ObjFW  Artifact [6fb92dcbb6]

Artifact 6fb92dcbb62c67cee957a8bb8f5e53b4e57db3b8093dd01f26c072559a809407:

  • File src/OFObject.m — part of check-in [6ce0093f8d] at 2023-04-10 19:22:32 on branch trunk — Remove OFSerialization

    While the idea sounds nice that the tag name is the class, this means the
    serialization includes whether something is mutable or immutable. This means
    doing as much as making something immutable changes the serialization, which
    can then cause issues after being deserialized. (user: js, size: 28645) [annotate] [blame] [check-ins using]


/*
 * Copyright (c) 2008-2023 Jonathan Schleifer <js@nil.im>
 *
 * 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 <string.h>
#include "unistd_wrapper.h"

#ifdef OF_APPLE_RUNTIME
# include <dlfcn.h>
#endif

#ifdef HAVE_GETRANDOM
# include <sys/random.h>
#endif

#import "OFObject.h"
#import "OFArray.h"
#ifdef OF_HAVE_ATOMIC_OPS
# import "OFAtomic.h"
#endif
#import "OFLocale.h"
#import "OFMethodSignature.h"
#import "OFRunLoop.h"
#if !defined(OF_HAVE_ATOMIC_OPS) && defined(OF_HAVE_THREADS)
# import "OFPlainMutex.h"	/* For OFSpinlock */
#endif
#import "OFStdIOStream.h"
#import "OFString.h"
#import "OFThread.h"
#import "OFTimer.h"
#import "OFValue.h"

#import "OFAllocFailedException.h"
#import "OFEnumerationMutationException.h"
#import "OFInitializationFailedException.h"
#import "OFInvalidArgumentException.h"
#import "OFNotImplementedException.h"
#import "OFOutOfMemoryException.h"
#import "OFOutOfRangeException.h"

#if defined(OF_APPLE_RUNTIME) && __OBJC2__
# import <objc/objc-exception.h>
#elif defined(OF_OBJFW_RUNTIME)
# import "ObjFWRT.h"
#endif

#ifdef OF_WINDOWS
# include <windows.h>
#endif

#ifdef OF_AMIGAOS
# define Class IntuitionClass
# include <proto/exec.h>
# undef Class
#endif

#ifdef OF_APPLE_RUNTIME
extern id _Nullable _objc_rootAutorelease(id _Nullable object);
#endif
#if defined(OF_HAVE_FORWARDING_TARGET_FOR_SELECTOR)
extern id OFForward(id, SEL, ...);
extern struct Stret OFForward_stret(id, SEL, ...);
#else
# define OFForward OFMethodNotFound
# define OFForward_stret OFMethodNotFound_stret
#endif

struct PreIvars {
	int retainCount;
#if !defined(OF_HAVE_ATOMIC_OPS) && !defined(OF_AMIGAOS)
	OFSpinlock retainCountSpinlock;
#endif
};

#define PRE_IVARS_ALIGN ((sizeof(struct PreIvars) + \
    (OF_BIGGEST_ALIGNMENT - 1)) & ~(OF_BIGGEST_ALIGNMENT - 1))
#define PRE_IVARS ((struct PreIvars *)(void *)((char *)self - PRE_IVARS_ALIGN))

static struct {
	Class isa;
} allocFailedException;

unsigned long OFHashSeed;

void *
OFAllocMemory(size_t count, size_t size)
{
	void *pointer;

	if OF_UNLIKELY (count == 0 || size == 0)
		return NULL;

	if OF_UNLIKELY (count > SIZE_MAX / size)
		@throw [OFOutOfRangeException exception];

	if OF_UNLIKELY ((pointer = malloc(count * size)) == NULL)
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: size];

	return pointer;
}

void *
OFAllocZeroedMemory(size_t count, size_t size)
{
	void *pointer;

	if OF_UNLIKELY (count == 0 || size == 0)
		return NULL;

