1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "base/callback_list.h"
6 
7 #include <gtest/gtest.h>
8 #include <utility>
9 
10 #include "base/bind.h"
11 #include "base/bind_helpers.h"
12 #include "base/macros.h"
13 #include "base/memory/scoped_ptr.h"
14 
15 namespace base {
16 namespace {
17 
18 class Listener {
19  public:
Listener()20   Listener() : total_(0), scaler_(1) {}
Listener(int scaler)21   explicit Listener(int scaler) : total_(0), scaler_(scaler) {}
IncrementTotal()22   void IncrementTotal() { total_++; }
IncrementByMultipleOfScaler(int x)23   void IncrementByMultipleOfScaler(int x) { total_ += x * scaler_; }
24 
total() const25   int total() const { return total_; }
26 
27  private:
28   int total_;
29   int scaler_;
30   DISALLOW_COPY_AND_ASSIGN(Listener);
31 };
32 
33 class Remover {
34  public:
Remover()35   Remover() : total_(0) {}
IncrementTotalAndRemove()36   void IncrementTotalAndRemove() {
37     total_++;
38     removal_subscription_.reset();
39   }
SetSubscriptionToRemove(scoped_ptr<CallbackList<void (void)>::Subscription> sub)40   void SetSubscriptionToRemove(
41       scoped_ptr<CallbackList<void(void)>::Subscription> sub) {
42     removal_subscription_ = std::move(sub);
43   }
44 
total() const45   int total() const { return total_; }
46 
47  private:
48   int total_;
49   scoped_ptr<CallbackList<void(void)>::Subscription> removal_subscription_;
50   DISALLOW_COPY_AND_ASSIGN(Remover);
51 };
52 
53 class Adder {
54  public:
Adder(CallbackList<void (void)> * cb_reg)55   explicit Adder(CallbackList<void(void)>* cb_reg)
56       : added_(false),
57         total_(0),
58         cb_reg_(cb_reg) {
59   }
AddCallback()60   void AddCallback() {
61     if (!added_) {
62       added_ = true;
63       subscription_ =
64           cb_reg_->Add(Bind(&Adder::IncrementTotal, Unretained(this)));
65     }
66   }
IncrementTotal()67   void IncrementTotal() { total_++; }
68 
added() const69   bool added() const { return added_; }
70 
total() const71   int total() const { return total_; }
72 
73  private:
74   bool added_;
75   int total_;
76   CallbackList<void(void)>* cb_reg_;
77   scoped_ptr<CallbackList<void(void)>::Subscription> subscription_;
78   DISALLOW_COPY_AND_ASSIGN(Adder);
79 };
80 
81 class Summer {
82  public:
Summer()83   Summer() : value_(0) {}
84 
AddOneParam(int a)85   void AddOneParam(int a) { value_ = a; }
AddTwoParam(int a,int b)86   void AddTwoParam(int a, int b) { value_ = a + b; }
AddThreeParam(int a,int b,int c)87   void AddThreeParam(int a, int b, int c) { value_ = a + b + c; }
AddFourParam(int a,int b,int c,int d)88   void AddFourParam(int a, int b, int c, int d) { value_ = a + b + c + d; }
AddFiveParam(int a,int b,int c,int d,int e)89   void AddFiveParam(int a, int b, int c, int d, int e) {
90     value_ = a + b + c + d + e;
91   }
AddSixParam(int a,int b,int c,int d,int e,int f)92   void AddSixParam(int a, int b, int c, int d, int e , int f) {
93     value_ = a + b + c + d + e + f;
94   }
95 
value() const96   int value() const { return value_; }
97 
98  private:
99   int value_;
100   DISALLOW_COPY_AND_ASSIGN(Summer);
101 };
102 
103 class Counter {
104  public:
Counter()105   Counter() : value_(0) {}
106 
Increment()107   void Increment() { value_++; }
108 
value() const109   int value() const { return value_; }
110 
111  private:
112   int value_;
113   DISALLOW_COPY_AND_ASSIGN(Counter);
114 };
115 
116 // Sanity check that we can instantiate a CallbackList for each arity.
