/**
* \brief Initialize a condition.
*
- * Allocs and creates the data for the condition. It have to be called before the utilisation of the condition.
+ * Allocates and creates the data for the condition.
+ * It have to be called before the use of the condition.
* \return A condition
*/
smx_cond_t SIMIX_cond_init()
void SIMIX_cond_wait(smx_cond_t cond, smx_mutex_t mutex)
{
smx_action_t act_sleep;
- xbt_assert0((mutex != NULL), "Invalid parameters");
DEBUG1("Wait condition %p", cond);
- cond->mutex = mutex;
- SIMIX_mutex_unlock(mutex);
- /* always create an action null in case there is a host failure */
-/* if (xbt_fifo_size(cond->actions) == 0) { */
+ /* If there is a mutex unlock it */
+ if(mutex != NULL){
+ cond->mutex = mutex;
+ SIMIX_mutex_unlock(mutex);
+ }
+
+ /* 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("Wait condition %p", cond));
SIMIX_process_self()->waiting_action = act_sleep;
SIMIX_register_action_to_condition(act_sleep, cond);
__SIMIX_cond_wait(cond);
SIMIX_process_self()->waiting_action = NULL;
SIMIX_unregister_action_to_condition(act_sleep, cond);
SIMIX_action_destroy(act_sleep);
-/* } else { */
-/* __SIMIX_cond_wait(cond); */
-/* } */
- /* get the mutex again */
- SIMIX_mutex_lock(cond->mutex);
+
+ /* get the mutex again if necessary */
+ if(mutex != NULL)
+ SIMIX_mutex_lock(cond->mutex);
return;
}
SIMIX_process_yield();
}
return;
-
}
/**
void SIMIX_cond_wait_timeout(smx_cond_t cond, smx_mutex_t mutex,
double max_duration)
{
-
smx_action_t act_sleep;
- xbt_assert0((mutex != NULL), "Invalid parameters");
DEBUG1("Timed wait condition %p", cond);
- cond->mutex = mutex;
- SIMIX_mutex_unlock(mutex);
+ /* If there is a mutex unlock it */
+ if(mutex != NULL){
+ cond->mutex = mutex;
+ SIMIX_mutex_unlock(mutex);
+ }
+
if (max_duration >= 0) {
act_sleep = SIMIX_action_sleep(SIMIX_host_self(), max_duration);
+ SIMIX_action_set_name(act_sleep,bprintf("Timed wait condition %p (max_duration:%f)", cond,max_duration));
SIMIX_register_action_to_condition(act_sleep, cond);
SIMIX_process_self()->waiting_action = act_sleep;
__SIMIX_cond_wait(cond);
SIMIX_unregister_action_to_condition(act_sleep, cond);
if (SIMIX_action_get_state(act_sleep) == SURF_ACTION_DONE) {
SIMIX_action_destroy(act_sleep);
- THROW0(timeout_error, 0, "Condition timeout");
+ THROW1(timeout_error, 0, "Condition timeout after %f",max_duration);
} else {
SIMIX_action_destroy(act_sleep);
}
} else
- __SIMIX_cond_wait(cond);
+ SIMIX_cond_wait(cond,NULL);
- /* get the mutex again */
- SIMIX_mutex_lock(cond->mutex);
-
- return;
+ /* get the mutex again if necessary */
+ if(mutex != NULL)
+ SIMIX_mutex_lock(cond->mutex);
}
/**
xbt_swag_remove(proc, cond->sleeping);
xbt_swag_insert(proc, simix_global->process_to_run);
}
-
- return;
}
/**
}
}
}
+
+/* ************************** Semaphores ************************************** */
+#define SMX_SEM_NOLIMIT 99999
+/** @brief Initialize a semaphore */
+smx_sem_t SIMIX_sem_init(int capacity) {
+ smx_sem_t sem = xbt_new0(s_smx_sem_t, 1);
+ s_smx_process_t p;
+
+ sem->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
+ sem->actions = xbt_fifo_new();
+ sem->capacity = capacity;
+ return sem;
+}
+/** @brief Destroys a semaphore */
+void SIMIX_sem_destroy(smx_sem_t sem) {
+ DEBUG1("Destroy semaphore %p", sem);
+ if (sem == NULL)
+ return;
+
+ xbt_fifo_item_t item = NULL;
+ smx_action_t action = NULL;
+
+ xbt_assert0(xbt_swag_size(sem->sleeping) == 0,
+ "Cannot destroy semaphore since someone is still using it");
+ xbt_swag_free(sem->sleeping);
+
+ DEBUG1("%d actions registered", xbt_fifo_size(sem->actions));
+ xbt_fifo_foreach(sem->actions, item, action, smx_action_t) {
+ SIMIX_unregister_action_to_semaphore(action, sem);
+ }
+
+ xbt_fifo_free(sem->actions);
+ xbt_free(sem);
+}
+
+/** @brief release the semaphore
+ *
+ * The first locked process on this semaphore is unlocked.
+ * If no one was blocked, the semaphore capacity is increased by 1.
+ * */
+void SIMIX_sem_release(smx_sem_t sem) {
+ if (xbt_swag_size(sem->sleeping) >= 1) {
+ smx_process_t proc = xbt_swag_extract(sem->sleeping);
+ xbt_swag_insert(proc, simix_global->process_to_run);
+ } else if (sem->capacity != SMX_SEM_NOLIMIT) {
+ sem->capacity++;
+ }
+}
+/** @brief make sure the semaphore will never be blocking again
+ *
+ * This function is not really in the semaphore spirit. It makes
+ * sure that the semaphore will never be blocking anymore.
+ *
+ * Releasing and acquiring the semaphore after calling this
+ * function is a noop. Such "broken" semaphores are useful to
+ * implement something between condition variables (with broadcast)
+ * and semaphore (with memory). It's like a semaphore signaled for ever.
+ *
+ * There is no way to reset the semaphore to a more regular state afterward.
+ * */
+void SIMIX_sem_release_forever(smx_sem_t sem) {
+ smx_process_t proc = NULL;
+ smx_process_t proc_next = NULL;
+
+ DEBUG1("Broadcast semaphore %p", sem);
+ xbt_swag_foreach_safe(proc, proc_next, sem->sleeping) {
+ xbt_swag_remove(proc, sem->sleeping);
+ xbt_swag_insert(proc, simix_global->process_to_run);
+ }
+}
+
+static inline void SIMIX_sem_block_onto(smx_sem_t sem) {
+ smx_process_t self = SIMIX_process_self();
+
+ /* process status */
+ self->sem = sem;
+ xbt_swag_insert(self, sem->sleeping);
+ SIMIX_process_yield();
+ self->sem = NULL;
+ while (self->suspended)
+ SIMIX_process_yield();
+}
+
+/** @brief Returns true if acquiring this semaphore would block */
+int SIMIX_sem_would_block(smx_sem_t sem) {
+ return (sem->capacity>0);
+}
+
+/**
+ * \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;
+ }
+
+ /* 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);
+}
+/**
+ * \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) {
+ 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);
+ }
+
+ } else
+ SIMIX_sem_acquire(sem);
+}
