X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/87bf71ddfe2611ffedaabe6c3a9030957ae4a080..2c8e75834bbb63acef15c560c3de978ab3cb6fbf:/src/simix/smx_synchro.c

diff --git a/src/simix/smx_synchro.c b/src/simix/smx_synchro.c
index 5de5313823..bf66a9d8db 100644
--- a/src/simix/smx_synchro.c
+++ b/src/simix/smx_synchro.c
@@ -340,9 +340,8 @@ void SIMIX_cond_display_info(smx_cond_t cond)
 /** @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->sleeping = xbt_fifo_new();
   sem->actions = xbt_fifo_new();
   sem->capacity = capacity;
   return sem;
@@ -354,9 +353,9 @@ void SIMIX_sem_destroy(smx_sem_t sem) {
   if (sem == NULL)
     return;
 
-  xbt_assert0(xbt_swag_size(sem->sleeping) == 0,
+  xbt_assert0(xbt_fifo_size(sem->sleeping) == 0,
       "Cannot destroy semaphore since someone is still using it");
-  xbt_swag_free(sem->sleeping);
+  xbt_fifo_free(sem->sleeping);
 
   DEBUG1("%d actions registered", xbt_fifo_size(sem->actions));
   while((action=xbt_fifo_pop(sem->actions)))
@@ -372,13 +371,15 @@ void SIMIX_sem_destroy(smx_sem_t sem) {
  * If no one was blocked, the semaphore capacity is increased by 1.
  * */
 void SIMIX_sem_release(smx_sem_t sem) {
-	DEBUG1("Sem release semaphore %p", 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) {
+  smx_process_t proc;
+
+  if (sem->capacity != SMX_SEM_NOLIMIT) {
     sem->capacity++;
   }
+  DEBUG1("Sem release semaphore %p", sem);
+  if ((proc = xbt_fifo_shift(sem->sleeping)) != NULL) {
+    xbt_swag_insert(proc, simix_global->process_to_run);
+  }
 }
 /** @brief make sure the semaphore will never be blocking again
  *
@@ -393,15 +394,13 @@ void SIMIX_sem_release(smx_sem_t sem) {
  * 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;
+  smx_process_t proc;
 
+  sem->capacity = SMX_SEM_NOLIMIT;
   DEBUG1("Broadcast semaphore %p", sem);
-  xbt_swag_foreach_safe(proc, proc_next, sem->sleeping) {
-    xbt_swag_remove(proc, sem->sleeping);
+  while ((proc = xbt_fifo_shift(sem->sleeping)) != NULL) {
     xbt_swag_insert(proc, simix_global->process_to_run);
   }
-  sem->capacity = SMX_SEM_NOLIMIT;
 }
 
 /**
@@ -419,7 +418,7 @@ void SIMIX_sem_block_onto(smx_sem_t sem) {
 
   /* process status */
   self->sem = sem;
-  xbt_swag_insert(self, sem->sleeping);
+  xbt_fifo_push (sem->sleeping, self);
   SIMIX_process_yield();
   self->sem = NULL;
   while (self->suspended)
@@ -428,7 +427,7 @@ void SIMIX_sem_block_onto(smx_sem_t sem) {
 
 /** @brief Returns true if acquiring this semaphore would block */
 XBT_INLINE int SIMIX_sem_would_block(smx_sem_t sem) {
-  return (sem->capacity>0);
+  return (sem->capacity<=0);
 }
 
 /** @brief Returns the current capacity of the semaphore
@@ -448,32 +447,9 @@ int SIMIX_sem_get_capacity(smx_sem_t sem){
  * 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;
-  }
-
-  sem->capacity--;
-  /* 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);
-  DEBUG1("End of Wait on semaphore %p", sem);
-  sem->capacity++;
+  SIMIX_sem_acquire_timeout (sem, -1);
 }
+
 /**
  * \brief Tries to acquire a semaphore before a timeout
  *
@@ -482,36 +458,39 @@ void SIMIX_sem_acquire(smx_sem_t sem) {
 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);
+  DEBUG2("Wait semaphore %p (timeout:%f)", sem, max_duration);
 
-  if (sem->capacity == SMX_SEM_NOLIMIT)
+  if (sem->capacity == SMX_SEM_NOLIMIT) {
+    DEBUG1("semaphore %p wide open", sem);
     return; /* don't even decrease it if wide open */
+  }
 
   /* If capacity sufficient, decrease it */
   if (sem->capacity>0) {
+    DEBUG1("semaphore %p has enough capacity", sem);
     sem->capacity--;
     return;
   }
 
-  if (max_duration >= 0) {
-    sem->capacity--;
-    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);
+  /* Always create an action null in case there is a host failure */
+  act_sleep = SIMIX_action_sleep(SIMIX_host_self(), max_duration);
+  SIMIX_action_set_name(act_sleep,bprintf("Locked in semaphore %p (max_duration:%f)", sem, max_duration));
+  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);
+  if (max_duration >= 0 && 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 {
+    if (sem->capacity != SMX_SEM_NOLIMIT) {
+      /* Take the released token */
+      sem->capacity--;
     }
-    sem->capacity++;
-
-  } else
-    SIMIX_sem_acquire(sem);
+    SIMIX_action_destroy(act_sleep);
+  }
+  DEBUG1("End of Wait on semaphore %p", sem);
 }
 /**
  * \brief Blocks on a set of semaphore
@@ -529,12 +508,14 @@ unsigned int SIMIX_sem_acquire_any(xbt_dynar_t sems) {
 
   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);
+  DEBUG2("Wait on semaphore set %p (containing %ld semaphores)", sems,xbt_dynar_length(sems));
 
   xbt_dynar_foreach(sems,counter,sem) {
-    if (!SIMIX_sem_would_block(sem))
+    if (!SIMIX_sem_would_block(sem)) {
+      DEBUG1("Semaphore %p wouldn't block; get it without waiting",sem);
       SIMIX_sem_acquire(sem);
-    return counter;
+      return counter;
+    }
   }
 
   /* Always create an action null in case there is a host failure */
@@ -546,23 +527,24 @@ unsigned int SIMIX_sem_acquire_any(xbt_dynar_t sems) {
   /* 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);
+    xbt_fifo_push(sem->sleeping, self);
   }
   SIMIX_process_yield();
   self->sem = NULL;
   while (self->suspended)
     SIMIX_process_yield();
 
-  /* one of the semaphore unsuspended us -- great, let's search which one (and get out of the others) */
+  /* at least one of the semaphore unsuspended us -- great, let's search the first one (and get out of the others) */
   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");
+    if (!xbt_fifo_remove(sem->sleeping, self) && result == -1) {
+      if (sem->capacity != SMX_SEM_NOLIMIT) {
+        /* Take the released token */
+        sem->capacity--;
+      }
       result = counter;
     }
   }
-  xbt_assert0(counter!=-1,"Cannot find which semaphore unlocked me!");
+  xbt_assert0(result!=-1,"Cannot find which semaphore unlocked me!");
 
   /* Destroy the waiting action */
   self->waiting_action = NULL;