src/internal.h

/*
 * Copyright (c) 2008-2013 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@
 */

/*
 * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
 * which are subject to change in future releases of Mac OS X. Any applications
 * relying on these interfaces WILL break.
 */

#ifndef __DISPATCH_INTERNAL__
#define __DISPATCH_INTERNAL__

#if __has_include(<config/config_ac.h>)
#include <config/config_ac.h>
#else
#include <config/config.h>
#endif

#define __DISPATCH_BUILDING_DISPATCH__
#define __DISPATCH_INDIRECT__

#ifdef __APPLE__
#include <Availability.h>
#include <os/availability.h>
#include <TargetConditionals.h>

#ifndef TARGET_OS_MAC_DESKTOP
#define TARGET_OS_MAC_DESKTOP  (TARGET_OS_MAC && \
		!TARGET_OS_SIMULATOR && !TARGET_OS_IPHONE && !TARGET_OS_EMBEDDED)
#endif

#if TARGET_OS_MAC_DESKTOP
#  define DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(x) \
		(__MAC_OS_X_VERSION_MIN_REQUIRED >= (x))
#  if !DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(101200)
#    error "OS X hosts older than OS X 10.12 aren't supported anymore"
#  endif // !DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(101200)
#elif TARGET_OS_SIMULATOR
#  define DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(x) \
		(IPHONE_SIMULATOR_HOST_MIN_VERSION_REQUIRED >= (x))
#  if !DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(101200)
#    error "Simulator hosts older than OS X 10.12 aren't supported anymore"
#  endif // !DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(101200)
#else
#  define DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(x) 1
#  if __IPHONE_OS_VERSION_MIN_REQUIRED < 90000
#    error "iOS hosts older than iOS 9.0 aren't supported anymore"
#  endif
#endif

#else // !__APPLE__
#define DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(x) 0
#endif // !__APPLE__


#if !defined(DISPATCH_MACH_SPI) && TARGET_OS_MAC
#define DISPATCH_MACH_SPI 1
#endif
#if !defined(OS_VOUCHER_CREATION_SPI) && TARGET_OS_MAC
#define OS_VOUCHER_CREATION_SPI 1
#endif
#if !defined(OS_VOUCHER_ACTIVITY_SPI) && TARGET_OS_MAC
#define OS_VOUCHER_ACTIVITY_SPI 1
#endif
#if !defined(OS_VOUCHER_ACTIVITY_GENERATE_SWAPS)
#define OS_VOUCHER_ACTIVITY_GENERATE_SWAPS 0
#endif
#if !defined(OS_FIREHOSE_SPI) && TARGET_OS_MAC
#define OS_FIREHOSE_SPI 1
#endif
#if !defined(DISPATCH_LAYOUT_SPI) && TARGET_OS_MAC
#define DISPATCH_LAYOUT_SPI 1
#endif

#if __has_include(<mach-o/dyld_priv.h>)
#include <mach-o/dyld_priv.h>
#if !defined(HAVE_DYLD_IS_MEMORY_IMMUTABLE)
#if defined(DYLD_MACOSX_VERSION_10_12) || defined(DYLD_IOS_VERSION_10_0)
#define HAVE_DYLD_IS_MEMORY_IMMUTABLE 1
#else
#define HAVE_DYLD_IS_MEMORY_IMMUTABLE 0
#endif
#endif // !defined(HAVE_DYLD_IS_MEMORY_IMMUTABLE)
#endif // __has_include(<mach-o/dyld_priv.h>)

#if !defined(USE_OBJC) && HAVE_OBJC
#define USE_OBJC 1
#endif

#if USE_OBJC
#define OS_OBJECT_HAVE_OBJC_SUPPORT 1
#if defined(__OBJC__)
#define OS_OBJECT_USE_OBJC 1
// Force internal Objective-C sources to use class-visible headers
// even when not compiling in Swift.
#define OS_OBJECT_SWIFT3 1
#else
#define OS_OBJECT_USE_OBJC 0
#endif // __OBJC__
#else
#define OS_OBJECT_HAVE_OBJC_SUPPORT 0
#endif // USE_OBJC

#include <dispatch/dispatch.h>
#include <dispatch/base.h>

#define __DISPATCH_HIDE_SYMBOL(sym, version) \
	__asm__(".section __TEXT,__const\n\t" \
			".globl $ld$hide$os" #version "$_" #sym "\n\t" \
			"$ld$hide$os" #version "$_" #sym ":\n\t" \
			"    .byte 0\n\t" \
			".previous")


#ifndef DISPATCH_HIDE_SYMBOL
#if TARGET_OS_MAC && !TARGET_OS_IPHONE
#define DISPATCH_HIDE_SYMBOL(sym, osx, ios, tvos, watchos) \
		__DISPATCH_HIDE_SYMBOL(sym, osx)
#else
#define DISPATCH_HIDE_SYMBOL(sym, osx, ios, tvos, watchos)
#endif
#endif

