/* * $Id: pa_memorybarrier.h 1240 2007-07-17 13:05:07Z bjornroche $ * Portable Audio I/O Library * Memory barrier utilities * * Author: Bjorn Roche, XO Audio, LLC * * This program uses the PortAudio Portable Audio Library. * For more information see: http://www.portaudio.com * Copyright (c) 1999-2000 Ross Bencina and Phil Burk * * 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. */ /* * The text above constitutes the entire PortAudio license; however, * the PortAudio community also makes the following non-binding requests: * * Any person wishing to distribute modifications to the Software is * requested to send the modifications to the original developer so that * they can be incorporated into the canonical version. It is also * requested that these non-binding requests be included along with the * license above. */ /** @file pa_memorybarrier.h @ingroup common_src */ /**************** * Some memory barrier primitives based on the system. * right now only OS X, FreeBSD, and Linux are supported. In addition to *providing memory barriers, these functions should ensure that data cached in *registers is written out to cache where it can be snooped by other CPUs. (ie, *the volatile keyword should not be required) * * the primitives that must be defined are: * * PaUtil_FullMemoryBarrier() * PaUtil_ReadMemoryBarrier() * PaUtil_WriteMemoryBarrier() * ****************/ #ifndef MODULES_THIRD_PARTY_PORTAUDIO_PA_MEMORYBARRIER_H_ #define MODULES_THIRD_PARTY_PORTAUDIO_PA_MEMORYBARRIER_H_ #if defined(__APPLE__) /* Support for the atomic library was added in C11. */ #if (__STDC_VERSION__ < 201112L) || defined(__STDC_NO_ATOMICS__) #include /* Here are the memory barrier functions. Mac OS X only provides full memory barriers, so the three types of barriers are the same, however, these barriers are superior to compiler-based ones. These were deprecated in MacOS 10.12. */ #define PaUtil_FullMemoryBarrier() OSMemoryBarrier() #define PaUtil_ReadMemoryBarrier() OSMemoryBarrier() #define PaUtil_WriteMemoryBarrier() OSMemoryBarrier() #else #include #define PaUtil_FullMemoryBarrier() atomic_thread_fence(memory_order_seq_cst) #define PaUtil_ReadMemoryBarrier() atomic_thread_fence(memory_order_acquire) #define PaUtil_WriteMemoryBarrier() atomic_thread_fence(memory_order_release) #endif #elif defined(__GNUC__) /* GCC >= 4.1 has built-in intrinsics. We'll use those */ #if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1) #define PaUtil_FullMemoryBarrier() __sync_synchronize() #define PaUtil_ReadMemoryBarrier() __sync_synchronize() #define PaUtil_WriteMemoryBarrier() __sync_synchronize() /* as a fallback, GCC understands volatile asm and "memory" to mean it * should not reorder memory read/writes */ /* Note that it is not clear that any compiler actually defines __PPC__, * it can probably removed safely. */ #elif defined(__ppc__) || defined(__powerpc__) || defined(__PPC__) #define PaUtil_FullMemoryBarrier() asm volatile("sync" ::: "memory") #define PaUtil_ReadMemoryBarrier() asm volatile("sync" ::: "memory") #define PaUtil_WriteMemoryBarrier() asm volatile("sync" ::: "memory") #elif defined(__i386__) || defined(__i486__) || defined(__i586__) || \ defined(__i686__) || defined(__x86_64__) #define PaUtil_FullMemoryBarrier() asm volatile("mfence" ::: "memory") #define PaUtil_ReadMemoryBarrier() asm volatile("lfence" ::: "memory") #define PaUtil_WriteMemoryBarrier() asm volatile("sfence" ::: "memory") #else #ifdef ALLOW_SMP_DANGERS #warning Memory barriers not defined on this system or system unknown #warning For SMP safety, you should fix this. #define PaUtil_FullMemoryBarrier() #define PaUtil_ReadMemoryBarrier() #define PaUtil_WriteMemoryBarrier() #else # error Memory barriers are not defined on this system. You can still compile by defining ALLOW_SMP_DANGERS, but SMP safety will not be guaranteed. #endif #endif #elif (_MSC_VER >= 1400) && !defined(_WIN32_WCE) #include #pragma intrinsic(_ReadWriteBarrier) #pragma intrinsic(_ReadBarrier) #pragma intrinsic(_WriteBarrier) /* note that MSVC intrinsics _ReadWriteBarrier(), _ReadBarrier(), * _WriteBarrier() are just compiler barriers *not* memory barriers */ #define PaUtil_FullMemoryBarrier() _ReadWriteBarrier() #define PaUtil_ReadMemoryBarrier() _ReadBarrier() #define PaUtil_WriteMemoryBarrier() _WriteBarrier() #elif defined(_WIN32_WCE) #define PaUtil_FullMemoryBarrier() #define PaUtil_ReadMemoryBarrier() #define PaUtil_WriteMemoryBarrier() #elif defined(_MSC_VER) || defined(__BORLANDC__) #define PaUtil_FullMemoryBarrier() _asm { lock add [esp], 0} #define PaUtil_ReadMemoryBarrier() _asm { lock add [esp], 0} #define PaUtil_WriteMemoryBarrier() _asm { lock add [esp], 0} #else #ifdef ALLOW_SMP_DANGERS #warning Memory barriers not defined on this system or system unknown #warning For SMP safety, you should fix this. #define PaUtil_FullMemoryBarrier() #define PaUtil_ReadMemoryBarrier() #define PaUtil_WriteMemoryBarrier() #else # error Memory barriers are not defined on this system. You can still compile by defining ALLOW_SMP_DANGERS, but SMP safety will not be guaranteed. #endif #endif #endif /* MODULES_THIRD_PARTY_PORTAUDIO_PA_MEMORYBARRIER_H_ */