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/****************************************************************************
* libc/audio/lib_buffer.c
*
* Copyright (C) 2013 Ken Pettit. All rights reserved.
* Author: Ken Pettit <pettitkd@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <semaphore.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/audio/audio.h>
#include <nuttx/usb/audio.h>
#include "lib_internal.h"
#if defined(CONFIG_AUDIO)
/****************************************************************************
* Preprocessor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: apb_semtake
*
* Take an Audio Pipeline Buffer.
*
****************************************************************************/
static void apb_semtake(FAR struct ap_buffer_s *apb)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&apb->sem) != 0)
{
/* The only case that an error should occr here is if
* the wait was awakened by a signal.
*/
ASSERT(errno == EINTR);
}
}
/****************************************************************************
* Name: apb_semgive
****************************************************************************/
#define apb_semgive(b) sem_post(&b->sem)
/****************************************************************************
* Name: apb_alloc
*
* Allocate an Audio Pipeline Buffer for use in the Audio sub-system. This
* will perform the actual allocate based on buffer data format, number of
* channels, etc. and prepare the buffer for consumption.
*
****************************************************************************/
int apb_alloc(FAR struct audio_buf_desc_s *bufdesc)
{
uint32_t bufsize;
int ret;
struct ap_buffer_s *pBuf;
DEBUGASSERT(bufdesc->u.ppBuffer != NULL);
/* Perform a user mode allocation */
bufsize = sizeof(struct ap_buffer_s) + bufdesc->numbytes;
pBuf = lib_umalloc(bufsize);
*bufdesc->u.ppBuffer = pBuf;
/* Test if the allocation was successful or not */
if (*bufdesc->u.ppBuffer == NULL)
{
ret = -ENOMEM;
}
else
{
/* Populate the buffer contents */
memset(pBuf, bufsize, 0);
pBuf->i.channels = 1;
pBuf->crefs = 1;
pBuf->nmaxbytes = bufdesc->numbytes;
pBuf->nbytes = 0;
#ifdef CONFIG_AUDIO_MULTI_SESSION
pBuf->session = bufdesc->session;
#endif
sem_init(&pBuf->sem, 0, 1);
ret = sizeof(struct audio_buf_desc_s);
}
return ret;
}
/****************************************************************************
* Name: apb_free
*
* Free's a previously allocated or referenced Audio Pipeline Buffer
*
****************************************************************************/
void apb_free(FAR struct ap_buffer_s *apb)
{
int refcount;
/* Perform a reference count decrement and possibly release the memory */
apb_semtake(apb);
refcount = apb->crefs--;
apb_semgive(apb);
if (refcount <= 1)
{
auddbg("Freeing %p\n", apb);
lib_ufree(apb);
}
}
/****************************************************************************
* Name: apb_reference
*
* Claim a reference to an Audio Pipeline Buffer. Each call to apb_reference
* will increment the reference count and must have a matching apb_free
* call. When the refcount decrements to zero, the buffer will be freed.
*
****************************************************************************/
void apb_reference(FAR struct ap_buffer_s *apb)
{
/* Do we need any thread protection here? Almost certaily... */
apb_semtake(apb);
apb->crefs++;
apb_semgive(apb);
}
#endif /* CONFIG_AUDIO */
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