ObjFW  Check-in [5337be0924]

	NO_CONST_CFSTRINGS="-fno-constant-cfstrings"
	OBJCFLAGS="$OBJCFLAGS -fno-constant-cfstrings"])
AC_SUBST(NO_CONST_CFSTRINGS)

AC_CHECK_HEADER(objc/runtime.h,
	[AC_DEFINE(HAVE_OBJC_RUNTIME_H, 1, [Whether we have objc/runtime.h])])

AC_CHECK_FUNC(objc_sync_enter,, AC_SUBST(OBJC_SYNC_M, "objc_sync.m"))
AC_CHECK_FUNC(objc_sync_enter,, [
	AC_SUBST(OBJC_SYNC_M, "objc_sync.m")
	AC_DEFINE(NEED_OBJC_SYNC_INIT, 1,
		[Whether objc_sync_init needs to be called])])

test x"$GCC" = x"yes" && CFLAGS="$CFLAGS -Werror"
if test x"$GOBJC" = x"yes"; then
	old_OBJCFLAGS="$OBJCFLAGS"
	OBJCFLAGS="$OBJCFLAGS -Werror"

	AC_MSG_CHECKING(whether gcc has bug objc/27438)

/*
 * Copyright (c) 2008 - 2009
 *   Jonathan Schleifer <js@webkeks.org>
 *
 * All rights reserved.
 *
 * This file is part of libobjfw. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE included in
 * the packaging of this file.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <assert.h>

#import "OFObject.h"
#import "OFAutoreleasePool.h"

/* Hopefully no arch needs more than 16 bytes padding */
#define PRE_IVAR_ALIGN ((sizeof(struct pre_ivar) + 15) & ~15)
#define PRE_IVAR ((struct pre_ivar*)((char*)self - PRE_IVAR_ALIGN))

static struct {
	Class isa;
} alloc_failed_exception;

#ifdef NEED_OBJC_SYNC_INIT
extern BOOL objc_sync_init();
#endif

@implementation OFObject
+ (void)initialize
{
#ifdef NEED_OBJC_SYNC_INIT
	if (!objc_sync_init()) {
		fputs("Runtime error: objc_sync_init() failed!\n", stderr);
		abort();
	}
#endif
}

+ alloc
{
	OFObject *instance;
#ifdef __objc_INCLUDE_GNU
	size_t isize = class_get_instance_size(self);

#include "config.h"

#include <stddef.h>
#include <stdlib.h>

#ifndef _WIN32
#include <pthread.h>
#else
#endif

#import <objc/objc.h>

#ifdef _WIN32
#include <windows.h>
#endif

#import "OFMacros.h"

struct locks_s {
	id		obj;
	size_t		count;
	size_t		recursion;
#ifndef _WIN32
	pthread_t	thread;
	pthread_mutex_t	mutex;
#else
	HANDLE		thread;
	HANDLE		mutex;
#endif
};

static int initialized = 0;
#ifndef _WIN32
static pthread_mutex_t mutex;
#else
static HANDLE mutex;
#endif
static struct locks_s *locks = NULL;
static size_t num_locks = 0;

#ifndef _WIN32
static OF_INLINE BOOL
mutex_new(pthread_mutex_t *m)
{
	return (pthread_mutex_init(m, NULL) ? NO : YES);
}

static OF_INLINE BOOL
mutex_free(pthread_mutex_t *m)
{
	return (pthread_mutex_destroy(m) ? NO : YES);
}

static OF_INLINE BOOL
mutex_lock(pthread_mutex_t *m)
{
	return (pthread_mutex_lock(m) ? NO : YES);
}

static OF_INLINE BOOL
mutex_unlock(pthread_mutex_t *m)
{
	return (pthread_mutex_unlock(m) ? NO : YES);
}

static OF_INLINE BOOL
thread_is_current(pthread_t t)
{
	return (pthread_equal(t, pthread_self()) ? YES : NO);
}

static OF_INLINE pthread_t
thread_current()
{
	return pthread_self();
}
#else
static OF_INLINE BOOL
mutex_new(HANDLE *m)
{
	return (((*m = CreateMutex(NULL, FALSE, NULL)) != NULL) ? YES : NO);
}

static OF_INLINE BOOL
mutex_free(HANDLE *m)
{
	return (CloseHandle(*m) ? YES : NO);
}

static OF_INLINE BOOL
mutex_lock(HANDLE *m)
{
	return (WaitForSingleObject(*m, INFINITE) == WAIT_OBJECT_0 ? YES : NO);
}

static OF_INLINE BOOL
mutex_unlock(HANDLE *m)
{
	return (ReleaseMutex(*m) ? YES : NO);
}

static OF_INLINE BOOL
thread_is_current(HANDLE t)
{
	return (t == GetCurrentThread() ? YES : NO);
}

static OF_INLINE HANDLE
thread_current()
{
	return GetCurrentThread();
}
#endif

BOOL
objc_sync_init()
{
	return (mutex_new(&mutex) ? YES : NO);
}

int
objc_sync_enter(id obj)
{
	size_t i;

