X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/07b23e956e96e9a73b3acbbf4639b3d464604a44..1c6ecd7825422241dd932318a4ba03c3df1de985:/src/simix/smx_synchro.c

diff --git a/src/simix/smx_synchro.c b/src/simix/smx_synchro.c
index dd084b1f3e..f5ccd07033 100644
--- a/src/simix/smx_synchro.c
+++ b/src/simix/smx_synchro.c
@@ -1,7 +1,5 @@
-/* 	$Id$	 */
-
-/* Copyright (c) 2007 Arnaud Legrand, Bruno Donnassolo.
-   All rights reserved.                                          */
+/* Copyright (c) 2007, 2008, 2009, 2010. The SimGrid Team.
+ * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -11,214 +9,497 @@
 
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix,
-				"Logging specific to SIMIX (synchronization)");
+                                "Logging specific to SIMIX (synchronization)");
 
+static smx_action_t SIMIX_synchro_wait(smx_host_t smx_host, double timeout);
+static void SIMIX_synchro_finish(smx_action_t action);
+static void _SIMIX_cond_wait(smx_cond_t cond, smx_mutex_t mutex, double timeout,
+                             smx_process_t issuer, smx_req_t req);
+static void _SIMIX_sem_wait(smx_sem_t sem, double timeout, smx_process_t issuer,
+                            smx_req_t req);
 
-/****************************** Synchronization *******************************/
+/***************************** Synchro action *********************************/
 
-/*********************************** Mutex ************************************/
-smx_mutex_t SIMIX_mutex_init()
-{
-	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;
-}
-
-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();
-		/* verify if the process was suspended */
-		while (self->simdata->suspended) {
-			xbt_context_yield();
-		}
-
-		self->simdata->mutex = NULL;
-		mutex->using = 1;
-	}
-	else {
-		/* mutex free */
-		mutex->using = 1;
-	}
-	return;
-}
-
-/* return 1 if the process got the mutex, else 0. */
-int SIMIX_mutex_trylock(smx_mutex_t mutex)
-{
-	xbt_assert0((mutex != NULL), "Invalid parameters");
-	
-	if (mutex->using) 
-		return 0;
-	else {
-		mutex->using = 1;
-		return 1;
-	}
-}
-
-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;
+static smx_action_t SIMIX_synchro_wait(smx_host_t smx_host, double timeout)
+{
+  XBT_IN("(%p, %f)",smx_host,timeout);
+  smx_action_t action;
+  action = xbt_mallocator_get(simix_global->action_mallocator);
+  action->type = SIMIX_ACTION_SYNCHRO;
+  action->name = xbt_strdup("synchro");
+  action->synchro.sleep = 
+    surf_workstation_model->extension.workstation.sleep(smx_host->host, timeout);
+
+  surf_workstation_model->action_data_set(action->synchro.sleep, action);
+  XBT_OUT();
+  return action;
 }
 
-void SIMIX_mutex_destroy(smx_mutex_t mutex)
+void SIMIX_synchro_stop_waiting(smx_process_t process, smx_req_t req)
 {
-	if ( mutex == NULL )
-		return ;
-	else {
-		xbt_swag_free(mutex->sleeping);
-		xbt_free(mutex);
-		return ;
-	}
+  XBT_IN("(%p, %p)",process,req);
+  switch (req->call) {
+
+    case REQ_MUTEX_LOCK:
+      xbt_swag_remove(process, req->mutex_lock.mutex->sleeping);
+      break;
+
+    case REQ_COND_WAIT:
+      xbt_swag_remove(process, req->cond_wait.cond->sleeping);
+      break;
+
+    case REQ_COND_WAIT_TIMEOUT:
+      xbt_swag_remove(process, req->cond_wait_timeout.cond->sleeping);
+      break;
+
+    case REQ_SEM_ACQUIRE:
+      xbt_swag_remove(process, req->sem_acquire.sem->sleeping);
+      break;
+
+    case REQ_SEM_ACQUIRE_TIMEOUT:
+      xbt_swag_remove(process, req->sem_acquire_timeout.sem->sleeping);
+      break;
+
+    default:
+      THROW_IMPOSSIBLE;
+  }
+  XBT_OUT();
 }
 
