ObjFW  Artifact [4b700a1d09]

Artifact 4b700a1d09a47531cd78f09534b25ac63bfd05e385fb564c8fbaff66de5ad2da:

• File src/OFBlock.m — part of check-in [e1e7ffa903] at 2011-09-22 23:25:42 on branch trunk — Exceptions are now autoreleased.

  This is safe as an "exception loop" can't happen, since if allocating
  an exception fails, it throws an OFAllocFailedException which is
  preallocated and can always be thrown.

  So, the worst case would be that an autorelease of an exception fails,
  triggering an OFOutOfMemoryException for which there is no memory,
  resulting in an OFAllocFailedException to be thrown. (user: js, size: 12361) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011
 *   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 <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <assert.h>

#if defined(OF_APPLE_RUNTIME) && !defined(__OBJC2__)
# import <objc/runtime.h>
#endif

#import "OFBlock.h"

#import "OFAllocFailedException.h"
#import "OFInitializationFailedException.h"
#import "OFNotImplementedException.h"

#ifdef OF_ATOMIC_OPS
# import "atomic.h"
#endif
#ifdef OF_THREADS
# import "threading.h"
#endif

typedef struct of_block_byref_t of_block_byref_t;
struct of_block_byref_t {
	Class isa;
	of_block_byref_t *forwarding;
	int flags;
	int size;
	void (*byref_keep)(void *dest, void *src);
	void (*byref_dispose)(void*);
};

enum {
	OF_BLOCK_HAS_COPY_DISPOSE = (1 << 25),
	OF_BLOCK_HAS_CTOR	  = (1 << 26),
	OF_BLOCK_IS_GLOBAL	  = (1 << 28),
	OF_BLOCK_HAS_STRET	  = (1 << 29),
	OF_BLOCK_HAS_SIGNATURE	  = (1 << 30),
};
#define OF_BLOCK_REFCOUNT_MASK \
	~(OF_BLOCK_HAS_COPY_DISPOSE | OF_BLOCK_HAS_CTOR | OF_BLOCK_IS_GLOBAL | \
	OF_BLOCK_HAS_STRET | OF_BLOCK_HAS_SIGNATURE)

enum {
	OF_BLOCK_FIELD_IS_OBJECT =   3,
	OF_BLOCK_FIELD_IS_BLOCK	 =   7,
	OF_BLOCK_FIELD_IS_BYREF	 =   8,
	OF_BLOCK_FIELD_IS_WEAK	 =  16,
	OF_BLOCK_BYREF_CALLER	 = 128,
};

@protocol RetainRelease
- retain;
- (void)release;
@end

#if defined(OF_OBJFW_RUNTIME) || defined(OF_GNU_RUNTIME) || \
    defined(OF_OLD_GNU_RUNTIME)
struct objc_abi_class {
	struct objc_abi_metaclass *metaclass;
	const char *superclass, *name;
	unsigned long version, info, instance_size;
	void *ivars, *methodlist, *dtable, *subclass_list, *sibling_class;
	void *protocols, *gc_object_type;
	long abi_version;
	void *ivar_offsets, *properties;
};

struct objc_abi_metaclass {
	const char *metaclass, *superclass, *name;
	unsigned long version, info, instance_size;
	void *ivars, *methodlist, *dtable, *subclass_list, *sibling_class;
	void *protocols, *gc_object_type;
	long abi_version;
	void *ivar_offsets, *properties;
};

#ifndef OF_OBJFW_RUNTIME
/* ObjFW-RT already defines those */
enum objc_abi_class_info {
	OBJC_CLASS_INFO_CLASS	  = 0x01,
	OBJC_CLASS_INFO_METACLASS = 0x02
};
#endif

extern void __objc_exec_class(void*);