#include <os/object.h>
#include <dispatch/time.h>
#include <dispatch/object.h>
#include <dispatch/queue.h>
#include <dispatch/block.h>
#include <dispatch/source.h>
#include <dispatch/group.h>
#include <dispatch/semaphore.h>
#include <dispatch/once.h>
#include <dispatch/data.h>
#if !TARGET_OS_WIN32
#include <dispatch/io.h>
#endif

#if defined(__OBJC__) || defined(__cplusplus)
#define DISPATCH_PURE_C 0
#else
#define DISPATCH_PURE_C 1
#endif

/* private.h must be included last to avoid picking up installed headers. */
#include <pthread.h>
#include "os/object_private.h"
#include "queue_private.h"
#include "source_private.h"
#include "mach_private.h"
#include "data_private.h"
#include "os/voucher_private.h"
#include "os/voucher_activity_private.h"
#if !TARGET_OS_WIN32
#include "io_private.h"
#endif
#include "layout_private.h"
#include "benchmark.h"
#include "private.h"

/* SPI for Libsystem-internal use */
DISPATCH_EXPORT DISPATCH_NOTHROW void libdispatch_init(void);
#if !TARGET_OS_WIN32
DISPATCH_EXPORT DISPATCH_NOTHROW void dispatch_atfork_prepare(void);
DISPATCH_EXPORT DISPATCH_NOTHROW void dispatch_atfork_parent(void);
DISPATCH_EXPORT DISPATCH_NOTHROW void dispatch_atfork_child(void);
#endif

/* More #includes at EOF (dependent on the contents of internal.h) ... */

// Abort on uncaught exceptions thrown from client callouts rdar://8577499
#if !defined(DISPATCH_USE_CLIENT_CALLOUT)
#define DISPATCH_USE_CLIENT_CALLOUT 1
#endif

#define DISPATCH_ALLOW_NON_LEAF_RETARGET 1

/* The "_debug" library build */
#ifndef DISPATCH_DEBUG
#define DISPATCH_DEBUG 0
#endif

#ifndef DISPATCH_PROFILE
#define DISPATCH_PROFILE 0
#endif

#if (!TARGET_OS_EMBEDDED || DISPATCH_DEBUG || DISPATCH_PROFILE) && \
		!defined(DISPATCH_USE_DTRACE)
#define DISPATCH_USE_DTRACE 1
#endif

#if DISPATCH_USE_DTRACE && (DISPATCH_INTROSPECTION || DISPATCH_DEBUG || \
		DISPATCH_PROFILE) && !defined(DISPATCH_USE_DTRACE_INTROSPECTION)
#define DISPATCH_USE_DTRACE_INTROSPECTION 1
#endif

#ifndef DISPATCH_DEBUG_QOS
#define DISPATCH_DEBUG_QOS DISPATCH_DEBUG
#endif

#if HAVE_LIBKERN_OSCROSSENDIAN_H
#include <libkern/OSCrossEndian.h>
#endif
#if HAVE_LIBKERN_OSATOMIC_H
#include <libkern/OSAtomic.h>
#endif
#if HAVE_MACH
#include <mach/boolean.h>
#include <mach/clock_types.h>
#include <mach/clock.h>
#include <mach/exception.h>
#include <mach/mach.h>
#include <mach/mach_error.h>
#include <mach/mach_host.h>
#include <mach/mach_interface.h>
#include <mach/mach_time.h>
#include <mach/mach_traps.h>
#include <mach/message.h>
#include <mach/mig_errors.h>
#include <mach/host_special_ports.h>
#include <mach/host_info.h>
#include <mach/notify.h>
#include <mach/mach_vm.h>
#include <mach/vm_map.h>
#endif /* HAVE_MACH */
#if HAVE_MALLOC_MALLOC_H
#include <malloc/malloc.h>
#endif

#include <sys/stat.h>

#if !TARGET_OS_WIN32
#include <sys/mount.h>
#include <sys/queue.h>
#ifdef __ANDROID__
#include <linux/sysctl.h>
#else
#include <sys/sysctl.h>
#endif /* __ANDROID__ */
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <netinet/in.h>
#endif

#ifdef __BLOCKS__
#if __has_include(<Block_private.h>)
#include <Block_private.h>
#else
#include "BlocksRuntime/Block_private.h"
#endif // __has_include(<Block_private.h>)
#include <Block.h>
#endif /* __BLOCKS__ */

#include <assert.h>
#include <errno.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <limits.h>
#include <search.h>
#if USE_POSIX_SEM
#include <semaphore.h>
#endif
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif

#if __GNUC__
#define DISPATCH_NOINLINE __attribute__((__noinline__))
#define DISPATCH_USED __attribute__((__used__))
#define DISPATCH_UNUSED __attribute__((__unused__))
#define DISPATCH_WEAK __attribute__((__weak__))
#define DISPATCH_OVERLOADABLE __attribute__((__overloadable__))
#define DISPATCH_PACKED __attribute__((__packed__))
#if DISPATCH_DEBUG
#define DISPATCH_ALWAYS_INLINE_NDEBUG
#else
#define DISPATCH_ALWAYS_INLINE_NDEBUG __attribute__((__always_inline__))
#endif
#else	/* __GNUC__ */
#define DISPATCH_NOINLINE
#define DISPATCH_USED
#define DISPATCH_UNUSED
#define DISPATCH_WEAK
#define DISPATCH_ALWAYS_INLINE_NDEBUG
#endif	/* __GNUC__ */

