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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/quic/quic_connection_helper.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/metrics/sparse_histogram.h"
#include "base/task_runner.h"
#include "base/time/time.h"
#include "net/base/io_buffer.h"
#include "net/base/net_errors.h"
#include "net/quic/quic_utils.h"
namespace net {
namespace {
class QuicChromeAlarm : public QuicAlarm {
public:
QuicChromeAlarm(const QuicClock* clock,
base::TaskRunner* task_runner,
QuicAlarm::Delegate* delegate)
: QuicAlarm(delegate),
clock_(clock),
task_runner_(task_runner),
task_deadline_(QuicTime::Zero()),
weak_factory_(this) {}
protected:
void SetImpl() override {
DCHECK(deadline().IsInitialized());
if (task_deadline_.IsInitialized()) {
if (task_deadline_ <= deadline()) {
// Since tasks can not be un-posted, OnAlarm will be invoked which
// will notice that deadline has not yet been reached, and will set
// the alarm for the new deadline.
return;
}
// The scheduled task is after new deadline. Invalidate the weak ptrs
// so that task does not execute when we're not expecting it.
weak_factory_.InvalidateWeakPtrs();
}
int64 delay_us = deadline().Subtract(clock_->Now()).ToMicroseconds();
if (delay_us < 0) {
delay_us = 0;
}
task_runner_->PostDelayedTask(
FROM_HERE,
base::Bind(&QuicChromeAlarm::OnAlarm, weak_factory_.GetWeakPtr()),
base::TimeDelta::FromMicroseconds(delay_us));
task_deadline_ = deadline();
}
void CancelImpl() override {
DCHECK(!deadline().IsInitialized());
// Since tasks can not be un-posted, OnAlarm will be invoked which
// will notice that deadline is not Initialized and will do nothing.
}
private:
void OnAlarm() {
DCHECK(task_deadline_.IsInitialized());
task_deadline_ = QuicTime::Zero();
// The alarm may have been cancelled.
if (!deadline().IsInitialized()) {
return;
}
// The alarm may have been re-set to a later time.
if (clock_->Now() < deadline()) {
SetImpl();
return;
}
Fire();
}
const QuicClock* clock_;
base::TaskRunner* task_runner_;
// If a task has been posted to the message loop, this is the time it
// was scheduled to fire. Tracking this allows us to avoid posting a
// new tast if the new deadline is in the future, but permits us to
// post a new task when the new deadline now earlier than when
// previously posted.
QuicTime task_deadline_;
base::WeakPtrFactory<QuicChromeAlarm> weak_factory_;
};
} // namespace
QuicConnectionHelper::QuicConnectionHelper(base::TaskRunner* task_runner,
const QuicClock* clock,
QuicRandom* random_generator)
: task_runner_(task_runner),
clock_(clock),
random_generator_(random_generator),
weak_factory_(this) {
}
QuicConnectionHelper::~QuicConnectionHelper() {
}
const QuicClock* QuicConnectionHelper::GetClock() const {
return clock_;
}
QuicRandom* QuicConnectionHelper::GetRandomGenerator() {
return random_generator_;
}
QuicAlarm* QuicConnectionHelper::CreateAlarm(QuicAlarm::Delegate* delegate) {
return new QuicChromeAlarm(clock_, task_runner_, delegate);
}
} // namespace net
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