zend_atomic.h

/*
 +----------------------------------------------------------------------+
 | 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> |
 +----------------------------------------------------------------------+
 */

#ifndefZEND_ATOMIC_H
#defineZEND_ATOMIC_H

#include"zend_portability.h"

#include<stdbool.h>

#defineZEND_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__)
#defineHAVE_C11_ATOMICS 1
#elifZEND_GCC_PREREQ(4, 7)
#defineHAVE_GNUC_ATOMICS 1
#elif defined(__GNUC__)
#defineHAVE_SYNC_ATOMICS 1
#elif !defined(ZEND_WIN32)
#defineHAVE_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)
typedefstructzend_atomic_bool_s {
volatilecharvalue;
} zend_atomic_bool;
#elif defined(HAVE_C11_ATOMICS)
typedefstructzend_atomic_bool_s {
 _Atomic(bool) value;
} zend_atomic_bool;
#else
typedefstructzend_atomic_bool_s {
volatileboolvalue;
} zend_atomic_bool;
#endif

BEGIN_EXTERN_C()

#ifdefZEND_WIN32

#ifndefInterlockedExchange8
#defineInterlockedExchange8 _InterlockedExchange8
#endif
#ifndefInterlockedOr8
#defineInterlockedOr8 _InterlockedOr8
#endif

#defineZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))

staticzend_always_inlineboolzend_atomic_bool_exchange_ex(zend_atomic_bool*obj, booldesired) {
returnInterlockedExchange8(&obj->value, desired);
}

/* On this platform it is non-const due to Iterlocked API*/
staticzend_always_inlineboolzend_atomic_bool_load_ex(zend_atomic_bool*obj) {
/* Or'ing with false won't change the value. */
returnInterlockedOr8(&obj->value, false);
}

staticzend_always_inlinevoidzend_atomic_bool_store_ex(zend_atomic_bool*obj, booldesired) {
 (void)InterlockedExchange8(&obj->value, desired);
}

#elif defined(HAVE_C11_ATOMICS)

#defineZEND_ATOMIC_BOOL_INIT(obj, desired) __c11_atomic_init(&(obj)->value, (desired))

staticzend_always_inlineboolzend_atomic_bool_exchange_ex(zend_atomic_bool*obj, booldesired) {
return__c11_atomic_exchange(&obj->value, desired, __ATOMIC_SEQ_CST);
}

staticzend_always_inlineboolzend_atomic_bool_load_ex(constzend_atomic_bool*obj) {
return__c11_atomic_load(&obj->value, __ATOMIC_SEQ_CST);
}

staticzend_always_inlinevoidzend_atomic_bool_store_ex(zend_atomic_bool*obj, booldesired) {
__c11_atomic_store(&obj->value, desired, __ATOMIC_SEQ_CST);
}

#elif defined(HAVE_GNUC_ATOMICS)

#defineZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))

staticzend_always_inlineboolzend_atomic_bool_exchange_ex(zend_atomic_bool*obj, booldesired) {
boolprev= false;
__atomic_exchange(&obj->value, &desired, &prev, __ATOMIC_SEQ_CST);
returnprev;
}

staticzend_always_inlineboolzend_atomic_bool_load_ex(constzend_atomic_bool*obj) {
boolprev= false;
__atomic_load(&obj->value, &prev, __ATOMIC_SEQ_CST);
returnprev;
}

staticzend_always_inlinevoidzend_atomic_bool_store_ex(zend_atomic_bool*obj, booldesired) {
__atomic_store(&obj->value, &desired, __ATOMIC_SEQ_CST);
}

#elif defined(HAVE_SYNC_ATOMICS)

#defineZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))

staticzend_always_inlineboolzend_atomic_bool_exchange_ex(zend_atomic_bool*obj, booldesired) {
boolprev=__sync_lock_test_and_set(&obj->value, desired);

/* __sync_lock_test_and_set only does an acquire barrier, so sync
 * immediately after.
 */
__sync_synchronize();
returnprev;
}

staticzend_always_inlineboolzend_atomic_bool_load_ex(zend_atomic_bool*obj) {
/* Or'ing false won't change the value */
return__sync_fetch_and_or(&obj->value, false);
}

staticzend_always_inlinevoidzend_atomic_bool_store_ex(zend_atomic_bool*obj, booldesired) {
__sync_synchronize();
obj->value=desired;
__sync_synchronize();
}

#elif defined(HAVE_NO_ATOMICS)

#warning No atomics support detected. Please open an issue with platform details.

#defineZEND_ATOMIC_BOOL_INIT(obj, desired) ((obj)->value = (desired))

staticzend_always_inlinevoidzend_atomic_bool_store_ex(zend_atomic_bool*obj, booldesired) {
obj->value=desired;
}

staticzend_always_inlineboolzend_atomic_bool_load_ex(constzend_atomic_bool*obj) {
returnobj->value;
}

staticzend_always_inlineboolzend_atomic_bool_exchange_ex(zend_atomic_bool*obj, booldesired) {
boolprev=obj->value;
obj->value=desired;
returnprev;
}

#endif

ZEND_APIvoidzend_atomic_bool_init(zend_atomic_bool*obj, booldesired);
ZEND_APIboolzend_atomic_bool_exchange(zend_atomic_bool*obj, booldesired);
ZEND_APIvoidzend_atomic_bool_store(zend_atomic_bool*obj, booldesired);

#if defined(ZEND_WIN32) || defined(HAVE_SYNC_ATOMICS)
/* On these platforms it is non-const due to underlying APIs. */
ZEND_APIboolzend_atomic_bool_load(zend_atomic_bool*obj);
#else
ZEND_APIboolzend_atomic_bool_load(constzend_atomic_bool*obj);
#endif

END_EXTERN_C()

#endif