#define DISPATCH_CONCAT(x,y) DISPATCH_CONCAT1(x,y)
#define DISPATCH_CONCAT1(x,y) x ## y

#define DISPATCH_COUNT_ARGS(...) DISPATCH_COUNT_ARGS1(, ## __VA_ARGS__, \
		_8, _7, _6, _5, _4, _3, _2, _1, _0)
#define DISPATCH_COUNT_ARGS1(z, a, b, c, d, e, f, g, h, cnt, ...) cnt

#if BYTE_ORDER == LITTLE_ENDIAN
#define DISPATCH_STRUCT_LE_2(a, b)        struct { a; b; }
#define DISPATCH_STRUCT_LE_3(a, b, c)     struct { a; b; c; }
#define DISPATCH_STRUCT_LE_4(a, b, c, d)  struct { a; b; c; d; }
#else
#define DISPATCH_STRUCT_LE_2(a, b)        struct { b; a; }
#define DISPATCH_STRUCT_LE_3(a, b, c)     struct { c; b; a; }
#define DISPATCH_STRUCT_LE_4(a, b, c, d)  struct { d; c; b; a; }
#endif
#if __has_feature(c_startic_assert)
#define DISPATCH_UNION_ASSERT(alias, st) \
		_Static_assert(sizeof(struct { alias; }) == sizeof(st), "bogus union");
#else
#define DISPATCH_UNION_ASSERT(alias, st)
#endif
#define DISPATCH_UNION_LE(alias, ...) \
		DISPATCH_UNION_ASSERT(alias, DISPATCH_CONCAT(DISPATCH_STRUCT_LE, \
				DISPATCH_COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)) \
		union { alias; DISPATCH_CONCAT(DISPATCH_STRUCT_LE, \
				DISPATCH_COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__); }

// workaround 6368156
#ifdef NSEC_PER_SEC
#undef NSEC_PER_SEC
#endif
#ifdef USEC_PER_SEC
#undef USEC_PER_SEC
#endif
#ifdef NSEC_PER_USEC
#undef NSEC_PER_USEC
#endif
#define NSEC_PER_SEC 1000000000ull
#define USEC_PER_SEC 1000000ull
#define NSEC_PER_USEC 1000ull

/* I wish we had __builtin_expect_range() */
#if __GNUC__
#define _safe_cast_to_long(x) \
		({ _Static_assert(sizeof(typeof(x)) <= sizeof(long), \
				"__builtin_expect doesn't support types wider than long"); \
				(long)(x); })
#define fastpath(x) ((typeof(x))__builtin_expect(_safe_cast_to_long(x), ~0l))
#define slowpath(x) ((typeof(x))__builtin_expect(_safe_cast_to_long(x), 0l))
#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)
#else
#define fastpath(x) (x)
#define slowpath(x) (x)
#define likely(x) (!!(x))
#define unlikely(x) (!!(x))
#endif // __GNUC__

#define _TAILQ_IS_ENQUEUED(elm, field) \
		((elm)->field.tqe_prev != NULL)
#define _TAILQ_MARK_NOT_ENQUEUED(elm, field) \
		do { (elm)->field.tqe_prev = NULL; } while (0)

// sys/queue.h debugging
#ifndef TRASHIT
#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
#endif

#define _TAILQ_TRASH_ENTRY(elm, field) do { \
			TRASHIT((elm)->field.tqe_next); \
			TRASHIT((elm)->field.tqe_prev); \
		} while (0)
#define _TAILQ_TRASH_HEAD(head) do { \
			TRASHIT((head)->tqh_first); \
			TRASHIT((head)->tqh_last); \
		} while (0)

DISPATCH_EXPORT DISPATCH_NOINLINE
void _dispatch_bug(size_t line, long val);

DISPATCH_NOINLINE
void _dispatch_bug_client(const char* msg);
#if HAVE_MACH
DISPATCH_NOINLINE
void _dispatch_bug_mach_client(const char *msg, mach_msg_return_t kr);
#endif // HAVE_MACH
DISPATCH_NOINLINE
void _dispatch_bug_kevent_client(const char* msg, const char* filter,
		const char *operation, int err);

DISPATCH_NOINLINE
void _dispatch_bug_deprecated(const char *msg);

DISPATCH_NOINLINE DISPATCH_NORETURN
void _dispatch_abort(size_t line, long val);

#if !defined(DISPATCH_USE_OS_DEBUG_LOG) && DISPATCH_DEBUG
#if __has_include(<os/debug_private.h>)
#define DISPATCH_USE_OS_DEBUG_LOG 1
#include <os/debug_private.h>
#endif
#endif // DISPATCH_USE_OS_DEBUG_LOG

