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671ec859e5
The SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO ioctl sets the tempo and the ppq in a single call, while the current implementation updates each value one by one. This is a bit racy, and also suboptimal from the performance POV, as each call does re-acquire the lock and invokes the update of ALSA timer resolution. This patch reorganizes the code slightly so that we change both the tempo and the ppq in a shot. The skew value can be put into the same lock, but this is rather a rarely used feature and completely independent from the temp/ppq (it's evaluated only in the interrupt), so it's left as it was. Signed-off-by: Takashi Iwai <tiwai@suse.de>
149 lines
4.7 KiB
C
149 lines
4.7 KiB
C
/*
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* ALSA sequencer Timer
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* Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#ifndef __SND_SEQ_TIMER_H
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#define __SND_SEQ_TIMER_H
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#include <sound/timer.h>
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#include <sound/seq_kernel.h>
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struct snd_seq_timer_tick {
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snd_seq_tick_time_t cur_tick; /* current tick */
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unsigned long resolution; /* time per tick in nsec */
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unsigned long fraction; /* current time per tick in nsec */
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};
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struct snd_seq_timer {
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/* ... tempo / offset / running state */
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unsigned int running:1, /* running state of queue */
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initialized:1; /* timer is initialized */
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unsigned int tempo; /* current tempo, us/tick */
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int ppq; /* time resolution, ticks/quarter */
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snd_seq_real_time_t cur_time; /* current time */
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struct snd_seq_timer_tick tick; /* current tick */
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int tick_updated;
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int type; /* timer type */
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struct snd_timer_id alsa_id; /* ALSA's timer ID */
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struct snd_timer_instance *timeri; /* timer instance */
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unsigned int ticks;
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unsigned long preferred_resolution; /* timer resolution, ticks/sec */
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unsigned int skew;
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unsigned int skew_base;
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struct timespec64 last_update; /* time of last clock update, used for interpolation */
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spinlock_t lock;
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};
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/* create new timer (constructor) */
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struct snd_seq_timer *snd_seq_timer_new(void);
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/* delete timer (destructor) */
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void snd_seq_timer_delete(struct snd_seq_timer **tmr);
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/* */
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static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
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unsigned long resolution)
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{
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if (tick->resolution > 0) {
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tick->fraction += resolution;
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tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
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tick->fraction %= tick->resolution;
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}
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}
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/* compare timestamp between events */
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/* return 1 if a >= b; otherwise return 0 */
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static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
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{
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/* compare ticks */
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return (*a >= *b);
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}
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static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
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{
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/* compare real time */
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if (a->tv_sec > b->tv_sec)
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return 1;
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if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
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return 1;
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return 0;
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}
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static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
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{
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while (tm->tv_nsec >= 1000000000) {
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/* roll-over */
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tm->tv_nsec -= 1000000000;
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tm->tv_sec++;
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}
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}
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/* increment timestamp */
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static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
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{
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tm->tv_sec += inc->tv_sec;
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tm->tv_nsec += inc->tv_nsec;
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snd_seq_sanity_real_time(tm);
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}
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static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
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{
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tm->tv_nsec += nsec;
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snd_seq_sanity_real_time(tm);
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}
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/* called by timer isr */
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struct snd_seq_queue;
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int snd_seq_timer_open(struct snd_seq_queue *q);
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int snd_seq_timer_close(struct snd_seq_queue *q);
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int snd_seq_timer_midi_open(struct snd_seq_queue *q);
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int snd_seq_timer_midi_close(struct snd_seq_queue *q);
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void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
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void snd_seq_timer_reset(struct snd_seq_timer *tmr);
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int snd_seq_timer_stop(struct snd_seq_timer *tmr);
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int snd_seq_timer_start(struct snd_seq_timer *tmr);
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int snd_seq_timer_continue(struct snd_seq_timer *tmr);
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int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
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int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq);
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int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
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int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
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int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);
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snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr);
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snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr);
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extern int seq_default_timer_class;
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extern int seq_default_timer_sclass;
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extern int seq_default_timer_card;
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extern int seq_default_timer_device;
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extern int seq_default_timer_subdevice;
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extern int seq_default_timer_resolution;
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#endif
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