X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/568db0c9329e157e88f25ba85c515cb9f596f03a..090cf2282f07bf598ff25bf0740e35268b20b699:/src/simix/smx_synchro.c

diff --git a/src/simix/smx_synchro.c b/src/simix/smx_synchro.c
index 74fd1f0707..42d67bc080 100644
--- a/src/simix/smx_synchro.c
+++ b/src/simix/smx_synchro.c
@@ -11,7 +11,7 @@
 
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix,
-				"Logging specific to SIMIX (synchronization)");
+                                "Logging specific to SIMIX (synchronization)");
 
 
 /****************************** Synchronization *******************************/
@@ -27,9 +27,9 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix,
 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 */
+  s_smx_process_t p;            /* useful to initialize sleeping swag */
   /* structures initialization */
-  m->using = 0;
+  m->refcount = 0;
   m->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
   return m;
 }
@@ -46,23 +46,23 @@ void SIMIX_mutex_lock(smx_mutex_t mutex)
   xbt_assert0((mutex != NULL), "Invalid parameters");
 
 
-  if (mutex->using) {
+  if (mutex->refcount) {
     /* somebody using the mutex, block */
     xbt_swag_insert(self, mutex->sleeping);
-    self->simdata->mutex = mutex;
+    self->mutex = mutex;
     /* wait for some process make the unlock and wake up me from mutex->sleeping */
-    xbt_context_yield();
-    self->simdata->mutex = NULL;
+    SIMIX_process_yield();
+    self->mutex = NULL;
 
     /* verify if the process was suspended */
-    while (self->simdata->suspended) {
-      xbt_context_yield();
+    while (self->suspended) {
+      SIMIX_process_yield();
     }
 
-    mutex->using = 1;
+    mutex->refcount = 1;
   } else {
     /* mutex free */
-    mutex->using = 1;
+    mutex->refcount = 1;
   }
   return;
 }
@@ -78,10 +78,10 @@ int SIMIX_mutex_trylock(smx_mutex_t mutex)
 {
   xbt_assert0((mutex != NULL), "Invalid parameters");
 
-  if (mutex->using)
+  if (mutex->refcount)
     return 0;
   else {
-    mutex->using = 1;
+    mutex->refcount = 1;
     return 1;
   }
 }
@@ -94,17 +94,17 @@ int SIMIX_mutex_trylock(smx_mutex_t mutex)
  */
 void SIMIX_mutex_unlock(smx_mutex_t mutex)
 {
-  smx_process_t p;		/*process to wake up */
+  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;
+    mutex->refcount = 0;
     xbt_swag_insert(p, simix_global->process_to_run);
   } else {
     /* nobody to wake up */
-    mutex->using = 0;
+    mutex->refcount = 0;
   }
   return;
 }
@@ -131,7 +131,8 @@ void SIMIX_mutex_destroy(smx_mutex_t mutex)
 /**
  * \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()
@@ -148,15 +149,15 @@ smx_cond_t SIMIX_cond_init()
 /**
  * \brief Signalizes a condition.
  *
- * Signalizes a condition and wakes up a sleping process. If there are no process sleeping, no action is done.
+ * 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)
 {
-	smx_process_t proc = NULL;
+  smx_process_t proc = NULL;
   DEBUG1("Signal condition %p", cond);
   xbt_assert0((cond != NULL), "Invalid parameters");
- 
+
 
   if (xbt_swag_size(cond->sleeping) >= 1) {
     proc = xbt_swag_extract(cond->sleeping);
@@ -176,24 +177,28 @@ void SIMIX_cond_signal(smx_cond_t cond)
 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) { */
-    act_sleep = SIMIX_action_sleep(SIMIX_host_self(), -1);
-    SIMIX_register_action_to_condition(act_sleep, cond);
-    __SIMIX_cond_wait(cond);
-    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);
+  /* 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);
+
+  /* get the mutex again if necessary */
+  if(mutex != NULL)
+    SIMIX_mutex_lock(cond->mutex);
 
   return;
 }
@@ -211,15 +216,14 @@ void __SIMIX_cond_wait(smx_cond_t cond)
 
   /* process status */
 
-  self->simdata->cond = cond;
+  self->cond = cond;
   xbt_swag_insert(self, cond->sleeping);
-  xbt_context_yield();
-  self->simdata->cond = NULL;
-  while (self->simdata->suspended) {
-    xbt_context_yield();
+  SIMIX_process_yield();
+  self->cond = NULL;
+  while (self->suspended) {
+    SIMIX_process_yield();
   }
   return;
-
 }
 
 /**
@@ -231,35 +235,39 @@ void __SIMIX_cond_wait(smx_cond_t cond)
  * \param max_duration Timeout time
  */
 void SIMIX_cond_wait_timeout(smx_cond_t cond, smx_mutex_t mutex,
-			     double max_duration)
+                             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_process_self()->waiting_action = NULL;
     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);
 }
 
 /**
@@ -273,15 +281,13 @@ void SIMIX_cond_broadcast(smx_cond_t cond)
   smx_process_t proc = NULL;
   smx_process_t proc_next = NULL;
 
-   xbt_assert0((cond != NULL), "Invalid parameters");
+  xbt_assert0((cond != NULL), "Invalid parameters");
 
   DEBUG1("Broadcast 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);
   }
-
-  return;
 }
 
 /**
@@ -300,7 +306,7 @@ void SIMIX_cond_destroy(smx_cond_t cond)
     smx_action_t action = NULL;
 
     xbt_assert0(xbt_swag_size(cond->sleeping) == 0,
-		"Cannot destroy conditional since someone is still using it");
+                "Cannot destroy conditional since someone is still using it");
     xbt_swag_free(cond->sleeping);
 
     DEBUG1("%d actions registered", xbt_fifo_size(cond->actions));
@@ -315,3 +321,232 @@ void SIMIX_cond_destroy(smx_cond_t cond)
     return;
   }
 }
+
+void SIMIX_cond_display_info(smx_cond_t cond)
+{
+  if (cond == NULL)
+    return;
+  else {
+    smx_process_t process = NULL;
+
+    INFO0("Blocked process on this condition:");
+    xbt_swag_foreach(process, cond->sleeping) {
+      INFO2("\t %s running on host %s", process->name,
+            process->smx_host->name);
+    }
+  }
+}
+
+/* ************************** 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);
+}
+/**
+ * \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;
+}