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// Copyright (c) 2013 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 "chrome/browser/net/network_time_tracker.h"
#include "base/sequenced_task_runner.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/io_thread.h"
namespace {
// Helper functions for interacting with the NetworkTimeNotifier.
// Registration happens as follows (assuming tracker lives on thread N):
// | Thread N | | UI thread| | IO Thread |
// Start
// RegisterObserverOnUIThread
// RegisterObserverOnIOThread
// NetworkTimeNotifier::AddObserver
// after which updates to the notifier and the subsequent observer calls
// happen as follows (assuming the network time update comes from the same
// thread):
// | Thread N | | UI thread| | IO Thread |
// UpdateNetworkNotifier
// UpdateNetworkNotifierOnIOThread
// NetworkTimeNotifier::UpdateNetworkTime
// OnNetworkTimeUpdatedOnIOThread
// OnNetworkTimeUpdated
void RegisterObserverOnIOThread(
IOThread* io_thread,
const net::NetworkTimeNotifier::ObserverCallback& observer_callback) {
DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
io_thread->globals()->network_time_notifier->AddObserver(observer_callback);
}
void RegisterObserverOnUIThread(
const net::NetworkTimeNotifier::ObserverCallback& observer_callback) {
DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
content::BrowserThread::PostTask(
content::BrowserThread::IO, FROM_HERE,
base::Bind(&RegisterObserverOnIOThread,
g_browser_process->io_thread(),
observer_callback));
}
void UpdateNetworkNotifierOnIOThread(IOThread* io_thread,
const base::Time& network_time,
const base::TimeDelta& resolution,
const base::TimeDelta& latency,
const base::TimeTicks& post_time) {
DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
io_thread->globals()->network_time_notifier->UpdateNetworkTime(
network_time, resolution, latency, post_time);
}
void UpdateNetworkNotifier(IOThread* io_thread,
const base::Time& network_time,
const base::TimeDelta& resolution,
const base::TimeDelta& latency) {
content::BrowserThread::PostTask(
content::BrowserThread::IO,
FROM_HERE,
base::Bind(&UpdateNetworkNotifierOnIOThread,
io_thread,
network_time,
resolution,
latency,
base::TimeTicks::Now()));
}
void OnNetworkTimeUpdatedOnIOThread(
const scoped_refptr<base::SequencedTaskRunner>& task_runner,
const net::NetworkTimeNotifier::ObserverCallback& observer_callback,
const base::Time& network_time,
const base::TimeTicks& network_time_ticks,
const base::TimeDelta& network_time_uncertainty) {
task_runner->PostTask(
FROM_HERE,
base::Bind(observer_callback,
network_time,
network_time_ticks,
network_time_uncertainty));
}
} // namespace
NetworkTimeTracker::NetworkTimeTracker()
: weak_ptr_factory_(this) {
}
NetworkTimeTracker::~NetworkTimeTracker() {
}
void NetworkTimeTracker::Start() {
DCHECK(thread_checker_.CalledOnValidThread());
content::BrowserThread::PostTask(
content::BrowserThread::UI,
FROM_HERE,
base::Bind(&RegisterObserverOnUIThread,
BuildObserverCallback()));
}
bool NetworkTimeTracker::GetNetworkTime(const base::TimeTicks& time_ticks,
base::Time* network_time,
base::TimeDelta* uncertainty) const {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(network_time);
if (network_time_.is_null())
return false;
DCHECK(!network_time_ticks_.is_null());
*network_time = network_time_ + (time_ticks - network_time_ticks_);
if (uncertainty)
*uncertainty = network_time_uncertainty_;
return true;
}
// static
// Note: UpdateNetworkNotifier is exposed via callback because getting the IO
// thread pointer must be done on the UI thread, while components that provide
// network time updates may live on other threads.
NetworkTimeTracker::UpdateCallback
NetworkTimeTracker::BuildNotifierUpdateCallback() {
DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
return base::Bind(&UpdateNetworkNotifier,
g_browser_process->io_thread());
}
net::NetworkTimeNotifier::ObserverCallback
NetworkTimeTracker::BuildObserverCallback() {
return base::Bind(&OnNetworkTimeUpdatedOnIOThread,
MessageLoop::current()->message_loop_proxy(),
base::Bind(&NetworkTimeTracker::OnNetworkTimeUpdate,
weak_ptr_factory_.GetWeakPtr()));
}
void NetworkTimeTracker::OnNetworkTimeUpdate(
const base::Time& network_time,
const base::TimeTicks& network_time_ticks,
const base::TimeDelta& network_time_uncertainty) {
DCHECK(thread_checker_.CalledOnValidThread());
network_time_ = network_time;
network_time_ticks_ = network_time_ticks;
network_time_uncertainty_ = network_time_uncertainty;
}
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