#if !defined(DISPATCH_USE_SIMPLE_ASL) && !DISPATCH_USE_OS_DEBUG_LOG
#if __has_include(<_simple.h>)
#define DISPATCH_USE_SIMPLE_ASL 1
#include <_simple.h>
#endif
#endif // DISPATCH_USE_SIMPLE_ASL

#if !DISPATCH_USE_SIMPLE_ASL && !DISPATCH_USE_OS_DEBUG_LOG && !TARGET_OS_WIN32
#include <syslog.h>
#endif

#if DISPATCH_USE_OS_DEBUG_LOG
#define _dispatch_log(msg, ...) os_debug_log("libdispatch", msg, ## __VA_ARGS__)
#else
DISPATCH_EXPORT DISPATCH_NOINLINE __attribute__((__format__(__printf__,1,2)))
void _dispatch_log(const char *msg, ...);
#endif // DISPATCH_USE_OS_DEBUG_LOG

#define dsnprintf(buf, siz, ...) \
		({ size_t _siz = siz; int _r = snprintf(buf, _siz, __VA_ARGS__); \
		 _r < 0 ? 0u : ((size_t)_r > _siz ? _siz : (size_t)_r); })

#if __GNUC__
#define dispatch_static_assert(e) ({ \
		char __compile_time_assert__[(bool)(e) ? 1 : -1] DISPATCH_UNUSED; \
	})
#else
#define dispatch_static_assert(e)
#endif

#define DISPATCH_BAD_INPUT		((void *_Nonnull)0)
#define DISPATCH_OUT_OF_MEMORY	((void *_Nonnull)0)

/*
 * For reporting bugs within libdispatch when using the "_debug" version of the
 * library.
 */
#if __APPLE__
#define dispatch_assert(e) do { \
		if (__builtin_constant_p(e)) { \
			dispatch_static_assert(e); \
		} else { \
			typeof(e) _e = (e); /* always eval 'e' */ \
			if (unlikely(DISPATCH_DEBUG && !_e)) { \
				_dispatch_abort(__LINE__, (long)_e); \
			} \
		} \
	} while (0)
#else
static inline void
_dispatch_assert(long e, size_t line)
{
	if (DISPATCH_DEBUG && !e) _dispatch_abort(line, e);
}
#define dispatch_assert(e) _dispatch_assert((long)(e), __LINE__)
#endif	/* __GNUC__ */

#if __APPLE__
/*
 * A lot of API return zero upon success and not-zero on fail. Let's capture
 * and log the non-zero value
 */
#define dispatch_assert_zero(e) do { \
		if (__builtin_constant_p(e)) { \
			dispatch_static_assert(e); \
		} else { \
			typeof(e) _e = (e); /* always eval 'e' */ \
			if (unlikely(DISPATCH_DEBUG && _e)) { \
				_dispatch_abort(__LINE__, (long)_e); \
			} \
		} \
	} while (0)
#else
static inline void
_dispatch_assert_zero(long e, size_t line)
{
	if (DISPATCH_DEBUG && e) _dispatch_abort(line, e);
}
#define dispatch_assert_zero(e) _dispatch_assert_zero((long)(e), __LINE__)
#endif	/* __GNUC__ */

/*
 * For reporting bugs or impedance mismatches between libdispatch and external
 * subsystems. These do NOT abort(), and are always compiled into the product.
 *
 * In particular, we wrap all system-calls with assume() macros.
 */
#if __GNUC__
#define dispatch_assume(e) ({ \
		typeof(e) _e = (e); /* always eval 'e' */ \
		if (unlikely(!_e)) { \
			if (__builtin_constant_p(e)) { \
				dispatch_static_assert(e); \
			} \
			_dispatch_bug(__LINE__, (long)_e); \
		} \
		_e; \
	})
#else
static inline long
_dispatch_assume(long e, long line)
{
	if (!e) _dispatch_bug(line, e);
	return e;
}
#define dispatch_assume(e) _dispatch_assume((long)(e), __LINE__)
#endif	/* __GNUC__ */

/*
 * A lot of API return zero upon success and not-zero on fail. Let's capture
 * and log the non-zero value
 */
#if __GNUC__
#define dispatch_assume_zero(e) ({ \
		typeof(e) _e = (e); /* always eval 'e' */ \
		if (unlikely(_e)) { \
			if (__builtin_constant_p(e)) { \
				dispatch_static_assert(e); \
			} \
			_dispatch_bug(__LINE__, (long)_e); \
		} \
		_e; \
	})
#else
static inline long
_dispatch_assume_zero(long e, long line)
{
	if (e) _dispatch_bug(line, e);
	return e;
}
#define dispatch_assume_zero(e) _dispatch_assume_zero((long)(e), __LINE__)
#endif	/* __GNUC__ */

