helgrind/tests/tc24_nonzero_sem.c

   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
  15 static sem_t* my_sem_init(char*, int, unsigned);
  16 static int my_sem_destroy(sem_t*);
  17 static int my_sem_wait(sem_t*); //static int my_sem_post(sem_t*);
  18
  19 void* 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
  26 int 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
  49 static sem_t* my_sem_init (char* identity, int pshared, unsigned count)
  50 {
  51    sem_t* s;
  52
  53 #if defined(VGO_linux) || defined(VGO_solaris)
  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
  79 static int my_sem_destroy ( sem_t* s )
  80 {
  81    return sem_destroy(s);
  82 }
  83
  84 static int my_sem_wait(sem_t* s)
  85 {
  86   return sem_wait(s);
  87 }
  88
  89 #if 0
  90 static int my_sem_post(sem_t* s)
  91 {
  92   return sem_post(s);
  93 }
  94 #endif