+ return t?t->param:NULL;
+}
+
+typedef struct xbt_os_sem_ {
+ #ifndef HAVE_SEM_WAIT
+ char* name;
+ sem_t* s;
+ #else
+ sem_t s;
+ #endif
+}s_xbt_os_sem_t ;
+
+xbt_os_sem_t
+xbt_os_sem_init(unsigned int value)
+{
+ xbt_os_sem_t res = xbt_new(s_xbt_os_sem_t,1);
+ int errcode;
+
+ /* On MAC OS X, it seems that the sem_init is failing with ENOSYS,
+ * which means the sem_init function is not implemented use sem_open()
+ * instead
+ */
+ #ifndef HAVE_SEM_INIT
+ res->name = (char*) calloc(MAX_SEM_NAME + 1,sizeof(char));
+
+ if((errcode = pthread_mutex_lock(&__next_sem_ID_lock)))
+ THROW1(system_error,errcode,"pthread_mutex_lock() failed: %s", strerror(errcode));
+
+ __next_sem_ID++;
+
+ if((errcode = pthread_mutex_unlock(&__next_sem_ID_lock)))
+ THROW1(system_error,errcode,"pthread_mutex_unlock() failed: %s", strerror(errcode));
+
+ sprintf(res->name,"/%d.%d",(*xbt_getpid)(),__next_sem_ID);
+
+ if((res->s = sem_open(res->name, O_CREAT, 0644, value)) == (sem_t*)SEM_FAILED)
+ THROW1(system_error,errno,"sem_open() failed: %s",strerror(errno));
+
+ if(sem_unlink(res->name) < 0)
+ THROW1(system_error,errno,"sem_unlink() failed: %s", strerror(errno));
+
+
+ #else
+ /* sem_init() is implemented, use it */
+ if(sem_init(&(res->s),0,value) < 0)
+ THROW1(system_error,errno,"sem_init() failed: %s",
+ strerror(errno));
+ #endif
+
+ return res;
+}
+
+void
+xbt_os_sem_acquire(xbt_os_sem_t sem)
+{
+ if(!sem)
+ THROW0(arg_error,EINVAL,"Cannot acquire of the NULL semaphore");
+ #ifndef HAVE_SEM_WAIT
+ if(sem_wait((sem->s)) < 0)
+ THROW1(system_error,errno,"sem_wait() failed: %s",
+ strerror(errno));
+ #else
+ if(sem_wait(&(sem->s)) < 0)
+ THROW1(system_error,errno,"sem_wait() failed: %s",
+ strerror(errno));
+ #endif
+}
+
+#ifndef HAVE_SEM_TIMEDWAIT
+/* if the function is not availabled or if is MAC OS X use sem_trywait() to define
+ * it.
+ */
+#include <time.h> /* declaration of the timespec structure and of the nanosleep() function */
+int sem_timedwait(sem_t* sem, const struct timespec * abs_timeout)
+{
+ int rv;
+ long ellapsed_time = 0;
+ struct timespec ts;
+
+ do
+ {
+ rv = sem_trywait(sem);
+ ts.tv_sec = 0;
+ ts.tv_nsec = 2.5e7 /* (25 ms (2 * context switch + 5 ms)) */;
+
+ do
+ {
+ nanosleep(&ts, &ts);
+ }while(EINTR == errno);
+
+ ellapsed_time += ts.tv_nsec;
+
+ }
+ while(/* locked */ (EAGAIN == rv) && /* !timeout */ ellapsed_time < ((long)(abs_timeout->tv_sec * 1e9) + abs_timeout->tv_nsec));
+
+ return (EAGAIN == rv) ? ETIMEDOUT : rv;
+}
+
+#endif
+
+void xbt_os_sem_timedacquire(xbt_os_sem_t sem,double timeout)
+{
+ int errcode;
+ struct timespec ts_end;
+ double end = timeout + xbt_os_time();
+
+ if(!sem)
+ THROW0(arg_error,EINVAL,"Cannot acquire of the NULL semaphore");
+
+ if (timeout < 0)
+ {
+ xbt_os_sem_acquire(sem);
+ }
+ else if(!timeout)
+ {
+ #ifndef HAVE_SEM_TIMEDWAIT
+ if(sem_trywait(sem->s) < 0)
+ THROW2(system_error,errno,"sem_trywait(%p) failed: %s",sem,strerror(errno));
+ #else
+ if(sem_trywait(&(sem->s)) < 0)
+ THROW2(system_error,errno,"sem_trywait(%p) failed: %s",sem,strerror(errno));
+ #endif
+ }
+ else
+ {
+ ts_end.tv_sec = (time_t) floor(end);
+ ts_end.tv_nsec = (long) ( ( end - ts_end.tv_sec) * 1000000000);
+ DEBUG2("sem_timedwait(%p,%p)",&(sem->s),&ts_end);
+
+ #ifndef HAVE_SEM_WAIT
+ switch ((errcode = sem_timedwait(sem->s,&ts_end)))
+ #else
+ switch ((errcode = sem_timedwait(&(sem->s),&ts_end)))
+ #endif
+ {
+ case 0:
+ return;
+
+ case ETIMEDOUT:
+ THROW2(timeout_error,errcode,"semaphore %p wasn't signaled before timeout (%f)",sem,timeout);
+
+ default:
+ THROW3(system_error,errcode,"sem_timedwait(%p,%f) failed: %s",sem,timeout, strerror(errcode));
+ }
+ }
+
+}
+
+void
+xbt_os_sem_release(xbt_os_sem_t sem)
+{
+ if(!sem)
+ THROW0(arg_error,EINVAL,"Cannot release of the NULL semaphore");
+
+ #ifndef HAVE_SEM_WAIT
+ if(sem_post((sem->s)) < 0)
+ THROW1(system_error,errno,"sem_post() failed: %s",
+ strerror(errno));
+ #else
+ if(sem_post(&(sem->s)) < 0)
+ THROW1(system_error,errno,"sem_post() failed: %s",
+ strerror(errno));
+ #endif
+}
+
+void
+xbt_os_sem_destroy(xbt_os_sem_t sem)
+{
+ if(!sem)
+ THROW0(arg_error,EINVAL,"Cannot destroy the NULL sempahore");
+
+ #ifndef HAVE_SEM_WAIT
+ /* MAC OS X does not implement the sem_init() function so,
+ * we use the named semaphore (sem_open)
+ */
+ if(sem_close((sem->s)) < 0)
+ THROW1(system_error,errno,"sem_close() failed: %s",
+ strerror(errno));
+
+ xbt_free(sem->name);
+
+ #else
+ if(sem_destroy(&(sem->s)) < 0)
+ THROW1(system_error,errno,"sem_destroy() failed: %s",
+ strerror(errno));
+ #endif
+
+ xbt_free(sem);
+}
+
+void
+xbt_os_sem_get_value(xbt_os_sem_t sem, int* svalue)
+{
+ if(!sem)
+ THROW0(arg_error,EINVAL,"Cannot get the value of the NULL semaphore");
+
+ #ifndef HAVE_SEM_WAIT
+ if(sem_getvalue((sem->s),svalue) < 0)
+ THROW1(system_error,errno,"sem_getvalue() failed: %s",
+ strerror(errno));
+ #else
+ if(sem_getvalue(&(sem->s),svalue) < 0)
+ THROW1(system_error,errno,"sem_getvalue() failed: %s",
+ strerror(errno));
+ #endif