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 #if defined(VGO_freebsd)
  13 # include <sys/fcntl.h>
  14 #endif
  15
  16 #define N_THREADS 3
  17
  18 static sem_t* my_sem_init(char*, int, unsigned);
  19 static int my_sem_destroy(sem_t*);
  20 static int my_sem_wait(sem_t*); //static int my_sem_post(sem_t*);
  21
  22 void* child_fn ( void* semV ) {
  23    int r;
  24    sem_t* sem = (sem_t*)semV;
  25    r= my_sem_wait(sem); assert(!r);
  26    return NULL;
  27 }
  28
  29 int main ( void )
  30 {
  31    int r, i;
  32    sem_t* sem;
  33    pthread_t child[N_THREADS];
  34
  35    sem= my_sem_init("sem1", 0, N_THREADS); assert(sem);
  36
  37    for (i = 0; i < N_THREADS; i++) {
  38       r= pthread_create( &child[i], NULL, child_fn, sem );
  39       assert(!r);
  40    }
  41
  42    for (i = 0; i < N_THREADS; i++) {
  43       r= pthread_join( child[i], NULL );
  44       assert(!r);
  45    }
  46
  47    r= my_sem_destroy(sem); assert(!r);
  48    return 0;
  49 }
  50
  51
  52 static sem_t* my_sem_init (char* identity, int pshared, unsigned count)
  53 {
  54    sem_t* s;
  55
  56 #if defined(VGO_linux) || defined(VGO_solaris) || defined(VGO_freebsd)
  57    s = malloc(sizeof(*s));
  58    if (s) {
  59       if (sem_init(s, pshared, count) < 0) {
  60          perror("sem_init");
  61          free(s);
  62          s = NULL;
  63       }
  64    }
  65 #elif defined(VGO_darwin)
  66    char name[100];
  67    sprintf(name, "anonsem_%s_pid%d", identity, (int)getpid());
  68    name[ sizeof(name)-1 ] = 0;
  69    if (0) printf("name = %s\n", name);
  70    s = sem_open(name, O_CREAT | O_EXCL, 0600, count);
  71    if (s == SEM_FAILED) {
  72       perror("sem_open");
  73       s = NULL;
  74    }
  75 #else
  76 #  error "Unsupported OS"
  77 #endif
  78
  79    return s;
  80 }
  81
  82 static int my_sem_destroy ( sem_t* s )
  83 {
  84    return sem_destroy(s);
  85 }
  86
  87 static int my_sem_wait(sem_t* s)
  88 {
  89   return sem_wait(s);
  90 }
  91
  92 #if 0
  93 static int my_sem_post(sem_t* s)
  94 {
  95   return sem_post(s);
  96 }
  97 #endif