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Diffstat (limited to 'src/include/stdatomic.h')
| -rw-r--r-- | src/include/stdatomic.h | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/src/include/stdatomic.h b/src/include/stdatomic.h new file mode 100644 index 0000000..780e5a0 --- /dev/null +++ b/src/include/stdatomic.h @@ -0,0 +1,364 @@ +#pragma once +/* + * An implementation of C11 stdatomic.h directly borrowed from FreeBSD + * (original copyright follows), with minor modifications for + * portability to other systems. Works for recent Clang (that + * implement the feature c_atomic) and GCC 4.7+; includes + * compatibility for GCC below 4.7 but I wouldn't recommend it. + * + * Caveats and limitations: + * - Only the ``_Atomic parentheses'' notation is implemented, while + * the ``_Atomic space'' one is not. + * - _Atomic types must be typedef'ed, or programs using them will + * not type check correctly (incompatible anonymous structure + * types). + * - Non-scalar _Atomic types would require runtime support for + * runtime locking, which, as far as I know, is not currently + * available on any system. + */ + +/*- + * @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: src/include/stdatomic.h,v 1.10.2.2 2012/05/30 19:21:54 theraven Exp $ + */ +#include <stddef.h> +#include <stdint.h> + +#if !defined(__has_feature) +#define __has_feature(x) 0 +#endif +#if !defined(__has_builtin) +#define __has_builtin(x) 0 +#endif +#if !defined(__GNUC_PREREQ__) +#if defined(__GNUC__) && defined(__GNUC_MINOR__) +#define __GNUC_PREREQ__(maj, min) \ + ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) +#else +#define __GNUC_PREREQ__(maj, min) 0 +#endif +#endif + +#if !defined(__CLANG_ATOMICS) && !defined(__GNUC_ATOMICS) +#if __has_feature(c_atomic) +#define __CLANG_ATOMICS +#elif __GNUC_PREREQ__(4, 7) +#define __GNUC_ATOMICS +#elif !defined(__GNUC__) +#error "stdatomic.h does not support your compiler" +#endif +#endif + +#if !defined(__CLANG_ATOMICS) +#define _Atomic(T) struct { volatile __typeof__(T) __val; } +#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) do { \ + (obj)->__val = (value); \ +} while (0) +#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. + */ + +enum memory_order { + 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 +}; + +typedef enum memory_order memory_order; + +/* + * 7.17.4 Fences. + */ + +#ifdef __CLANG_ATOMICS +#define atomic_thread_fence(order) __c11_atomic_thread_fence(order) +#define atomic_signal_fence(order) __c11_atomic_signal_fence(order) +#elif defined(__GNUC_ATOMICS) +#define atomic_thread_fence(order) __atomic_thread_fence(order) +#define atomic_signal_fence(order) __atomic_signal_fence(order) +#else +#define atomic_thread_fence(order) __sync_synchronize() +#define atomic_signal_fence(order) __asm volatile ("" : : : "memory") +#endif + +/* + * 7.17.5 Lock-free property. + */ + +#if defined(__CLANG_ATOMICS) +#define atomic_is_lock_free(obj) \ + __c11_atomic_is_lock_free(sizeof(obj)) +#elif defined(__GNUC_ATOMICS) +#define atomic_is_lock_free(obj) \ + __atomic_is_lock_free(sizeof((obj)->__val)) +#else +#define atomic_is_lock_free(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; +#if 0 +typedef _Atomic(char16_t) atomic_char16_t; +typedef _Atomic(char32_t) atomic_char32_t; +#endif +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_compare_exchange_strong_explicit(object, expected, \ + desired, success, failure) ({ \ + __typeof__((object)->__val) __v; \ + _Bool __r; \ + __v = __sync_val_compare_and_swap(&(object)->__val, \ + *(expected), desired); \ + __r = *(expected) == __v; \ + *(expected) = __v; \ + __r; \ +}) + +#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) \ + __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 after + * it. + */ +#define atomic_exchange_explicit(object, desired, order) ({ \ + __typeof__((object)->__val) __v; \ + __v = __sync_lock_test_and_set(&(object)->__val, desired); \ + __sync_synchronize(); \ + __v; \ +}) +#endif +#define atomic_fetch_add_explicit(object, operand, order) \ + __sync_fetch_and_add(&(object)->__val, operand) +#define atomic_fetch_and_explicit(object, operand, order) \ + __sync_fetch_and_and(&(object)->__val, operand) +#define atomic_fetch_or_explicit(object, operand, order) \ + __sync_fetch_and_or(&(object)->__val, operand) +#define atomic_fetch_sub_explicit(object, operand, order) \ + __sync_fetch_and_sub(&(object)->__val, operand) +#define atomic_fetch_xor_explicit(object, operand, order) \ + __sync_fetch_and_xor(&(object)->__val, operand) +#define atomic_load_explicit(object, order) \ + __sync_fetch_and_add(&(object)->__val, 0) +#define atomic_store_explicit(object, desired, order) do { \ + __sync_synchronize(); \ + (object)->__val = (desired); \ + __sync_synchronize(); \ +} while (0) +#endif + +/* + * Convenience functions. + */ + +#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) + +/* + * 7.17.8 Atomic flag type and operations. + */ + +typedef atomic_bool atomic_flag; + +#define ATOMIC_FLAG_INIT ATOMIC_VAR_INIT(0) + +#define atomic_flag_clear_explicit(object, order) \ + atomic_store_explicit(object, 0, order) +#define atomic_flag_test_and_set_explicit(object, order) \ + atomic_compare_exchange_strong_explicit(object, 0, 1, order, order) + +#define atomic_flag_clear(object) \ + atomic_flag_clear_explicit(object, memory_order_seq_cst) +#define atomic_flag_test_and_set(object) \ + atomic_flag_test_and_set_explicit(object, memory_order_seq_cst) |