src/object.m - third_party/swift-corelibs-libdispatch - Git at Google

 /*
  * Copyright (c) 2011-2014 Apple Inc. All rights reserved.
  *
  * @APPLE_APACHE_LICENSE_HEADER_START@
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  * @APPLE_APACHE_LICENSE_HEADER_END@
  */

 #include "internal.h"

 #if USE_OBJC

 #if _OS_OBJECT_OBJC_ARC
 #error "Cannot build with ARC"
 #endif
 #if defined(__OBJC_GC__)
 #error Objective C GC isn't supported anymore
 #endif

 #if __has_include(<objc/objc-internal.h>)
 #include <objc/objc-internal.h>
 #else
 extern id _Nullable objc_retain(id _Nullable obj) __asm__("_objc_retain");
 extern void objc_release(id _Nullable obj) __asm__("_objc_release");
 extern void _objc_init(void);
 extern void _objc_atfork_prepare(void);
 extern void _objc_atfork_parent(void);
 extern void _objc_atfork_child(void);
 #endif // __has_include(<objc/objc-internal.h>)
 #include <objc/objc-exception.h>
 #include <Foundation/NSString.h>

 // NOTE: this file must not contain any atomic operations

 #pragma mark -
 #pragma mark _os_object_t

 static inline id
 _os_objc_alloc(Class cls, size_t size)
 {
 	id obj;
 	size -= sizeof(((struct _os_object_s *)NULL)->os_obj_isa);
 	while (!fastpath(obj = class_createInstance(cls, size))) {
 		_dispatch_temporary_resource_shortage();
 	}
 	return obj;
 }

 static void*
 _os_objc_destructInstance(id obj)
 {
 	// noop if only Libystem is loaded
 	return obj;
 }

 #if DISPATCH_COCOA_COMPAT
 static bool _os_object_debug_missing_pools;
 #endif

 void
 _os_object_init(void)
 {
 	_objc_init();
 	Block_callbacks_RR callbacks = {
 		sizeof(Block_callbacks_RR),
 		(void (*)(const void *))&objc_retain,
 		(void (*)(const void *))&objc_release,
 		(void (*)(const void *))&_os_objc_destructInstance
 	};
 	_Block_use_RR2(&callbacks);
 #if DISPATCH_COCOA_COMPAT
 	const char *v = getenv("OBJC_DEBUG_MISSING_POOLS");
 	_os_object_debug_missing_pools = v && !strcmp(v, "YES");
 #endif
 }

 _os_object_t
 _os_object_alloc_realized(const void *cls, size_t size)
 {
 	dispatch_assert(size >= sizeof(struct _os_object_s));
 	return _os_objc_alloc(cls, size);
 }

 _os_object_t
 _os_object_alloc(const void *_cls, size_t size)
 {
 	dispatch_assert(size >= sizeof(struct _os_object_s));
 	Class cls = _cls ? [(id)_cls class] : [OS_OBJECT_CLASS(object) class];
 	return _os_objc_alloc(cls, size);
 }

 void
 _os_object_dealloc(_os_object_t obj)
 {
 	[obj dealloc];
 }

 void
 _os_object_xref_dispose(_os_object_t obj)
 {
 	struct _os_object_s *o = (struct _os_object_s *)obj;
 	_os_object_xrefcnt_dispose_barrier(o);
 	[obj _xref_dispose];
 }

 void
 _os_object_dispose(_os_object_t obj)
 {
 	struct _os_object_s *o = (struct _os_object_s *)obj;
 	_os_object_refcnt_dispose_barrier(o);
 	[obj _dispose];
 }

 #undef os_retain
 void*
 os_retain(void *obj)
 {
 	return objc_retain(obj);
 }

 #undef os_release
 void
 os_release(void *obj)
 {
 	return objc_release(obj);
 }

 void
 _os_object_atfork_prepare(void)
 {
 	return _objc_atfork_prepare();
 }

 void
 _os_object_atfork_parent(void)
 {
 	return _objc_atfork_parent();
 }

 void
 _os_object_atfork_child(void)
 {
 	return _objc_atfork_child();
 }

 #pragma mark -
 #pragma mark _os_object

 @implementation OS_OBJECT_CLASS(object)
 DISPATCH_UNAVAILABLE_INIT()

