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1/* SPDX-License-Identifier: GPL-2.0-or-later */2/*3 * ALSA sequencer FIFO4 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>5 */6#ifndef __SND_SEQ_FIFO_H7#define __SND_SEQ_FIFO_H8 9#include "seq_memory.h"10#include "seq_lock.h"11 12 13/* === FIFO === */14 15struct snd_seq_fifo {16 struct snd_seq_pool *pool; /* FIFO pool */17 struct snd_seq_event_cell *head; /* pointer to head of fifo */18 struct snd_seq_event_cell *tail; /* pointer to tail of fifo */19 int cells;20 spinlock_t lock;21 snd_use_lock_t use_lock;22 wait_queue_head_t input_sleep;23 atomic_t overflow;24 25};26 27/* create new fifo (constructor) */28struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);29 30/* delete fifo (destructor) */31void snd_seq_fifo_delete(struct snd_seq_fifo **f);32 33 34/* enqueue event to fifo */35int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);36 37/* lock fifo from release */38#define snd_seq_fifo_lock(fifo) snd_use_lock_use(&(fifo)->use_lock)39#define snd_seq_fifo_unlock(fifo) snd_use_lock_free(&(fifo)->use_lock)40 41/* get a cell from fifo - fifo should be locked */42int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);43 44/* free dequeued cell - fifo should be locked */45void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);46 47/* clean up queue */48void snd_seq_fifo_clear(struct snd_seq_fifo *f);49 50/* polling */51int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);52 53/* resize pool in fifo */54int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);55 56/* get the number of unused cells safely */57int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f);58 59#endif60