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/*
* Phusion Passenger - https://www.phusionpassenger.com/
* Copyright (c) 2010 Phusion
*
* "Phusion Passenger" is a trademark of Hongli Lai & Ninh Bui.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef _PASSENGER_MEMORY_BARRIER_H_
#define _PASSENGER_MEMORY_BARRIER_H_
// Memory barrier macros. Also act as compiler barriers.
#if defined(__GNUC__) || defined(__INTEL_COMPILER)
#if defined(__i386__)
#if defined(HAS_SSE2) || (defined(HAS_LFENCE) && defined(HAS_SFENCE))
#define P_READ_BARRIER() \
do { __asm__ __volatile__ ("lfence" ::: "memory"); } while (false)
#define P_WRITE_BARRIER() \
do { __asm__ __volatile__ ("sfence" ::: "memory"); } while (false)
#else
#define P_READ_BARRIER() \
do { __asm__ __volatile__ ("" ::: "memory"); } while (false)
#define P_WRITE_BARRIER() \
do { __asm__ __volatile__ ("lock; addl $0,0(%%esp)" ::: "memory"); } while (false)
#endif
#elif defined(__x86_64__)
#define P_READ_BARRIER() \
do { __asm__ __volatile__ ("lfence" ::: "memory"); } while (false)
#define P_WRITE_BARRIER() \
do { __asm__ __volatile__ ("sfence" ::: "memory"); } while (false)
#endif
#endif
#endif /* _PASSENGER_MEMORY_BARRIER_H_ */
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