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Diffstat (limited to 'src/pa_memorybarrier.h')
| -rw-r--r-- | src/pa_memorybarrier.h | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/pa_memorybarrier.h b/src/pa_memorybarrier.h new file mode 100644 index 0000000..6f07b60 --- /dev/null +++ b/src/pa_memorybarrier.h @@ -0,0 +1,138 @@ +/* + * $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() + * + ****************/ + +#if defined(__APPLE__) +/* Support for the atomic library was added in C11. + */ +# if (__STDC_VERSION__ < 201112L) || defined(__STDC_NO_ATOMICS__) +# include <libkern/OSAtomic.h> + /* 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 <stdatomic.h> +# 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 <intrin.h> +# 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 |