 -(id)retain {
 	return _os_object_retain(self);
 }

 -(oneway void)release {
 	return _os_object_release(self);
 }

 -(NSUInteger)retainCount {
 	return _os_object_retain_count(self);
 }

 -(BOOL)retainWeakReference {
 	return _os_object_retain_weak(self);
 }

 -(BOOL)allowsWeakReference {
 	return _os_object_allows_weak_reference(self);
 }

 - (void)_xref_dispose {
 	return _os_object_release_internal(self);
 }

 - (void)_dispose {
 	return _os_object_dealloc(self);
 }

 @end

 #pragma mark -
 #pragma mark _dispatch_objc
 #if OS_OBJECT_HAVE_OBJC2

 id
 _dispatch_objc_alloc(Class cls, size_t size)
 {
 	return _os_objc_alloc(cls, size);
 }

 void
 _dispatch_objc_retain(dispatch_object_t dou)
 {
 	return (void)os_retain(dou);
 }

 void
 _dispatch_objc_release(dispatch_object_t dou)
 {
 	return os_release(dou);
 }

 void
 _dispatch_objc_set_context(dispatch_object_t dou, void *context)
 {
 	return [dou _setContext:context];
 }

 void *
 _dispatch_objc_get_context(dispatch_object_t dou)
 {
 	return [dou _getContext];
 }

 void
 _dispatch_objc_set_finalizer_f(dispatch_object_t dou,
 		dispatch_function_t finalizer)
 {
 	return [dou _setFinalizer:finalizer];
 }

 void
 _dispatch_objc_set_target_queue(dispatch_object_t dou, dispatch_queue_t queue)
 {
 	return [dou _setTargetQueue:queue];
 }

 void
 _dispatch_objc_suspend(dispatch_object_t dou)
 {
 	return [dou _suspend];
 }

 void
 _dispatch_objc_resume(dispatch_object_t dou)
 {
 	return [dou _resume];
 }

 void
 _dispatch_objc_activate(dispatch_object_t dou)
 {
 	return [dou _activate];
 }

 size_t
 _dispatch_objc_debug(dispatch_object_t dou, char* buf, size_t bufsiz)
 {
 	NSUInteger offset = 0;
 	NSString *desc = [dou debugDescription];
 	[desc getBytes:buf maxLength:bufsiz-1 usedLength:&offset
 			encoding:NSUTF8StringEncoding options:(NSStringEncodingConversionOptions)0
 			range:NSMakeRange(0, [desc length]) remainingRange:NULL];
 	if (offset) buf[offset] = 0;
 	return offset;
 }

 #endif
 #pragma mark -
 #pragma mark _dispatch_object

 // Force non-lazy class realization rdar://10640168
 #define DISPATCH_OBJC_LOAD() + (void)load {}

 @implementation DISPATCH_CLASS(object)
 DISPATCH_UNAVAILABLE_INIT()

 - (void)_dispose {
 	return _dispatch_dispose(self); // calls _os_object_dealloc()
 }

 - (NSString *)debugDescription {
 	Class nsstring = objc_lookUpClass("NSString");
 	if (!nsstring) return nil;
 	char buf[2048];
 	struct dispatch_object_s *obj = (struct dispatch_object_s *)self;
 	if (dx_vtable(obj)->do_debug) {
 		dx_debug(obj, buf, sizeof(buf));
 	} else {
 		strlcpy(buf, dx_kind(obj), sizeof(buf));
 	}
 	NSString *format = [nsstring stringWithUTF8String:"<%s: %s>"];
 	if (!format) return nil;
 	return [nsstring stringWithFormat:format, class_getName([self class]), buf];
 }

 - (void)dealloc DISPATCH_NORETURN {
 	DISPATCH_INTERNAL_CRASH(0, "Calling dealloc on a dispatch object");
 	[super dealloc]; // make clang happy
 }

 @end

 @implementation DISPATCH_CLASS(queue)
 DISPATCH_OBJC_LOAD()
 DISPATCH_UNAVAILABLE_INIT()

 - (NSString *)description {
 	Class nsstring = objc_lookUpClass("NSString");
 	if (!nsstring) return nil;
 	NSString *format = [nsstring stringWithUTF8String:"<%s: %s>"];
 	if (!format) return nil;
 	return [nsstring stringWithFormat:format, class_getName([self class]),
 			dispatch_queue_get_label(self), self];
 }

