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/*
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| https://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Levi Morrison <morrison.levi@gmail.com> |
+----------------------------------------------------------------------+
*/
#ifndef ZEND_ATOMIC_H
#define ZEND_ATOMIC_H
#include "zend_portability.h"
#include <stdbool.h>
#define ZEND_GCC_PREREQ(x, y) \
((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) || (__GNUC__ > (x)))
/* Builtins are used to avoid library linkage */
#if __has_feature(c_atomic) && defined(__clang__)
#define HAVE_C11_ATOMICS 1
#elif ZEND_GCC_PREREQ(4, 7)
#define HAVE_GNUC_ATOMICS 1
#elif defined(__GNUC__)
#define HAVE_SYNC_ATOMICS 1
#elif !defined(ZEND_WIN32)
#define HAVE_NO_ATOMICS 1
#endif
#undef ZEND_GCC_PREREQ
/* Treat zend_atomic_* types as opaque. They have definitions only for size
* and alignment purposes.
*/
#if defined(ZEND_WIN32) || defined(HAVE_SYNC_ATOMICS)
typedef struct zend_atomic_bool_s {
volatile char value;
} zend_atomic_bool;
#elif defined(HAVE_C11_ATOMICS)
typedef struct zend_atomic_bool_s {
_Atomic(bool) value;
} zend_atomic_bool;
#else
typedef struct zend_atomic_bool_s {
volatile bool value;
} zend_atomic_bool;
#endif
BEGIN_EXTERN_C()
#ifdef ZEND_WIN32
#ifndef InterlockedExchange8
#define InterlockedExchange8 _InterlockedExchange8
#endif
#ifndef InterlockedOr8
#define InterlockedOr8 _InterlockedOr8
#endif
#define ZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))
static zend_always_inline bool zend_atomic_bool_exchange_ex(zend_atomic_bool *obj, bool desired) {
return InterlockedExchange8(&obj->value, desired);
}
/* On this platform it is non-const due to Iterlocked API*/
static zend_always_inline bool zend_atomic_bool_load_ex(zend_atomic_bool *obj) {
/* Or'ing with false won't change the value. */
return InterlockedOr8(&obj->value, false);
}
static zend_always_inline void zend_atomic_bool_store_ex(zend_atomic_bool *obj, bool desired) {
(void)InterlockedExchange8(&obj->value, desired);
}
#elif defined(HAVE_C11_ATOMICS)
#define ZEND_ATOMIC_BOOL_INIT(obj, desired) __c11_atomic_init(&(obj)->value, (desired))
static zend_always_inline bool zend_atomic_bool_exchange_ex(zend_atomic_bool *obj, bool desired) {
return __c11_atomic_exchange(&obj->value, desired, __ATOMIC_SEQ_CST);
}
static zend_always_inline bool zend_atomic_bool_load_ex(const zend_atomic_bool *obj) {
return __c11_atomic_load(&obj->value, __ATOMIC_SEQ_CST);
}
static zend_always_inline void zend_atomic_bool_store_ex(zend_atomic_bool *obj, bool desired) {
__c11_atomic_store(&obj->value, desired, __ATOMIC_SEQ_CST);
}
#elif defined(HAVE_GNUC_ATOMICS)
#define ZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))
static zend_always_inline bool zend_atomic_bool_exchange_ex(zend_atomic_bool *obj, bool desired) {
bool prev = false;
__atomic_exchange(&obj->value, &desired, &prev, __ATOMIC_SEQ_CST);
return prev;
}
static zend_always_inline bool zend_atomic_bool_load_ex(const zend_atomic_bool *obj) {
bool prev = false;
__atomic_load(&obj->value, &prev, __ATOMIC_SEQ_CST);
return prev;
}
static zend_always_inline void zend_atomic_bool_store_ex(zend_atomic_bool *obj, bool desired) {
__atomic_store(&obj->value, &desired, __ATOMIC_SEQ_CST);
}
#elif defined(HAVE_SYNC_ATOMICS)
#define ZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))
static zend_always_inline bool zend_atomic_bool_exchange_ex(zend_atomic_bool *obj, bool desired) {
bool prev = __sync_lock_test_and_set(&obj->value, desired);
/* __sync_lock_test_and_set only does an acquire barrier, so sync
* immediately after.
*/
__sync_synchronize();
return prev;
}
static zend_always_inline bool zend_atomic_bool_load_ex(zend_atomic_bool *obj) {
/* Or'ing false won't change the value */
return __sync_fetch_and_or(&obj->value, false);
}
static zend_always_inline void zend_atomic_bool_store_ex(zend_atomic_bool *obj, bool desired) {
__sync_synchronize();
obj->value = desired;
__sync_synchronize();
}
#elif defined(HAVE_NO_ATOMICS)
#warning No atomics support detected. Please open an issue with platform details.
#define ZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))
static zend_always_inline void zend_atomic_bool_store_ex(zend_atomic_bool *obj, bool desired) {
obj->value = desired;
}
static zend_always_inline bool zend_atomic_bool_load_ex(const zend_atomic_bool *obj) {
return obj->value;
}
static zend_always_inline bool zend_atomic_bool_exchange_ex(zend_atomic_bool *obj, bool desired) {
bool prev = obj->value;
obj->value = desired;
return prev;
}
#endif
ZEND_API void zend_atomic_bool_init(zend_atomic_bool *obj, bool desired);
ZEND_API bool zend_atomic_bool_exchange(zend_atomic_bool *obj, bool desired);
ZEND_API void zend_atomic_bool_store(zend_atomic_bool *obj, bool desired);
#if defined(ZEND_WIN32) || defined(HAVE_SYNC_ATOMICS)
/* On these platforms it is non-const due to underlying APIs. */
ZEND_API bool zend_atomic_bool_load(zend_atomic_bool *obj);
#else
ZEND_API bool zend_atomic_bool_load(const zend_atomic_bool *obj);
#endif
END_EXTERN_C()
#endif
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