	/* Not all calloc implementations check for overflow. */
	if OF_UNLIKELY (count > SIZE_MAX / size)
		@throw [OFOutOfRangeException exception];

	if OF_UNLIKELY ((pointer = calloc(count, size)) == NULL)
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: size];

	return pointer;
}

void *
OFResizeMemory(void *pointer, size_t count, size_t size)
{
	if OF_UNLIKELY (count == 0 || size == 0) {
		free(pointer);
		return NULL;
	}

	if OF_UNLIKELY (count > SIZE_MAX / size)
		@throw [OFOutOfRangeException exception];

	if OF_UNLIKELY ((pointer = realloc(pointer, count * size)) == NULL)
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: size];

	return pointer;
}

void
OFFreeMemory(void *pointer)
{
	free(pointer);
}

#if !defined(HAVE_ARC4RANDOM) && !defined(HAVE_GETRANDOM)
static void
initRandom(void)
{
	struct timeval tv;

# ifdef HAVE_RANDOM
	gettimeofday(&tv, NULL);
	srandom((unsigned)(tv.tv_sec ^ tv.tv_usec));
# else
	gettimeofday(&tv, NULL);
	srand((unsigned)(tv.tv_sec ^ tv.tv_usec));
# endif
}
#endif

uint16_t
OFRandom16(void)
{
#if defined(HAVE_ARC4RANDOM)
	return arc4random();
#elif defined(HAVE_GETRANDOM)
	uint16_t buffer;

	OFEnsure(getrandom(&buffer, sizeof(buffer), 0) == sizeof(buffer));

	return buffer;
#else
	static OFOnceControl onceControl = OFOnceControlInitValue;
	OFOnce(&onceControl, initRandom);
# ifdef HAVE_RANDOM
	return random() & 0xFFFF;
# else
	return rand() & 0xFFFF;
# endif
#endif
}

uint32_t
OFRandom32(void)
{
#if defined(HAVE_ARC4RANDOM)
	return arc4random();
#elif defined(HAVE_GETRANDOM)
	uint32_t buffer;

	OFEnsure(getrandom(&buffer, sizeof(buffer), 0) == sizeof(buffer));

	return buffer;
#else
	return ((uint32_t)OFRandom16() << 16) | OFRandom16();
#endif
}

uint64_t
OFRandom64(void)
{
#if defined(HAVE_ARC4RANDOM_BUF)
	uint64_t buffer;

	arc4random_buf(&buffer, sizeof(buffer));

	return buffer;
#elif defined(HAVE_GETRANDOM)
	uint64_t buffer;

	OFEnsure(getrandom(&buffer, sizeof(buffer), 0) == sizeof(buffer));

	return buffer;
#else
	return ((uint64_t)OFRandom32() << 32) | OFRandom32();
#endif
}

void
OFHashInit(unsigned long *hash)
{
	*hash = OFHashSeed;
}

static const char *
typeEncodingForSelector(Class class, SEL selector)
{
	Method method;

	if ((method = class_getInstanceMethod(class, selector)) == NULL)
		return NULL;

	return method_getTypeEncoding(method);
}

#if !defined(OF_APPLE_RUNTIME) || defined(__OBJC2__)
static void
uncaughtExceptionHandler(id exception)
{
	OFArray OF_GENERIC(OFValue *) *stackTraceAddresses = nil;
	OFArray OF_GENERIC(OFString *) *stackTraceSymbols = nil;
	OFStringEncoding encoding = [OFLocale encoding];

	OFLog(@"Runtime error: Unhandled exception:");
	OFLog(@"%@", exception);

	if ([exception respondsToSelector: @selector(stackTraceAddresses)])
		stackTraceAddresses = [exception stackTraceAddresses];

	if (stackTraceAddresses != nil) {
		size_t count = stackTraceAddresses.count;

		if ([exception respondsToSelector:
		    @selector(stackTraceSymbols)])
			stackTraceSymbols = [exception stackTraceSymbols];

		if (stackTraceSymbols.count != count)
			stackTraceSymbols = nil;

		OFLog(@"");
		OFLog(@"Stack trace:");

		if (stackTraceSymbols != nil) {
			for (size_t i = 0; i < count; i++) {
				void *address = [[stackTraceAddresses
				    objectAtIndex: i] pointerValue];
				const char *symbol = [[stackTraceSymbols
				    objectAtIndex: i]
				    cStringWithEncoding: encoding];