/*
 * For reporting bugs in clients when using the "_debug" version of the library.
 */
#if __GNUC__
#define dispatch_debug_assert(e, msg, args...) do { \
		if (__builtin_constant_p(e)) { \
			dispatch_static_assert(e); \
		} else { \
			typeof(e) _e = (e); /* always eval 'e' */ \
			if (unlikely(DISPATCH_DEBUG && !_e)) { \
				_dispatch_log("%s() 0x%lx: " msg, __func__, (long)_e, ##args); \
				abort(); \
			} \
		} \
	} while (0)
#else
#define dispatch_debug_assert(e, msg, args...) do { \
	typeof(e) _e = (e); /* always eval 'e' */ \
	if (unlikely(DISPATCH_DEBUG && !_e)) { \
		_dispatch_log("%s() 0x%lx: " msg, __FUNCTION__, _e, ##args); \
		abort(); \
	} \
} while (0)
#endif	/* __GNUC__ */

/* Make sure the debug statments don't get too stale */
#define _dispatch_debug(x, args...) do { \
	if (DISPATCH_DEBUG) { \
		_dispatch_log("%u\t%p\t" x, __LINE__, \
				(void *)_dispatch_thread_self(), ##args); \
	} \
} while (0)

#if DISPATCH_DEBUG
/* This is the private version of the deprecated dispatch_debug() */
DISPATCH_NONNULL2 DISPATCH_NOTHROW
__attribute__((__format__(printf,2,3)))
void
_dispatch_object_debug(dispatch_object_t object, const char *message, ...);
#else
#define _dispatch_object_debug(object, message, ...)
#endif // DISPATCH_DEBUG

#ifdef __BLOCKS__
#define _dispatch_Block_invoke(bb) \
		((dispatch_function_t)((struct Block_layout *)bb)->invoke)
void *_dispatch_Block_copy(void *block);
#if __GNUC__
#define _dispatch_Block_copy(x) ((typeof(x))_dispatch_Block_copy(x))
#endif
void _dispatch_call_block_and_release(void *block);
#endif /* __BLOCKS__ */

void _dispatch_temporary_resource_shortage(void);
void *_dispatch_calloc(size_t num_items, size_t size);
const char *_dispatch_strdup_if_mutable(const char *str);
void _dispatch_vtable_init(void);
char *_dispatch_get_build(void);
int _dispatch_sigmask(void);

uint64_t _dispatch_timeout(dispatch_time_t when);
uint64_t _dispatch_time_nanoseconds_since_epoch(dispatch_time_t when);

#define _DISPATCH_UNSAFE_FORK_MULTITHREADED  ((uint8_t)1)
#define _DISPATCH_UNSAFE_FORK_PROHIBIT       ((uint8_t)2)
extern uint8_t _dispatch_unsafe_fork;
extern bool _dispatch_child_of_unsafe_fork;
void _dispatch_fork_becomes_unsafe_slow(void);

#define _dispatch_is_multithreaded_inline() \
	((_dispatch_unsafe_fork & _DISPATCH_UNSAFE_FORK_MULTITHREADED) != 0)

DISPATCH_ALWAYS_INLINE
static inline void
_dispatch_fork_becomes_unsafe(void)
{
	if (unlikely(!_dispatch_is_multithreaded_inline())) {
		_dispatch_fork_becomes_unsafe_slow();
		DISPATCH_COMPILER_CAN_ASSUME(_dispatch_is_multithreaded_inline());
	}
}

#if DISPATCH_INTROSPECTION
#undef DISPATCH_PERF_MON
#define DISPATCH_PERF_MON 0
#endif

/* #includes dependent on internal.h */
#include "shims.h"
#include "event/event_internal.h"

// Older Mac OS X and iOS Simulator fallbacks

#if HAVE__PTHREAD_WORKQUEUE_INIT && PTHREAD_WORKQUEUE_SPI_VERSION >= 20140213 \
		&& !defined(HAVE_PTHREAD_WORKQUEUE_QOS)
#define HAVE_PTHREAD_WORKQUEUE_QOS 1
#endif
#if HAVE__PTHREAD_WORKQUEUE_INIT && PTHREAD_WORKQUEUE_SPI_VERSION >= 20150304 \
		&& !defined(HAVE_PTHREAD_WORKQUEUE_KEVENT)
#define HAVE_PTHREAD_WORKQUEUE_KEVENT 1
#endif


#ifndef HAVE_PTHREAD_WORKQUEUE_NARROWING
#if !DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(109900)
#define HAVE_PTHREAD_WORKQUEUE_NARROWING 0
#else
#define HAVE_PTHREAD_WORKQUEUE_NARROWING 1
#endif
#endif

#ifdef EVFILT_MEMORYSTATUS
#ifndef DISPATCH_USE_MEMORYSTATUS
#define DISPATCH_USE_MEMORYSTATUS 1
#endif
#endif // EVFILT_MEMORYSTATUS

#if TARGET_OS_SIMULATOR
#undef DISPATCH_USE_MEMORYPRESSURE_SOURCE
#define DISPATCH_USE_MEMORYPRESSURE_SOURCE 0
#endif // TARGET_OS_SIMULATOR
#if !defined(DISPATCH_USE_MEMORYPRESSURE_SOURCE) && DISPATCH_USE_MEMORYSTATUS
#define DISPATCH_USE_MEMORYPRESSURE_SOURCE 1
#endif
#if DISPATCH_USE_MEMORYPRESSURE_SOURCE
#if __has_include(<malloc_private.h>)
#include <malloc_private.h>
#else
extern void malloc_memory_event_handler(unsigned long);
#endif // __has_include(<malloc_private.h)
extern bool _dispatch_memory_warn;
#endif