/* Begin of ObjC module */
static struct objc_abi_metaclass _NSConcreteStackBlock_metaclass = {
	"OFBlock", "OFBlock", "OFStackBlock", 8, OBJC_CLASS_INFO_METACLASS,
	sizeof(struct objc_class), NULL, NULL
};

struct objc_abi_class _NSConcreteStackBlock = {
	&_NSConcreteStackBlock_metaclass, "OFBlock", "OFStackBlock", 8,
	OBJC_CLASS_INFO_CLASS, sizeof(of_block_literal_t), NULL, NULL
};

static struct objc_abi_metaclass _NSConcreteGlobalBlock_metaclass = {
	"OFBlock", "OFBlock", "OFGlobalBlock", 8, OBJC_CLASS_INFO_METACLASS,
	sizeof(struct objc_class), NULL, NULL
};

struct objc_abi_class _NSConcreteGlobalBlock = {
	&_NSConcreteGlobalBlock_metaclass, "OFBlock", "OFGlobalBlock",
	8, OBJC_CLASS_INFO_CLASS, sizeof(of_block_literal_t), NULL, NULL
};

static struct objc_abi_metaclass _NSConcreteMallocBlock_metaclass = {
	"OFBlock", "OFBlock", "OFMallocBlock", 8, OBJC_CLASS_INFO_METACLASS,
	sizeof(struct objc_class), NULL, NULL
};

struct objc_abi_class _NSConcreteMallocBlock = {
	&_NSConcreteMallocBlock_metaclass, "OFBlock", "OFMallocBlock",
	8, OBJC_CLASS_INFO_CLASS, sizeof(of_block_literal_t), NULL, NULL
};

static struct {
	unsigned int unknown;
	struct objc_abi_selector *sel_refs;
	uint16_t cls_def_cnt, cat_def_cnt;
	void *defs[4];
} symtab = { 0, NULL, 3, 0, {
	&_NSConcreteStackBlock, &_NSConcreteGlobalBlock,
	&_NSConcreteMallocBlock, NULL
}};

static struct {
	unsigned long version, size;
	const char *name;
	void *symtab;
} module = { 8, sizeof(module), NULL, &symtab };

static void __attribute__((constructor))
constructor(void)
{
	__objc_exec_class(&module);
}
/* End of ObjC module */
#elif defined(OF_APPLE_RUNTIME) && !defined(__OBJC2__)
struct class {
	struct class *isa, *super_class;
	const char *name;
	long version, info, instance_size;
	struct ivar_list *ivars;
	struct method_list **methodLists;
	struct cache *cache;
	struct protocol_list *protocols;
	const char *ivar_layout;
	struct class_ext *ext;
};

struct class _NSConcreteStackBlock;
struct class _NSConcreteGlobalBlock;
struct class _NSConcreteMallocBlock;
#else
extern void *_NSConcreteStackBlock;
extern void *_NSConcreteGlobalBlock;
extern void *_NSConcreteMallocBlock;
#endif

static struct {
	Class isa;
} alloc_failed_exception;

#if !defined(OF_ATOMIC_OPS) && defined(OF_THREADS)
# define NUM_SPINLOCKS 8	/* needs to be a power of 2 */
# define SPINLOCK_HASH(p) ((uintptr_t)p >> 4) & (NUM_SPINLOCKS - 1)
static of_spinlock_t spinlocks[NUM_SPINLOCKS];
#endif

void*
_Block_copy(const void *block_)
{
	of_block_literal_t *block = (of_block_literal_t*)block_;

	if (block->isa == (Class)&_NSConcreteStackBlock) {
		of_block_literal_t *copy;

		if ((copy = malloc(block->descriptor->size)) == NULL) {
			alloc_failed_exception.isa =
			    [OFAllocFailedException class];
			@throw (OFAllocFailedException*)&alloc_failed_exception;
		}
		memcpy(copy, block, block->descriptor->size);

		copy->isa = (Class)&_NSConcreteMallocBlock;
		copy->flags++;

		if (block->flags & OF_BLOCK_HAS_COPY_DISPOSE)
			block->descriptor->copy_helper(copy, block);

		return copy;
	}

	if (block->isa == (Class)&_NSConcreteMallocBlock) {
#if defined(OF_ATOMIC_OPS)
		of_atomic_inc_int(&block->flags);
#else
		unsigned hash = SPINLOCK_HASH(block);

		assert(of_spinlock_lock(&spinlocks[hash]));
		block->flags++;
		assert(of_spinlock_unlock(&spinlocks[hash]));
#endif
	}

	return block;
}

void
_Block_release(const void *block_)
{
	of_block_literal_t *block = (of_block_literal_t*)block_;

	if (block->isa != (Class)&_NSConcreteMallocBlock)
		return;

