1 /* 2 * ALSA sequencer FIFO 3 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl> 4 * 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 * 20 */ 21 #ifndef __SND_SEQ_FIFO_H 22 #define __SND_SEQ_FIFO_H 23 24 #include "seq_memory.h" 25 #include "seq_lock.h" 26 27 28 /* === FIFO === */ 29 30 struct snd_seq_fifo { 31 struct snd_seq_pool *pool; /* FIFO pool */ 32 struct snd_seq_event_cell *head; /* pointer to head of fifo */ 33 struct snd_seq_event_cell *tail; /* pointer to tail of fifo */ 34 int cells; 35 spinlock_t lock; 36 snd_use_lock_t use_lock; 37 wait_queue_head_t input_sleep; 38 atomic_t overflow; 39 40 }; 41 42 /* create new fifo (constructor) */ 43 struct snd_seq_fifo *snd_seq_fifo_new(int poolsize); 44 45 /* delete fifo (destructor) */ 46 void snd_seq_fifo_delete(struct snd_seq_fifo **f); 47 48 49 /* enqueue event to fifo */ 50 int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event); 51 52 /* lock fifo from release */ 53 #define snd_seq_fifo_lock(fifo) snd_use_lock_use(&(fifo)->use_lock) 54 #define snd_seq_fifo_unlock(fifo) snd_use_lock_free(&(fifo)->use_lock) 55 56 /* get a cell from fifo - fifo should be locked */ 57 int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock); 58 59 /* free dequeued cell - fifo should be locked */ 60 void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell); 61 62 /* clean up queue */ 63 void snd_seq_fifo_clear(struct snd_seq_fifo *f); 64 65 /* polling */ 66 int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait); 67 68 /* resize pool in fifo */ 69 int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize); 70 71 72 #endif 73