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
|
// Copyright 2015 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 "ui/base/win/session_change_observer.h"
#include <wtsapi32.h>
#include <memory>
#include <utility>
#include "base/bind.h"
#include "base/callback.h"
#include "base/callback_helpers.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/singleton.h"
#include "base/observer_list.h"
#include "base/task/post_task.h"
#include "base/task/thread_pool.h"
#include "ui/gfx/win/singleton_hwnd.h"
#include "ui/gfx/win/singleton_hwnd_observer.h"
namespace ui {
class SessionChangeObserver::WtsRegistrationNotificationManager {
public:
static WtsRegistrationNotificationManager* GetInstance() {
return base::Singleton<WtsRegistrationNotificationManager>::get();
}
WtsRegistrationNotificationManager() {
DCHECK(!singleton_hwnd_observer_);
singleton_hwnd_observer_ = std::make_unique<gfx::SingletonHwndObserver>(
base::BindRepeating(&WtsRegistrationNotificationManager::OnWndProc,
base::Unretained(this)));
base::OnceClosure wts_register = base::BindOnce(
base::IgnoreResult(&WTSRegisterSessionNotification),
gfx::SingletonHwnd::GetInstance()->hwnd(), NOTIFY_FOR_THIS_SESSION);
base::ThreadPool::CreateCOMSTATaskRunner({})->PostTask(
FROM_HERE, std::move(wts_register));
}
~WtsRegistrationNotificationManager() { RemoveSingletonHwndObserver(); }
void AddObserver(SessionChangeObserver* observer) {
DCHECK(singleton_hwnd_observer_);
observer_list_.AddObserver(observer);
}
void RemoveObserver(SessionChangeObserver* observer) {
observer_list_.RemoveObserver(observer);
}
private:
friend struct base::DefaultSingletonTraits<
WtsRegistrationNotificationManager>;
void OnWndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
switch (message) {
case WM_WTSSESSION_CHANGE:
if (wparam == WTS_SESSION_LOCK || wparam == WTS_SESSION_UNLOCK) {
bool is_current_session;
const bool* is_current_session_ptr = &is_current_session;
DWORD current_session_id = 0;
if (!::ProcessIdToSessionId(::GetCurrentProcessId(),
¤t_session_id)) {
PLOG(ERROR) << "ProcessIdToSessionId failed";
is_current_session_ptr = nullptr;
} else {
is_current_session =
(static_cast<DWORD>(lparam) == current_session_id);
}
for (SessionChangeObserver& observer : observer_list_)
observer.OnSessionChange(wparam, is_current_session_ptr);
}
break;
case WM_DESTROY:
RemoveSingletonHwndObserver();
break;
}
}
void RemoveSingletonHwndObserver() {
if (!singleton_hwnd_observer_)
return;
singleton_hwnd_observer_.reset(nullptr);
// There is no race condition between this code and the worker thread.
// RemoveSingletonHwndObserver is only called from two places:
// 1) Destruction due to Singleton Destruction.
// 2) WM_DESTROY fired by SingletonHwnd.
// Under both cases we are in shutdown, which means no other worker threads
// can be running.
WTSUnRegisterSessionNotification(gfx::SingletonHwnd::GetInstance()->hwnd());
for (SessionChangeObserver& observer : observer_list_)
observer.ClearCallback();
}
base::ObserverList<SessionChangeObserver, true>::Unchecked observer_list_;
std::unique_ptr<gfx::SingletonHwndObserver> singleton_hwnd_observer_;
DISALLOW_COPY_AND_ASSIGN(WtsRegistrationNotificationManager);
};
SessionChangeObserver::SessionChangeObserver(const WtsCallback& callback)
: callback_(callback) {
DCHECK(!callback_.is_null());
WtsRegistrationNotificationManager::GetInstance()->AddObserver(this);
}
SessionChangeObserver::~SessionChangeObserver() {
ClearCallback();
}
void SessionChangeObserver::OnSessionChange(WPARAM wparam,
const bool* is_current_session) {
callback_.Run(wparam, is_current_session);
}
void SessionChangeObserver::ClearCallback() {
if (!callback_.is_null()) {
callback_.Reset();
WtsRegistrationNotificationManager::GetInstance()->RemoveObserver(this);
}
}
} // namespace ui
|
