/****************************** Synchronization *******************************/
/*********************************** Mutex ************************************/
+
+/**
+ * \brief Initialize a mutex.
+ *
+ * Allocs and creates the data for the mutex. It have to be called before the utilisation of the mutex.
+ * \return A mutex
+ */
smx_mutex_t SIMIX_mutex_init()
{
- return xbt_new0(s_smx_mutex_t,1);
+ smx_mutex_t m = xbt_new0(s_smx_mutex_t,1);
+ s_smx_process_t p; /* useful to initialize sleeping swag */
+ /* structures initialization */
+ m->using = 0;
+ m->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
+ return m;
}
+/**
+ * \brief Locks a mutex.
+ *
+ * Tries to lock a mutex, if the mutex isn't used yet, the process can continue its execution, else it'll be blocked here. You have to call #SIMIX_mutex_unlock to free the mutex.
+ * \param mutex The mutex
+ */
void SIMIX_mutex_lock(smx_mutex_t mutex)
{
+ smx_process_t self = SIMIX_process_self();
+ xbt_assert0((mutex != NULL), "Invalid parameters");
+
+
+ if (mutex->using) {
+ /* somebody using the mutex, block */
+ xbt_swag_insert(self, mutex->sleeping);
+ self->simdata->mutex = mutex;
+ /* wait for some process make the unlock and wake up me from mutex->sleeping */
+ xbt_context_yield();
+ self->simdata->mutex = NULL;
+
+ /* verify if the process was suspended */
+ while (self->simdata->suspended) {
+ xbt_context_yield();
+ }
+
+ mutex->using = 1;
+ }
+ else {
+ /* mutex free */
+ mutex->using = 1;
+ }
return;
}
-void SIMIX_mutex_trylock(smx_mutex_t mutex)
+/**
+ * \brief Tries to lock a mutex.
+ *
+ * Tries to lock a mutex, return 1 if the mutex is free, 0 else. This function does not block the process if the mutex is used.
+ * \param mutex The mutex
+ * \return 1 - mutex free, 0 - mutex used
+ */
+int SIMIX_mutex_trylock(smx_mutex_t mutex)
{
- return;
+ xbt_assert0((mutex != NULL), "Invalid parameters");
+
+ if (mutex->using)
+ return 0;
+ else {
+ mutex->using = 1;
+ return 1;
+ }
}
+/**
+ * \brief Unlocks a mutex.
+ *
+ * Unlocks the mutex and wakes up a process blocked on it. If there are no process sleeping, only sets the mutex as free.
+ * \param mutex The mutex
+ */
void SIMIX_mutex_unlock(smx_mutex_t mutex)
{
+ smx_process_t p; /*process to wake up */
+
+ xbt_assert0((mutex != NULL), "Invalid parameters");
+
+ if (xbt_swag_size(mutex->sleeping) > 0) {
+ p = xbt_swag_extract(mutex->sleeping);
+ mutex->using = 0;
+ xbt_swag_insert(p, simix_global->process_to_run);
+ }
+ else {
+ /* nobody to wake up */
+ mutex->using = 0;
+ }
return;
}
+/**
+ * \brief Destroys a mutex.
+ *
+ * Destroys and frees the mutex's memory.
+ * \param mutex A mutex
+ */
void SIMIX_mutex_destroy(smx_mutex_t mutex)
{
- return;
+ if ( mutex == NULL )
+ return ;
+ else {
+ xbt_swag_free(mutex->sleeping);
+ xbt_free(mutex);
+ return ;
+ }
}
/******************************** Conditional *********************************/
+
+/**
+ * \brief Initialize a condition.
+ *
+ * Allocs and creates the data for the condition. It have to be called before the utilisation of the condition.
+ * \return A condition
+ */
smx_cond_t SIMIX_cond_init()
{
- return xbt_new0(s_smx_cond_t,1);
+ smx_cond_t cond = xbt_new0(s_smx_cond_t,1);
+ s_smx_process_t p;
+
+ cond->sleeping = xbt_swag_new(xbt_swag_offset(p,synchro_hookup));
+ cond->actions = xbt_fifo_new();
+ cond->mutex = NULL;
+ return cond;
}
+/**
+ * \brief Signalizes a condition.
+ *
+ * Signalizes a condition and wakes up a sleping process. If there are no process sleeping, no action is done.
+ * \param cond A condition
+ */
void SIMIX_cond_signal(smx_cond_t cond)
{
+ xbt_assert0((cond != NULL), "Invalid parameters");
+ smx_process_t proc = NULL;
+
+ if (xbt_swag_size(cond->sleeping) >= 1) {
+ proc = xbt_swag_extract(cond->sleeping);
+ xbt_swag_insert(proc, simix_global->process_to_run);
+ }
+
return;
}
+/**
+ * \brief Waits on a condition.
