicks();
if (next_fire_time_ < current)
return base::TimeDelta();
return next_fire_time_ - current;
}
void TimerBase::MoveToNewTaskRunner(
scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
#if DCHECK_IS_ON()
DCHECK_EQ(thread_, CurrentThread());
DCHECK(task_runner->RunsTasksInCurrentSequence());
#endif
// If the underlying task runner stays the same, ignore it.
if (web_task_runner_ == task_runner) {
return;
}
bool active = IsActive();
delayed_task_handle_.CancelTask();
web_task_runner_ = std::move(task_runner);
if (!active)
return;
base::TimeTicks next_fire_time =
std::exchange(next_fire_time_, base::TimeTicks::Max());
SetNextFireTime(next_fire_time);
}
void TimerBase::SetTaskRunnerForTesting(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
const base::TickClock* tick_clock) {
DCHECK(!IsActive());
web_task_runner_ = std::move(task_runner);
tick_clock_ = tick_clock;
}
void TimerBase::SetNextFireTime(base::TimeTicks next_fire_time) {
#if DCHECK_IS_ON()
DCHECK_EQ(thread_, CurrentThread());
#endif
if (next_fire_time_ != next_fire_time ||
(repeat_interval_ && repeat_interval_->is_zero())) {
next_fire_time_ = next_fire_time;
// Cancel any previously posted task.
delayed_task_handle_.CancelTask();
delayed_task_handle_ = web_task_runner_->PostCancelableDelayedTaskAt(
base::subtle::PostDelayedTaskPassKey(), location_, BindTimerClosure(),
next_fire_time_, delay_policy_);
}
}
NO_SANITIZE_ADDRESS
void TimerBase::RunInternal() {
DCHECK(!delayed_task_handle_.IsValid());
TRACE_EVENT0("blink", "TimerBase::run");
#if DCHECK_IS_ON()
DCHECK_EQ(thread_, CurrentThread())
<< "Timer posted by " << location_.function_name() << " "
<< location_.file_name() << " was run on a different thread";
#endif
if (repeat_interval_) {
if (repeat_interval_->is_zero()) {
SetNextFireTime(base::TimeTicks());
} else {
// The next tick is `next_fire_time_ + repeat_interval_`, but if late
// wakeup happens we could miss ticks. To avoid posting immediate
// "catch-up" tasks, the next task targets the tick following a minimum
// interval of repeat_interval_ / 20.
base::TimeTicks now = TimerCurrentTimeTicks();
SetNextFireTime(
(now + *repeat_interval_ / 20)
.SnappedToNextTick(next_fire_time_, *repeat_interval_));
}
} else {
next_fire_time_ = base::TimeTicks::Max();
}
Fired();
}
// static
base::TimeTicks TimerBase::TimerCurrentTimeTicks() const {
return tick_clock_
? tick_clock_->NowTicks()
: ThreadScheduler::Current()->MonotonicallyIncreasingVirtualTime();
}
} // namespace blink
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