				OFLog(@"  %p  %s", address, symbol);
			}
		} else {
			for (size_t i = 0; i < count; i++) {
				void *address = [[stackTraceAddresses
				    objectAtIndex: i] pointerValue];

				OFLog(@"  %p", address);
			}
		}
	}

	abort();
}
#endif

static void
enumerationMutationHandler(id object)
{
	@throw [OFEnumerationMutationException exceptionWithObject: object];
}

void OF_NO_RETURN_FUNC
OFMethodNotFound(id object, SEL selector)
{
	[object doesNotRecognizeSelector: selector];

	/*
	 * Just in case doesNotRecognizeSelector: returned, even though it must
	 * never return.
	 */
	abort();

	OF_UNREACHABLE
}

void OF_NO_RETURN_FUNC
OFMethodNotFound_stret(void *stret, id object, SEL selector)
{
	OFMethodNotFound(object, selector);
}

id
OFAllocObject(Class class, size_t extraSize, size_t extraAlignment,
    void **extra)
{
	OFObject *instance;
	size_t instanceSize;

	instanceSize = class_getInstanceSize(class);

	if OF_UNLIKELY (extraAlignment > 1)
		extraAlignment = ((instanceSize + extraAlignment - 1) &
		    ~(extraAlignment - 1)) - extraAlignment;

	instance = calloc(1, PRE_IVARS_ALIGN + instanceSize +
	    extraAlignment + extraSize);

	if OF_UNLIKELY (instance == nil) {
		allocFailedException.isa = [OFAllocFailedException class];
		@throw (id)&allocFailedException;
	}

	((struct PreIvars *)instance)->retainCount = 1;

#if !defined(OF_HAVE_ATOMIC_OPS) && !defined(OF_AMIGAOS)
	if OF_UNLIKELY (OFSpinlockNew(
	    &((struct PreIvars *)instance)->retainCountSpinlock) != 0) {
		free(instance);
		@throw [OFInitializationFailedException
		    exceptionWithClass: class];
	}
#endif

	instance = (OFObject *)(void *)((char *)instance + PRE_IVARS_ALIGN);

	if (!objc_constructInstance(class, instance)) {
#if !defined(OF_HAVE_ATOMIC_OPS) && !defined(OF_AMIGAOS)
		OFSpinlockFree(&((struct PreIvars *)(void *)
		    ((char *)instance - PRE_IVARS_ALIGN))->retainCountSpinlock);
#endif
		free((char *)instance - PRE_IVARS_ALIGN);
		@throw [OFInitializationFailedException
		    exceptionWithClass: class];
	}

	if OF_UNLIKELY (extra != NULL)
		*extra = (char *)instance + instanceSize + extraAlignment;

	return instance;
}

const char *
_NSPrintForDebugger(id object)
{
	return [[object description] cStringWithEncoding: [OFLocale encoding]];
}

/* References for static linking */
void
_references_to_categories_of_OFObject(void)
{
	_OFObject_KeyValueCoding_reference = 1;
}

@implementation OFObject
+ (void)load
{
#if !defined(OF_APPLE_RUNTIME) || defined(__OBJC2__)
	objc_setUncaughtExceptionHandler(uncaughtExceptionHandler);
#endif

#if defined(OF_APPLE_RUNTIME)
	/*
	 * If the NSFoundationVersionNumber symbol is defined, we are linked
	 * against Foundation. Since CoreFoundation sets its own forward
	 * handler on load, we should not set ours, as this will break
	 * Foundation.
	 *
	 * Unfortunately, there is no way to check if a forward handler has
	 * already been set, so this is the best we can do.
	 */
	if (dlsym(RTLD_DEFAULT, "NSFoundationVersionNumber") == NULL)
		objc_setForwardHandler((void *)&OFForward,
		    (void *)&OFForward_stret);
#else
	objc_setForwardHandler((IMP)&OFForward, (IMP)&OFForward_stret);
#endif

	objc_setEnumerationMutationHandler(enumerationMutationHandler);

	do {
		OFHashSeed = OFRandom32();
	} while (OFHashSeed == 0);

#ifdef OF_OBJFW_RUNTIME
	objc_setTaggedPointerSecret(sizeof(uintptr_t) == 4
	    ? (uintptr_t)OFRandom32() : (uintptr_t)OFRandom64());
#endif
}

