-/* $Id$ */
-
-/* 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. */
/** @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;
}
/** @brief Destroys a semaphore */
void SIMIX_sem_destroy(smx_sem_t sem) {
+ smx_action_t action = NULL;
DEBUG1("Destroy semaphore %p", sem);
if (sem == NULL)
return;
- smx_action_t action = NULL;
-
- 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)))
* 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);
+ smx_process_t proc;
+
+ DEBUG1("Sem release semaphore %p", sem);
+ if ((proc = xbt_fifo_shift(sem->sleeping)) != NULL) {
xbt_swag_insert(proc, simix_global->process_to_run);
} else if (sem->capacity != SMX_SEM_NOLIMIT) {
sem->capacity++;
* 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;
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;
}
/**
/* 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)
/** @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
DEBUG1("Wait semaphore %p", sem);
- 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;
}
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 */
/* 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) */
- 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");
+ if (!xbt_fifo_remove(sem->sleeping, self)) {
+ xbt_assert1(result == -1, "You're trying to wait more than once on semaphore %p, don't you ?", sem);
result = counter;
}
}