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>
31 struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
33 struct snd_seq_fifo *f;
35 f = kzalloc(sizeof(*f), GFP_KERNEL);
37 snd_printd("malloc failed for snd_seq_fifo_new() \n");
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 snd_assert(fifo != NULL, return);
70 snd_assert(f != NULL, return);
73 snd_seq_fifo_clear(f);
75 /* wake up clients if any */
76 if (waitqueue_active(&f->input_sleep))
77 wake_up(&f->input_sleep);
79 /* release resources...*/
80 /*....................*/
83 snd_seq_pool_done(f->pool);
84 snd_seq_pool_delete(&f->pool);
90 static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
93 void snd_seq_fifo_clear(struct snd_seq_fifo *f)
95 struct snd_seq_event_cell *cell;
98 /* clear overflow flag */
99 atomic_set(&f->overflow, 0);
101 snd_use_lock_sync(&f->use_lock);
102 spin_lock_irqsave(&f->lock, flags);
104 while ((cell = fifo_cell_out(f)) != NULL) {
105 snd_seq_cell_free(cell);
107 spin_unlock_irqrestore(&f->lock, flags);
111 /* enqueue event to fifo */
112 int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
113 struct snd_seq_event *event)
115 struct snd_seq_event_cell *cell;
119 snd_assert(f != NULL, return -EINVAL);
121 snd_use_lock_use(&f->use_lock);
122 err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
125 atomic_inc(&f->overflow);
126 snd_use_lock_free(&f->use_lock);
130 /* append new cells to fifo */
131 spin_lock_irqsave(&f->lock, flags);
133 f->tail->next = cell;
138 spin_unlock_irqrestore(&f->lock, flags);
141 if (waitqueue_active(&f->input_sleep))
142 wake_up(&f->input_sleep);
144 snd_use_lock_free(&f->use_lock);
146 return 0; /* success */
150 /* dequeue cell from fifo */
151 static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
153 struct snd_seq_event_cell *cell;
155 if ((cell = f->head) != NULL) {
156 f->head = cell->next;
158 /* reset tail if this was the last element */
169 /* dequeue cell from fifo and copy on user space */
170 int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
171 struct snd_seq_event_cell **cellp, int nonblock)
173 struct snd_seq_event_cell *cell;
177 snd_assert(f != NULL, return -EINVAL);
180 init_waitqueue_entry(&wait, current);
181 spin_lock_irqsave(&f->lock, flags);
182 while ((cell = fifo_cell_out(f)) == NULL) {
184 /* non-blocking - return immediately */
185 spin_unlock_irqrestore(&f->lock, flags);
188 set_current_state(TASK_INTERRUPTIBLE);
189 add_wait_queue(&f->input_sleep, &wait);
190 spin_unlock_irq(&f->lock);
192 spin_lock_irq(&f->lock);
193 remove_wait_queue(&f->input_sleep, &wait);
194 if (signal_pending(current)) {
195 spin_unlock_irqrestore(&f->lock, flags);
199 spin_unlock_irqrestore(&f->lock, flags);
206 void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
207 struct snd_seq_event_cell *cell)
212 spin_lock_irqsave(&f->lock, flags);
213 cell->next = f->head;
216 spin_unlock_irqrestore(&f->lock, flags);
221 /* polling; return non-zero if queue is available */
222 int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
225 poll_wait(file, &f->input_sleep, wait);
226 return (f->cells > 0);
229 /* change the size of pool; all old events are removed */
230 int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
233 struct snd_seq_pool *newpool, *oldpool;
234 struct snd_seq_event_cell *cell, *next, *oldhead;
236 snd_assert(f != NULL && f->pool != NULL, return -EINVAL);
238 /* allocate new pool */
239 newpool = snd_seq_pool_new(poolsize);
242 if (snd_seq_pool_init(newpool) < 0) {
243 snd_seq_pool_delete(&newpool);
247 spin_lock_irqsave(&f->lock, flags);
248 /* remember old pool */
256 /* NOTE: overflow flag is not cleared */
257 spin_unlock_irqrestore(&f->lock, flags);
259 /* release cells in old pool */
260 for (cell = oldhead; cell; cell = next) {
262 snd_seq_cell_free(cell);
264 snd_seq_pool_delete(&oldpool);