+ (void)unload
{
}

+ (void)initialize
{
}

+ (instancetype)alloc
{
	return OFAllocObject(self, 0, 0, NULL);
}

+ (Class)class
{
	return self;
}

+ (OFString *)className
{
	return [OFString stringWithCString: class_getName(self)
				  encoding: OFStringEncodingASCII];
}

+ (bool)isSubclassOfClass: (Class)class
{
	for (Class iter = self; iter != Nil; iter = class_getSuperclass(iter))
		if (iter == class)
			return true;

	return false;
}

+ (Class)superclass
{
	return class_getSuperclass(self);
}

+ (bool)instancesRespondToSelector: (SEL)selector
{
	return class_respondsToSelector(self, selector);
}

+ (bool)conformsToProtocol: (Protocol *)protocol
{
	Class c;

	for (c = self; c != Nil; c = class_getSuperclass(c))
		if (class_conformsToProtocol(c, protocol))
			return true;

	return false;
}

+ (IMP)instanceMethodForSelector: (SEL)selector
{
	return class_getMethodImplementation(self, selector);
}

+ (OFMethodSignature *)instanceMethodSignatureForSelector: (SEL)selector
{
	const char *typeEncoding = typeEncodingForSelector(self, selector);

	if (typeEncoding == NULL)
		return nil;

	return [OFMethodSignature signatureWithObjCTypes: typeEncoding];
}

+ (OFString *)description
{
	return [self className];
}

+ (IMP)replaceClassMethod: (SEL)selector withMethodFromClass: (Class)class
{
	IMP method = [class methodForSelector: selector];

	if (method == NULL)
		@throw [OFInvalidArgumentException exception];

	return class_replaceMethod(object_getClass(self), selector, method,
	    typeEncodingForSelector(object_getClass(class), selector));
}

+ (IMP)replaceInstanceMethod: (SEL)selector withMethodFromClass: (Class)class
{
	IMP method = [class instanceMethodForSelector: selector];

	if (method == NULL)
		@throw [OFInvalidArgumentException exception];

	return class_replaceMethod(self, selector, method,
	    typeEncodingForSelector(class, selector));
}

+ (void)inheritMethodsFromClass: (Class)class
{
	Class superclass = [self superclass];
	Method *methodList;
	unsigned int count;

	if ([self isSubclassOfClass: class])
		return;

	methodList = class_copyMethodList(object_getClass(class), &count);
	@try {
		for (unsigned int i = 0; i < count; i++) {
			SEL selector = method_getName(methodList[i]);

			/*
			 * Don't replace methods implemented in the receiving
			 * class.
			 */
			if ([self methodForSelector: selector] !=
			    [superclass methodForSelector: selector])
				continue;

			[self replaceClassMethod: selector
			     withMethodFromClass: class];
		}
	} @finally {
		free(methodList);
	}

	methodList = class_copyMethodList(class, &count);
	@try {
		for (unsigned int i = 0; i < count; i++) {
			SEL selector = method_getName(methodList[i]);

			/*
			 * Don't replace methods implemented in the receiving
			 * class.
			 */
			if ([self instanceMethodForSelector: selector] !=
			    [superclass instanceMethodForSelector: selector])
				continue;

			[self replaceInstanceMethod: selector
				withMethodFromClass: class];
		}
	} @finally {
		free(methodList);
	}

	[self inheritMethodsFromClass: superclass];
}

+ (bool)resolveClassMethod: (SEL)selector
{
	return NO;
}

+ (bool)resolveInstanceMethod: (SEL)selector
{
	return NO;
}

- (instancetype)init
{
	return self;
}

- (Class)class
{
	return object_getClass(self);
}

- (Class)superclass
{
	return class_getSuperclass(object_getClass(self));
}

- (OFString *)className
{
	return [OFString stringWithCString: object_getClassName(self)
				  encoding: OFStringEncodingASCII];
}

- (bool)isKindOfClass: (Class)class
{
	for (Class iter = object_getClass(self); iter != Nil;
	    iter = class_getSuperclass(iter))
		if (iter == class)
			return true;

	return false;
}

- (bool)isMemberOfClass: (Class)class
{
	return (object_getClass(self) == class);
}

