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/* Check that Helgrind does not complain about semaphores with a
nonzero initial value, when said semaphores are correctly used.
Also useful for generating VCG of simple semaphore activity, for
inspection. */
#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>
#define N_THREADS 3
static sem_t* my_sem_init(char*, int, unsigned);
static int my_sem_destroy(sem_t*);
static int my_sem_wait(sem_t*); //static int my_sem_post(sem_t*);
void* child_fn ( void* semV ) {
int r;
sem_t* sem = (sem_t*)semV;
r= my_sem_wait(sem); assert(!r);
return NULL;
}
int main ( void )
{
int r, i;
sem_t* sem;
pthread_t child[N_THREADS];
sem= my_sem_init("sem1", 0, N_THREADS); assert(sem);
for (i = 0; i < N_THREADS; i++) {
r= pthread_create( &child[i], NULL, child_fn, sem );
assert(!r);
}
for (i = 0; i < N_THREADS; i++) {
r= pthread_join( child[i], NULL );
assert(!r);
}
r= my_sem_destroy(sem); assert(!r);
return 0;
}
static sem_t* my_sem_init (char* identity, int pshared, unsigned count)
{
sem_t* s;
#if defined(VGO_linux) || defined(VGO_solaris)
s = malloc(sizeof(*s));
if (s) {
if (sem_init(s, pshared, count) < 0) {
perror("sem_init");
free(s);
s = NULL;
}
}
#elif defined(VGO_darwin)
char name[100];
sprintf(name, "anonsem_%s_pid%d", identity, (int)getpid());
name[ sizeof(name)-1 ] = 0;
if (0) printf("name = %s\n", name);
s = sem_open(name, O_CREAT | O_EXCL, 0600, count);
if (s == SEM_FAILED) {
perror("sem_open");
s = NULL;
}
#else
# error "Unsupported OS"
#endif
return s;
}
static int my_sem_destroy ( sem_t* s )
{
return sem_destroy(s);
}
static int my_sem_wait(sem_t* s)
{
return sem_wait(s);
}
#if 0
static int my_sem_post(sem_t* s)
{
return sem_post(s);
}
#endif
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