-/******************************** Conditional *********************************/
-smx_cond_t SIMIX_cond_init()
+void SIMIX_synchro_destroy(smx_action_t action)
 {
-	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;
+  XBT_IN("(%p)",action);
+  XBT_DEBUG("Destroying synchro %p", action);
+  action->synchro.sleep->model_type->action_unref(action->synchro.sleep);
+  xbt_free(action->name);
+  xbt_mallocator_release(simix_global->action_mallocator, action);
+  XBT_OUT();
 }
 
-void SIMIX_cond_signal(smx_cond_t cond)
+void SIMIX_post_synchro(smx_action_t action)
 {
-	xbt_assert0((cond != NULL), "Invalid parameters");
-	smx_process_t proc = NULL;
+  XBT_IN("(%p)",action);
+  if (surf_workstation_model->action_state_get(action->synchro.sleep) == SURF_ACTION_FAILED)
+    action->state = SIMIX_FAILED;
+  else if(surf_workstation_model->action_state_get(action->synchro.sleep) == SURF_ACTION_DONE)
+    action->state = SIMIX_SRC_TIMEOUT;
+
+  SIMIX_synchro_finish(action);  
+  XBT_OUT();
+}
 
-	if (xbt_swag_size(cond->sleeping) >= 1) {
-		proc = xbt_swag_extract(cond->sleeping);
-		xbt_swag_insert(proc, simix_global->process_to_run);
-	}
+static void SIMIX_synchro_finish(smx_action_t action)
+{
+  XBT_IN("(%p)",action);
+  smx_req_t req = xbt_fifo_shift(action->request_list);
+
+  switch (action->state) {
+
+    case SIMIX_SRC_TIMEOUT:
+      TRY {
+        THROWF(timeout_error, 0, "Synchro's wait timeout");
+      }
+      CATCH(req->issuer->running_ctx->exception) {
+        req->issuer->doexception = 1;
+      }
+      break;
+
+    case SIMIX_FAILED:
+      TRY {
+        THROWF(host_error, 0, "Host failed");
+      }
+      CATCH(req->issuer->running_ctx->exception) {
+        req->issuer->doexception = 1;
+      }
+      break;
+
+    default:
+      THROW_IMPOSSIBLE;
+      break;
+  }
+
+  SIMIX_synchro_stop_waiting(req->issuer, req);
+  SIMIX_synchro_destroy(action);
+  SIMIX_request_answer(req);
+  XBT_OUT();
+}
+/*********************************** Mutex ************************************/
 
-	return;
+/**
+ * \brief Initialize a mutex.
+ *
+ * Allocs and creates the data for the mutex.
+ * \return A mutex
+ */
+smx_mutex_t SIMIX_mutex_init(void)
+{
+  XBT_IN("()");
+  s_smx_process_t p;            /* useful to initialize sleeping swag */
+
+  smx_mutex_t mutex = xbt_new0(s_smx_mutex_t, 1);
+  mutex->locked = 0;
+  mutex->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
+  XBT_OUT();
+  return mutex;
 }
 
-void SIMIX_cond_wait(smx_cond_t cond,smx_mutex_t mutex)
+/**
+ * \brief Handle mutex lock request
+ * \param req The request
+ */
+void SIMIX_pre_mutex_lock(smx_req_t req)
 {
-	smx_process_t self = SIMIX_process_self();
-	smx_action_t act_sleep;
-	xbt_assert0((mutex != NULL), "Invalid parameters");
-	
-	cond->mutex = mutex;
+  XBT_IN("(%p)",req);
+  /* FIXME: check where to validate the arguments */
+  smx_action_t sync_act = NULL;
+  smx_mutex_t mutex = req->mutex_lock.mutex;
+  smx_process_t process = req->issuer;
+
+  if (mutex->locked) {
+    /* FIXME: check if the host is active ? */
+    /* Somebody using the mutex, use a synchro action to get host failures */
+    sync_act = SIMIX_synchro_wait(process->smx_host, -1);
+    xbt_fifo_push(sync_act->request_list, req);
+    req->issuer->waiting_action = sync_act;
+    xbt_swag_insert(req->issuer, mutex->sleeping);   
+  } else {
+    /* mutex free */
+    mutex->locked = 1;
+    mutex->owner = req->issuer;
+    SIMIX_request_answer(req);
+  }
+  XBT_OUT();
+}
 