#ifdef OF_ATOMIC_OPS
	if ((of_atomic_dec_int(&block->flags) & OF_BLOCK_REFCOUNT_MASK) == 0) {
		if (block->flags & OF_BLOCK_HAS_COPY_DISPOSE)
			block->descriptor->dispose_helper(block);

		free(block);
	}
#else
	unsigned hash = SPINLOCK_HASH(block);

	assert(of_spinlock_lock(&spinlocks[hash]));
	if ((--block->flags & OF_BLOCK_REFCOUNT_MASK) == 0) {
		assert(of_spinlock_unlock(&spinlocks[hash]));

		if (block->flags & OF_BLOCK_HAS_COPY_DISPOSE)
			block->descriptor->dispose_helper(block);

		free(block);

		return;
	}
	assert(of_spinlock_unlock(&spinlocks[hash]));
#endif
}

void
_Block_object_assign(void *dst_, const void *src_, const int flags_)
{
	int flags = flags_ & (OF_BLOCK_FIELD_IS_BLOCK |
	    OF_BLOCK_FIELD_IS_OBJECT | OF_BLOCK_FIELD_IS_BYREF);

	if (src_ == NULL)
		return;

	if (flags_ & OF_BLOCK_BYREF_CALLER)
		return;

	switch (flags) {
	case OF_BLOCK_FIELD_IS_BLOCK:
		*(of_block_literal_t**)dst_ = _Block_copy(src_);
		break;
	case OF_BLOCK_FIELD_IS_OBJECT:
		*(id*)dst_ = [(id)src_ retain];
		break;
	case OF_BLOCK_FIELD_IS_BYREF:;
		of_block_byref_t *src = (of_block_byref_t*)src_;
		of_block_byref_t **dst = (of_block_byref_t**)dst_;

		if ((src->flags & OF_BLOCK_REFCOUNT_MASK) == 0) {
			if ((*dst = malloc(src->size)) == NULL) {
				alloc_failed_exception.isa =
				    [OFAllocFailedException class];
				@throw (OFAllocFailedException*)
				    &alloc_failed_exception;
			}

			if (src->forwarding == src)
				(*dst)->forwarding = *dst;

			memcpy(*dst, src, src->size);

			if (src->size >= sizeof(of_block_byref_t))
				src->byref_keep(*dst, src);
		} else
			*dst = src;

		(*dst)->flags++;
		break;
	}
}

void
_Block_object_dispose(const void *obj_, const int flags_)
{
	const int flags = flags_ & (OF_BLOCK_FIELD_IS_BLOCK |
	    OF_BLOCK_FIELD_IS_OBJECT | OF_BLOCK_FIELD_IS_BYREF);

	if (obj_ == NULL)
		return;

	if (flags_ & OF_BLOCK_BYREF_CALLER)
		return;

	switch (flags) {
	case OF_BLOCK_FIELD_IS_BLOCK:
		_Block_release(obj_);
		break;
	case OF_BLOCK_FIELD_IS_OBJECT:
		[(id)obj_ release];
		break;
	case OF_BLOCK_FIELD_IS_BYREF:;
		of_block_byref_t *obj = (of_block_byref_t*)obj_;

		if ((--obj->flags & OF_BLOCK_REFCOUNT_MASK) == 0) {
			if (obj->size >= sizeof(of_block_byref_t))
				obj->byref_dispose(obj);

			free(obj);
		}
		break;
	}
}

@implementation OFBlock
#if defined(OF_APPLE_RUNTIME) && !defined(__OBJC2__)
+ (void)load
{
	Class tmp;