	/*
	 * FIXME:
	 * Theoretically, it's possible to encounter a race condition during
	 * initialization.
	 */
	if (!initialized) {
	if (obj == nil)
#ifndef _WIN32
		if (pthread_mutex_init(&mutex, NULL))
#else
		if ((mutex = CreateMutex(NULL, FALSE, NULL)) == NULL)
#endif
			return 1;
		return 0;

		initialized = 1;
	}

#ifndef _WIN32
	if (pthread_mutex_lock(&mutex))
	if (!mutex_lock(&mutex))
#else
	if (WaitForSingleObject(mutex, INFINITE) != WAIT_OBJECT_0)
		return 1;
#endif

	for (i = 0; i < num_locks; i++) {
		if (locks[i].obj == obj) {
#ifndef _WIN32
			if (pthread_equal(pthread_self(), locks[i].thread))
			if (thread_is_current(locks[i].thread))
#else
			if (locks[i].thread == GetCurrentThread())
#endif
				locks[i].recursion++;
			else
#ifndef _WIN32
				if (pthread_mutex_lock(&locks[i].mutex)) {
					pthread_mutex_unlock(&mutex);
				if (!mutex_lock(&locks[i].mutex)) {
					mutex_unlock(&mutex);
					return 1;
				}
#else
				if (WaitForSingleObject(locks[i].mutex,
				    INFINITE) != WAIT_OBJECT_0) {
					ReleaseMutex(mutex);
					return 1;
				}
#endif

			locks[i].count++;

#ifndef _WIN32
			if (pthread_mutex_unlock(&locks[i].mutex))
			if (!mutex_unlock(&mutex))
#else
			if (!ReleaseMutex(mutex))
#endif
				return 1;

			return 0;
		}
	}

	if (locks == NULL) {
		if ((locks = malloc(sizeof(struct locks_s))) == NULL) {
#ifndef _WIN32
			pthread_mutex_unlock(&mutex);
			mutex_unlock(&mutex);
#else
			ReleaseMutex(mutex);
#endif
			return 1;
		}
	} else {
		struct locks_s *new_locks;

		if ((new_locks = realloc(locks, (num_locks + 1) *
		    sizeof(struct locks_s))) == NULL) {
#ifndef _WIN32
			pthread_mutex_unlock(&mutex);
			mutex_unlock(&mutex);
#else
			ReleaseMutex(mutex);
#endif
			return 1;
		}

		locks = new_locks;
	}

	locks[num_locks].obj = obj;
	locks[num_locks].count = 1;
	locks[num_locks].recursion = 0;

#ifndef _WIN32
	locks[num_locks].thread = pthread_self();
	locks[num_locks].thread = thread_current();

	if (pthread_mutex_init(&locks[num_locks].mutex, NULL)) {
		pthread_mutex_unlock(&mutex);
	if (!mutex_new(&locks[num_locks].mutex)) {
		mutex_unlock(&mutex);
		return 1;
	}

	if (pthread_mutex_lock(&locks[num_locks].mutex)) {
		pthread_mutex_unlock(&mutex);
	if (!mutex_lock(&locks[num_locks].mutex)) {
		mutex_unlock(&mutex);
		return 1;
	}
#else
	locks[num_locks].thread = GetCurrentThread();

	if ((locks[num_locks].mutex = CreateMutex(NULL, TRUE, NULL)) == NULL) {
		ReleaseMutex(mutex);
		return 1;
	}
#endif

	num_locks++;

#ifndef _WIN32
	if (pthread_mutex_unlock(&mutex))
	if (!mutex_unlock(&mutex))
#else
	if (!ReleaseMutex(mutex))
#endif
		return 1;

	return 0;
}

int
objc_sync_exit(id obj)
{
	size_t i;

	if (obj == nil)
		return 0;
#ifndef _WIN32
	if (pthread_mutex_lock(&mutex))

	if (!mutex_lock(&mutex))
#else
	if (WaitForSingleObject(mutex, INFINITE) != WAIT_OBJECT_0)
		return 1;
#endif

	for (i = 0; i < num_locks; i++) {
		if (locks[i].obj == obj) {
#ifndef _WIN32
			if (pthread_equal(pthread_self(), locks[i].thread) &&
			    locks[i].recursion) {
			if (locks[i].recursion > 0 &&
			    thread_is_current(locks[i].thread)) {
				locks[i].recursion--;

				if (pthread_mutex_unlock(&mutex))
				if (!mutex_unlock(&mutex))
					return 1;

				return 0;
			}
#else
			if (locks[i].thread == GetCurrentThread() &&
			    locks[i].recursion) {
				locks[i].recursion--;

				if (!ReleaseMutex(mutex))
					return 1;

				return 0;
			}
#endif

#ifndef _WIN32
			if (pthread_mutex_unlock(&locks[i].mutex)) {
				pthread_mutex_unlock(&mutex);
			if (!mutex_unlock(&locks[i].mutex)) {
				mutex_unlock(&mutex);
				return 1;
			}
#else
			if (!ReleaseMutex(locks[i].mutex)) {
				ReleaseMutex(mutex);
				return 1;
			}
#endif

			locks[i].count--;

			if (locks[i].count == 0) {
				struct locks_s *new_locks;

#ifndef _WIN32
				if (pthread_mutex_destroy(&locks[i].mutex)) {
					pthread_mutex_unlock(&mutex);
				if (!mutex_free(&locks[i].mutex)) {
					mutex_unlock(&mutex);
					return 1;
				}
#else
				if (!CloseHandle(locks[i].mutex)) {
					ReleaseMutex(mutex);
					return 1;
				}
#endif

				num_locks--;
				locks[i] = locks[num_locks];

				if ((new_locks = realloc(locks, (num_locks) *
				    sizeof(struct locks_s))) == NULL) {
#ifndef _WIN32
					pthread_mutex_unlock(&mutex);
					mutex_unlock(&mutex);
#else
					ReleaseMutex(mutex);
#endif
					return 1;
				}

				locks = new_locks;
			}

#ifndef _WIN32
			if (pthread_mutex_unlock(&mutex))
			if (!mutex_unlock(&mutex))
#else
			if (!ReleaseMutex(mutex))
#endif
				return 1;

			return 0;
		}
	}

#ifndef _WIN32
	pthread_mutex_unlock(&mutex);
	mutex_unlock(&mutex);
#else
	ReleaseMutex(mutex);
#endif

	return 1;
}