- (bool)respondsToSelector: (SEL)selector
{
	return class_respondsToSelector(object_getClass(self), selector);
}

- (bool)conformsToProtocol: (Protocol *)protocol
{
	return [object_getClass(self) conformsToProtocol: protocol];
}

- (IMP)methodForSelector: (SEL)selector
{
	return class_getMethodImplementation(object_getClass(self), selector);
}

- (id)performSelector: (SEL)selector
{
#if defined(OF_OBJFW_RUNTIME)
	id (*imp)(id, SEL) = (id (*)(id, SEL))objc_msg_lookup(self, selector);
#elif defined(OF_APPLE_RUNTIME)
	id (*imp)(id, SEL) = (id (*)(id, SEL))objc_msgSend;
#endif

	return imp(self, selector);
}

- (id)performSelector: (SEL)selector withObject: (id)object
{
#if defined(OF_OBJFW_RUNTIME)
	id (*imp)(id, SEL, id) =
	    (id (*)(id, SEL, id))objc_msg_lookup(self, selector);
#elif defined(OF_APPLE_RUNTIME)
	id (*imp)(id, SEL, id) = (id (*)(id, SEL, id))objc_msgSend;
#endif

	return imp(self, selector, object);
}

- (id)performSelector: (SEL)selector
	   withObject: (id)object1
	   withObject: (id)object2
{
#if defined(OF_OBJFW_RUNTIME)
	id (*imp)(id, SEL, id, id) =
	    (id (*)(id, SEL, id, id))objc_msg_lookup(self, selector);
#elif defined(OF_APPLE_RUNTIME)
	id (*imp)(id, SEL, id, id) = (id (*)(id, SEL, id, id))objc_msgSend;
#endif

	return imp(self, selector, object1, object2);
}

- (id)performSelector: (SEL)selector
	   withObject: (id)object1
	   withObject: (id)object2
	   withObject: (id)object3
{
#if defined(OF_OBJFW_RUNTIME)
	id (*imp)(id, SEL, id, id, id) =
	    (id (*)(id, SEL, id, id, id))objc_msg_lookup(self, selector);
#elif defined(OF_APPLE_RUNTIME)
	id (*imp)(id, SEL, id, id, id) =
	    (id (*)(id, SEL, id, id, id))objc_msgSend;
#endif

	return imp(self, selector, object1, object2, object3);
}

- (id)performSelector: (SEL)selector
	   withObject: (id)object1
	   withObject: (id)object2
	   withObject: (id)object3
	   withObject: (id)object4
{
#if defined(OF_OBJFW_RUNTIME)
	id (*imp)(id, SEL, id, id, id, id) =
	    (id (*)(id, SEL, id, id, id, id))objc_msg_lookup(self, selector);
#elif defined(OF_APPLE_RUNTIME)
	id (*imp)(id, SEL, id, id, id, id) =
	    (id (*)(id, SEL, id, id, id, id))objc_msgSend;
#endif

	return imp(self, selector, object1, object2, object3, object4);
}

- (void)performSelector: (SEL)selector afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[OFTimer scheduledTimerWithTimeInterval: delay
					 target: self
				       selector: selector
					repeats: false];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	     withObject: (id)object
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[OFTimer scheduledTimerWithTimeInterval: delay
					 target: self
				       selector: selector
					 object: object
					repeats: false];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	     withObject: (id)object1
	     withObject: (id)object2
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[OFTimer scheduledTimerWithTimeInterval: delay
					 target: self
				       selector: selector
					 object: object1
					 object: object2
					repeats: false];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	     withObject: (id)object1
	     withObject: (id)object2
	     withObject: (id)object3
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[OFTimer scheduledTimerWithTimeInterval: delay
					 target: self
				       selector: selector
					 object: object1
					 object: object2
					 object: object3
					repeats: false];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	     withObject: (id)object1
	     withObject: (id)object2
	     withObject: (id)object3
	     withObject: (id)object4
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[OFTimer scheduledTimerWithTimeInterval: delay
					 target: self
				       selector: selector
					 object: object1
					 object: object2
					 object: object3
					 object: object4
					repeats: false];

