freebsd-dev/sys/sys/stdatomic.h
Pedro F. Giffuni c4e20cad00 sys/sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:01:59 +00:00

414 lines
14 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
* David Chisnall <theraven@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _STDATOMIC_H_
#define _STDATOMIC_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
#if __has_extension(c_atomic) || __has_extension(cxx_atomic)
#define __CLANG_ATOMICS
#elif __GNUC_PREREQ__(4, 7)
#define __GNUC_ATOMICS
#elif defined(__GNUC__)
#define __SYNC_ATOMICS
#else
#error "stdatomic.h does not support your compiler"
#endif
/*
* 7.17.1 Atomic lock-free macros.
*/
#ifdef __GCC_ATOMIC_BOOL_LOCK_FREE
#define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_CHAR_LOCK_FREE
#define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_CHAR16_T_LOCK_FREE
#define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_CHAR32_T_LOCK_FREE
#define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_WCHAR_T_LOCK_FREE
#define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_SHORT_LOCK_FREE
#define ATOMIC_SHORT_LOCK_FREE __GCC_ATOMIC_SHORT_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_INT_LOCK_FREE
#define ATOMIC_INT_LOCK_FREE __GCC_ATOMIC_INT_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_LONG_LOCK_FREE
#define ATOMIC_LONG_LOCK_FREE __GCC_ATOMIC_LONG_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_LLONG_LOCK_FREE
#define ATOMIC_LLONG_LOCK_FREE __GCC_ATOMIC_LLONG_LOCK_FREE
#endif
#ifdef __GCC_ATOMIC_POINTER_LOCK_FREE
#define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE
#endif
/*
* 7.17.2 Initialization.
*/
#if defined(__CLANG_ATOMICS)
#define ATOMIC_VAR_INIT(value) (value)
#define atomic_init(obj, value) __c11_atomic_init(obj, value)
#else
#define ATOMIC_VAR_INIT(value) { .__val = (value) }
#define atomic_init(obj, value) ((void)((obj)->__val = (value)))
#endif
/*
* Clang and recent GCC both provide predefined macros for the memory
* orderings. If we are using a compiler that doesn't define them, use the
* clang values - these will be ignored in the fallback path.
*/
#ifndef __ATOMIC_RELAXED
#define __ATOMIC_RELAXED 0
#endif
#ifndef __ATOMIC_CONSUME
#define __ATOMIC_CONSUME 1
#endif
#ifndef __ATOMIC_ACQUIRE
#define __ATOMIC_ACQUIRE 2
#endif
#ifndef __ATOMIC_RELEASE
#define __ATOMIC_RELEASE 3
#endif
#ifndef __ATOMIC_ACQ_REL
#define __ATOMIC_ACQ_REL 4
#endif
#ifndef __ATOMIC_SEQ_CST
#define __ATOMIC_SEQ_CST 5
#endif
/*
* 7.17.3 Order and consistency.
*
* The memory_order_* constants that denote the barrier behaviour of the
* atomic operations.
*/
typedef enum {
memory_order_relaxed = __ATOMIC_RELAXED,
memory_order_consume = __ATOMIC_CONSUME,
memory_order_acquire = __ATOMIC_ACQUIRE,
memory_order_release = __ATOMIC_RELEASE,
memory_order_acq_rel = __ATOMIC_ACQ_REL,
memory_order_seq_cst = __ATOMIC_SEQ_CST
} memory_order;
/*
* 7.17.4 Fences.
*/
static __inline void
atomic_thread_fence(memory_order __order __unused)
{
#ifdef __CLANG_ATOMICS
__c11_atomic_thread_fence(__order);
#elif defined(__GNUC_ATOMICS)
__atomic_thread_fence(__order);
#else
__sync_synchronize();
#endif
}
static __inline void
atomic_signal_fence(memory_order __order __unused)
{
#ifdef __CLANG_ATOMICS
__c11_atomic_signal_fence(__order);
#elif defined(__GNUC_ATOMICS)
__atomic_signal_fence(__order);
#else
__asm volatile ("" ::: "memory");
#endif
}
/*
* 7.17.5 Lock-free property.
*/
#if defined(_KERNEL)
/* Atomics in kernelspace are always lock-free. */
#define atomic_is_lock_free(obj) \
((void)(obj), (_Bool)1)
#elif defined(__CLANG_ATOMICS)
#define atomic_is_lock_free(obj) \
__atomic_is_lock_free(sizeof(*(obj)), obj)
#elif defined(__GNUC_ATOMICS)
#define atomic_is_lock_free(obj) \
__atomic_is_lock_free(sizeof((obj)->__val), &(obj)->__val)
#else
#define atomic_is_lock_free(obj) \
((void)(obj), sizeof((obj)->__val) <= sizeof(void *))
#endif
/*
* 7.17.6 Atomic integer types.