-	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);
-	/* get the mutex again */
-	self->simdata->mutex = cond->mutex;
-	SIMIX_mutex_lock(cond->mutex);
+/**
+ * \brief Tries to lock a mutex.
+ *
+ * Tries to lock a mutex, return 1 if the mutex is unlocked, else 0.
+ * This function does not block and wait for the mutex to be unlocked.
+ * \param mutex The mutex
+ * \param issuer The process that tries to acquire the mutex
+ * \return 1 - mutex free, 0 - mutex used
+ */
+int SIMIX_mutex_trylock(smx_mutex_t mutex, smx_process_t issuer)
+{
+  XBT_IN("(%p, %p)",mutex,issuer);
+  if (mutex->locked){
+	  XBT_OUT();
+	  return 0;
+  }
+
+  mutex->locked = 1;
+  mutex->owner = issuer;
+  XBT_OUT();
+  return 1;
+}
 
-	return;
+/**
+ * \brief Unlocks a mutex.
+ *
+ * Unlocks the mutex and gives it to a process waiting for it. 
+ * If the unlocker is not the owner of the mutex nothing happens.
+ * If there are no process waiting, it sets the mutex as free.
+ * \param mutex The mutex
+ * \param issuer The process trying to unlock the mutex
+ */
+void SIMIX_mutex_unlock(smx_mutex_t mutex, smx_process_t issuer)
+{
+  XBT_IN("(%p, %p)",mutex,issuer);
+  smx_process_t p;              /*process to wake up */
+
+  /* If the mutex is not owned by the issuer do nothing */
+  if (issuer != mutex->owner){
+	  XBT_OUT();
+	  return;
+  }
+
+  if (xbt_swag_size(mutex->sleeping) > 0) {
+    p = xbt_swag_extract(mutex->sleeping);
+    SIMIX_synchro_destroy(p->waiting_action);
+    p->waiting_action = NULL;
+    mutex->owner = p;
+    SIMIX_request_answer(&p->request);
+  } else {
+    /* nobody to wake up */
+    mutex->locked = 0;
+    mutex->owner = NULL;
+  }
+  XBT_OUT();
 }
 
-void __SIMIX_cond_wait(smx_cond_t cond)
+/**
+ * \brief Destroys a mutex.
+ *
+ * Destroys and frees the mutex's memory. 
+ * \param mutex A mutex
+ */
+void SIMIX_mutex_destroy(smx_mutex_t mutex)
 {
-	smx_process_t self = SIMIX_process_self();
-	xbt_assert0((cond != NULL), "Invalid parameters");
-	
-	/* process status */	
-	self->simdata->cond = cond;
+  XBT_IN("(%p)",mutex);
+  if (mutex){
+    xbt_swag_free(mutex->sleeping);
+    xbt_free(mutex);
+  }
+  XBT_OUT();
+}
 
-	xbt_swag_insert(self, cond->sleeping);
-	xbt_context_yield();
-	self->simdata->cond = NULL;
-	while (self->simdata->suspended) {
-		xbt_context_yield();
-	}
-	return;
+/********************************* Condition **********************************/
 
+/**
+ * \brief Initialize a 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()
+{
+  XBT_IN("()");
+  s_smx_process_t p;
+  smx_cond_t cond = xbt_new0(s_smx_cond_t, 1);
+  cond->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
+  cond->mutex = NULL;
+  XBT_OUT();
+  return cond;
 }
 
-void SIMIX_cond_wait_timeout(smx_cond_t cond,smx_mutex_t mutex, double max_duration)
+/**
+ * \brief Handle condition waiting requests without timeouts
+ * \param The request
+ */
+void SIMIX_pre_cond_wait(smx_req_t req)
 {
-	smx_process_t self = SIMIX_process_self();
-	xbt_assert0((mutex != NULL), "Invalid parameters");
-	smx_action_t act_sleep;
+  XBT_IN("(%p)",req);
+  smx_process_t issuer = req->issuer;
+  smx_cond_t cond = req->cond_wait.cond;
+  smx_mutex_t mutex = req->cond_wait.mutex;
+
+  _SIMIX_cond_wait(cond, mutex, -1, issuer, req);
+  XBT_OUT();
+}
 