	objc_autoreleasePoolPop(pool);
}

#ifdef OF_HAVE_THREADS
- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	  waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						repeats: false];
	[thread.runLoop addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object
	  waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object
						repeats: false];
	[thread.runLoop addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object1
	     withObject: (id)object2
	  waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object1
						 object: object2
						repeats: false];
	[thread.runLoop addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object1
	     withObject: (id)object2
	     withObject: (id)object3
	  waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object1
						 object: object2
						 object: object3
						repeats: false];
	[thread.runLoop addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object1
	     withObject: (id)object2
	     withObject: (id)object3
	     withObject: (id)object4
	  waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object1
						 object: object2
						 object: object3
						 object: object4
						repeats: false];
	[thread.runLoop addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelectorOnMainThread: (SEL)selector
		      waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						repeats: false];
	[[OFRunLoop mainRunLoop] addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelectorOnMainThread: (SEL)selector
			 withObject: (id)object
		      waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object
						repeats: false];
	[[OFRunLoop mainRunLoop] addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelectorOnMainThread: (SEL)selector
			 withObject: (id)object1
			 withObject: (id)object2
		      waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object1
						 object: object2
						repeats: false];
	[[OFRunLoop mainRunLoop] addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelectorOnMainThread: (SEL)selector
			 withObject: (id)object1
			 withObject: (id)object2
			 withObject: (id)object3
		      waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object1
						 object: object2
						 object: object3
						repeats: false];
	[[OFRunLoop mainRunLoop] addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelectorOnMainThread: (SEL)selector
			 withObject: (id)object1
			 withObject: (id)object2
			 withObject: (id)object3
			 withObject: (id)object4
		      waitUntilDone: (bool)waitUntilDone
{
	void *pool = objc_autoreleasePoolPush();
	OFTimer *timer = [OFTimer timerWithTimeInterval: 0
						 target: self
					       selector: selector
						 object: object1
						 object: object2
						 object: object3
						 object: object4
						repeats: false];
	[[OFRunLoop mainRunLoop] addTimer: timer];

	if (waitUntilDone)
		[timer waitUntilDone];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[thread.runLoop addTimer: [OFTimer timerWithTimeInterval: delay
							  target: self
							selector: selector
							 repeats: false]];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[thread.runLoop addTimer: [OFTimer timerWithTimeInterval: delay
							  target: self
							selector: selector
							  object: object
							 repeats: false]];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object1
	     withObject: (id)object2
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[thread.runLoop addTimer: [OFTimer timerWithTimeInterval: delay
							  target: self
							selector: selector
							  object: object1
							  object: object2
							 repeats: false]];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object1
	     withObject: (id)object2
	     withObject: (id)object3
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[thread.runLoop addTimer: [OFTimer timerWithTimeInterval: delay
							  target: self
							selector: selector
							  object: object1
							  object: object2
							  object: object3
							 repeats: false]];

	objc_autoreleasePoolPop(pool);
}

- (void)performSelector: (SEL)selector
	       onThread: (OFThread *)thread
	     withObject: (id)object1
	     withObject: (id)object2
	     withObject: (id)object3
	     withObject: (id)object4
	     afterDelay: (OFTimeInterval)delay
{
	void *pool = objc_autoreleasePoolPush();

	[thread.runLoop addTimer: [OFTimer timerWithTimeInterval: delay
							  target: self
							selector: selector
							  object: object1
							  object: object2
							  object: object3
							  object: object4
							 repeats: false]];

	objc_autoreleasePoolPop(pool);
}
#endif

- (OFMethodSignature *)methodSignatureForSelector: (SEL)selector
{
	const char *typeEncoding =
	    typeEncodingForSelector(object_getClass(self), selector);

	if (typeEncoding == NULL)
		return nil;

	return [OFMethodSignature signatureWithObjCTypes: typeEncoding];
}

- (bool)isEqual: (id)object
{
	return (object == self);
}

- (unsigned long)hash
{
	uintptr_t ptr = (uintptr_t)self;
	unsigned long hash;

	OFHashInit(&hash);

	for (size_t i = 0; i < sizeof(ptr); i++) {
		OFHashAddByte(&hash, ptr & 0xFF);
		ptr >>= 8;
	}

