AuroraOpenALSoft/OpenAL32/alThunk.c
2017-04-14 16:14:05 -07:00

109 lines
2.9 KiB
C

/**
* OpenAL cross platform audio library
* Copyright (C) 1999-2007 by authors.
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
* Or go to http://www.gnu.org/copyleft/lgpl.html
*/
#include "config.h"
#include <stdlib.h>
#include "alMain.h"
#include "alThunk.h"
#include "almalloc.h"
static ATOMIC_FLAG *ThunkArray;
static ALsizei ThunkArraySize;
static RWLock ThunkLock;
void ThunkInit(void)
{
RWLockInit(&ThunkLock);
ThunkArraySize = 1024;
ThunkArray = al_calloc(16, ThunkArraySize * sizeof(*ThunkArray));
}
void ThunkExit(void)
{
al_free(ThunkArray);
ThunkArray = NULL;
ThunkArraySize = 0;
}
ALenum NewThunkEntry(ALuint *index)
{
void *NewList;
ALsizei i;
ReadLock(&ThunkLock);
for(i = 0;i < ThunkArraySize;i++)
{
if(!ATOMIC_FLAG_TEST_AND_SET(&ThunkArray[i], almemory_order_acq_rel))
{
ReadUnlock(&ThunkLock);
*index = i+1;
return AL_NO_ERROR;
}
}
ReadUnlock(&ThunkLock);
WriteLock(&ThunkLock);
/* Double-check that there's still no free entries, in case another
* invocation just came through and increased the size of the array.
*/
for(;i < ThunkArraySize;i++)
{
if(!ATOMIC_FLAG_TEST_AND_SET(&ThunkArray[i], almemory_order_acq_rel))
{
WriteUnlock(&ThunkLock);
*index = i+1;
return AL_NO_ERROR;
}
}
NewList = al_calloc(16, ThunkArraySize*2 * sizeof(*ThunkArray));
if(!NewList)
{
WriteUnlock(&ThunkLock);
ERR("Realloc failed to increase to %u entries!\n", ThunkArraySize*2);
return AL_OUT_OF_MEMORY;
}
memcpy(NewList, ThunkArray, ThunkArraySize*sizeof(*ThunkArray));
al_free(ThunkArray);
ThunkArray = NewList;
ThunkArraySize *= 2;
ATOMIC_FLAG_TEST_AND_SET(&ThunkArray[i], almemory_order_seq_cst);
*index = ++i;
for(;i < ThunkArraySize;i++)
ATOMIC_FLAG_CLEAR(&ThunkArray[i], almemory_order_relaxed);
WriteUnlock(&ThunkLock);
return AL_NO_ERROR;
}
void FreeThunkEntry(ALuint index)
{
ReadLock(&ThunkLock);
if(index > 0 && (ALsizei)index <= ThunkArraySize)
ATOMIC_FLAG_CLEAR(&ThunkArray[index-1], almemory_order_release);
ReadUnlock(&ThunkLock);
}