| /* |
| * $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__) |
| # 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. */ |
| # define PaUtil_FullMemoryBarrier() OSMemoryBarrier() |
| # define PaUtil_ReadMemoryBarrier() OSMemoryBarrier() |
| # define PaUtil_WriteMemoryBarrier() OSMemoryBarrier() |
| #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) |
| # 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 |
