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 <memory>
8 #include <utility>
9 
10 #include "base/bind.h"
11 #include "base/bind_helpers.h"
12 #include "base/macros.h"
13 #include "testing/gtest/include/gtest/gtest.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(std::unique_ptr<CallbackList<void (void)>::Subscription> sub)40   void SetSubscriptionToRemove(
41       std::unique_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   std::unique_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(BindRepeating(&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   std::unique_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   std::unique_ptr<CallbackList<void(int)>::Subscription> subscription1 =
122       c1.Add(BindRepeating(&Summer::AddOneParam, Unretained(&s)));
123 
124   c1.Notify(1);
125   EXPECT_EQ(1, s.value());
126 
127   CallbackList<void(int, int)> c2;
128   std::unique_ptr<CallbackList<void(int, int)>::Subscription> subscription2 =
129       c2.Add(BindRepeating(&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   std::unique_ptr<CallbackList<void(int, int, int)>::Subscription>
136       subscription3 =
137           c3.Add(BindRepeating(&Summer::AddThreeParam, Unretained(&s)));
138 
139   c3.Notify(1, 2, 3);
140   EXPECT_EQ(6, s.value());
141 
142   CallbackList<void(int, int, int, int)> c4;
143   std::unique_ptr<CallbackList<void(int, int, int, int)>::Subscription>
144       subscription4 =
145           c4.Add(BindRepeating(&Summer::AddFourParam, Unretained(&s)));
146 
147   c4.Notify(1, 2, 3, 4);
148   EXPECT_EQ(10, s.value());
149 
150   CallbackList<void(int, int, int, int, int)> c5;
151   std::unique_ptr<CallbackList<void(int, int, int, int, int)>::Subscription>
152       subscription5 =
153           c5.Add(BindRepeating(&Summer::AddFiveParam, Unretained(&s)));
154 
155   c5.Notify(1, 2, 3, 4, 5);
156   EXPECT_EQ(15, s.value());
157 
158   CallbackList<void(int, int, int, int, int, int)> c6;
159   std::unique_ptr<
160       CallbackList<void(int, int, int, int, int, int)>::Subscription>
161       subscription6 =
162           c6.Add(BindRepeating(&Summer::AddSixParam, Unretained(&s)));
163 
164   c6.Notify(1, 2, 3, 4, 5, 6);
165   EXPECT_EQ(21, s.value());
166 }
167 
168 // Sanity check that closures added to the list will be run, and those removed
169 // from the list will not be run.
TEST(CallbackListTest,BasicTest)170 TEST(CallbackListTest, BasicTest) {
171   CallbackList<void(void)> cb_reg;
172   Listener a, b, c;
173 
174   std::unique_ptr<CallbackList<void(void)>::Subscription> a_subscription =
175       cb_reg.Add(BindRepeating(&Listener::IncrementTotal, Unretained(&a)));
176   std::unique_ptr<CallbackList<void(void)>::Subscription> b_subscription =
177       cb_reg.Add(BindRepeating(&Listener::IncrementTotal, Unretained(&b)));
178 
179   EXPECT_TRUE(a_subscription.get());
180   EXPECT_TRUE(b_subscription.get());
181 
182   cb_reg.Notify();
183 
184   EXPECT_EQ(1, a.total());
185   EXPECT_EQ(1, b.total());
186 
187   b_subscription.reset();
188 
189   std::unique_ptr<CallbackList<void(void)>::Subscription> c_subscription =
190       cb_reg.Add(BindRepeating(&Listener::IncrementTotal, Unretained(&c)));
191 
192   cb_reg.Notify();
193 
194   EXPECT_EQ(2, a.total());
195   EXPECT_EQ(1, b.total());
196   EXPECT_EQ(1, c.total());
197 
198   a_subscription.reset();
199   b_subscription.reset();
200   c_subscription.reset();
201 }
202 
203 // Sanity check that callbacks with details added to the list will be run, with
204 // the correct details, and those removed from the list will not be run.
TEST(CallbackListTest,BasicTestWithParams)205 TEST(CallbackListTest, BasicTestWithParams) {
206   CallbackList<void(int)> cb_reg;
207   Listener a(1), b(-1), c(1);
208 
209   std::unique_ptr<CallbackList<void(int)>::Subscription> a_subscription =
210       cb_reg.Add(BindRepeating(&Listener::IncrementByMultipleOfScaler,
211                                Unretained(&a)));
212   std::unique_ptr<CallbackList<void(int)>::Subscription> b_subscription =
213       cb_reg.Add(BindRepeating(&Listener::IncrementByMultipleOfScaler,
214                                Unretained(&b)));
215 
216   EXPECT_TRUE(a_subscription.get());
217   EXPECT_TRUE(b_subscription.get());
218 
219   cb_reg.Notify(10);
220 
221   EXPECT_EQ(10, a.total());
222   EXPECT_EQ(-10, b.total());
223 
224   b_subscription.reset();
225 
226   std::unique_ptr<CallbackList<void(int)>::Subscription> c_subscription =
227       cb_reg.Add(BindRepeating(&Listener::IncrementByMultipleOfScaler,
228                                Unretained(&c)));
229 
230   cb_reg.Notify(10);
231 
232   EXPECT_EQ(20, a.total());
233   EXPECT_EQ(-10, b.total());
234   EXPECT_EQ(10, c.total());
235 
236   a_subscription.reset();
237   b_subscription.reset();
238   c_subscription.reset();
239 }
240 
241 // Test the a callback can remove itself or a different callback from the list
242 // during iteration without invalidating the iterator.
