/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012
* Jonathan Schleifer <js@webkeks.org>
*
* All rights reserved.
*
* This file is part of ObjFW. It may be distributed under the terms of the
* Q Public License 1.0, which can be found in the file LICENSE.QPL included in
* the packaging of this file.
*
* Alternatively, it may be distributed under the terms of the GNU General
* Public License, either version 2 or 3, which can be found in the file
* LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
* file.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <sys/types.h>
#import "runtime.h"
#import "threading.h"
struct lock_s {
id object;
size_t count;
size_t recursion;
of_thread_t thread;
of_mutex_t mutex;
};
static of_mutex_t mutex;
static struct lock_s *locks = NULL;
static ssize_t numLocks = 0;
#define SYNC_ERR(f) \
{ \
fprintf(stderr, "WARNING: %s failed in line %d!\n" \
"WARNING: This might result in a race " \
"condition!\n", f, __LINE__); \
return 1; \
}
BOOL
objc_sync_init(void)
{
return of_mutex_new(&mutex);
}
int
objc_sync_enter(id object)
{
ssize_t i;
if (object == nil)
return 0;
if (!of_mutex_lock(&mutex))
SYNC_ERR("of_mutex_lock(&mutex)");
for (i = numLocks - 1; i >= 0; i--) {
if (locks[i].object == object) {
if (of_thread_is_current(locks[i].thread))
locks[i].recursion++;
else {
/* Make sure objc_sync_exit doesn't free it */
locks[i].count++;
/* Unlock so objc_sync_exit can return */
if (!of_mutex_unlock(&mutex))
SYNC_ERR("of_mutex_unlock(&mutex)");
if (!of_mutex_lock(&locks[i].mutex)) {
of_mutex_unlock(&mutex);
SYNC_ERR(
"of_mutex_lock(&locks[i].mutex");
}
if (!of_mutex_lock(&mutex))
SYNC_ERR("of_mutex_lock(&mutex)");
assert(locks[i].recursion == 0);
/* Update lock's active thread */
locks[i].thread = of_thread_current();
}
if (!of_mutex_unlock(&mutex))
SYNC_ERR("of_mutex_unlock(&mutex)");
return 0;
}
}
if (locks == NULL) {
if ((locks = malloc(sizeof(struct lock_s))) == NULL) {
of_mutex_unlock(&mutex);
SYNC_ERR("malloc(...)");
}
} else {
struct lock_s *new_locks;
if ((new_locks = realloc(locks, (numLocks + 1) *
sizeof(struct lock_s))) == NULL) {
of_mutex_unlock(&mutex);
SYNC_ERR("realloc(...)");
}
locks = new_locks;
}
locks[numLocks].object = object;
locks[numLocks].count = 1;
locks[numLocks].recursion = 0;
locks[numLocks].thread = of_thread_current();
if (!of_mutex_new(&locks[numLocks].mutex)) {
of_mutex_unlock(&mutex);
SYNC_ERR("of_mutex_new(&locks[numLocks].mutex");
}
if (!of_mutex_lock(&locks[numLocks].mutex)) {
of_mutex_unlock(&mutex);
SYNC_ERR("of_mutex_lock(&locks[numLocks].mutex");
}
numLocks++;
if (!of_mutex_unlock(&mutex))
SYNC_ERR("of_mutex_unlock(&mutex)");
return 0;
}
int
objc_sync_exit(id object)
{
ssize_t i;
if (object == nil)
return 0;
if (!of_mutex_lock(&mutex))
SYNC_ERR("of_mutex_lock(&mutex)");
for (i = numLocks - 1; i >= 0; i--) {
if (locks[i].object == object) {
if (locks[i].recursion > 0 &&
of_thread_is_current(locks[i].thread)) {
locks[i].recursion--;
if (!of_mutex_unlock(&mutex))
SYNC_ERR("of_mutex_unlock(&mutex)");
return 0;
}
if (!of_mutex_unlock(&locks[i].mutex)) {
of_mutex_unlock(&mutex);
SYNC_ERR("of_mutex_unlock(&locks[i].mutex)");
}
locks[i].count--;
if (locks[i].count == 0) {
struct lock_s *new_locks = NULL;
if (!of_mutex_free(&locks[i].mutex)) {
of_mutex_unlock(&mutex);
SYNC_ERR(
"of_mutex_free(&locks[i].mutex");
}
numLocks--;
locks[i] = locks[numLocks];
if (numLocks == 0) {
free(locks);
new_locks = NULL;
} else if ((new_locks = realloc(locks,
numLocks * sizeof(struct lock_s))) ==
NULL) {
of_mutex_unlock(&mutex);
SYNC_ERR("realloc(...)");
}
locks = new_locks;
}
if (!of_mutex_unlock(&mutex))
SYNC_ERR("of_mutex_unlock(&mutex)");
return 0;
}
}
of_mutex_unlock(&mutex);
SYNC_ERR("objc_sync_exit()");
}