#if HAVE_PTHREAD_WORKQUEUE_KEVENT && defined(KEVENT_FLAG_WORKQ) && \
		!defined(DISPATCH_USE_KEVENT_WORKQUEUE)
#define DISPATCH_USE_KEVENT_WORKQUEUE 1
#endif

#if (!DISPATCH_USE_KEVENT_WORKQUEUE || DISPATCH_DEBUG || DISPATCH_PROFILE) && \
		!defined(DISPATCH_USE_MGR_THREAD)
#define DISPATCH_USE_MGR_THREAD 1
#endif


#if defined(MACH_SEND_SYNC_OVERRIDE) && defined(MACH_RCV_SYNC_WAIT) && \
		DISPATCH_MIN_REQUIRED_OSX_AT_LEAST(109900) && \
		!defined(DISPATCH_USE_MACH_SEND_SYNC_OVERRIDE)
#define DISPATCH_USE_MACH_SEND_SYNC_OVERRIDE 1
#endif

#if defined(F_SETNOSIGPIPE) && defined(F_GETNOSIGPIPE)
#ifndef DISPATCH_USE_SETNOSIGPIPE
#define DISPATCH_USE_SETNOSIGPIPE 1
#endif
#endif // F_SETNOSIGPIPE

#if defined(MACH_SEND_NOIMPORTANCE)
#ifndef DISPATCH_USE_CHECKIN_NOIMPORTANCE
#define DISPATCH_USE_CHECKIN_NOIMPORTANCE 1 // rdar://problem/16996737
#endif
#ifndef DISPATCH_USE_NOIMPORTANCE_QOS
#define DISPATCH_USE_NOIMPORTANCE_QOS 1 // rdar://problem/21414476
#endif
#endif // MACH_SEND_NOIMPORTANCE


#if HAVE_LIBPROC_INTERNAL_H
#include <libproc.h>
#include <libproc_internal.h>
#ifndef DISPATCH_USE_IMPORTANCE_ASSERTION
#define DISPATCH_USE_IMPORTANCE_ASSERTION 1
#endif
#endif // HAVE_LIBPROC_INTERNAL_H

#if HAVE_SYS_GUARDED_H
#include <sys/guarded.h>
#ifndef DISPATCH_USE_GUARDED_FD
#define DISPATCH_USE_GUARDED_FD 1
#endif
#endif // HAVE_SYS_GUARDED_H


#if DISPATCH_USE_DTRACE || DISPATCH_USE_DTRACE_INTROSPECTION
typedef struct dispatch_trace_timer_params_s {
	int64_t deadline, interval, leeway;
} *dispatch_trace_timer_params_t;

#ifdef __cplusplus
extern "C++" {
#endif
#include "provider.h"
#ifdef __cplusplus
}
#endif
#endif // DISPATCH_USE_DTRACE || DISPATCH_USE_DTRACE_INTROSPECTION

#if __has_include(<sys/kdebug.h>)
#include <sys/kdebug.h>
#ifndef DBG_DISPATCH
#define DBG_DISPATCH 46
#endif
#ifndef KDBG_CODE
#define KDBG_CODE(...) 0
#define DBG_FUNC_START 0
#define DBG_FUNC_END 0
#endif
#define DISPATCH_CODE(subclass, code) \
		KDBG_CODE(DBG_DISPATCH, DISPATCH_TRACE_SUBCLASS_##subclass, code)
#define DISPATCH_CODE_START(subclass, code) \
		(DISPATCH_CODE(subclass, code) | DBG_FUNC_START)
#define DISPATCH_CODE_END(subclass, code) \
		(DISPATCH_CODE(subclass, code) | DBG_FUNC_END)
#ifdef ARIADNEDBG_CODE
#define ARIADNE_ENTER_DISPATCH_MAIN_CODE ARIADNEDBG_CODE(220, 2)
#else
#define ARIADNE_ENTER_DISPATCH_MAIN_CODE 0
#endif
#if !defined(DISPATCH_USE_VOUCHER_KDEBUG_TRACE) && \
		(DISPATCH_INTROSPECTION || DISPATCH_PROFILE || DISPATCH_DEBUG)
#define DISPATCH_USE_VOUCHER_KDEBUG_TRACE 1
#endif

#define DISPATCH_TRACE_SUBCLASS_DEFAULT 0
#define DISPATCH_TRACE_SUBCLASS_VOUCHER 1
#define DISPATCH_TRACE_SUBCLASS_PERF 2
#define DISPATCH_TRACE_SUBCLASS_MACH_MSG 3
#define DISPATCH_TRACE_SUBCLASS_PERF_MON 4