TEST(CallbackListTest,ArityTest)117 TEST(CallbackListTest, ArityTest) {
118   Summer s;
119 
120   CallbackList<void(int)> c1;
121   scoped_ptr<CallbackList<void(int)>::Subscription> subscription1 =
122       c1.Add(Bind(&Summer::AddOneParam, Unretained(&s)));
123 
124   c1.Notify(1);
125   EXPECT_EQ(1, s.value());
126 
127   CallbackList<void(int, int)> c2;
128   scoped_ptr<CallbackList<void(int, int)>::Subscription> subscription2 =
129       c2.Add(Bind(&Summer::AddTwoParam, Unretained(&s)));
130 
131   c2.Notify(1, 2);
132   EXPECT_EQ(3, s.value());
133 
134   CallbackList<void(int, int, int)> c3;
135   scoped_ptr<CallbackList<void(int, int, int)>::Subscription>
136       subscription3 = c3.Add(Bind(&Summer::AddThreeParam, Unretained(&s)));
137 
138   c3.Notify(1, 2, 3);
139   EXPECT_EQ(6, s.value());
140 
141   CallbackList<void(int, int, int, int)> c4;
142   scoped_ptr<CallbackList<void(int, int, int, int)>::Subscription>
143       subscription4 = c4.Add(Bind(&Summer::AddFourParam, Unretained(&s)));
144 
145   c4.Notify(1, 2, 3, 4);
146   EXPECT_EQ(10, s.value());
147 
148   CallbackList<void(int, int, int, int, int)> c5;
149   scoped_ptr<CallbackList<void(int, int, int, int, int)>::Subscription>
150       subscription5 = c5.Add(Bind(&Summer::AddFiveParam, Unretained(&s)));
151 
152   c5.Notify(1, 2, 3, 4, 5);
153   EXPECT_EQ(15, s.value());
154 
155   CallbackList<void(int, int, int, int, int, int)> c6;
156   scoped_ptr<CallbackList<void(int, int, int, int, int, int)>::Subscription>
157       subscription6 = c6.Add(Bind(&Summer::AddSixParam, Unretained(&s)));
158 
159   c6.Notify(1, 2, 3, 4, 5, 6);
160   EXPECT_EQ(21, s.value());
161 }
162 
163 // Sanity check that closures added to the list will be run, and those removed
164 // from the list will not be run.
TEST(CallbackListTest,BasicTest)165 TEST(CallbackListTest, BasicTest) {
166   CallbackList<void(void)> cb_reg;
167   Listener a, b, c;
168 
169   scoped_ptr<CallbackList<void(void)>::Subscription> a_subscription =
170       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&a)));
171   scoped_ptr<CallbackList<void(void)>::Subscription> b_subscription =
172       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&b)));
173 
174   EXPECT_TRUE(a_subscription.get());
175   EXPECT_TRUE(b_subscription.get());
176 
177   cb_reg.Notify();
178 
179   EXPECT_EQ(1, a.total());
180   EXPECT_EQ(1, b.total());
181 
182   b_subscription.reset();
183 
184   scoped_ptr<CallbackList<void(void)>::Subscription> c_subscription =
185       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&c)));
186 
187   cb_reg.Notify();
188 
189   EXPECT_EQ(2, a.total());
190   EXPECT_EQ(1, b.total());
191   EXPECT_EQ(1, c.total());
192 
193   a_subscription.reset();
194   b_subscription.reset();
195   c_subscription.reset();
196 }
197 
198 // Sanity check that callbacks with details added to the list will be run, with
199 // the correct details, and those removed from the list will not be run.
TEST(CallbackListTest,BasicTestWithParams)200 TEST(CallbackListTest, BasicTestWithParams) {
201   CallbackList<void(int)> cb_reg;
202   Listener a(1), b(-1), c(1);
203 
204   scoped_ptr<CallbackList<void(int)>::Subscription> a_subscription =
205       cb_reg.Add(Bind(&Listener::IncrementByMultipleOfScaler, Unretained(&a)));
206   scoped_ptr<CallbackList<void(int)>::Subscription> b_subscription =
207       cb_reg.Add(Bind(&Listener::IncrementByMultipleOfScaler, Unretained(&b)));
208 
209   EXPECT_TRUE(a_subscription.get());
210   EXPECT_TRUE(b_subscription.get());
211 
212   cb_reg.Notify(10);
213 
214   EXPECT_EQ(10, a.total());
215   EXPECT_EQ(-10, b.total());
216 
217   b_subscription.reset();
218 
219   scoped_ptr<CallbackList<void(int)>::Subscription> c_subscription =
220       cb_reg.Add(Bind(&Listener::IncrementByMultipleOfScaler, Unretained(&c)));
221 
222   cb_reg.Notify(10);
223 
224   EXPECT_EQ(20, a.total());
225   EXPECT_EQ(-10, b.total());
226   EXPECT_EQ(10, c.total());
227 
228   a_subscription.reset();
229   b_subscription.reset();
230   c_subscription.reset();
231 }
232 
233 // Test the a callback can remove itself or a different callback from the list
234 // during iteration without invalidating the iterator.