TEST(CallbackListTest,RemoveCallbacksDuringIteration)243 TEST(CallbackListTest, RemoveCallbacksDuringIteration) {
244   CallbackList<void(void)> cb_reg;
245   Listener a, b;
246   Remover remover_1, remover_2;
247 
248   std::unique_ptr<CallbackList<void(void)>::Subscription> remover_1_sub =
249       cb_reg.Add(BindRepeating(&Remover::IncrementTotalAndRemove,
250                                Unretained(&remover_1)));
251   std::unique_ptr<CallbackList<void(void)>::Subscription> remover_2_sub =
252       cb_reg.Add(BindRepeating(&Remover::IncrementTotalAndRemove,
253                                Unretained(&remover_2)));
254   std::unique_ptr<CallbackList<void(void)>::Subscription> a_subscription =
255       cb_reg.Add(BindRepeating(&Listener::IncrementTotal, Unretained(&a)));
256   std::unique_ptr<CallbackList<void(void)>::Subscription> b_subscription =
257       cb_reg.Add(BindRepeating(&Listener::IncrementTotal, Unretained(&b)));
258 
259   // |remover_1| will remove itself.
260   remover_1.SetSubscriptionToRemove(std::move(remover_1_sub));
261   // |remover_2| will remove a.
262   remover_2.SetSubscriptionToRemove(std::move(a_subscription));
263 
264   cb_reg.Notify();
265 
266   // |remover_1| runs once (and removes itself), |remover_2| runs once (and
267   // removes a), |a| never runs, and |b| runs once.
268   EXPECT_EQ(1, remover_1.total());
269   EXPECT_EQ(1, remover_2.total());
270   EXPECT_EQ(0, a.total());
271   EXPECT_EQ(1, b.total());
272 
273   cb_reg.Notify();
274 
275   // Only |remover_2| and |b| run this time.
276   EXPECT_EQ(1, remover_1.total());
277   EXPECT_EQ(2, remover_2.total());
278   EXPECT_EQ(0, a.total());
279   EXPECT_EQ(2, b.total());
280 }
281 
282 // Test that a callback can add another callback to the list durning iteration
283 // without invalidating the iterator. The newly added callback should be run on
284 // the current iteration as will all other callbacks in the list.
TEST(CallbackListTest,AddCallbacksDuringIteration)285 TEST(CallbackListTest, AddCallbacksDuringIteration) {
286   CallbackList<void(void)> cb_reg;
287   Adder a(&cb_reg);
288   Listener b;
289   std::unique_ptr<CallbackList<void(void)>::Subscription> a_subscription =
290       cb_reg.Add(BindRepeating(&Adder::AddCallback, Unretained(&a)));
291   std::unique_ptr<CallbackList<void(void)>::Subscription> b_subscription =
292       cb_reg.Add(BindRepeating(&Listener::IncrementTotal, Unretained(&b)));
293 
294   cb_reg.Notify();
295 
296   EXPECT_EQ(1, a.total());
297   EXPECT_EQ(1, b.total());
298   EXPECT_TRUE(a.added());
299 
300   cb_reg.Notify();
301 
302   EXPECT_EQ(2, a.total());
303   EXPECT_EQ(2, b.total());
304 }
305 
306 // Sanity check: notifying an empty list is a no-op.
TEST(CallbackListTest,EmptyList)307 TEST(CallbackListTest, EmptyList) {
308   CallbackList<void(void)> cb_reg;
309 
310   cb_reg.Notify();
311 }
312 
TEST(CallbackList,RemovalCallback)313 TEST(CallbackList, RemovalCallback) {
314   Counter remove_count;
315   CallbackList<void(void)> cb_reg;
316   cb_reg.set_removal_callback(
317       BindRepeating(&Counter::Increment, Unretained(&remove_count)));
318 
319   std::unique_ptr<CallbackList<void(void)>::Subscription> subscription =
320       cb_reg.Add(DoNothing());
321 
322   // Removing a subscription outside of iteration signals the callback.
323   EXPECT_EQ(0, remove_count.value());
324   subscription.reset();
325   EXPECT_EQ(1, remove_count.value());
326 
327   // Configure two subscriptions to remove themselves.
328   Remover remover_1, remover_2;
329   std::unique_ptr<CallbackList<void(void)>::Subscription> remover_1_sub =
330       cb_reg.Add(BindRepeating(&Remover::IncrementTotalAndRemove,
331                                Unretained(&remover_1)));
332   std::unique_ptr<CallbackList<void(void)>::Subscription> remover_2_sub =
333       cb_reg.Add(BindRepeating(&Remover::IncrementTotalAndRemove,
334                                Unretained(&remover_2)));
335   remover_1.SetSubscriptionToRemove(std::move(remover_1_sub));
336   remover_2.SetSubscriptionToRemove(std::move(remover_2_sub));
337 
338   // The callback should be signaled exactly once.
339   EXPECT_EQ(1, remove_count.value());
340   cb_reg.Notify();
341   EXPECT_EQ(2, remove_count.value());
342   EXPECT_TRUE(cb_reg.empty());
343 }
344 
TEST(CallbackList,AbandonSubscriptions)345 TEST(CallbackList, AbandonSubscriptions) {
346   Listener listener;
347   std::unique_ptr<CallbackList<void(void)>::Subscription> subscription;
348   {
349     CallbackList<void(void)> cb_reg;
350     subscription = cb_reg.Add(
351         BindRepeating(&Listener::IncrementTotal, Unretained(&listener)));
352     // Make sure the callback is signaled while cb_reg is in scope.
353     cb_reg.Notify();
354     // Exiting this scope and running the cb_reg destructor shouldn't fail.
355   }
356   EXPECT_EQ(1, listener.total());
357   // The subscription from the destroyed callback list should be cancelled now.
358   EXPECT_TRUE(subscription->IsCancelled());
359 }
360 
361 }  // namespace
362 }  // namespace base
363