blob: 7b75c15dee3e12a0db788bd22b1a548bd28b7447 [file] [log] [blame]
// 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 <windows.h>
#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/non_thread_safe.h"
#include "base/timer/timer.h"
#include "base/win/object_watcher.h"
#include "net/base/net_export.h"
#include "net/base/network_change_notifier.h"
namespace net {
// NetworkChangeNotifierWin inherits from NonThreadSafe, as all its internal
// notification code must be called on the thread it is created and destroyed
// on. All the NetworkChangeNotifier methods it implements are threadsafe.
class NET_EXPORT_PRIVATE NetworkChangeNotifierWin
: public NetworkChangeNotifier,
public base::win::ObjectWatcher::Delegate,
NON_EXPORTED_BASE(public base::NonThreadSafe) {
// Begins listening for a single subsequent address change. If it fails to
// start watching, it retries on a timer. Must be called only once, on the
// thread |this| was created on. This cannot be called in the constructor, as
// WatchForAddressChangeInternal is mocked out in unit tests.
// TODO(mmenke): Consider making this function a part of the
// NetworkChangeNotifier interface, so other subclasses can be
// unit tested in similar fashion, as needed.
void WatchForAddressChange();
virtual ~NetworkChangeNotifierWin();
// For unit tests only.
bool is_watching() { return is_watching_; }
void set_is_watching(bool is_watching) { is_watching_ = is_watching; }
int sequential_failures() { return sequential_failures_; }
class DnsConfigServiceThread;
friend class NetworkChangeNotifierWinTest;
// NetworkChangeNotifier methods:
virtual ConnectionType GetCurrentConnectionType() const OVERRIDE;
// ObjectWatcher::Delegate methods:
// Must only be called on the thread |this| was created on.
virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
// Does the actual work to determine the current connection type.
// It is not thread safe, see
virtual ConnectionType RecomputeCurrentConnectionType() const;
void SetCurrentConnectionType(ConnectionType connection_type);
// Notifies IP address change observers of a change immediately, and notifies
// network state change observers on a delay. Must only be called on the
// thread |this| was created on.
void NotifyObservers();
// Forwards connection type notifications to parent class.
void NotifyParentOfConnectionTypeChange();
// Tries to start listening for a single subsequent address change. Returns
// false on failure. The caller is responsible for updating |is_watching_|.
// Virtual for unit tests. Must only be called on the thread |this| was
// created on.
virtual bool WatchForAddressChangeInternal();
static NetworkChangeCalculatorParams NetworkChangeCalculatorParamsWin();
// All member variables may only be accessed on the thread |this| was created
// on.
// False when not currently watching for network change events. This only
// happens on initialization and when WatchForAddressChangeInternal fails and
// there is a pending task to try again. Needed for safe cleanup.
bool is_watching_;
base::win::ObjectWatcher addr_watcher_;
OVERLAPPED addr_overlapped_;
base::OneShotTimer<NetworkChangeNotifierWin> timer_;
// Number of times WatchForAddressChange has failed in a row.
int sequential_failures_;
// Used for calling WatchForAddressChange again on failure.
base::WeakPtrFactory<NetworkChangeNotifierWin> weak_factory_;
// Thread on which we can run DnsConfigService.
scoped_ptr<DnsConfigServiceThread> dns_config_service_thread_;
mutable base::Lock last_computed_connection_type_lock_;
ConnectionType last_computed_connection_type_;
// Result of IsOffline() when NotifyObserversOfConnectionTypeChange()
// was last called.
bool last_announced_offline_;
// Number of times polled to check if still offline.
int offline_polls_;
} // namespace net