locked_vs_unlocked3.c revision b32f58018498ea2225959b0ba11c18f0c433deef 
1
2/* Needed for older glibcs (2.3 and older, at least) who don't
3   otherwise "know" about pthread_rwlock_anything or about
4   PTHREAD_MUTEX_RECURSIVE (amongst things). */
5#define _GNU_SOURCE 1
6
7#include <pthread.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <assert.h>
11#include <unistd.h>
12
13/* Test of the mechanism for showing all locks held by a thread.  This
14   is like locked_vs_unlocked.c, except that it uses a recursively
15   lockable lock, and one thread holds the lock more than once.  Point
16   is to check that the lock showing mechanism shows the
17   lock-number-of-times-held count. */
18
19pthread_mutex_t mx;
20
21int x = 0;
22
23void* child_fn1 ( void* arg )
24{
25   int r;
26   r= pthread_mutex_lock(&mx);  assert(!r);
27   r= pthread_mutex_lock(&mx);  assert(!r);
28   x = 1;
29   r= pthread_mutex_unlock(&mx);  assert(!r);
30   r= pthread_mutex_unlock(&mx);  assert(!r);
31   sleep(1);
32   return NULL;
33}
34
35void* child_fn2 ( void* arg )
36{
37   sleep(1);
38   x = 1;
39   return NULL;
40}
41
42int main ( int argc, char** argv )
43{
44   int r;
45   pthread_t child1, child2;
46   pthread_mutexattr_t attr;
47   r = pthread_mutexattr_init( &attr );
48   assert(!r);
49   r = pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
50   assert(!r);
51   r= pthread_mutex_init(&mx, &attr);  assert(!r);
52
53   r= pthread_create(&child2, NULL, child_fn2, NULL);  assert(!r);
54   r= pthread_create(&child1, NULL, child_fn1, NULL);  assert(!r);
55
56   r= pthread_join(child1, NULL);  assert(!r);
57   r= pthread_join(child2, NULL);  assert(!r);
58
59   r= pthread_mutex_destroy(&mx);  assert(!r);
60
61   return 0;
62}
63