 - (void)_xref_dispose {
 	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 	[super _xref_dispose];
 }

 @end

 @implementation DISPATCH_CLASS(source)
 DISPATCH_OBJC_LOAD()
 DISPATCH_UNAVAILABLE_INIT()

 - (void)_xref_dispose {
 	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 	_dispatch_source_xref_dispose(self);
 	[super _xref_dispose];
 }

 @end

 @implementation DISPATCH_CLASS(mach)
 DISPATCH_OBJC_LOAD()
 DISPATCH_UNAVAILABLE_INIT()

 - (void)_xref_dispose {
 	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 	_dispatch_mach_xref_dispose((struct dispatch_mach_s *)self);
 	[super _xref_dispose];
 }

 @end

 @implementation DISPATCH_CLASS(queue_runloop)
 DISPATCH_OBJC_LOAD()
 DISPATCH_UNAVAILABLE_INIT()

 - (void)_xref_dispose {
 	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 	_dispatch_runloop_queue_xref_dispose(self);
 	[super _xref_dispose];
 }

 @end

 #define DISPATCH_CLASS_IMPL(name) \
 		@implementation DISPATCH_CLASS(name) \
 		DISPATCH_OBJC_LOAD() \
 		DISPATCH_UNAVAILABLE_INIT() \
 		@end

 #if !DISPATCH_DATA_IS_BRIDGED_TO_NSDATA
 DISPATCH_CLASS_IMPL(data)
 #endif
 DISPATCH_CLASS_IMPL(semaphore)
 DISPATCH_CLASS_IMPL(group)
 DISPATCH_CLASS_IMPL(queue_serial)
 DISPATCH_CLASS_IMPL(queue_concurrent)
 DISPATCH_CLASS_IMPL(queue_main)
 DISPATCH_CLASS_IMPL(queue_root)
 DISPATCH_CLASS_IMPL(queue_mgr)
 DISPATCH_CLASS_IMPL(queue_specific_queue)
 DISPATCH_CLASS_IMPL(queue_attr)
 DISPATCH_CLASS_IMPL(mach_msg)
 DISPATCH_CLASS_IMPL(io)
 DISPATCH_CLASS_IMPL(operation)
 DISPATCH_CLASS_IMPL(disk)

 @implementation OS_OBJECT_CLASS(voucher)
 DISPATCH_UNAVAILABLE_INIT()
 DISPATCH_OBJC_LOAD()

 -(id)retain {
 	return (id)_voucher_retain_inline((struct voucher_s *)self);
 }

 -(oneway void)release {
 	return _voucher_release_inline((struct voucher_s *)self);
 }

 - (void)_xref_dispose {
 	return _voucher_xref_dispose(self); // calls _os_object_release_internal()
 }

 - (void)_dispose {
 	return _voucher_dispose(self); // calls _os_object_dealloc()
 }

 - (NSString *)debugDescription {
 	Class nsstring = objc_lookUpClass("NSString");
 	if (!nsstring) return nil;
 	char buf[2048];
 	_voucher_debug(self, buf, sizeof(buf));
 	NSString *format = [nsstring stringWithUTF8String:"<%s: %s>"];
 	if (!format) return nil;
 	return [nsstring stringWithFormat:format, class_getName([self class]), buf];
 }

 @end

 #if VOUCHER_ENABLE_RECIPE_OBJECTS
 @implementation OS_OBJECT_CLASS(voucher_recipe)
 DISPATCH_UNAVAILABLE_INIT()
 DISPATCH_OBJC_LOAD()

 - (void)_dispose {

 }

 - (NSString *)debugDescription {
 	return nil; // TODO: voucher_recipe debugDescription
 }

 @end
 #endif


 #pragma mark -
 #pragma mark dispatch_last_resort_autorelease_pool

 #if DISPATCH_COCOA_COMPAT

 void
 _dispatch_last_resort_autorelease_pool_push(dispatch_invoke_context_t dic)
 {
 	if (!slowpath(_os_object_debug_missing_pools)) {
 		dic->dic_autorelease_pool = _dispatch_autorelease_pool_push();
 	}
 }

 void
 _dispatch_last_resort_autorelease_pool_pop(dispatch_invoke_context_t dic)
 {
 	if (!slowpath(_os_object_debug_missing_pools)) {
 		_dispatch_autorelease_pool_pop(dic->dic_autorelease_pool);
 		dic->dic_autorelease_pool = NULL;
 	}
 }