*/
typedef _Atomic(_Bool) atomic_bool;
typedef _Atomic(char) atomic_char;
typedef _Atomic(signed char) atomic_schar;
typedef _Atomic(unsigned char) atomic_uchar;
typedef _Atomic(short) atomic_short;
typedef _Atomic(unsigned short) atomic_ushort;
typedef _Atomic(int) atomic_int;
typedef _Atomic(unsigned int) atomic_uint;
typedef _Atomic(long) atomic_long;
typedef _Atomic(unsigned long) atomic_ulong;
typedef _Atomic(long long) atomic_llong;
typedef _Atomic(unsigned long long) atomic_ullong;
typedef _Atomic(__char16_t) atomic_char16_t;
typedef _Atomic(__char32_t) atomic_char32_t;
typedef _Atomic(___wchar_t) atomic_wchar_t;
typedef _Atomic(__int_least8_t) atomic_int_least8_t;
typedef _Atomic(__uint_least8_t) atomic_uint_least8_t;
typedef _Atomic(__int_least16_t) atomic_int_least16_t;
typedef _Atomic(__uint_least16_t) atomic_uint_least16_t;
typedef _Atomic(__int_least32_t) atomic_int_least32_t;
typedef _Atomic(__uint_least32_t) atomic_uint_least32_t;
typedef _Atomic(__int_least64_t) atomic_int_least64_t;
typedef _Atomic(__uint_least64_t) atomic_uint_least64_t;
typedef _Atomic(__int_fast8_t) atomic_int_fast8_t;
typedef _Atomic(__uint_fast8_t) atomic_uint_fast8_t;
typedef _Atomic(__int_fast16_t) atomic_int_fast16_t;
typedef _Atomic(__uint_fast16_t) atomic_uint_fast16_t;
typedef _Atomic(__int_fast32_t) atomic_int_fast32_t;
typedef _Atomic(__uint_fast32_t) atomic_uint_fast32_t;
typedef _Atomic(__int_fast64_t) atomic_int_fast64_t;
typedef _Atomic(__uint_fast64_t) atomic_uint_fast64_t;
typedef _Atomic(__intptr_t) atomic_intptr_t;
typedef _Atomic(__uintptr_t) atomic_uintptr_t;
typedef _Atomic(__size_t) atomic_size_t;
typedef _Atomic(__ptrdiff_t) atomic_ptrdiff_t;
typedef _Atomic(__intmax_t) atomic_intmax_t;
typedef _Atomic(__uintmax_t) atomic_uintmax_t;
/*
* 7.17.7 Operations on atomic types.
*/
/*
* Compiler-specific operations.
*/
#if defined(__CLANG_ATOMICS)
#define atomic_compare_exchange_strong_explicit(object, expected, \
desired, success, failure) \
__c11_atomic_compare_exchange_strong(object, expected, desired, \
success, failure)
#define atomic_compare_exchange_weak_explicit(object, expected, \
desired, success, failure) \
__c11_atomic_compare_exchange_weak(object, expected, desired, \
success, failure)
#define atomic_exchange_explicit(object, desired, order) \
__c11_atomic_exchange(object, desired, order)
#define atomic_fetch_add_explicit(object, operand, order) \
__c11_atomic_fetch_add(object, operand, order)
#define atomic_fetch_and_explicit(object, operand, order) \
__c11_atomic_fetch_and(object, operand, order)
#define atomic_fetch_or_explicit(object, operand, order) \
__c11_atomic_fetch_or(object, operand, order)
#define atomic_fetch_sub_explicit(object, operand, order) \
__c11_atomic_fetch_sub(object, operand, order)
#define atomic_fetch_xor_explicit(object, operand, order) \
__c11_atomic_fetch_xor(object, operand, order)
#define atomic_load_explicit(object, order) \
__c11_atomic_load(object, order)
#define atomic_store_explicit(object, desired, order) \
__c11_atomic_store(object, desired, order)
#elif defined(__GNUC_ATOMICS)
#define atomic_compare_exchange_strong_explicit(object, expected, \
desired, success, failure) \
__atomic_compare_exchange_n(&(object)->__val, expected, \
desired, 0, success, failure)
#define atomic_compare_exchange_weak_explicit(object, expected, \
desired, success, failure) \
__atomic_compare_exchange_n(&(object)->__val, expected, \
desired, 1, success, failure)
#define atomic_exchange_explicit(object, desired, order) \
__atomic_exchange_n(&(object)->__val, desired, order)
#define atomic_fetch_add_explicit(object, operand, order) \
__atomic_fetch_add(&(object)->__val, operand, order)
#define atomic_fetch_and_explicit(object, operand, order) \
__atomic_fetch_and(&(object)->__val, operand, order)
#define atomic_fetch_or_explicit(object, operand, order) \
__atomic_fetch_or(&(object)->__val, operand, order)
#define atomic_fetch_sub_explicit(object, operand, order) \
__atomic_fetch_sub(&(object)->__val, operand, order)
#define atomic_fetch_xor_explicit(object, operand, order) \
__atomic_fetch_xor(&(object)->__val, operand, order)
#define atomic_load_explicit(object, order) \
__atomic_load_n(&(object)->__val, order)
#define atomic_store_explicit(object, desired, order) \
__atomic_store_n(&(object)->__val, desired, order)
#else
#define __atomic_apply_stride(object, operand) \
(((__typeof__((object)->__val))0) + (operand))
#define atomic_compare_exchange_strong_explicit(object, expected, \
desired, success, failure) __extension__ ({ \
__typeof__(expected) __ep = (expected); \
__typeof__(*__ep) __e = *__ep; \
(void)(success); (void)(failure); \
(_Bool)((*__ep = __sync_val_compare_and_swap(&(object)->__val, \
__e, desired)) == __e); \
})
#define atomic_compare_exchange_weak_explicit(object, expected, \
desired, success, failure) \
atomic_compare_exchange_strong_explicit(object, expected, \
desired, success, failure)
#if __has_builtin(__sync_swap)
/* Clang provides a full-barrier atomic exchange - use it if available. */
#define atomic_exchange_explicit(object, desired, order) \
((void)(order), __sync_swap(&(object)->__val, desired))
#else
/*
* __sync_lock_test_and_set() is only an acquire barrier in theory (although in
* practice it is usually a full barrier) so we need an explicit barrier before
* it.
