platform_bionic/libc/include/stdatomic.h
Hans Boehm 00aaea3645 Fix, generalize stdatomic.h; improve test.
We seem to use this stdatomic.h sometimes, and slightly different prebuilts
at other times, making them all difficult to test, and making it unclear
which one we're testing.  This generalizes the bionic header so that it
can be used directly as the prebuilt header as well.  So long as they
don't diverge again, that should somewhat improve test coverage.

Use the correct builtin for atomic_is_lock_free.

Fix atomic_flag_init.

Turn on atomic tests even with __GLIBC__, since they now appear to pass.

Include uchar.h in stdatomic.h where needed.

Add a basic memory ordering test.

Fix bit-rotted comments in bionic tests makefile.

Change-Id: If6a14c1075b379395ba5d93357d56025c0ffab68
2014-08-22 15:50:17 -07:00

521 lines
17 KiB
C++

/*-
* 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>
#if defined(__cplusplus) && defined(_USING_LIBCXX) && \
(__has_feature(cxx_atomic) || _GNUC_VER >= 407)
/* We have a usable C++ <atomic>; use it instead. */
#include <atomic>
#define _Atomic(t) std::atomic<t>
using std::atomic_is_lock_free;
using std::atomic_init;
using std::atomic_store;
using std::atomic_store_explicit;
using std::atomic_load;
using std::atomic_load_explicit;
using std::atomic_exchange;
using std::atomic_exchange_explicit;
using std::atomic_compare_exchange_strong;
using std::atomic_compare_exchange_strong_explicit;
using std::atomic_compare_exchange_weak;
using std::atomic_compare_exchange_weak_explicit;
using std::atomic_fetch_add;
using std::atomic_fetch_add_explicit;
using std::atomic_fetch_sub;
using std::atomic_fetch_sub_explicit;
using std::atomic_fetch_or;
using std::atomic_fetch_or_explicit;
using std::atomic_fetch_xor;
using std::atomic_fetch_xor_explicit;
using std::atomic_fetch_and;
using std::atomic_fetch_and_explicit;
using std::atomic_thread_fence;
using std::atomic_signal_fence;
using std::memory_order;
using std::memory_order_relaxed;
using std::memory_order_consume;
using std::memory_order_release;
using std::memory_order_acq_rel;
using std::memory_order_seq_cst;
using std::atomic_bool;
using std::atomic_char;
using std::atomic_schar;
using std::atomic_uchar;
using std::atomic_short;
using std::atomic_ushort;
using std::atomic_int;
using std::atomic_uint;
using std::atomic_long;
using std::atomic_ulong;
using std::atomic_llong;
using std::atomic_ullong;
using std::atomic_char16_t;
using std::atomic_char32_t;
using std::atomic_wchar_t;
using std::atomic_int_least8_t;
using std::atomic_uint_least8_t;
using std::atomic_int_least16_t;
using std::atomic_uint_least16_t;
using std::atomic_int_least32_t;
using std::atomic_uint_least32_t;
using std::atomic_int_least64_t;
using std::atomic_uint_least64_t;
using std::atomic_int_fast8_t;
using std::atomic_uint_fast8_t;
using std::atomic_int_fast16_t;
using std::atomic_uint_fast16_t;
using std::atomic_int_fast32_t;
using std::atomic_uint_fast32_t;
using std::atomic_int_fast64_t;
using std::atomic_uint_fast64_t;
using std::atomic_intptr_t;
using std::atomic_uintptr_t;
using std::atomic_size_t;
using std::atomic_ptrdiff_t;
using std::atomic_intmax_t;
using std::atomic_uintmax_t;
#else /* <atomic> unavailable, possibly because this is C, not C++ */
#include <sys/types.h>
#include <stdbool.h>
/*
* C: Do it ourselves.
* Note that the runtime representation defined here should be compatible
* with the C++ one, i.e. an _Atomic(T) needs to contain the same
* bits as a T.
*/
#include <stddef.h> /* For ptrdiff_t. */
#include <stdint.h> /* TODO: Should pollute namespace less. */
#if __STDC_VERSION__ >= 201112L
# include <uchar.h> /* For char16_t and char32_t. */
#endif
#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.
* The enum values must be identical to those used by the
* C++ <atomic> header.
*/
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 __attribute__((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 __attribute__((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) \
__c11_atomic_is_lock_free(sizeof(*(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.
*/
#if !__has_extension(c_atomic) && !__has_extension(cxx_atomic)
/*
* No native support for _Atomic(). Place object in structure to prevent
* most forms of direct non-atomic access.
*/
#define _Atomic(T) struct { T volatile __val; }
#endif
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 __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L
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_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(false) }
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 /* <atomic> unavailable */
#endif /* !_STDATOMIC_H_ */