#define DISPATCH_PERF_non_leaf_retarget DISPATCH_CODE(PERF, 1)
#define DISPATCH_PERF_post_activate_retarget DISPATCH_CODE(PERF, 2)
#define DISPATCH_PERF_post_activate_mutation DISPATCH_CODE(PERF, 3)
#define DISPATCH_PERF_delayed_registration DISPATCH_CODE(PERF, 4)
#define DISPATCH_PERF_mutable_target DISPATCH_CODE(PERF, 5)
#define DISPATCH_PERF_strict_bg_timer DISPATCH_CODE(PERF, 6)

#define DISPATCH_MACH_MSG_hdr_move DISPATCH_CODE(MACH_MSG, 1)

#define DISPATCH_PERF_MON_worker_thread_start DISPATCH_CODE_START(PERF_MON, 1)
#define DISPATCH_PERF_MON_worker_thread_end DISPATCH_CODE_END(PERF_MON, 1)
#define DISPATCH_PERF_MON_worker_useless DISPATCH_CODE(PERF_MON, 2)

DISPATCH_ALWAYS_INLINE
static inline void
_dispatch_ktrace_impl(uint32_t code, uint64_t a, uint64_t b,
		uint64_t c, uint64_t d)
{
	if (!code) return;
#ifdef _COMM_PAGE_KDEBUG_ENABLE
	if (likely(*(volatile uint32_t *)_COMM_PAGE_KDEBUG_ENABLE == 0)) return;
#endif
	kdebug_trace(code, a, b, c, d);
}
#define _dispatch_cast_to_uint64(e) \
		__builtin_choose_expr(sizeof(e) > 4, \
				((uint64_t)(e)), ((uint64_t)(uintptr_t)(e)))
#define _dispatch_ktrace(code, a, b, c, d)  _dispatch_ktrace_impl(code, \
		_dispatch_cast_to_uint64(a), _dispatch_cast_to_uint64(b), \
		_dispatch_cast_to_uint64(c), _dispatch_cast_to_uint64(d))

#else // __has_include(<sys/kdebug.h>)
#define DISPATCH_CODE(subclass, code) 0
#define ARIADNE_ENTER_DISPATCH_MAIN_CODE 0
#define DISPATCH_USE_VOUCHER_KDEBUG_TRACE 0
#define _dispatch_ktrace(code, a, b, c, d)
#endif // !__has_include(<sys/kdebug.h>)
#define _dispatch_ktrace4(code, a, b, c, d) _dispatch_ktrace(code, a, b, c, d)
#define _dispatch_ktrace3(code, a, b, c)    _dispatch_ktrace(code, a, b, c, 0)
#define _dispatch_ktrace2(code, a, b)       _dispatch_ktrace(code, a, b, 0, 0)
#define _dispatch_ktrace1(code, a)          _dispatch_ktrace(code, a, 0, 0, 0)
#define _dispatch_ktrace0(code)             _dispatch_ktrace(code, 0, 0, 0, 0)

#ifndef MACH_MSGH_BITS_VOUCHER_MASK
#define MACH_MSGH_BITS_VOUCHER_MASK	0x001f0000
#define	MACH_MSGH_BITS_SET_PORTS(remote, local, voucher)	\
	(((remote) & MACH_MSGH_BITS_REMOTE_MASK) | 		\
	 (((local) << 8) & MACH_MSGH_BITS_LOCAL_MASK) | 	\
	 (((voucher) << 16) & MACH_MSGH_BITS_VOUCHER_MASK))
#define	MACH_MSGH_BITS_VOUCHER(bits)				\
		(((bits) & MACH_MSGH_BITS_VOUCHER_MASK) >> 16)
#define MACH_MSGH_BITS_HAS_VOUCHER(bits)			\
	(MACH_MSGH_BITS_VOUCHER(bits) != MACH_MSGH_BITS_ZERO)
#define msgh_voucher_port msgh_reserved
#define mach_voucher_t mach_port_t
#define MACH_VOUCHER_NULL MACH_PORT_NULL
#define MACH_SEND_INVALID_VOUCHER 0x10000005
#endif

#ifndef VOUCHER_USE_MACH_VOUCHER
#if __has_include(<mach/mach_voucher.h>)
#define VOUCHER_USE_MACH_VOUCHER 1
#endif
#endif // VOUCHER_USE_MACH_VOUCHER

#ifndef VOUCHER_USE_EMPTY_MACH_BASE_VOUCHER
#if RDAR_24272659 // FIXME: <rdar://problem/24272659>
#define VOUCHER_USE_EMPTY_MACH_BASE_VOUCHER 1
#else // RDAR_24272659
#define VOUCHER_USE_EMPTY_MACH_BASE_VOUCHER 0
#endif // RDAR_24272659
#endif

#ifndef VOUCHER_USE_PERSONA
#if VOUCHER_USE_MACH_VOUCHER && defined(BANK_PERSONA_TOKEN) && \
		TARGET_OS_IOS && !TARGET_OS_SIMULATOR
#define VOUCHER_USE_PERSONA 1
#else
#define VOUCHER_USE_PERSONA 0
#endif
#endif // VOUCHER_USE_PERSONA