	OFHashFinalize(&hash);

	return hash;
}

- (OFString *)description
{
	/* Classes containing data should reimplement this! */

	return [OFString stringWithFormat: @"<%@>", self.className];
}

- (id)forwardingTargetForSelector: (SEL)selector
{
	return nil;
}

- (void)doesNotRecognizeSelector: (SEL)selector
{
	@throw [OFNotImplementedException exceptionWithSelector: selector
							 object: self];
}

- (instancetype)retain
{
#if defined(OF_HAVE_ATOMIC_OPS)
	OFAtomicIntIncrease(&PRE_IVARS->retainCount);
#elif defined(OF_AMIGAOS)
	/*
	 * On AmigaOS, we can only have one CPU. As increasing a variable is a
	 * single instruction on M68K, we don't need Forbid() / Permit() on
	 * M68K.
	 */
# ifndef OF_AMIGAOS_M68K
	Forbid();
# endif
	PRE_IVARS->retainCount++;
# ifndef OF_AMIGAOS_M68K
	Permit();
# endif
#else
	OFEnsure(OFSpinlockLock(&PRE_IVARS->retainCountSpinlock) == 0);
	PRE_IVARS->retainCount++;
	OFEnsure(OFSpinlockUnlock(&PRE_IVARS->retainCountSpinlock) == 0);
#endif

	return self;
}

- (unsigned int)retainCount
{
	OFAssert(PRE_IVARS->retainCount >= 0);
	return PRE_IVARS->retainCount;
}

- (void)release
{
#if defined(OF_HAVE_ATOMIC_OPS)
	OFReleaseMemoryBarrier();

	if (OFAtomicIntDecrease(&PRE_IVARS->retainCount) <= 0) {
		OFAcquireMemoryBarrier();

		[self dealloc];
	}
#elif defined(OF_AMIGAOS)
	int retainCount;

	Forbid();
	retainCount = --PRE_IVARS->retainCount;
	Permit();

	if (retainCount == 0)
		[self dealloc];
#else
	int retainCount;

	OFEnsure(OFSpinlockLock(&PRE_IVARS->retainCountSpinlock) == 0);
	retainCount = --PRE_IVARS->retainCount;
	OFEnsure(OFSpinlockUnlock(&PRE_IVARS->retainCountSpinlock) == 0);

	if (retainCount == 0)
		[self dealloc];
#endif
}

- (instancetype)autorelease
{
	return _objc_rootAutorelease(self);
}

- (instancetype)self
{
	return self;
}

- (bool)isProxy
{
	return false;
}

- (bool)allowsWeakReference
{
	return true;
}

- (bool)retainWeakReference
{
	[self retain];

	return true;
}

- (void)dealloc
{
	objc_destructInstance(self);

#if !defined(OF_HAVE_ATOMIC_OPS) && !defined(OF_AMIGAOS)
	OFSpinlockFree(&PRE_IVARS->retainCountSpinlock);
#endif

	free((char *)self - PRE_IVARS_ALIGN);
}

/* Required to use properties with the Apple runtime */
- (id)copyWithZone: (void *)zone
{
	if OF_UNLIKELY (zone != NULL) {
		[self doesNotRecognizeSelector: _cmd];
		abort();
	}

	return [(id)self copy];
}

- (id)mutableCopyWithZone: (void *)zone
{
	if OF_UNLIKELY (zone != NULL) {
		[self doesNotRecognizeSelector: _cmd];
		abort();
	}

	return [(id)self mutableCopy];
}

/*
 * The following are needed as the root class is the superclass of the root
 * class's metaclass and thus instance methods can be sent to class objects as
 * well.
 */

+ (id)retain
{
	return self;
}

+ (id)autorelease
{
	return self;
}

+ (unsigned int)retainCount
{
	return OFMaxRetainCount;
}

+ (void)release
{
}

+ (void)dealloc
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (id)copy
{
	return self;
}

+ (id)mutableCopyWithZone: (void *)zone
{
	OF_UNRECOGNIZED_SELECTOR
}

/* Required to use ObjFW from Swift */
+ (instancetype)allocWithZone: (void *)zone
{
	if OF_UNLIKELY (zone != NULL) {
		[self doesNotRecognizeSelector: _cmd];
		abort();
	}

	return [self alloc];
}
@end