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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
// Copyright (c) 2011 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 "base/cancelable_callback.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/memory/ref_counted.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace {
class TestRefCounted : public RefCountedThreadSafe<TestRefCounted> {
private:
friend class RefCountedThreadSafe<TestRefCounted>;
~TestRefCounted() {};
};
void Increment(int* count) { (*count)++; }
void IncrementBy(int* count, int n) { (*count) += n; }
void RefCountedParam(const scoped_refptr<TestRefCounted>& ref_counted) {}
// Cancel().
// - Callback can be run multiple times.
// - After Cancel(), Run() completes but has no effect.
TEST(CancelableCallbackTest, Cancel) {
int count = 0;
CancelableClosure cancelable(
base::Bind(&Increment, base::Unretained(&count)));
base::Closure callback = cancelable.callback();
callback.Run();
EXPECT_EQ(1, count);
callback.Run();
EXPECT_EQ(2, count);
cancelable.Cancel();
callback.Run();
EXPECT_EQ(2, count);
}
// Cancel() called multiple times.
// - Cancel() cancels all copies of the wrapped callback.
// - Calling Cancel() more than once has no effect.
// - After Cancel(), callback() returns a null callback.
TEST(CancelableCallbackTest, MultipleCancel) {
int count = 0;
CancelableClosure cancelable(
base::Bind(&Increment, base::Unretained(&count)));
base::Closure callback1 = cancelable.callback();
base::Closure callback2 = cancelable.callback();
cancelable.Cancel();
callback1.Run();
EXPECT_EQ(0, count);
callback2.Run();
EXPECT_EQ(0, count);
// Calling Cancel() again has no effect.
cancelable.Cancel();
// callback() of a cancelled callback is null.
base::Closure callback3 = cancelable.callback();
EXPECT_TRUE(callback3.is_null());
}
// CancelableCallback destroyed before callback is run.
// - Destruction of CancelableCallback cancels outstanding callbacks.
TEST(CancelableCallbackTest, CallbackCanceledOnDestruction) {
int count = 0;
base::Closure callback;
{
CancelableClosure cancelable(
base::Bind(&Increment, base::Unretained(&count)));
callback = cancelable.callback();
callback.Run();
EXPECT_EQ(1, count);
}
callback.Run();
EXPECT_EQ(1, count);
}
// Cancel() called on bound closure with a RefCounted parameter.
// - Cancel drops wrapped callback (and, implicitly, its bound arguments).
TEST(CancelableCallbackTest, CancelDropsCallback) {
scoped_refptr<TestRefCounted> ref_counted = new TestRefCounted;
EXPECT_TRUE(ref_counted->HasOneRef());
CancelableClosure cancelable(base::Bind(RefCountedParam, ref_counted));
EXPECT_FALSE(cancelable.IsCancelled());
EXPECT_TRUE(ref_counted.get());
EXPECT_FALSE(ref_counted->HasOneRef());
// There is only one reference to |ref_counted| after the Cancel().
cancelable.Cancel();
EXPECT_TRUE(cancelable.IsCancelled());
EXPECT_TRUE(ref_counted.get());
EXPECT_TRUE(ref_counted->HasOneRef());
}
// Reset().
// - Reset() replaces the existing wrapped callback with a new callback.
// - Reset() deactivates outstanding callbacks.
TEST(CancelableCallbackTest, Reset) {
int count = 0;
CancelableClosure cancelable(
base::Bind(&Increment, base::Unretained(&count)));
base::Closure callback = cancelable.callback();
callback.Run();
EXPECT_EQ(1, count);
callback.Run();
EXPECT_EQ(2, count);
cancelable.Reset(
base::Bind(&IncrementBy, base::Unretained(&count), 3));
EXPECT_FALSE(cancelable.IsCancelled());
// The stale copy of the cancelable callback is non-null.
ASSERT_FALSE(callback.is_null());
// The stale copy of the cancelable callback is no longer active.
callback.Run();
EXPECT_EQ(2, count);
base::Closure callback2 = cancelable.callback();
ASSERT_FALSE(callback2.is_null());
callback2.Run();
EXPECT_EQ(5, count);
}
// IsCanceled().
// - Cancel() transforms the CancelableCallback into a cancelled state.
TEST(CancelableCallbackTest, IsNull) {
CancelableClosure cancelable;
EXPECT_TRUE(cancelable.IsCancelled());
int count = 0;
cancelable.Reset(base::Bind(&Increment,
base::Unretained(&count)));
EXPECT_FALSE(cancelable.IsCancelled());
cancelable.Cancel();
EXPECT_TRUE(cancelable.IsCancelled());
}
// CancelableCallback posted to a MessageLoop with PostTask.
// - Callbacks posted to a MessageLoop can be cancelled.
TEST(CancelableCallbackTest, PostTask) {
MessageLoop loop;
int count = 0;
CancelableClosure cancelable(base::Bind(&Increment,
base::Unretained(&count)));
MessageLoop::current()->PostTask(FROM_HERE, cancelable.callback());
RunLoop().RunUntilIdle();
EXPECT_EQ(1, count);
MessageLoop::current()->PostTask(FROM_HERE, cancelable.callback());
// Cancel before running the message loop.
cancelable.Cancel();
RunLoop().RunUntilIdle();
// Callback never ran due to cancellation; count is the same.
EXPECT_EQ(1, count);
}
} // namespace
} // namespace base
|
