X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7f85c01fa01dfbf9b06f6e8c1fa01e34f49647db..4e7eb5ee8613f100bfefeb6475d93ce9c58c75ea:/src/simix/smx_synchro.c

diff --git a/src/simix/smx_synchro.c b/src/simix/smx_synchro.c
index b6d418b0c6..4e715105d5 100644
--- a/src/simix/smx_synchro.c
+++ b/src/simix/smx_synchro.c
@@ -17,6 +17,13 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix,
 /****************************** 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()
 {
 	smx_mutex_t m = xbt_new0(s_smx_mutex_t,1);
@@ -27,24 +34,31 @@ smx_mutex_t SIMIX_mutex_init()
 	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();
 		}
 
-		self->simdata->mutex = NULL;
 		mutex->using = 1;
 	}
 	else {
@@ -54,7 +68,13 @@ void SIMIX_mutex_lock(smx_mutex_t mutex)
 	return;
 }
 
-/* return 1 if the process got the mutex, else 0. */
+/**
+ * \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)
 {
 	xbt_assert0((mutex != NULL), "Invalid parameters");
@@ -67,6 +87,12 @@ int SIMIX_mutex_trylock(smx_mutex_t mutex)
 	}
 }
 
+/**
+ * \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 */
@@ -85,6 +111,12 @@ void SIMIX_mutex_unlock(smx_mutex_t mutex)
 	return;
 }
 
+/**
+ * \brief Destroys a mutex.
+ *
+ * Destroys and frees the mutex's memory. 
+ * \param mutex A mutex
+ */
 void SIMIX_mutex_destroy(smx_mutex_t mutex)
 {
 	if ( mutex == NULL )
@@ -97,6 +129,13 @@ void SIMIX_mutex_destroy(smx_mutex_t mutex)
 }
 
 /******************************** 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()
 {
 	smx_cond_t cond = xbt_new0(s_smx_cond_t,1);
@@ -108,6 +147,12 @@ smx_cond_t SIMIX_cond_init()
 	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");
@@ -121,32 +166,54 @@ void SIMIX_cond_signal(smx_cond_t cond)
 	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_process_t self = SIMIX_process_self();
+	smx_action_t act_sleep;
 	xbt_assert0((mutex != NULL), "Invalid parameters");
 	
 	cond->mutex = mutex;
 
 	SIMIX_mutex_unlock(mutex);
-	__SIMIX_cond_wait(cond);
+	/* 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 */
-	self->simdata->mutex = cond->mutex;
 	SIMIX_mutex_lock(cond->mutex);
 
 	return;
 }
 
+xbt_fifo_t SIMIX_cond_get_actions(smx_cond_t cond)
+{
+	xbt_assert0((cond != NULL), "Invalid parameters");
+	return cond->actions;
+}
+
 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;
 
+	self->simdata->cond = cond;
 	xbt_swag_insert(self, cond->sleeping);
-	
 	xbt_context_yield();
 	self->simdata->cond = NULL;
 	while (self->simdata->suspended) {
@@ -156,9 +223,16 @@ void __SIMIX_cond_wait(smx_cond_t cond)
 
 }
 
+/**
+ * \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)
 {
-	smx_process_t self = SIMIX_process_self();
 	xbt_assert0((mutex != NULL), "Invalid parameters");
 	smx_action_t act_sleep;
 
@@ -169,16 +243,25 @@ void SIMIX_cond_wait_timeout(smx_cond_t cond,smx_mutex_t mutex, double max_durat
 		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);
+		xbt_fifo_remove(act_sleep->cond_list,cond);
+		SIMIX_action_destroy(act_sleep);
 	}
-	__SIMIX_cond_wait(cond);
+	else
+		__SIMIX_cond_wait(cond);
 
 	/* get the mutex again */
-	self->simdata->mutex = cond->mutex;
 	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");
@@ -193,14 +276,18 @@ void SIMIX_cond_broadcast(smx_cond_t cond)
 	return;
 }
 
+/**
+ * \brief Destroys a contidion.
+ *
+ * Destroys and frees the condition's memory. 
+ * \param cond A condition
+ */
 void SIMIX_cond_destroy(smx_cond_t cond)
 {
-	
 	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);
@@ -208,6 +295,13 @@ void SIMIX_cond_destroy(smx_cond_t cond)
 	}
 }
 
+/**
+ * 	\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");