xref: /third_party/libuv/test/test-async.c (revision e66f31c5) 
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#include <stdio.h>
25#include <stdlib.h>
26
27static uv_thread_t thread;
28static uv_mutex_t mutex;
29
30static uv_prepare_t prepare;
31static uv_async_t async;
32
33static volatile int async_cb_called;
34static int prepare_cb_called;
35static int close_cb_called;
36
37
38static void thread_cb(void *arg) {
39  int n;
40  int r;
41
42  for (;;) {
43    uv_mutex_lock(&mutex);
44    n = async_cb_called;
45    uv_mutex_unlock(&mutex);
46
47    if (n == 3) {
48      break;
49    }
50
51    r = uv_async_send(&async);
52    ASSERT_OK(r);
53
54    /* Work around a bug in Valgrind.
55     *
56     * Valgrind runs threads not in parallel but sequentially, i.e. one after
57     * the other. It also doesn't preempt them, instead it depends on threads
58     * yielding voluntarily by making a syscall.
59     *
60     * That never happens here: the pipe that is associated with the async
61     * handle is written to once but that's too early for Valgrind's scheduler
62     * to kick in. Afterwards, the thread busy-loops, starving the main thread.
63     * Therefore, we yield.
64     *
65     * This behavior has been observed with Valgrind 3.7.0 and 3.9.0.
66     */
67    uv_sleep(0);
68  }
69}
70
71
72static void close_cb(uv_handle_t* handle) {
73  ASSERT_NOT_NULL(handle);
74  close_cb_called++;
75}
76
77
78static void async_cb(uv_async_t* handle) {
79  int n;
80
81  ASSERT_PTR_EQ(handle, &async);
82
83  uv_mutex_lock(&mutex);
84  n = ++async_cb_called;
85  uv_mutex_unlock(&mutex);
86
87  if (n == 3) {
88    uv_close((uv_handle_t*)&async, close_cb);
89    uv_close((uv_handle_t*)&prepare, close_cb);
90  }
91}
92
93
94static void prepare_cb(uv_prepare_t* handle) {
95  int r;
96
97  ASSERT_PTR_EQ(handle, &prepare);
98
99  if (prepare_cb_called++)
100    return;
101
102  r = uv_thread_create(&thread, thread_cb, NULL);
103  ASSERT_OK(r);
104  uv_mutex_unlock(&mutex);
105}
106
107
108TEST_IMPL(async) {
109  int r;
110
111  r = uv_mutex_init(&mutex);
112  ASSERT_OK(r);
113  uv_mutex_lock(&mutex);
114
115  r = uv_prepare_init(uv_default_loop(), &prepare);
116  ASSERT_OK(r);
117  r = uv_prepare_start(&prepare, prepare_cb);
118  ASSERT_OK(r);
119
120  r = uv_async_init(uv_default_loop(), &async, async_cb);
121  ASSERT_OK(r);
122
123  r = uv_run(uv_default_loop(), UV_RUN_DEFAULT);
124  ASSERT_OK(r);
125
126  ASSERT_GT(prepare_cb_called, 0);
127  ASSERT_EQ(3, async_cb_called);
128  ASSERT_EQ(2, close_cb_called);
129
130  ASSERT_OK(uv_thread_join(&thread));
131
132  MAKE_VALGRIND_HAPPY(uv_default_loop());
133  return 0;
134}
135