 #endif // DISPATCH_COCOA_COMPAT

 #pragma mark -
 #pragma mark dispatch_client_callout

 // Abort on uncaught exceptions thrown from client callouts rdar://8577499
 #if DISPATCH_USE_CLIENT_CALLOUT && !__USING_SJLJ_EXCEPTIONS__ && \
 		OS_OBJECT_HAVE_OBJC2
 // On platforms with zero-cost exceptions, use a compiler-generated catch-all
 // exception handler.

 DISPATCH_NORETURN extern void objc_terminate(void);

 #undef _dispatch_client_callout
 void
 _dispatch_client_callout(void *ctxt, dispatch_function_t f)
 {
 	@try {
 		return f(ctxt);
 	}
 	@catch (...) {
 		objc_terminate();
 	}
 }

 #undef _dispatch_client_callout2
 void
 _dispatch_client_callout2(void *ctxt, size_t i, void (*f)(void *, size_t))
 {
 	@try {
 		return f(ctxt, i);
 	}
 	@catch (...) {
 		objc_terminate();
 	}
 }

 #if HAVE_MACH
 #undef _dispatch_client_callout3
 void
 _dispatch_client_callout3(void *ctxt, dispatch_mach_reason_t reason,
 		dispatch_mach_msg_t dmsg, dispatch_mach_async_reply_callback_t f)
 {
 	@try {
 		return f(ctxt, reason, dmsg);
 	}
 	@catch (...) {
 		objc_terminate();
 	}
 }

 #undef _dispatch_client_callout4
 void
 _dispatch_client_callout4(void *ctxt, dispatch_mach_reason_t reason,
 		dispatch_mach_msg_t dmsg, mach_error_t error,
 		dispatch_mach_handler_function_t f)
 {
 	@try {
 		return f(ctxt, reason, dmsg, error);
 	}
 	@catch (...) {
 		objc_terminate();
 	}
 }
 #endif // HAVE_MACH

 #endif // DISPATCH_USE_CLIENT_CALLOUT

 #endif // USE_OBJC
	/*
	* Copyright (c) 2011-2014 Apple Inc. All rights reserved.
	*
	* @APPLE_APACHE_LICENSE_HEADER_START@
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	* @APPLE_APACHE_LICENSE_HEADER_END@
	*/

	#include "internal.h"

	#if USE_OBJC

	#if _OS_OBJECT_OBJC_ARC
	#error "Cannot build with ARC"
	#endif
	#if defined(__OBJC_GC__)
	#error Objective C GC isn't supported anymore
	#endif

	#if __has_include(<objc/objc-internal.h>)
	#include <objc/objc-internal.h>
	#else
	extern id _Nullable objc_retain(id _Nullable obj) __asm__("_objc_retain");
	extern void objc_release(id _Nullable obj) __asm__("_objc_release");
	extern void _objc_init(void);
	extern void _objc_atfork_prepare(void);
	extern void _objc_atfork_parent(void);
	extern void _objc_atfork_child(void);
	#endif // __has_include(<objc/objc-internal.h>)
	#include <objc/objc-exception.h>
	#include <Foundation/NSString.h>

	// NOTE: this file must not contain any atomic operations

	#pragma mark -
	#pragma mark _os_object_t

	static inline id
	_os_objc_alloc(Class cls, size_t size)
	{
	id obj;
	size -= sizeof(((struct _os_object_s *)NULL)->os_obj_isa);
	while (!fastpath(obj = class_createInstance(cls, size))) {
	_dispatch_temporary_resource_shortage();
	}
	return obj;
	}

	static void*
	_os_objc_destructInstance(id obj)
	{
	// noop if only Libystem is loaded
	return obj;
	}

