/* * 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 * David Chisnall * 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 $ */ #ifndef _STDATOMIC_H_ #define _STDATOMIC_H_ #include #include #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) #endif /* !_STDATOMIC_H_ */