3 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
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.
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.
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
22 #include <sound/core.h>
23 #include <linux/slab.h>
24 #include <linux/sched/signal.h>
33 struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
35 struct snd_seq_fifo *f;
37 f = kzalloc(sizeof(*f), GFP_KERNEL);
41 f->pool = snd_seq_pool_new(poolsize);
42 if (f->pool == NULL) {
46 if (snd_seq_pool_init(f->pool) < 0) {
47 snd_seq_pool_delete(&f->pool);
52 spin_lock_init(&f->lock);
53 snd_use_lock_init(&f->use_lock);
54 init_waitqueue_head(&f->input_sleep);
55 atomic_set(&f->overflow, 0);
64 void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
66 struct snd_seq_fifo *f;
68 if (snd_BUG_ON(!fifo))
75 snd_seq_fifo_clear(f);
77 /* wake up clients if any */
78 if (waitqueue_active(&f->input_sleep))
79 wake_up(&f->input_sleep);
81 /* release resources...*/
82 /*....................*/
85 snd_seq_pool_done(f->pool);
86 snd_seq_pool_delete(&f->pool);
92 static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
95 void snd_seq_fifo_clear(struct snd_seq_fifo *f)
97 struct snd_seq_event_cell *cell;
100 /* clear overflow flag */
101 atomic_set(&f->overflow, 0);
103 snd_use_lock_sync(&f->use_lock);
104 spin_lock_irqsave(&f->lock, flags);
106 while ((cell = fifo_cell_out(f)) != NULL) {
107 snd_seq_cell_free(cell);
109 spin_unlock_irqrestore(&f->lock, flags);
113 /* enqueue event to fifo */
114 int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
115 struct snd_seq_event *event)
117 struct snd_seq_event_cell *cell;
124 snd_use_lock_use(&f->use_lock);
125 err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
127 if ((err == -ENOMEM) || (err == -EAGAIN))
128 atomic_inc(&f->overflow);
129 snd_use_lock_free(&f->use_lock);
133 /* append new cells to fifo */
134 spin_lock_irqsave(&f->lock, flags);
136 f->tail->next = cell;
142 spin_unlock_irqrestore(&f->lock, flags);
145 if (waitqueue_active(&f->input_sleep))
146 wake_up(&f->input_sleep);
148 snd_use_lock_free(&f->use_lock);
150 return 0; /* success */
154 /* dequeue cell from fifo */
155 static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
157 struct snd_seq_event_cell *cell;
159 if ((cell = f->head) != NULL) {
160 f->head = cell->next;
162 /* reset tail if this was the last element */
173 /* dequeue cell from fifo and copy on user space */
174 int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
175 struct snd_seq_event_cell **cellp, int nonblock)
177 struct snd_seq_event_cell *cell;
185 init_waitqueue_entry(&wait, current);
186 spin_lock_irqsave(&f->lock, flags);
187 while ((cell = fifo_cell_out(f)) == NULL) {
189 /* non-blocking - return immediately */
190 spin_unlock_irqrestore(&f->lock, flags);
193 set_current_state(TASK_INTERRUPTIBLE);
194 add_wait_queue(&f->input_sleep, &wait);
195 spin_unlock_irq(&f->lock);
197 spin_lock_irq(&f->lock);
198 remove_wait_queue(&f->input_sleep, &wait);
199 if (signal_pending(current)) {
200 spin_unlock_irqrestore(&f->lock, flags);
204 spin_unlock_irqrestore(&f->lock, flags);
211 void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
212 struct snd_seq_event_cell *cell)
217 spin_lock_irqsave(&f->lock, flags);
218 cell->next = f->head;
223 spin_unlock_irqrestore(&f->lock, flags);
228 /* polling; return non-zero if queue is available */
229 int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
232 poll_wait(file, &f->input_sleep, wait);
233 return (f->cells > 0);
236 /* change the size of pool; all old events are removed */
237 int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
240 struct snd_seq_pool *newpool, *oldpool;
241 struct snd_seq_event_cell *cell, *next, *oldhead;
243 if (snd_BUG_ON(!f || !f->pool))
246 /* allocate new pool */
247 newpool = snd_seq_pool_new(poolsize);
250 if (snd_seq_pool_init(newpool) < 0) {
251 snd_seq_pool_delete(&newpool);
255 spin_lock_irqsave(&f->lock, flags);
256 /* remember old pool */
264 /* NOTE: overflow flag is not cleared */
265 spin_unlock_irqrestore(&f->lock, flags);
267 /* release cells in old pool */
268 for (cell = oldhead; cell; cell = next) {
270 snd_seq_cell_free(cell);
272 snd_seq_pool_delete(&oldpool);