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/*
* Copyright (C) 2003-2009 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "buffer.h"
#include "chunk.h"
#include "poison.h"
#include <glib.h>
#include <assert.h>
struct music_buffer {
struct music_chunk *chunks;
unsigned num_chunks;
struct music_chunk *available;
/** a mutex which protects #available */
GMutex *mutex;
#ifndef NDEBUG
unsigned num_allocated;
#endif
};
struct music_buffer *
music_buffer_new(unsigned num_chunks)
{
struct music_buffer *buffer;
struct music_chunk *chunk;
assert(num_chunks > 0);
buffer = g_new(struct music_buffer, 1);
buffer->chunks = g_new(struct music_chunk, num_chunks);
buffer->num_chunks = num_chunks;
chunk = buffer->available = buffer->chunks;
poison_undefined(chunk, sizeof(*chunk));
for (unsigned i = 1; i < num_chunks; ++i) {
chunk->next = &buffer->chunks[i];
chunk = chunk->next;
poison_undefined(chunk, sizeof(*chunk));
}
chunk->next = NULL;
buffer->mutex = g_mutex_new();
#ifndef NDEBUG
buffer->num_allocated = 0;
#endif
return buffer;
}
void
music_buffer_free(struct music_buffer *buffer)
{
assert(buffer->chunks != NULL);
assert(buffer->num_chunks > 0);
assert(buffer->num_allocated == 0);
g_mutex_free(buffer->mutex);
g_free(buffer->chunks);
g_free(buffer);
}
unsigned
music_buffer_size(const struct music_buffer *buffer)
{
return buffer->num_chunks;
}
struct music_chunk *
music_buffer_allocate(struct music_buffer *buffer)
{
struct music_chunk *chunk;
g_mutex_lock(buffer->mutex);
chunk = buffer->available;
if (chunk != NULL) {
buffer->available = chunk->next;
music_chunk_init(chunk);
#ifndef NDEBUG
++buffer->num_allocated;
#endif
}
g_mutex_unlock(buffer->mutex);
return chunk;
}
void
music_buffer_return(struct music_buffer *buffer, struct music_chunk *chunk)
{
assert(buffer != NULL);
assert(chunk != NULL);
g_mutex_lock(buffer->mutex);
music_chunk_free(chunk);
poison_undefined(chunk, sizeof(*chunk));
chunk->next = buffer->available;
buffer->available = chunk;
#ifndef NDEBUG
--buffer->num_allocated;
#endif
g_mutex_unlock(buffer->mutex);
}
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