1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "../BlockingQueue.h"
18
19
20 #include <gtest/gtest.h>
21 #include <thread>
22
23 namespace android {
24
25
26 // --- BlockingQueueTest ---
27
28 /**
29 * Sanity check of basic pop and push operation.
30 */
TEST(BlockingQueueTest,Queue_AddAndRemove)31 TEST(BlockingQueueTest, Queue_AddAndRemove) {
32 constexpr size_t capacity = 10;
33 BlockingQueue<int> queue(capacity);
34
35 ASSERT_TRUE(queue.push(1));
36 ASSERT_EQ(queue.pop(), 1);
37 }
38
39 /**
40 * Make sure the queue has strict capacity limits.
41 */
TEST(BlockingQueueTest,Queue_ReachesCapacity)42 TEST(BlockingQueueTest, Queue_ReachesCapacity) {
43 constexpr size_t capacity = 3;
44 BlockingQueue<int> queue(capacity);
45
46 // First 3 elements should be added successfully
47 ASSERT_TRUE(queue.push(1));
48 ASSERT_TRUE(queue.push(2));
49 ASSERT_TRUE(queue.push(3));
50 ASSERT_FALSE(queue.push(4)) << "Queue should reach capacity at size " << capacity;
51 }
52
53 /**
54 * Make sure the queue maintains FIFO order.
55 * Add elements and remove them, and check the order.
56 */
TEST(BlockingQueueTest,Queue_isFIFO)57 TEST(BlockingQueueTest, Queue_isFIFO) {
58 constexpr size_t capacity = 10;
59 BlockingQueue<int> queue(capacity);
60
61 for (size_t i = 0; i < capacity; i++) {
62 ASSERT_TRUE(queue.push(static_cast<int>(i)));
63 }
64 for (size_t i = 0; i < capacity; i++) {
65 ASSERT_EQ(queue.pop(), static_cast<int>(i));
66 }
67 }
68
TEST(BlockingQueueTest,Queue_Clears)69 TEST(BlockingQueueTest, Queue_Clears) {
70 constexpr size_t capacity = 2;
71 BlockingQueue<int> queue(capacity);
72
73 queue.push(1);
74 queue.push(2);
75 queue.clear();
76 queue.push(3);
77 // Should no longer receive elements 1 and 2
78 ASSERT_EQ(3, queue.pop());
79 }
80
TEST(BlockingQueueTest,Queue_Erases)81 TEST(BlockingQueueTest, Queue_Erases) {
82 constexpr size_t capacity = 4;
83 BlockingQueue<int> queue(capacity);
84
85 queue.push(1);
86 queue.push(2);
87 queue.push(3);
88 queue.push(4);
89 // Erase elements 2 and 4
90 queue.erase([](int element) { return element == 2 || element == 4; });
91 // Should no longer receive elements 2 and 4
92 ASSERT_EQ(1, queue.pop());
93 ASSERT_EQ(3, queue.pop());
94 }
95
96 // --- BlockingQueueTest - Multiple threads ---
97
TEST(BlockingQueueTest,Queue_AllowsMultipleThreads)98 TEST(BlockingQueueTest, Queue_AllowsMultipleThreads) {
99 constexpr size_t capacity = 100; // large capacity to increase likelihood that threads overlap
100 BlockingQueue<int> queue(capacity);
101
102 // Fill queue from a different thread
103 std::thread fillQueue([&queue](){
104 for (size_t i = 0; i < capacity; i++) {
105 ASSERT_TRUE(queue.push(static_cast<int>(i)));
106 }
107 });
108
109 // Make sure all elements are received in correct order
110 for (size_t i = 0; i < capacity; i++) {
111 ASSERT_EQ(queue.pop(), static_cast<int>(i));
112 }
113
114 fillQueue.join();
115 }
116
117 /**
118 * When the queue has no elements, and pop is called, it should block
119 * the current thread until an element is added to the queue (from another thread).
120 * Here we create a separate thread and call pop on an empty queue. Next,
121 * we check that the thread is blocked.
122 */
TEST(BlockingQueueTest,Queue_BlocksWhileWaitingForElements)123 TEST(BlockingQueueTest, Queue_BlocksWhileWaitingForElements) {
124 constexpr size_t capacity = 1;
125 BlockingQueue<int> queue(capacity);
126
127 std::atomic_bool hasReceivedElement = false;
128
129 // fill queue from a different thread
130 std::thread waitUntilHasElements([&queue, &hasReceivedElement](){
131 queue.pop(); // This should block until an element has been added
132 hasReceivedElement = true;
133 });
134
135 ASSERT_FALSE(hasReceivedElement);
136 queue.push(1);
137 waitUntilHasElements.join();
138 ASSERT_TRUE(hasReceivedElement);
139 }
140
141
142 } // namespace android
143