1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef NET_BASE_NETWORK_CHANGE_NOTIFIER_WIN_H_
#define NET_BASE_NETWORK_CHANGE_NOTIFIER_WIN_H_
#include <windows.h>
#include <atomic>
#include "base/compiler_specific.h"
#include "base/functional/callback.h"
#include "base/memory/scoped_refptr.h"
#include "base/memory/weak_ptr.h"
#include "base/sequence_checker.h"
#include "base/thread_annotations.h"
#include "base/threading/sequence_bound.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 base {
class SequencedTaskRunner;
} // namespace base
namespace net {
class NetworkCostChangeNotifierWin;
// NetworkChangeNotifierWin uses a SequenceChecker, as all its internal
// notification code must be called on the sequence 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 {
public:
NetworkChangeNotifierWin();
NetworkChangeNotifierWin(const NetworkChangeNotifierWin&) = delete;
NetworkChangeNotifierWin& operator=(const NetworkChangeNotifierWin&) = delete;
~NetworkChangeNotifierWin() override;
// 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
// sequence |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();
protected:
// For unit tests only.
bool is_watching() const { return is_watching_; }
void set_is_watching(bool is_watching) { is_watching_ = is_watching; }
int sequential_failures() const { return sequential_failures_; }
private:
friend class NetworkChangeNotifierWinTest;
friend class TestNetworkChangeNotifierWin;
// NetworkChangeNotifier methods:
ConnectionCost GetCurrentConnectionCost() override;
ConnectionType GetCurrentConnectionType() const override;
// ObjectWatcher::Delegate methods:
// Must only be called on the sequence |this| was created on.
void OnObjectSignaled(HANDLE object) override;
// Recompute the current connection type on newer versions of Windows (Win10
// Build 19041 and above).
static ConnectionType RecomputeCurrentConnectionTypeModern();
// Does the actual work to determine the current connection type. This will
// call into RecomputeCurrentConnectionTypeModern on modern OS. It is not
// thread safe, see crbug.com/324913.
static ConnectionType RecomputeCurrentConnectionType();
// Calls RecomputeCurrentConnectionTypeImpl on the DNS sequence and runs
// |reply_callback| with the type on the calling sequence.
virtual void RecomputeCurrentConnectionTypeOnBlockingSequence(
base::OnceCallback<void(ConnectionType)> reply_callback) 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
// sequence |this| was created on.
void NotifyObservers(ConnectionType connection_type);
// Forwards connection type notifications to parent class.
void NotifyParentOfConnectionTypeChange();
void NotifyParentOfConnectionTypeChangeImpl(ConnectionType connection_type);
// 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 sequence |this| was
// created on.
virtual bool WatchForAddressChangeInternal();
static NetworkChangeCalculatorParams NetworkChangeCalculatorParamsWin();
void OnCostChanged(NetworkChangeNotifier::ConnectionCost new_cost);
// All member variables may only be accessed on the sequence |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_ = false;
base::win::ObjectWatcher addr_watcher_;
OVERLAPPED addr_overlapped_;
base::OneShotTimer timer_;
// Number of times WatchForAddressChange has failed in a row.
int sequential_failures_ = 0;
scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
mutable base::Lock last_computed_connection_type_lock_;
ConnectionType last_computed_connection_type_;
std::atomic<NetworkChangeNotifier::ConnectionCost>
last_computed_connection_cost_ =
NetworkChangeNotifier::ConnectionCost::CONNECTION_COST_UNKNOWN;
// Provides the cost of the current connection. Uses the Windows OS APIs to
// monitor and determine cost.
base::SequenceBound<NetworkCostChangeNotifierWin> cost_change_notifier_;
// Result of IsOffline() when NotifyObserversOfConnectionTypeChange()
// was last called.
bool last_announced_offline_;
// Number of times polled to check if still offline.
int offline_polls_;
// Used to ensure that all registration actions are properly sequenced on the
// same thread regardless of which thread was used to call into the
// NetworkChangeNotifier API.
scoped_refptr<base::SequencedTaskRunner> sequence_runner_for_registration_;
SEQUENCE_CHECKER(sequence_checker_);
// Used for calling WatchForAddressChange again on failure.
base::WeakPtrFactory<NetworkChangeNotifierWin> weak_factory_{this};
};
} // namespace net
#endif // NET_BASE_NETWORK_CHANGE_NOTIFIER_WIN_H_
|