#if VOUCHER_USE_MACH_VOUCHER
#undef DISPATCH_USE_IMPORTANCE_ASSERTION
#define DISPATCH_USE_IMPORTANCE_ASSERTION 0
#else
#undef MACH_RCV_VOUCHER
#define MACH_RCV_VOUCHER 0
#define VOUCHER_USE_PERSONA 0
#endif // VOUCHER_USE_MACH_VOUCHER

#define _dispatch_hardware_crash() \
		__asm__(""); __builtin_trap() // <rdar://problem/17464981>

#define _dispatch_set_crash_log_cause_and_message(ac, msg) ((void)(ac))
#define _dispatch_set_crash_log_message(msg)
#define _dispatch_set_crash_log_message_dynamic(msg)

#if HAVE_MACH
// MIG_REPLY_MISMATCH means either:
// 1) A signal handler is NOT using async-safe API. See the sigaction(2) man
//    page for more info.
// 2) A hand crafted call to mach_msg*() screwed up. Use MIG.
#define DISPATCH_VERIFY_MIG(x) do { \
		if ((x) == MIG_REPLY_MISMATCH) { \
			_dispatch_set_crash_log_cause_and_message((x), \
					"MIG_REPLY_MISMATCH"); \
			_dispatch_hardware_crash(); \
		} \
	} while (0)
#endif

#define DISPATCH_INTERNAL_CRASH(c, x) do { \
		_dispatch_set_crash_log_cause_and_message((c), \
				"BUG IN LIBDISPATCH: " x); \
		_dispatch_hardware_crash(); \
	} while (0)

#define DISPATCH_CLIENT_CRASH(c, x) do { \
		_dispatch_set_crash_log_cause_and_message((c), \
				"BUG IN CLIENT OF LIBDISPATCH: " x); \
		_dispatch_hardware_crash(); \
	} while (0)

#define _OS_OBJECT_CLIENT_CRASH(x) do { \
		_dispatch_set_crash_log_message("API MISUSE: " x); \
		_dispatch_hardware_crash(); \
	} while (0)

#define DISPATCH_ASSERTION_FAILED_MESSAGE \
		"BUG IN CLIENT OF LIBDISPATCH: Assertion failed: "

#define _dispatch_assert_crash(msg)  do { \
		const char *__msg = (msg); \
		_dispatch_log("%s", __msg); \
		_dispatch_set_crash_log_message_dynamic(__msg); \
		_dispatch_hardware_crash(); \
	} while (0)

#define _dispatch_client_assert_fail(fmt, ...)  do { \
		char *_msg = NULL; \
		asprintf(&_msg, "%s" fmt, DISPATCH_ASSERTION_FAILED_MESSAGE, \
				##__VA_ARGS__); \
		_dispatch_assert_crash(_msg); \
		free(_msg); \
	} while (0)

#define DISPATCH_NO_VOUCHER ((voucher_t)(void*)~0ul)
#define DISPATCH_NO_PRIORITY ((pthread_priority_t)~0ul)
DISPATCH_ENUM(dispatch_thread_set_self, unsigned long,
	DISPATCH_PRIORITY_ENFORCE = 0x1,
	DISPATCH_VOUCHER_REPLACE = 0x2,
	DISPATCH_VOUCHER_CONSUME = 0x4,
	DISPATCH_THREAD_PARK = 0x8,
);
DISPATCH_WARN_RESULT
static inline voucher_t _dispatch_adopt_priority_and_set_voucher(
		pthread_priority_t priority, voucher_t voucher,
		dispatch_thread_set_self_t flags);
#if HAVE_MACH
mach_port_t _dispatch_get_mach_host_port(void);
#endif

#if HAVE_PTHREAD_WORKQUEUE_QOS
#if DISPATCH_DEBUG
extern int _dispatch_set_qos_class_enabled;
#else
#define _dispatch_set_qos_class_enabled (1)
#endif
#endif // HAVE_PTHREAD_WORKQUEUE_QOS
#if DISPATCH_USE_KEVENT_WORKQUEUE
#if !HAVE_PTHREAD_WORKQUEUE_QOS || !EV_UDATA_SPECIFIC
#error Invalid build configuration
#endif
#if DISPATCH_USE_MGR_THREAD
extern int _dispatch_kevent_workqueue_enabled;
#else
#define _dispatch_kevent_workqueue_enabled (1)
#endif
#else
#define _dispatch_kevent_workqueue_enabled (0)
#endif // DISPATCH_USE_KEVENT_WORKQUEUE


/* #includes dependent on internal.h */
#include "object_internal.h"
#include "semaphore_internal.h"
#include "introspection_internal.h"
#include "queue_internal.h"
#include "source_internal.h"
#include "mach_internal.h"
#include "voucher_internal.h"
#include "data_internal.h"
#if !TARGET_OS_WIN32
#include "io_internal.h"
#endif
#include "inline_internal.h"
#include "firehose/firehose_internal.h"

#endif /* __DISPATCH_INTERNAL__ */