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diff --git a/src/engine/external/portaudio/pa_ringbuffer.c b/src/engine/external/portaudio/pa_ringbuffer.c
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+/*
+ * $Id: pa_ringbuffer.c 1240 2007-07-17 13:05:07Z bjornroche $
+ * Portable Audio I/O Library
+ * Ring Buffer utility.
+ *
+ * Author: Phil Burk, http://www.softsynth.com
+ * modified for SMP safety on Mac OS X by Bjorn Roche
+ * modified for SMP safety on Linux by Leland Lucius
+ * also, allowed for const where possible
+ * Note that this is safe only for a single-thread reader and a
+ * single-thread writer.
+ *
+ * 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
+ @ingroup common_src
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include "pa_ringbuffer.h"
+#include <string.h>
+
+/****************
+ * First, we'll define 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 */
+#   elif 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
+#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
+
+/***************************************************************************
+ * Initialize FIFO.
+ * numBytes must be power of 2, returns -1 if not.
+ */
+long PaUtil_InitializeRingBuffer( PaUtilRingBuffer *rbuf, long numBytes, void *dataPtr )
+{
+    if( ((numBytes-1) & numBytes) != 0) return -1; /* Not Power of two. */
+    rbuf->bufferSize = numBytes;
+    rbuf->buffer = (char *)dataPtr;
+    PaUtil_FlushRingBuffer( rbuf );
+    rbuf->bigMask = (numBytes*2)-1;
+    rbuf->smallMask = (numBytes)-1;
+    return 0;
+}
+
+/***************************************************************************
+** Return number of bytes available for reading. */
+long PaUtil_GetRingBufferReadAvailable( PaUtilRingBuffer *rbuf )
+{
+    PaUtil_ReadMemoryBarrier();
+    return ( (rbuf->writeIndex - rbuf->readIndex) & rbuf->bigMask );
+}
+/***************************************************************************
+** Return number of bytes available for writing. */
+long PaUtil_GetRingBufferWriteAvailable( PaUtilRingBuffer *rbuf )
+{
+    /* Since we are calling PaUtil_GetRingBufferReadAvailable, we don't need an aditional MB */
+    return ( rbuf->bufferSize - PaUtil_GetRingBufferReadAvailable(rbuf));
+}
+
+/***************************************************************************
+** Clear buffer. Should only be called when buffer is NOT being read. */
+void PaUtil_FlushRingBuffer( PaUtilRingBuffer *rbuf )
+{
+    rbuf->writeIndex = rbuf->readIndex = 0;
+}
+
+/***************************************************************************
+** Get address of region(s) to which we can write data.
+** If the region is contiguous, size2 will be zero.
+** If non-contiguous, size2 will be the size of second region.
+** Returns room available to be written or numBytes, whichever is smaller.
+*/
+long PaUtil_GetRingBufferWriteRegions( PaUtilRingBuffer *rbuf, long numBytes,
+                                       void **dataPtr1, long *sizePtr1,
+                                       void **dataPtr2, long *sizePtr2 )
+{
+    long   index;
+    long   available = PaUtil_GetRingBufferWriteAvailable( rbuf );
+    if( numBytes > available ) numBytes = available;
+    /* Check to see if write is not contiguous. */
+    index = rbuf->writeIndex & rbuf->smallMask;
+    if( (index + numBytes) > rbuf->bufferSize )
+    {
+        /* Write data in two blocks that wrap the buffer. */
+        long   firstHalf = rbuf->bufferSize - index;
+        *dataPtr1 = &rbuf->buffer[index];
+        *sizePtr1 = firstHalf;
+        *dataPtr2 = &rbuf->buffer[0];
+        *sizePtr2 = numBytes - firstHalf;
+    }
+    else
+    {
+        *dataPtr1 = &rbuf->buffer[index];
+        *sizePtr1 = numBytes;
+        *dataPtr2 = NULL;
+        *sizePtr2 = 0;
+    }
+    return numBytes;
+}
+
+
+/***************************************************************************
+*/
+long PaUtil_AdvanceRingBufferWriteIndex( PaUtilRingBuffer *rbuf, long numBytes )
+{
+    /* we need to ensure that previous writes are seen before we update the write index */
+    PaUtil_WriteMemoryBarrier();
+    return rbuf->writeIndex = (rbuf->writeIndex + numBytes) & rbuf->bigMask;
+}
+
+/***************************************************************************
+** Get address of region(s) from which we can read data.
+** If the region is contiguous, size2 will be zero.
+** If non-contiguous, size2 will be the size of second region.
+** Returns room available to be written or numBytes, whichever is smaller.
+*/
+long PaUtil_GetRingBufferReadRegions( PaUtilRingBuffer *rbuf, long numBytes,
+                                void **dataPtr1, long *sizePtr1,
+                                void **dataPtr2, long *sizePtr2 )
+{
+    long   index;
+    long   available = PaUtil_GetRingBufferReadAvailable( rbuf );
+    if( numBytes > available ) numBytes = available;
+    /* Check to see if read is not contiguous. */
+    index = rbuf->readIndex & rbuf->smallMask;
+    if( (index + numBytes) > rbuf->bufferSize )
+    {
+        /* Write data in two blocks that wrap the buffer. */
+        long firstHalf = rbuf->bufferSize - index;
+        *dataPtr1 = &rbuf->buffer[index];
+        *sizePtr1 = firstHalf;
+        *dataPtr2 = &rbuf->buffer[0];
+        *sizePtr2 = numBytes - firstHalf;
+    }
+    else
+    {
+        *dataPtr1 = &rbuf->buffer[index];
+        *sizePtr1 = numBytes;
+        *dataPtr2 = NULL;
+        *sizePtr2 = 0;
+    }
+    return numBytes;
+}
+/***************************************************************************
+*/
+long PaUtil_AdvanceRingBufferReadIndex( PaUtilRingBuffer *rbuf, long numBytes )
+{
+    /* we need to ensure that previous writes are always seen before updating the index. */
+    PaUtil_WriteMemoryBarrier();
+    return rbuf->readIndex = (rbuf->readIndex + numBytes) & rbuf->bigMask;
+}
+
+/***************************************************************************
+** Return bytes written. */
+long PaUtil_WriteRingBuffer( PaUtilRingBuffer *rbuf, const void *data, long numBytes )
+{
+    long size1, size2, numWritten;
+    void *data1, *data2;
+    numWritten = PaUtil_GetRingBufferWriteRegions( rbuf, numBytes, &data1, &size1, &data2, &size2 );
+    if( size2 > 0 )
+    {
+
+        memcpy( data1, data, size1 );
+        data = ((char *)data) + size1;
+        memcpy( data2, data, size2 );
+    }
+    else
+    {
+        memcpy( data1, data, size1 );
+    }
+    PaUtil_AdvanceRingBufferWriteIndex( rbuf, numWritten );
+    return numWritten;
+}
+
+/***************************************************************************
+** Return bytes read. */
+long PaUtil_ReadRingBuffer( PaUtilRingBuffer *rbuf, void *data, long numBytes )
+{
+    long size1, size2, numRead;
+    void *data1, *data2;
+    numRead = PaUtil_GetRingBufferReadRegions( rbuf, numBytes, &data1, &size1, &data2, &size2 );
+    if( size2 > 0 )
+    {
+        memcpy( data, data1, size1 );
+        data = ((char *)data) + size1;
+        memcpy( data, data2, size2 );
+    }
+    else
+    {
+        memcpy( data, data1, size1 );
+    }
+    PaUtil_AdvanceRingBufferReadIndex( rbuf, numRead );
+    return numRead;
+}