1 /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22 #include "uv.h"
23 #include "task.h"
24
25 #include <string.h>
26 #include <errno.h>
27
28 struct worker_config;
29
30 typedef void (*signal_func)(struct worker_config* c, int* flag);
31 typedef int (*wait_func)(struct worker_config* c, const int* flag);
32
33 typedef struct worker_config {
34 uv_sem_t sem_waiting; /* post before waiting. */
35 uv_sem_t sem_signaled; /* post after signaling. */
36 uv_mutex_t mutex;
37 uv_cond_t cond;
38 int use_broadcast;
39 int posted_1;
40 int posted_2;
41 signal_func signal_cond;
42 wait_func wait_cond;
43 } worker_config;
44
worker_config_init(worker_config * wc,int use_broadcast,signal_func signal_f,wait_func wait_f)45 void worker_config_init(worker_config* wc,
46 int use_broadcast,
47 signal_func signal_f,
48 wait_func wait_f) {
49 /* Wipe. */
50 memset(wc, 0, sizeof(*wc));
51
52 /* Copy vars. */
53 wc->signal_cond = signal_f;
54 wc->wait_cond = wait_f;
55 wc->use_broadcast = use_broadcast;
56
57 /* Init. */
58 ASSERT_OK(uv_sem_init(&wc->sem_waiting, 0));
59 ASSERT_OK(uv_sem_init(&wc->sem_signaled, 0));
60 ASSERT_OK(uv_cond_init(&wc->cond));
61 ASSERT_OK(uv_mutex_init(&wc->mutex));
62 }
63
worker_config_destroy(worker_config * wc)64 void worker_config_destroy(worker_config* wc) {
65 uv_mutex_destroy(&wc->mutex);
66 uv_cond_destroy(&wc->cond);
67 uv_sem_destroy(&wc->sem_signaled);
68 uv_sem_destroy(&wc->sem_waiting);
69 }
70
71 /* arg is a worker_config.
72 * Call signal_cond then wait_cond.
73 * Partner should call wait then signal. */
worker(void * arg)74 static void worker(void* arg) {
75 worker_config* c = arg;
76 c->signal_cond(c, &c->posted_1);
77 c->wait_cond(c, &c->posted_2);
78 }
79
80 /* 1. Signal a waiting waiter.
81 * 2. Tell waiter we finished. */
condvar_signal(worker_config * c,int * flag)82 static void condvar_signal(worker_config* c, int* flag) {
83 /* Wait until waiter holds mutex and is preparing to wait. */
84 uv_sem_wait(&c->sem_waiting);
85
86 /* Make sure waiter has begun waiting. */
87 uv_mutex_lock(&c->mutex);
88
89 /* Help waiter differentiate between spurious and legitimate wakeup. */
90 ASSERT_OK(*flag);
91 *flag = 1;
92
93 if (c->use_broadcast)
94 uv_cond_broadcast(&c->cond);
95 else
96 uv_cond_signal(&c->cond);
97
98 uv_mutex_unlock(&c->mutex);
99
100 /* Done signaling. */
101 uv_sem_post(&c->sem_signaled);
102 }
103
104 /* 1. Wait on a signal.
105 * 2. Ensure that the signaler finished. */
condvar_wait(worker_config * c,const int * flag)106 static int condvar_wait(worker_config* c, const int* flag) {
107 uv_mutex_lock(&c->mutex);
108
109 /* Tell signal'er that I am waiting. */
110 uv_sem_post(&c->sem_waiting);
111
112 /* Wait until I get a non-spurious signal. */
113 do {
114 uv_cond_wait(&c->cond, &c->mutex);
115 } while (*flag == 0);
116 ASSERT_EQ(1, *flag);
117
118 uv_mutex_unlock(&c->mutex);
119
120 /* Wait for my signal'er to finish. */
121 uv_sem_wait(&c->sem_signaled);
122
123 return 0;
124 }
125
126 /* uv_cond_wait: One thread signals, the other waits. */
TEST_IMPL(condvar_1)127 TEST_IMPL(condvar_1) {
128 worker_config wc;
129 uv_thread_t thread;
130
131 /* Helper signal-then-wait. */
132 worker_config_init(&wc, 0, condvar_signal, condvar_wait);
133 ASSERT_OK(uv_thread_create(&thread, worker, &wc));
134
135 /* We wait-then-signal. */
136 ASSERT_OK(wc.wait_cond(&wc, &wc.posted_1));
137 wc.signal_cond(&wc, &wc.posted_2);
138
139 ASSERT_OK(uv_thread_join(&thread));
140 worker_config_destroy(&wc);
141
142 return 0;
143 }
144
145 /* uv_cond_wait: One thread broadcasts, the other waits. */
TEST_IMPL(condvar_2)146 TEST_IMPL(condvar_2) {
147 worker_config wc;
148 uv_thread_t thread;
149
150 /* Helper to signal-then-wait. */
151 worker_config_init(&wc, 1, condvar_signal, condvar_wait);
152 ASSERT_OK(uv_thread_create(&thread, worker, &wc));
153
154 /* We wait-then-signal. */
155 ASSERT_OK(wc.wait_cond(&wc, &wc.posted_1));
156 wc.signal_cond(&wc, &wc.posted_2);
157
158 ASSERT_OK(uv_thread_join(&thread));
159 worker_config_destroy(&wc);
160
161 return 0;
162 }
163
164 /* 1. Wait on a signal (hopefully not timeout, else we'll hang).
