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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef BIONIC_ATOMIC_GCC_BUILTIN_H
#define BIONIC_ATOMIC_GCC_BUILTIN_H
/* This header file is used by default if we don't have optimized atomic
* routines for a given platform. See bionic_atomic_arm.h and
* bionic_atomic_x86.h for examples.
*/
__ATOMIC_INLINE__ void
__bionic_memory_barrier(void)
{
__sync_synchronize();
}
__ATOMIC_INLINE__ int
__bionic_cmpxchg(int32_t old_value, int32_t new_value, volatile int32_t* ptr)
{
/* We must return 0 on success */
return __sync_val_compare_and_swap(ptr, old_value, new_value) != old_value;
}
__ATOMIC_INLINE__ int32_t
__bionic_swap(int32_t new_value, volatile int32_t* ptr)
{
int32_t old_value;
do {
old_value = *ptr;
} while (__sync_val_compare_and_swap(ptr, old_value, new_value) != old_value);
return old_value;
}
__ATOMIC_INLINE__ int32_t
__bionic_atomic_inc(volatile int32_t* ptr)
{
/* We must return the old value */
return __sync_fetch_and_add(ptr, 1);
}
__ATOMIC_INLINE__ int32_t
__bionic_atomic_dec(volatile int32_t* ptr)
{
/* We must return the old value */
return __sync_fetch_and_add(ptr, -1);
}
#endif /* BIONIC_ATOMIC_GCC_BUILTIN_H */