	#if DISPATCH_COCOA_COMPAT
	static bool _os_object_debug_missing_pools;
	#endif

	void
	_os_object_init(void)
	{
	_objc_init();
	Block_callbacks_RR callbacks = {
	sizeof(Block_callbacks_RR),
	(void ()(const void ))&objc_retain,
	(void ()(const void ))&objc_release,
	(void ()(const void ))&_os_objc_destructInstance
	};
	_Block_use_RR2(&callbacks);
	#if DISPATCH_COCOA_COMPAT
	const char *v = getenv("OBJC_DEBUG_MISSING_POOLS");
	_os_object_debug_missing_pools = v && !strcmp(v, "YES");
	#endif
	}

	_os_object_t
	_os_object_alloc_realized(const void *cls, size_t size)
	{
	dispatch_assert(size >= sizeof(struct _os_object_s));
	return _os_objc_alloc(cls, size);
	}

	_os_object_t
	_os_object_alloc(const void *_cls, size_t size)
	{
	dispatch_assert(size >= sizeof(struct _os_object_s));
	Class cls = _cls ? [(id)_cls class] : [OS_OBJECT_CLASS(object) class];
	return _os_objc_alloc(cls, size);
	}

	void
	_os_object_dealloc(_os_object_t obj)
	{
	[obj dealloc];
	}

	void
	_os_object_xref_dispose(_os_object_t obj)
	{
	struct _os_object_s o = (struct _os_object_s )obj;
	_os_object_xrefcnt_dispose_barrier(o);
	[obj _xref_dispose];
	}

	void
	_os_object_dispose(_os_object_t obj)
	{
	struct _os_object_s o = (struct _os_object_s )obj;
	_os_object_refcnt_dispose_barrier(o);
	[obj _dispose];
	}

	#undef os_retain
	void*
	os_retain(void *obj)
	{
	return objc_retain(obj);
	}

	#undef os_release
	void
	os_release(void *obj)
	{
	return objc_release(obj);
	}

	void
	_os_object_atfork_prepare(void)
	{
	return _objc_atfork_prepare();
	}

	void
	_os_object_atfork_parent(void)
	{
	return _objc_atfork_parent();
	}

	void
	_os_object_atfork_child(void)
	{
	return _objc_atfork_child();
	}

	#pragma mark -
	#pragma mark _os_object

	@implementation OS_OBJECT_CLASS(object)
	DISPATCH_UNAVAILABLE_INIT()

	-(id)retain {
	return _os_object_retain(self);
	}

	-(oneway void)release {
	return _os_object_release(self);
	}

	-(NSUInteger)retainCount {
	return _os_object_retain_count(self);
	}

	-(BOOL)retainWeakReference {
	return _os_object_retain_weak(self);
	}

	-(BOOL)allowsWeakReference {
	return _os_object_allows_weak_reference(self);
	}

	- (void)_xref_dispose {
	return _os_object_release_internal(self);
	}

	- (void)_dispose {
	return _os_object_dealloc(self);
	}

	@end

	#pragma mark -
	#pragma mark _dispatch_objc
	#if OS_OBJECT_HAVE_OBJC2

	id
	_dispatch_objc_alloc(Class cls, size_t size)
	{
	return _os_objc_alloc(cls, size);
	}

	void
	_dispatch_objc_retain(dispatch_object_t dou)
	{
	return (void)os_retain(dou);
	}

	void
	_dispatch_objc_release(dispatch_object_t dou)
	{
	return os_release(dou);
	}

	void
	_dispatch_objc_set_context(dispatch_object_t dou, void *context)
	{
	return [dou _setContext:context];
	}

	void *
	_dispatch_objc_get_context(dispatch_object_t dou)
	{
	return [dou _getContext];
	}

	void
	_dispatch_objc_set_finalizer_f(dispatch_object_t dou,
	dispatch_function_t finalizer)
	{
	return [dou _setFinalizer:finalizer];
	}

	void
	_dispatch_objc_set_target_queue(dispatch_object_t dou, dispatch_queue_t queue)
	{
	return [dou _setTargetQueue:queue];
	}

	void
	_dispatch_objc_suspend(dispatch_object_t dou)
	{
	return [dou _suspend];
	}

	void
	_dispatch_objc_resume(dispatch_object_t dou)
	{
	return [dou _resume];
	}

	void
	_dispatch_objc_activate(dispatch_object_t dou)
	{
	return [dou _activate];
	}

	size_t
	_dispatch_objc_debug(dispatch_object_t dou, char* buf, size_t bufsiz)
	{
	NSUInteger offset = 0;
	NSString *desc = [dou debugDescription];
	[desc getBytes:buf maxLength:bufsiz-1 usedLength:&offset
	encoding:NSUTF8StringEncoding options:(NSStringEncodingConversionOptions)0
	range:NSMakeRange(0, [desc length]) remainingRange:NULL];
	if (offset) buf[offset] = 0;
	return offset;
	}