-	cond->mutex = mutex;
+/**
+ * \brief Handle condition waiting requests with timeouts
+ * \param The request
+ */
+void SIMIX_pre_cond_wait_timeout(smx_req_t req)
+{
+  XBT_IN("(%p)",req);
+  smx_process_t issuer = req->issuer;
+  smx_cond_t cond = req->cond_wait_timeout.cond;
+  smx_mutex_t mutex = req->cond_wait_timeout.mutex;
+  double timeout = req->cond_wait_timeout.timeout;
+
+  _SIMIX_cond_wait(cond, mutex, timeout, issuer, req);
+  XBT_OUT();
+}
 
-	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 */
-	self->simdata->mutex = cond->mutex;
-	SIMIX_mutex_lock(cond->mutex);
+static void _SIMIX_cond_wait(smx_cond_t cond, smx_mutex_t mutex, double timeout,
+                             smx_process_t issuer, smx_req_t req)
+{
+  XBT_IN("(%p, %p, %f, %p,%p)",cond,mutex,timeout,issuer,req);
+  smx_action_t sync_act = NULL;
+
+  XBT_DEBUG("Wait condition %p", cond);
+
+  /* If there is a mutex unlock it */
+  /* FIXME: what happens if the issuer is not the owner of the mutex? */
+  if (mutex != NULL) {
+    cond->mutex = mutex;
+    SIMIX_mutex_unlock(mutex, issuer);
+  }
+
+  sync_act = SIMIX_synchro_wait(issuer->smx_host, timeout);
+  xbt_fifo_unshift(sync_act->request_list, req);
+  issuer->waiting_action = sync_act;
+  xbt_swag_insert(req->issuer, cond->sleeping);   
+  XBT_OUT();
+}
 
-	return;
+/**
+ * \brief Signalizes a condition.
+ *
+ * Signalizes a condition and wakes up a sleeping process. 
+ * If there are no process sleeping, no action is done.
+ * \param cond A condition
+ */
+void SIMIX_cond_signal(smx_cond_t cond)
+{
+  XBT_IN("(%p)",cond);
+  smx_process_t proc = NULL;
+  smx_mutex_t mutex = NULL;
+  smx_req_t req = NULL;
+
+  XBT_DEBUG("Signal condition %p", cond);
+
+  /* If there are processes waiting for the condition choose one and try 
+     to make it acquire the mutex */
+  if ((proc = xbt_swag_extract(cond->sleeping))) {
+
+    /* Destroy waiter's synchro action */
+    SIMIX_synchro_destroy(proc->waiting_action);
+    proc->waiting_action = NULL;
+
+    /* Now transform the cond wait request into a mutex lock one */
+    req = &proc->request;
+    if(req->call == REQ_COND_WAIT)
+      mutex = req->cond_wait.mutex;
+    else
+      mutex = req->cond_wait_timeout.mutex;
+
+    req->call = REQ_MUTEX_LOCK;
+    req->mutex_lock.mutex = mutex;
+
+    SIMIX_pre_mutex_lock(req);
+  }
+  XBT_OUT();
 }
 
+/**
+ * \brief Broadcasts a condition.
+ *
+ * Signal ALL processes waiting on a condition.
+ * If there are no process waiting, 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_IN("(%p)",cond);
+  XBT_DEBUG("Broadcast condition %p", cond);
+
+  /* Signal the condition until nobody is waiting on it */
+  while (xbt_swag_size(cond->sleeping)) {
+    SIMIX_cond_signal(cond);
+  }
+  XBT_OUT();
+}
+
+/**
+ * \brief Destroys a contidion.
+ *
+ * Destroys and frees the condition's memory. 
+ * \param cond A condition
+ */
+void SIMIX_cond_destroy(smx_cond_t cond)
+{
+  XBT_IN("(%p)",cond);
+  XBT_DEBUG("Destroy condition %p", cond);
 
-	xbt_swag_foreach_safe(proc,proc_next,cond->sleeping) {
-		xbt_swag_remove(proc,cond->sleeping);
-		xbt_swag_insert(proc, simix_global->process_to_run);
-	}
+  if (cond != NULL) {
+    xbt_assert(xbt_swag_size(cond->sleeping) == 0,
+                "Cannot destroy conditional since someone is still using it");
 
-	return;
+    xbt_swag_free(cond->sleeping);
+    xbt_free(cond);
+  }
+  XBT_OUT();
 }
 