TEST(CallbackListTest,RemoveCallbacksDuringIteration)235 TEST(CallbackListTest, RemoveCallbacksDuringIteration) {
236   CallbackList<void(void)> cb_reg;
237   Listener a, b;
238   Remover remover_1, remover_2;
239 
240   scoped_ptr<CallbackList<void(void)>::Subscription> remover_1_sub =
241       cb_reg.Add(Bind(&Remover::IncrementTotalAndRemove,
242           Unretained(&remover_1)));
243   scoped_ptr<CallbackList<void(void)>::Subscription> remover_2_sub =
244       cb_reg.Add(Bind(&Remover::IncrementTotalAndRemove,
245           Unretained(&remover_2)));
246   scoped_ptr<CallbackList<void(void)>::Subscription> a_subscription =
247       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&a)));
248   scoped_ptr<CallbackList<void(void)>::Subscription> b_subscription =
249       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&b)));
250 
251   // |remover_1| will remove itself.
252   remover_1.SetSubscriptionToRemove(std::move(remover_1_sub));
253   // |remover_2| will remove a.
254   remover_2.SetSubscriptionToRemove(std::move(a_subscription));
255 
256   cb_reg.Notify();
257 
258   // |remover_1| runs once (and removes itself), |remover_2| runs once (and
259   // removes a), |a| never runs, and |b| runs once.
260   EXPECT_EQ(1, remover_1.total());
261   EXPECT_EQ(1, remover_2.total());
262   EXPECT_EQ(0, a.total());
263   EXPECT_EQ(1, b.total());
264 
265   cb_reg.Notify();
266 
267   // Only |remover_2| and |b| run this time.
268   EXPECT_EQ(1, remover_1.total());
269   EXPECT_EQ(2, remover_2.total());
270   EXPECT_EQ(0, a.total());
271   EXPECT_EQ(2, b.total());
272 }
273 
274 // Test that a callback can add another callback to the list durning iteration
275 // without invalidating the iterator. The newly added callback should be run on
276 // the current iteration as will all other callbacks in the list.
TEST(CallbackListTest,AddCallbacksDuringIteration)277 TEST(CallbackListTest, AddCallbacksDuringIteration) {
278   CallbackList<void(void)> cb_reg;
279   Adder a(&cb_reg);
280   Listener b;
281   scoped_ptr<CallbackList<void(void)>::Subscription> a_subscription =
282       cb_reg.Add(Bind(&Adder::AddCallback, Unretained(&a)));
283   scoped_ptr<CallbackList<void(void)>::Subscription> b_subscription =
284       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&b)));
285 
286   cb_reg.Notify();
287 
288   EXPECT_EQ(1, a.total());
289   EXPECT_EQ(1, b.total());
290   EXPECT_TRUE(a.added());
291 
292   cb_reg.Notify();
293 
294   EXPECT_EQ(2, a.total());
295   EXPECT_EQ(2, b.total());
296 }
297 
298 // Sanity check: notifying an empty list is a no-op.
TEST(CallbackListTest,EmptyList)299 TEST(CallbackListTest, EmptyList) {
300   CallbackList<void(void)> cb_reg;
301 
302   cb_reg.Notify();
303 }
304 
TEST(CallbackList,RemovalCallback)305 TEST(CallbackList, RemovalCallback) {
306   Counter remove_count;
307   CallbackList<void(void)> cb_reg;
308   cb_reg.set_removal_callback(
309       Bind(&Counter::Increment, Unretained(&remove_count)));
310 
311   scoped_ptr<CallbackList<void(void)>::Subscription> subscription =
312       cb_reg.Add(Bind(&DoNothing));
313 
314   // Removing a subscription outside of iteration signals the callback.
315   EXPECT_EQ(0, remove_count.value());
316   subscription.reset();
317   EXPECT_EQ(1, remove_count.value());
318 
319   // Configure two subscriptions to remove themselves.
320   Remover remover_1, remover_2;
321   scoped_ptr<CallbackList<void(void)>::Subscription> remover_1_sub =
322       cb_reg.Add(Bind(&Remover::IncrementTotalAndRemove,
323           Unretained(&remover_1)));
324   scoped_ptr<CallbackList<void(void)>::Subscription> remover_2_sub =
325       cb_reg.Add(Bind(&Remover::IncrementTotalAndRemove,
326           Unretained(&remover_2)));
327   remover_1.SetSubscriptionToRemove(std::move(remover_1_sub));
328   remover_2.SetSubscriptionToRemove(std::move(remover_2_sub));
329 
330   // The callback should be signaled exactly once.
331   EXPECT_EQ(1, remove_count.value());
332   cb_reg.Notify();
333   EXPECT_EQ(2, remove_count.value());
334   EXPECT_TRUE(cb_reg.empty());
335 }
336 
337 }  // namespace
338 }  // namespace base
339