+/**
+ * \brief Waits on a semaphore
+ *
+ * If the capacity>0, decrease the capacity.
+ *
+ * If capacity==0, locks the current process
+ * until someone call SIMIX_sem_release() on this semaphore
+ */
+void SIMIX_sem_acquire(smx_sem_t sem) {
+ smx_action_t act_sleep;
+
+ DEBUG1("Wait semaphore %p", sem);
+
+ if (sem->capacity == SMX_SEM_NOLIMIT)
+ return; /* don't even decrease it if wide open */
+
+ /* If capacity sufficient, decrease it */
+ if (sem->capacity>0) {
+ sem->capacity--;
+ return;
+ }
+
+ sem->capacity--;
+ /* Always create an action null in case there is a host failure */
+ act_sleep = SIMIX_action_sleep(SIMIX_host_self(), -1);
+ SIMIX_action_set_name(act_sleep,bprintf("Locked in semaphore %p", sem));
+ SIMIX_process_self()->waiting_action = act_sleep;
+ SIMIX_register_action_to_semaphore(act_sleep, sem);
+ SIMIX_sem_block_onto(sem);
+ SIMIX_process_self()->waiting_action = NULL;
+ SIMIX_unregister_action_to_semaphore(act_sleep, sem);
+ SIMIX_action_destroy(act_sleep);
+ DEBUG1("End of Wait on semaphore %p", sem);
+ sem->capacity++;
+}
+/**
+ * \brief Tries to acquire a semaphore before a timeout
+ *
+ * Same behavior of #SIMIX_sem_acquire, but waits a maximum time and throws an timeout_error if it happens.
+ */
+void SIMIX_sem_acquire_timeout(smx_sem_t sem, double max_duration) {
+ smx_action_t act_sleep;
+
+ DEBUG2("Timed wait semaphore %p (timeout:%f)", sem,max_duration);
+
+ if (sem->capacity == SMX_SEM_NOLIMIT)
+ return; /* don't even decrease it if wide open */
+
+ /* If capacity sufficient, decrease it */
+ if (sem->capacity>0) {
+ sem->capacity--;
+ return;
+ }
+
+ if (max_duration >= 0) {
+ sem->capacity--;
+ act_sleep = SIMIX_action_sleep(SIMIX_host_self(), max_duration);
+ SIMIX_action_set_name(act_sleep,bprintf("Timed wait semaphore %p (max_duration:%f)", sem,max_duration));
+ SIMIX_register_action_to_semaphore(act_sleep, sem);
+ SIMIX_process_self()->waiting_action = act_sleep;
+ SIMIX_sem_block_onto(sem);
+ SIMIX_process_self()->waiting_action = NULL;
+ SIMIX_unregister_action_to_semaphore(act_sleep, sem);
+ if (SIMIX_action_get_state(act_sleep) == SURF_ACTION_DONE) {
+ SIMIX_action_destroy(act_sleep);
+ THROW1(timeout_error, 0, "Semaphore acquire timeouted after %f",max_duration);
+ } else {
+ SIMIX_action_destroy(act_sleep);
+ }
+ sem->capacity++;
+
+ } else
+ SIMIX_sem_acquire(sem);
+}
+/**
+ * \brief Blocks on a set of semaphore
+ *
+ * If any of the semaphores has some more capacity, it gets decreased.
+ * If not, blocks until the capacity of one of the semaphores becomes more friendly.
+ *
+ * \return the rank in the dynar of the semaphore which just got locked from the set
+ */
+unsigned int SIMIX_sem_acquire_any(xbt_dynar_t sems) {
+ smx_sem_t sem;
+ unsigned int counter,result=-1;
+ smx_action_t act_sleep;
+ smx_process_t self = SIMIX_process_self();
+
+ xbt_assert0(xbt_dynar_length(sems),
+ "I refuse to commit sucide by locking on an **empty** set of semaphores!!");
+ DEBUG1("Wait on semaphore set %p", sems);
+
+ xbt_dynar_foreach(sems,counter,sem) {
+ if (!SIMIX_sem_would_block(sem))
+ SIMIX_sem_acquire(sem);
+ return counter;
+ }
+
+ /* Always create an action null in case there is a host failure */
+ act_sleep = SIMIX_action_sleep(SIMIX_host_self(), -1);
+ SIMIX_action_set_name(act_sleep,bprintf("Locked in semaphore %p", sem));
+ self->waiting_action = act_sleep;
+ SIMIX_register_action_to_semaphore(act_sleep, xbt_dynar_get_as(sems,0,smx_sem_t));
+
+ /* Get listed as member of all the provided semaphores */
+ self->sem = (smx_sem_t)sems; /* FIXME: we pass a pointer to dynar where a pointer to sem is expected...*/
+ xbt_dynar_foreach(sems,counter,sem) {
+ xbt_swag_insert(self, sem->sleeping);
+ }
+ SIMIX_process_yield();
+ while (self->suspended)
+ SIMIX_process_yield();
+
+ /* one of the semaphore unsuspended us -- great, let's search which one (and get out of the others) */
+ self->sem = NULL;
+ xbt_dynar_foreach(sems,counter,sem) {
+ if (xbt_swag_belongs(self,sem->sleeping))
+ xbt_swag_remove(self,sem->sleeping);
+ else {
+ xbt_assert0(result==-1,"More than one semaphore unlocked us. Dunno what to do");
+ result = counter;
+ }
+ }
+ xbt_assert0(counter!=-1,"Cannot find which semaphore unlocked me!");
+
+ /* Destroy the waiting action */
+ self->waiting_action = NULL;
+ SIMIX_unregister_action_to_semaphore(act_sleep, xbt_dynar_get_as(sems,0,smx_sem_t));
+ SIMIX_action_destroy(act_sleep);
+ return result;
+}