/*
* Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3.0 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* version 3.0 for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* version 3.0 along with this program. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#import "ObjFWRT.h"
#import "private.h"
#ifdef OF_HAVE_THREADS
# import "OFPlainMutex.h"
#endif
struct WeakRef {
id **locations;
size_t count;
};
static struct objc_hashtable *hashtable;
#ifdef OF_HAVE_THREADS
static OFSpinlock spinlock;
#endif
static uint32_t
hash(const void *object)
{
return (uint32_t)(uintptr_t)object;
}
static bool
equal(const void *object1, const void *object2)
{
return (object1 == object2);
}
OF_CONSTRUCTOR()
{
hashtable = objc_hashtable_new(hash, equal, 2);
#ifdef OF_HAVE_THREADS
if (OFSpinlockNew(&spinlock) != 0)
OBJC_ERROR("Failed to create spinlock!");
#endif
}
id
objc_retain(id object)
{
return [object retain];
}
id
objc_retainBlock(id block)
{
return [block copy];
}
id
objc_retainAutorelease(id object)
{
return [[object retain] autorelease];
}
void
objc_release(id object)
{
[object release];
}
id
objc_autorelease(id object)
{
return [object autorelease];
}
id
objc_autoreleaseReturnValue(id object)
{
return objc_autorelease(object);
}
id
objc_retainAutoreleaseReturnValue(id object)
{
return objc_autoreleaseReturnValue(objc_retain(object));
}
id
objc_retainAutoreleasedReturnValue(id object)
{
return objc_retain(object);
}
id
objc_storeStrong(id *object, id value)
{
if (*object != value) {
id old = *object;
*object = objc_retain(value);
objc_release(old);
}
return value;
}
id
objc_storeWeak(id *object, id value)
{
struct WeakRef *old;
#ifdef OF_HAVE_THREADS
if (OFSpinlockLock(&spinlock) != 0)
OBJC_ERROR("Failed to lock spinlock!");
#endif
if (*object != nil &&
(old = objc_hashtable_get(hashtable, *object)) != NULL) {
for (size_t i = 0; i < old->count; i++) {
if (old->locations[i] == object) {
if (--old->count == 0) {
objc_hashtable_delete(hashtable,
*object);
free(old->locations);
free(old);
} else {
id **locations;
old->locations[i] =
old->locations[old->count];
/*
* We don't care if making it smaller
* fails.
*/
if ((locations = realloc(old->locations,
old->count * sizeof(id *))) != NULL)
old->locations = locations;
}
break;
}
}
}
if (value != nil && class_respondsToSelector(object_getClass(value),
@selector(allowsWeakReference)) && [value allowsWeakReference]) {
struct WeakRef *ref = objc_hashtable_get(hashtable, value);
if (ref == NULL) {
if ((ref = calloc(1, sizeof(*ref))) == NULL)
OBJC_ERROR("Not enough memory to allocate weak "
"reference!");
objc_hashtable_set(hashtable, value, ref);
}
if ((ref->locations = realloc(ref->locations,
(ref->count + 1) * sizeof(id *))) == NULL)
OBJC_ERROR("Not enough memory to allocate weak "
"reference!");
ref->locations[ref->count++] = object;
} else
value = nil;
*object = value;
#ifdef OF_HAVE_THREADS
if (OFSpinlockUnlock(&spinlock) != 0)
OBJC_ERROR("Failed to unlock spinlock!");
#endif
return value;
}
id
objc_loadWeakRetained(id *object)
{
id value = nil;
#ifdef OF_HAVE_THREADS
if (OFSpinlockLock(&spinlock) != 0)
OBJC_ERROR("Failed to lock spinlock!");
#endif
if (*object != nil && objc_hashtable_get(hashtable, *object) != NULL)
value = *object;
#ifdef OF_HAVE_THREADS
if (OFSpinlockUnlock(&spinlock) != 0)
OBJC_ERROR("Failed to unlock spinlock!");
#endif
if (class_respondsToSelector(object_getClass(value),
@selector(retainWeakReference)) && [value retainWeakReference])
return value;
return nil;
}
id
objc_initWeak(id *object, id value)
{
*object = nil;
return objc_storeWeak(object, value);
}
void
objc_destroyWeak(id *object)
{
objc_storeWeak(object, nil);
}
id
objc_loadWeak(id *object)
{
return objc_autorelease(objc_loadWeakRetained(object));
}
void
objc_copyWeak(id *dest, id *src)
{
objc_release(objc_initWeak(dest, objc_loadWeakRetained(src)));
}
void
objc_moveWeak(id *dest, id *src)
{
struct WeakRef *ref;
#ifdef OF_HAVE_THREADS
if (OFSpinlockLock(&spinlock) != 0)
OBJC_ERROR("Failed to lock spinlock!");
#endif
if (*src != nil &&
(ref = objc_hashtable_get(hashtable, *src)) != NULL) {
for (size_t i = 0; i < ref->count; i++) {
if (ref->locations[i] == src) {
ref->locations[i] = dest;
break;
}
}
}
*dest = *src;
*src = nil;
#ifdef OF_HAVE_THREADS
if (OFSpinlockUnlock(&spinlock) != 0)
OBJC_ERROR("Failed to unlock spinlock!");
#endif
}
void
objc_zeroWeakReferences(id value)
{
struct WeakRef *ref;
#ifdef OF_HAVE_THREADS
if (OFSpinlockLock(&spinlock) != 0)
OBJC_ERROR("Failed to lock spinlock!");
#endif
if ((ref = objc_hashtable_get(hashtable, value)) != NULL) {
for (size_t i = 0; i < ref->count; i++)
*ref->locations[i] = nil;
objc_hashtable_delete(hashtable, value);
free(ref->locations);
free(ref);
}
#ifdef OF_HAVE_THREADS
if (OFSpinlockUnlock(&spinlock) != 0)
OBJC_ERROR("Failed to unlock spinlock!");
#endif
}