1/* Check that Helgrind does not complain about semaphores with a
2   nonzero initial value, when said semaphores are correctly used.
3   Also useful for generating VCG of simple semaphore activity, for
4   inspection. */
5
6#include <stdio.h>
7#include <pthread.h>
8#include <semaphore.h>
9#include <assert.h>
10#include <stdlib.h>
11#include <unistd.h>
12
13#define N_THREADS 3
14
15static sem_t* my_sem_init(char*, int, unsigned);
16static int my_sem_destroy(sem_t*);
17static int my_sem_wait(sem_t*); //static int my_sem_post(sem_t*);
18
19void* child_fn ( void* semV ) {
20   int r;
21   sem_t* sem = (sem_t*)semV;
22   r= my_sem_wait(sem); assert(!r);
23   return NULL;
24}
25
26int main ( void )
27{
28   int r, i;
29   sem_t* sem;
30   pthread_t child[N_THREADS];
31
32   sem= my_sem_init("sem1", 0, N_THREADS); assert(sem);
33
34   for (i = 0; i < N_THREADS; i++) {
35      r= pthread_create( &child[i], NULL, child_fn, sem );
36      assert(!r);
37   }
38
39   for (i = 0; i < N_THREADS; i++) {
40      r= pthread_join( child[i], NULL );
41      assert(!r);
42   }
43
44   r= my_sem_destroy(sem); assert(!r);
45   return 0;
46}
47
48
49static sem_t* my_sem_init (char* identity, int pshared, unsigned count)
50{
51   sem_t* s;
52
53#if defined(VGO_linux)
54   s = malloc(sizeof(*s));
55   if (s) {
56      if (sem_init(s, pshared, count) < 0) {
57	 perror("sem_init");
58	 free(s);
59	 s = NULL;
60      }
61   }
62#elif defined(VGO_darwin)
63   char name[100];
64   sprintf(name, "anonsem_%s_pid%d", identity, (int)getpid());
65   name[ sizeof(name)-1 ] = 0;
66   if (0) printf("name = %s\n", name);
67   s = sem_open(name, O_CREAT | O_EXCL, 0600, count);
68   if (s == SEM_FAILED) {
69      perror("sem_open");
70      s = NULL;
71   }
72#else
73#  error "Unsupported OS"
74#endif
75
76   return s;
77}
78
79static int my_sem_destroy ( sem_t* s )
80{
81   return sem_destroy(s);
82}
83
84static int my_sem_wait(sem_t* s)
85{
86  return sem_wait(s);
87}
88
89#if 0
90static int my_sem_post(sem_t* s)
91{
92  return sem_post(s);
93}
94#endif
95