/* * 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); }