	#endif
	#pragma mark -
	#pragma mark _dispatch_object

	// Force non-lazy class realization rdar://10640168
	#define DISPATCH_OBJC_LOAD() + (void)load {}

	@implementation DISPATCH_CLASS(object)
	DISPATCH_UNAVAILABLE_INIT()

	- (void)_dispose {
	return _dispatch_dispose(self); // calls _os_object_dealloc()
	}

	- (NSString *)debugDescription {
	Class nsstring = objc_lookUpClass("NSString");
	if (!nsstring) return nil;
	char buf[2048];
	struct dispatch_object_s obj = (struct dispatch_object_s )self;
	if (dx_vtable(obj)->do_debug) {
	dx_debug(obj, buf, sizeof(buf));
	} else {
	strlcpy(buf, dx_kind(obj), sizeof(buf));
	}
	NSString *format = [nsstring stringWithUTF8String:"<%s: %s>"];
	if (!format) return nil;
	return [nsstring stringWithFormat:format, class_getName([self class]), buf];
	}

	- (void)dealloc DISPATCH_NORETURN {
	DISPATCH_INTERNAL_CRASH(0, "Calling dealloc on a dispatch object");
	[super dealloc]; // make clang happy
	}

	@end

	@implementation DISPATCH_CLASS(queue)
	DISPATCH_OBJC_LOAD()
	DISPATCH_UNAVAILABLE_INIT()

	- (NSString *)description {
	Class nsstring = objc_lookUpClass("NSString");
	if (!nsstring) return nil;
	NSString *format = [nsstring stringWithUTF8String:"<%s: %s>"];
	if (!format) return nil;
	return [nsstring stringWithFormat:format, class_getName([self class]),
	dispatch_queue_get_label(self), self];
	}

	- (void)_xref_dispose {
	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
	[super _xref_dispose];
	}

	@end

	@implementation DISPATCH_CLASS(source)
	DISPATCH_OBJC_LOAD()
	DISPATCH_UNAVAILABLE_INIT()

	- (void)_xref_dispose {
	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
	_dispatch_source_xref_dispose(self);
	[super _xref_dispose];
	}

	@end

	@implementation DISPATCH_CLASS(mach)
	DISPATCH_OBJC_LOAD()
	DISPATCH_UNAVAILABLE_INIT()

	- (void)_xref_dispose {
	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
	_dispatch_mach_xref_dispose((struct dispatch_mach_s *)self);
	[super _xref_dispose];
	}

	@end

	@implementation DISPATCH_CLASS(queue_runloop)
	DISPATCH_OBJC_LOAD()
	DISPATCH_UNAVAILABLE_INIT()

	- (void)_xref_dispose {
	_dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
	_dispatch_runloop_queue_xref_dispose(self);
	[super _xref_dispose];
	}

	@end

	#define DISPATCH_CLASS_IMPL(name) \
	@implementation DISPATCH_CLASS(name) \
	DISPATCH_OBJC_LOAD() \
	DISPATCH_UNAVAILABLE_INIT() \
	@end

	#if !DISPATCH_DATA_IS_BRIDGED_TO_NSDATA
	DISPATCH_CLASS_IMPL(data)
	#endif
	DISPATCH_CLASS_IMPL(semaphore)
	DISPATCH_CLASS_IMPL(group)
	DISPATCH_CLASS_IMPL(queue_serial)
	DISPATCH_CLASS_IMPL(queue_concurrent)
	DISPATCH_CLASS_IMPL(queue_main)
	DISPATCH_CLASS_IMPL(queue_root)
	DISPATCH_CLASS_IMPL(queue_mgr)
	DISPATCH_CLASS_IMPL(queue_specific_queue)
	DISPATCH_CLASS_IMPL(queue_attr)
	DISPATCH_CLASS_IMPL(mach_msg)
	DISPATCH_CLASS_IMPL(io)
	DISPATCH_CLASS_IMPL(operation)
	DISPATCH_CLASS_IMPL(disk)

