mpd/src/buffer.c
Avuton Olrich 0aee49bdf8 all: Update copyright header.
This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.
2009-03-13 11:51:55 -07:00

134 lines
2.8 KiB
C

/*
* 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);
}