1 /*
2 * Invoke pthread_cond_destroy() on a condition variable that is being waited
3 * upon.
4 */
5
6 #include <assert.h>
7 #include <errno.h>
8 #include <stdio.h> // printf()
9 #include <pthread.h>
10
11 static pthread_mutex_t s_mutex;
12 static pthread_cond_t s_cond;
13 static int s_i;
14
err_to_str(int errnum)15 static const char* err_to_str(int errnum)
16 {
17 switch (errnum) {
18 case 0: return "success";
19 case EBUSY: return "EBUSY";
20 case EINVAL: return "EINVAL";
21 default: return "?";
22 }
23 }
24
thread_func(void * thread_arg)25 static void* thread_func(void* thread_arg)
26 {
27 pthread_mutex_lock(&s_mutex);
28 s_i = 1;
29 pthread_cond_signal(&s_cond);
30 while (s_i == 1)
31 pthread_cond_wait(&s_cond, &s_mutex);
32 pthread_mutex_unlock(&s_mutex);
33
34 return 0;
35 }
36
main(int argc,char ** argv)37 int main(int argc, char** argv)
38 {
39 pthread_t threadid;
40 int ret;
41
42 pthread_mutex_init(&s_mutex, 0);
43 pthread_cond_init(&s_cond, 0);
44
45 pthread_create(&threadid, 0, thread_func, 0);
46
47 pthread_mutex_lock(&s_mutex);
48 while (s_i == 0)
49 pthread_cond_wait(&s_cond, &s_mutex);
50 pthread_mutex_unlock(&s_mutex);
51
52 ret = pthread_cond_destroy(&s_cond);
53 fprintf(stderr, "First pthread_cond_destroy() call returned %s.\n",
54 err_to_str(ret));
55
56 pthread_mutex_lock(&s_mutex);
57 s_i = 2;
58 pthread_cond_signal(&s_cond);
59 pthread_mutex_unlock(&s_mutex);
60
61 pthread_join(threadid, 0);
62
63 ret = pthread_cond_destroy(&s_cond);
64 fprintf(stderr, "Second pthread_cond_destroy() call returned %s.\n",
65 err_to_str(ret));
66 pthread_mutex_destroy(&s_mutex);
67
68 return 0;
69 }
70