+ *
+ * Blocks a process until the signal is called. This functions frees the mutex associated and locks it after its execution.
+ * \param cond A condition
+ * \param mutex A mutex
+ */
void SIMIX_cond_wait(smx_cond_t cond,smx_mutex_t mutex)
{
+ smx_action_t act_sleep;
+ xbt_assert0((mutex != NULL), "Invalid parameters");
+
+ cond->mutex = mutex;
+
+ SIMIX_mutex_unlock(mutex);
+ /* create an action null only if there are no actions already on the condition, usefull if the host crashs */
+ if (xbt_fifo_size(cond->actions) ==0 ) {
+ act_sleep = SIMIX_action_sleep(SIMIX_host_self(), -1);
+ SIMIX_register_action_to_condition(act_sleep,cond);
+ SIMIX_register_condition_to_action(act_sleep,cond);
+ __SIMIX_cond_wait(cond);
+ xbt_fifo_pop(act_sleep->cond_list);
+ SIMIX_action_destroy(act_sleep);
+ }
+ else {
+ __SIMIX_cond_wait(cond);
+ }
+ /* get the mutex again */
+ SIMIX_mutex_lock(cond->mutex);
+
return;
}
+
+void __SIMIX_cond_wait(smx_cond_t cond)
+{
+ smx_process_t self = SIMIX_process_self();
+ xbt_assert0((cond != NULL), "Invalid parameters");
+
+ /* process status */
+
+ self->simdata->cond = cond;
+ xbt_swag_insert(self, cond->sleeping);
+ xbt_context_yield();
+ self->simdata->cond = NULL;
+ while (self->simdata->suspended) {
+ xbt_context_yield();
+ }
+ return;
+
+}
+
+/**
+ * \brief Waits on a condition with timeout.
+ *
+ * Same behavior of #SIMIX_cond_wait, but waits a maximum time.
+ * \param cond A condition
+ * \param mutex A mutex
+ * \param max_duration Timeout time
+ */
void SIMIX_cond_wait_timeout(smx_cond_t cond,smx_mutex_t mutex, double max_duration)
{
+ xbt_assert0((mutex != NULL), "Invalid parameters");
+ smx_action_t act_sleep;
+
+ cond->mutex = mutex;
+
+ SIMIX_mutex_unlock(mutex);
+ if (max_duration >=0) {
+ act_sleep = SIMIX_action_sleep(SIMIX_host_self(), max_duration);
+ SIMIX_register_action_to_condition(act_sleep,cond);
+ SIMIX_register_condition_to_action(act_sleep,cond);
+ }
+ __SIMIX_cond_wait(cond);
+
+ /* get the mutex again */
+ SIMIX_mutex_lock(cond->mutex);
+
return;
}
+/**
+ * \brief Broadcasts a condition.
+ *
+ * Signalizes a condition and wakes up ALL sleping process. If there are no process sleeping, no action is done.
+ * \param cond A condition
+ */
void SIMIX_cond_broadcast(smx_cond_t cond)
{
+ xbt_assert0((cond != NULL), "Invalid parameters");
+ smx_process_t proc = NULL;
+ smx_process_t proc_next = NULL;
+
+ xbt_swag_foreach_safe(proc,proc_next,cond->sleeping) {
+ xbt_swag_remove(proc,cond->sleeping);
+ xbt_swag_insert(proc, simix_global->process_to_run);
+ }
+
return;
}
+/**
+ * \brief Destroys a contidion.
+ *
+ * Destroys and frees the condition's memory.
+ * \param cond A condition
+ */
void SIMIX_cond_destroy(smx_cond_t cond)
{
- return;
+ if ( cond == NULL )
+ return ;
+ else {
+ xbt_assert0( xbt_swag_size(cond->sleeping) == 0 , "Cannot destroy conditional");
+ xbt_swag_free(cond->sleeping);
+ xbt_fifo_free(cond->actions);
+ xbt_free(cond);
+ return;
+ }
}
+
+/**
+ * \brief Set a condition to an action
+ *
+ * Creates the "link" between an action and a condition. You have to call this function when you create an action and want to wait its ending.
+ * \param action SIMIX action
+ * \param cond SIMIX cond
+ */
+void SIMIX_register_condition_to_action(smx_action_t action, smx_cond_t cond)
+{
+ xbt_assert0( (action != NULL) && (cond != NULL), "Invalid parameters");
+
+ xbt_fifo_push(action->cond_list,cond);
+}
+
+