*/
#define atomic_exchange_explicit(object, desired, order) \
__extension__ ({ \
__typeof__(object) __o = (object); \
__typeof__(desired) __d = (desired); \
(void)(order); \
__sync_synchronize(); \
__sync_lock_test_and_set(&(__o)->__val, __d); \
})
#endif
#define atomic_fetch_add_explicit(object, operand, order) \
((void)(order), __sync_fetch_and_add(&(object)->__val, \
__atomic_apply_stride(object, operand)))
#define atomic_fetch_and_explicit(object, operand, order) \
((void)(order), __sync_fetch_and_and(&(object)->__val, operand))
#define atomic_fetch_or_explicit(object, operand, order) \
((void)(order), __sync_fetch_and_or(&(object)->__val, operand))
#define atomic_fetch_sub_explicit(object, operand, order) \
((void)(order), __sync_fetch_and_sub(&(object)->__val, \
__atomic_apply_stride(object, operand)))
#define atomic_fetch_xor_explicit(object, operand, order) \
((void)(order), __sync_fetch_and_xor(&(object)->__val, operand))
#define atomic_load_explicit(object, order) \
((void)(order), __sync_fetch_and_add(&(object)->__val, 0))
#define atomic_store_explicit(object, desired, order) \
((void)atomic_exchange_explicit(object, desired, order))
#endif
/*
* Convenience functions.
*
* Don't provide these in kernel space. In kernel space, we should be
* disciplined enough to always provide explicit barriers.
*/
#ifndef _KERNEL
#define atomic_compare_exchange_strong(object, expected, desired) \
atomic_compare_exchange_strong_explicit(object, expected, \
desired, memory_order_seq_cst, memory_order_seq_cst)
#define atomic_compare_exchange_weak(object, expected, desired) \
atomic_compare_exchange_weak_explicit(object, expected, \
desired, memory_order_seq_cst, memory_order_seq_cst)
#define atomic_exchange(object, desired) \
atomic_exchange_explicit(object, desired, memory_order_seq_cst)
#define atomic_fetch_add(object, operand) \
atomic_fetch_add_explicit(object, operand, memory_order_seq_cst)
#define atomic_fetch_and(object, operand) \
atomic_fetch_and_explicit(object, operand, memory_order_seq_cst)
#define atomic_fetch_or(object, operand) \
atomic_fetch_or_explicit(object, operand, memory_order_seq_cst)
#define atomic_fetch_sub(object, operand) \
atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst)
#define atomic_fetch_xor(object, operand) \
atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst)
#define atomic_load(object) \
atomic_load_explicit(object, memory_order_seq_cst)
#define atomic_store(object, desired) \
atomic_store_explicit(object, desired, memory_order_seq_cst)
#endif /* !_KERNEL */
/*
* 7.17.8 Atomic flag type and operations.
*
* XXX: Assume atomic_bool can be used as an atomic_flag. Is there some
* kind of compiler built-in type we could use?
*/
typedef struct {
atomic_bool __flag;
} atomic_flag;
#define ATOMIC_FLAG_INIT { ATOMIC_VAR_INIT(0) }
static __inline _Bool
atomic_flag_test_and_set_explicit(volatile atomic_flag *__object,
memory_order __order)
{
return (atomic_exchange_explicit(&__object->__flag, 1, __order));
}
static __inline void
atomic_flag_clear_explicit(volatile atomic_flag *__object, memory_order __order)
{
atomic_store_explicit(&__object->__flag, 0, __order);
}
#ifndef _KERNEL
static __inline _Bool
atomic_flag_test_and_set(volatile atomic_flag *__object)
{
return (atomic_flag_test_and_set_explicit(__object,
memory_order_seq_cst));
}
static __inline void
atomic_flag_clear(volatile atomic_flag *__object)
{
atomic_flag_clear_explicit(__object, memory_order_seq_cst);
}
#endif /* !_KERNEL */
#endif /* !_STDATOMIC_H_ */