-void SIMIX_cond_destroy(smx_cond_t cond)
+/******************************** Semaphores **********************************/
+#define SMX_SEM_NOLIMIT 99999
+/** @brief Initialize a semaphore */
+smx_sem_t SIMIX_sem_init(unsigned int value)
+{
+  XBT_IN("(%d)",value);
+  s_smx_process_t p;
+
+  smx_sem_t sem = xbt_new0(s_smx_sem_t, 1);
+  sem->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
+  sem->value = value;
+  XBT_OUT();
+  return sem;
+}
+
+/** @brief Destroys a semaphore */
+void SIMIX_sem_destroy(smx_sem_t sem)
 {
-	
-	if ( cond == NULL )
-		return ;
-	else {
-		xbt_assert0( xbt_swag_size(cond->sleeping) == 0 , "Cannot destroy conditional");
+  XBT_IN("(%p)",sem);
+  XBT_DEBUG("Destroy semaphore %p", sem);
+  if (sem != NULL) {
+    xbt_assert(xbt_swag_size(sem->sleeping) == 0,
+                "Cannot destroy semaphore since someone is still using it");
+    xbt_swag_free(sem->sleeping);
+    xbt_free(sem);
+  }
+  XBT_OUT();
+}
 
-		xbt_swag_free(cond->sleeping);
-		xbt_fifo_free(cond->actions);
-		xbt_free(cond);
-		return;
-	}
+/** @brief release the semaphore
+ *
+ * Unlock a process waiting on the semaphore.
+ * If no one was blocked, the semaphore capacity is increased by 1.
+ */
+void SIMIX_sem_release(smx_sem_t sem)
+{
+  XBT_IN("(%p)",sem);
+  smx_process_t proc;
+
+  XBT_DEBUG("Sem release semaphore %p", sem);
+  if ((proc = xbt_swag_extract(sem->sleeping))) {
+    proc = xbt_swag_extract(sem->sleeping);
+    SIMIX_synchro_destroy(proc->waiting_action);
+    proc->waiting_action = NULL;
+    SIMIX_request_answer(&proc->request);
+  } else if (sem->value < SMX_SEM_NOLIMIT) {
+    sem->value++;
+  }
+  XBT_OUT();
 }
 
-void SIMIX_register_condition_to_action(smx_action_t action, smx_cond_t cond)
+/** @brief Returns true if acquiring this semaphore would block */
+XBT_INLINE int SIMIX_sem_would_block(smx_sem_t sem)
 {
-	xbt_assert0( (action != NULL) && (cond != NULL), "Invalid parameters");
+  XBT_IN("(%p)",sem);
+  XBT_OUT();
+  return (sem->value <= 0);
+}
 
-	xbt_fifo_push(action->cond_list,cond);
+/** @brief Returns the current capacity of the semaphore */
+int SIMIX_sem_get_capacity(smx_sem_t sem)
+{
+  XBT_IN("(%p)",sem);
+  XBT_OUT();
+  return sem->value;
 }
 
+static void _SIMIX_sem_wait(smx_sem_t sem, double timeout, smx_process_t issuer,
+                            smx_req_t req)
+{
+  XBT_IN("(%p, %f, %p, %p)",sem,timeout,issuer,req);
+  smx_action_t sync_act = NULL;
+
+  XBT_DEBUG("Wait semaphore %p (timeout:%f)", sem, timeout);
+  if (sem->value <= 0) {
+    sync_act = SIMIX_synchro_wait(issuer->smx_host, timeout);
+    xbt_fifo_unshift(sync_act->request_list, req);
+    issuer->waiting_action = sync_act;
+    xbt_swag_insert(issuer, sem->sleeping);
+  } else {
+    sem->value--;
+    SIMIX_request_answer(req);
+  }
+  XBT_OUT();
+}
+
+/**
+ * \brief Handle sem acquire requests without timeouts
+ */
+void SIMIX_pre_sem_acquire(smx_req_t req)
+{
+  XBT_IN("(%p)",req);
+  _SIMIX_sem_wait(req->sem_acquire.sem, -1, req->issuer, req);
+  XBT_OUT();
+}
 
+/**
+ * \brief Handle sem acquire requests with timeouts
+ */
+void SIMIX_pre_sem_acquire_timeout(smx_req_t req)
+{
+  XBT_IN("(%p)",req);
+  _SIMIX_sem_wait(req->sem_acquire_timeout.sem,
+                  req->sem_acquire_timeout.timeout, req->issuer, req);  
+  XBT_OUT();
+}