	@implementation OS_OBJECT_CLASS(voucher)
	DISPATCH_UNAVAILABLE_INIT()
	DISPATCH_OBJC_LOAD()

	-(id)retain {
	return (id)_voucher_retain_inline((struct voucher_s *)self);
	}

	-(oneway void)release {
	return _voucher_release_inline((struct voucher_s *)self);
	}

	- (void)_xref_dispose {
	return _voucher_xref_dispose(self); // calls _os_object_release_internal()
	}

	- (void)_dispose {
	return _voucher_dispose(self); // calls _os_object_dealloc()
	}

	- (NSString *)debugDescription {
	Class nsstring = objc_lookUpClass("NSString");
	if (!nsstring) return nil;
	char buf[2048];
	_voucher_debug(self, buf, sizeof(buf));
	NSString *format = [nsstring stringWithUTF8String:"<%s: %s>"];
	if (!format) return nil;
	return [nsstring stringWithFormat:format, class_getName([self class]), buf];
	}

	@end

	#if VOUCHER_ENABLE_RECIPE_OBJECTS
	@implementation OS_OBJECT_CLASS(voucher_recipe)
	DISPATCH_UNAVAILABLE_INIT()
	DISPATCH_OBJC_LOAD()

	- (void)_dispose {

	}

	- (NSString *)debugDescription {
	return nil; // TODO: voucher_recipe debugDescription
	}

	@end
	#endif


	#pragma mark -
	#pragma mark dispatch_last_resort_autorelease_pool

	#if DISPATCH_COCOA_COMPAT

	void
	_dispatch_last_resort_autorelease_pool_push(dispatch_invoke_context_t dic)
	{
	if (!slowpath(_os_object_debug_missing_pools)) {
	dic->dic_autorelease_pool = _dispatch_autorelease_pool_push();
	}
	}

	void
	_dispatch_last_resort_autorelease_pool_pop(dispatch_invoke_context_t dic)
	{
	if (!slowpath(_os_object_debug_missing_pools)) {
	_dispatch_autorelease_pool_pop(dic->dic_autorelease_pool);
	dic->dic_autorelease_pool = NULL;
	}
	}

	#endif // DISPATCH_COCOA_COMPAT

	#pragma mark -
	#pragma mark dispatch_client_callout

	// Abort on uncaught exceptions thrown from client callouts rdar://8577499
	#if DISPATCH_USE_CLIENT_CALLOUT && !__USING_SJLJ_EXCEPTIONS__ && \
	OS_OBJECT_HAVE_OBJC2
	// On platforms with zero-cost exceptions, use a compiler-generated catch-all
	// exception handler.

	DISPATCH_NORETURN extern void objc_terminate(void);

	#undef _dispatch_client_callout
	void
	_dispatch_client_callout(void *ctxt, dispatch_function_t f)
	{
	@try {
	return f(ctxt);
	}
	@catch (...) {
	objc_terminate();
	}
	}

	#undef _dispatch_client_callout2
	void
	_dispatch_client_callout2(void ctxt, size_t i, void (f)(void *, size_t))
	{
	@try {
	return f(ctxt, i);
	}
	@catch (...) {
	objc_terminate();
	}
	}

	#if HAVE_MACH
	#undef _dispatch_client_callout3
	void
	_dispatch_client_callout3(void *ctxt, dispatch_mach_reason_t reason,
	dispatch_mach_msg_t dmsg, dispatch_mach_async_reply_callback_t f)
	{
	@try {
	return f(ctxt, reason, dmsg);
	}
	@catch (...) {
	objc_terminate();
	}
	}

	#undef _dispatch_client_callout4
	void
	_dispatch_client_callout4(void *ctxt, dispatch_mach_reason_t reason,
	dispatch_mach_msg_t dmsg, mach_error_t error,
	dispatch_mach_handler_function_t f)
	{
	@try {
	return f(ctxt, reason, dmsg, error);
	}
	@catch (...) {
	objc_terminate();
	}
	}
	#endif // HAVE_MACH

	#endif // DISPATCH_USE_CLIENT_CALLOUT

	#endif // USE_OBJC