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1 /* Expect 5 errors total (4 re cvs, 1 re exiting w/lock.).
2    Tests passing bogus mutexes to pthread_cond_wait. */
3 #define _GNU_SOURCE 1 /* needed by glibc <= 2.3 for pthread_rwlock_* */
4 #include <pthread.h>
5 #include <assert.h>
6 #include <unistd.h>
7 #include <semaphore.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 pthread_mutex_t mx[4];
11 pthread_cond_t cv; pthread_rwlock_t rwl;
12 sem_t* quit_now;
13 static sem_t* my_sem_init(char*, int, unsigned);
14 static int my_sem_destroy(sem_t*);
15 static int my_sem_wait(sem_t*); static int my_sem_post(sem_t*);
rescue_me(void * uu)16 void* rescue_me ( void* uu )
17 {
18   /* wait for, and unblock, the first wait */
19   sleep(1);
20   pthread_cond_signal( &cv );
21 
22   /* wait for, and unblock, the second wait */
23   sleep(1);
24   pthread_cond_signal( &cv );
25 
26   /* wait for, and unblock, the third wait */
27   sleep(1);
28   pthread_cond_signal( &cv );
29 
30   /* wait for, and unblock, the fourth wait */
31   sleep(1);
32   pthread_cond_signal( &cv );
33 
34   my_sem_wait( quit_now );
35   return NULL;
36 }
37 
grab_the_lock(void * uu)38 void* grab_the_lock ( void* uu )
39 {
40    int r= pthread_mutex_lock( &mx[2] ); assert(!r);
41    my_sem_wait( quit_now );
42    r= pthread_mutex_unlock( &mx[2] ); assert(!r);
43    return NULL;
44 }
45 
main(void)46 int main ( void )
47 {
48   int r;
49   pthread_t my_rescuer, grabber;
50 
51   r= pthread_mutex_init(&mx[0], NULL); assert(!r);
52   r= pthread_mutex_init(&mx[1], NULL); assert(!r);
53   r= pthread_mutex_init(&mx[2], NULL); assert(!r);
54   r= pthread_mutex_init(&mx[3], NULL); assert(!r);
55 
56   r= pthread_cond_init(&cv, NULL); assert(!r);
57   r= pthread_rwlock_init(&rwl, NULL); assert(!r);
58 
59   quit_now = my_sem_init( "quit_now", 0,0 ); assert(quit_now);
60 
61   r= pthread_create( &grabber, NULL, grab_the_lock, NULL ); assert(!r);
62   sleep(1); /* let the grabber get there first */
63 
64   r= pthread_create( &my_rescuer, NULL, rescue_me, NULL );  assert(!r);
65   /* Do stupid things and hope that rescue_me gets us out of
66      trouble */
67 
68   /* mx is bogus */
69   r= pthread_cond_wait(&cv, (pthread_mutex_t*)(4 + (char*)&mx[0]) );
70 
71   /* mx is not locked */
72   r= pthread_cond_wait(&cv, &mx[0]);
73 
74   /* wrong flavour of lock */
75   r= pthread_cond_wait(&cv, (pthread_mutex_t*)&rwl );
76 
77   /* mx is held by someone else. */
78   r= pthread_cond_wait(&cv, &mx[2] );
79 
80   r= my_sem_post( quit_now ); assert(!r);
81   r= my_sem_post( quit_now ); assert(!r);
82 
83   r= pthread_join( my_rescuer, NULL ); assert(!r);
84   r= pthread_join( grabber, NULL ); assert(!r);
85 
86   r= my_sem_destroy( quit_now ); assert(!r);
87   return 0;
88 }
89 
90 
91 
92 
93 
94 
95 
96 
my_sem_init(char * identity,int pshared,unsigned count)97 static sem_t* my_sem_init (char* identity, int pshared, unsigned count)
98 {
99    sem_t* s;
100 
101 #if defined(VGO_linux)
102    s = malloc(sizeof(*s));
103    if (s) {
104       if (sem_init(s, pshared, count) < 0) {
105 	 perror("sem_init");
106 	 free(s);
107 	 s = NULL;
108       }
109    }
110 #elif defined(VGO_darwin)
111    char name[100];
112    sprintf(name, "anonsem_%s_pid%d", identity, (int)getpid());
113    name[ sizeof(name)-1 ] = 0;
114    if (0) printf("name = %s\n", name);
115    s = sem_open(name, O_CREAT | O_EXCL, 0600, count);
116    if (s == SEM_FAILED) {
117       perror("sem_open");
118       s = NULL;
119    }
120 #else
121 #  error "Unsupported OS"
122 #endif
123 
124    return s;
125 }
126 
my_sem_destroy(sem_t * s)127 static int my_sem_destroy ( sem_t* s )
128 {
129    return sem_destroy(s);
130 }
131 
my_sem_wait(sem_t * s)132 static int my_sem_wait(sem_t* s)
133 {
134   return sem_wait(s);
135 }
136 
my_sem_post(sem_t * s)137 static int my_sem_post(sem_t* s)
138 {
139   return sem_post(s);
140 }
141