	/*
	 * There is no objc_initializeClassPair in 10.5.
	 * However, objc_allocateClassPair does not register the new class with
	 * the subclass in the ObjC1 runtime like the ObjC2 runtime does, so
	 * this workaround should be fine.
	 */
	if ((tmp = objc_allocateClassPair(self, "OFStackBlock", 0)) == NULL)
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
	memcpy(&_NSConcreteStackBlock, tmp, sizeof(_NSConcreteStackBlock));
	free(tmp);
	objc_registerClassPair((Class)&_NSConcreteStackBlock);

	if ((tmp = objc_allocateClassPair(self, "OFGlobalBlock", 0)) == NULL)
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
	memcpy(&_NSConcreteGlobalBlock, tmp, sizeof(_NSConcreteGlobalBlock));
	free(tmp);
	objc_registerClassPair((Class)&_NSConcreteGlobalBlock);

	if ((tmp = objc_allocateClassPair(self, "OFMallocBlock", 0)) == NULL)
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
	memcpy(&_NSConcreteMallocBlock, tmp, sizeof(_NSConcreteMallocBlock));
	free(tmp);
	objc_registerClassPair((Class)&_NSConcreteMallocBlock);
}
#endif

#if !defined(OF_ATOMIC_OPS)
+ (void)initialize
{
	size_t i;

	for (i = 0; i < NUM_SPINLOCKS; i++)
		if (!of_spinlock_new(&spinlocks[i]))
			@throw [OFInitializationFailedException
			    exceptionWithClass: self];
}
#endif

+ alloc
{
	@throw [OFNotImplementedException exceptionWithClass: self
						    selector: _cmd];
}

- init
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- (void)addMemoryToPool: (void*)ptr
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- (void*)allocMemoryWithSize: (size_t)size
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- (void*)allocMemoryForNItems: (size_t)nitems
		     withSize: (size_t)size
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- (void*)resizeMemory: (void*)ptr
	       toSize: (size_t)size
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- (void*)resizeMemory: (void*)ptr
	     toNItems: (size_t)nitems
	     withSize: (size_t)size
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- (void)freeMemory: (void*)ptr
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
}

- retain
{
	if (isa == (Class)&_NSConcreteMallocBlock)
		return Block_copy(self);

	return self;
}

- copy
{
	return Block_copy(self);
}

- autorelease
{
	if (isa == (Class)&_NSConcreteMallocBlock)
		return [super autorelease];

	return self;
}

- (unsigned int)retainCount
{
	if (isa == (Class)&_NSConcreteMallocBlock)
		return ((of_block_literal_t*)self)->flags &
		    OF_BLOCK_REFCOUNT_MASK;

	return OF_RETAIN_COUNT_MAX;
}

- (void)release
{
	if (isa == (Class)&_NSConcreteMallocBlock)
		Block_release(self);
}

- (void)dealloc
{
	@throw [OFNotImplementedException exceptionWithClass: isa
						    selector: _cmd];
	[super dealloc];	/* Get rid of a stupid warning */
}
@end

#if defined(OF_APPLE_RUNTIME) && defined(__OBJC2__)
@implementation OFStackBlock
+ (void)load
{
	/*
	 * Send a message to the class to ensure it's initialized. Otherwise it
	 * it might not get initialized as blocks are preallocated.
	 */
	[self class];
}
@end

@implementation OFGlobalBlock
+ (void)load
{
	/*
	 * Send a message to the class to ensure it's initialized. Otherwise it
	 * it might not get initialized as blocks are preallocated.
	 */
	[self class];
}
@end

@implementation OFMallocBlock
+ (void)load
{
	/*
	 * Send a message to the class to ensure it's initialized. Otherwise it
	 * it might not get initialized as blocks are preallocated.
	 */
	[self class];
}
@end
#endif