165 * 2. Ensure that the signaler finished. */
condvar_timedwait(worker_config * c,const int * flag)166 static int condvar_timedwait(worker_config* c, const int* flag) {
167 int r;
168
169 r = 0;
170
171 uv_mutex_lock(&c->mutex);
172
173 /* Tell signal'er that I am waiting. */
174 uv_sem_post(&c->sem_waiting);
175
176 /* Wait until I get a non-spurious signal. */
177 do {
178 r = uv_cond_timedwait(&c->cond, &c->mutex, (uint64_t)(1 * 1e9)); /* 1 s */
179 ASSERT_OK(r); /* Should not time out. */
180 } while (*flag == 0);
181 ASSERT_EQ(1, *flag);
182
183 uv_mutex_unlock(&c->mutex);
184
185 /* Wait for my signal'er to finish. */
186 uv_sem_wait(&c->sem_signaled);
187 return r;
188 }
189
190 /* uv_cond_timedwait: One thread signals, the other timedwaits. */
TEST_IMPL(condvar_3)191 TEST_IMPL(condvar_3) {
192 worker_config wc;
193 uv_thread_t thread;
194
195 /* Helper to signal-then-wait. */
196 worker_config_init(&wc, 0, condvar_signal, condvar_timedwait);
197 ASSERT_OK(uv_thread_create(&thread, worker, &wc));
198
199 /* We wait-then-signal. */
200 wc.wait_cond(&wc, &wc.posted_1);
201 wc.signal_cond(&wc, &wc.posted_2);
202
203 ASSERT_OK(uv_thread_join(&thread));
204 worker_config_destroy(&wc);
205
206 return 0;
207 }
208
209 /* uv_cond_timedwait: One thread broadcasts, the other waits. */
TEST_IMPL(condvar_4)210 TEST_IMPL(condvar_4) {
211 worker_config wc;
212 uv_thread_t thread;
213
214 /* Helper to signal-then-wait. */
215 worker_config_init(&wc, 1, condvar_signal, condvar_timedwait);
216 ASSERT_OK(uv_thread_create(&thread, worker, &wc));
217
218 /* We wait-then-signal. */
219 wc.wait_cond(&wc, &wc.posted_1);
220 wc.signal_cond(&wc, &wc.posted_2);
221
222 ASSERT_OK(uv_thread_join(&thread));
223 worker_config_destroy(&wc);
224
225 return 0;
226 }
227
228 /* uv_cond_timedwait: One thread waits, no signal. Timeout should be delivered. */
TEST_IMPL(condvar_5)229 TEST_IMPL(condvar_5) {
230 worker_config wc;
231 uint64_t timeout;
232
233 timeout = 100 * 1000 * 1000; /* 100 ms in ns */
234
235 /* Mostly irrelevant. We need cond and mutex initialized. */
236 worker_config_init(&wc, 0, NULL, NULL);
237
238 uv_mutex_lock(&wc.mutex);
239
240 /* We wait. No signaler, so this will only return if timeout is delivered. */
241 ASSERT_EQ(UV_ETIMEDOUT, uv_cond_timedwait(&wc.cond, &wc.mutex, timeout));
242
243 uv_mutex_unlock(&wc.mutex);
244
245 worker_config_destroy(&wc);
246
247 return 0;
248 }
249
