/* * ALSA sequencer Priority Queue * Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl> * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <linux/time.h> #include <linux/slab.h> #include <sound/core.h> #include "seq_timer.h" #include "seq_prioq.h" /* Implementation is a simple linked list for now... This priority queue orders the events on timestamp. For events with an equeal timestamp the queue behaves as a FIFO. * * +-------+ * Head --> | first | * +-------+ * |next * +-----v-+ * | | * +-------+ * | * +-----v-+ * | | * +-------+ * | * +-----v-+ * Tail --> | last | * +-------+ * */ /* create new prioq (constructor) */ struct snd_seq_prioq *snd_seq_prioq_new(void) { struct snd_seq_prioq *f; f = kzalloc(sizeof(*f), GFP_KERNEL); if (f == NULL) { pr_debug("ALSA: seq: malloc failed for snd_seq_prioq_new()\n"); return NULL; } spin_lock_init(&f->lock); f->head = NULL; f->tail = NULL; f->cells = 0; return f; } /* delete prioq (destructor) */ void snd_seq_prioq_delete(struct snd_seq_prioq **fifo) { struct snd_seq_prioq *f = *fifo; *fifo = NULL; if (f == NULL) { pr_debug("ALSA: seq: snd_seq_prioq_delete() called with NULL prioq\n"); return; } /* release resources...*/ /*....................*/ if (f->cells > 0) { /* drain prioQ */ while (f->cells > 0) snd_seq_cell_free(snd_seq_prioq_cell_out(f)); } kfree(f); } /* compare timestamp between events */ /* return 1 if a >= b; 0 */ static inline int compare_timestamp(struct snd_seq_event *a, struct snd_seq_event *b) { if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) { /* compare ticks */ return (snd_seq_compare_tick_time(&a->time.tick, &b->time.tick)); } else { /* compare real time */ return (snd_seq_compare_real_time(&a->time.time, &b->time.time)); } } /* compare timestamp between events */ /* return negative if a < b; * zero if a = b; * positive if a > b; */ static inline int compare_timestamp_rel(struct snd_seq_event *a, struct snd_seq_event *b) { if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) { /* compare ticks */ if (a->time.tick > b->time.tick) return 1; else if (a->time.tick == b->time.tick) return 0; else return -1; } else { /* compare real time */ if (a->time.time.tv_sec > b->time.time.tv_sec) return 1; else if (a->time.time.tv_sec == b->time.time.tv_sec) { if (a->time.time.tv_nsec > b->time.time.tv_nsec) return 1; else if (a->time.time.tv_nsec == b->time.time.tv_nsec) return 0; else return -1; } else return -1; } } /* enqueue cell to prioq */ int snd_seq_prioq_cell_in(struct snd_seq_prioq * f, struct snd_seq_event_cell * cell) { struct snd_seq_event_cell *cur, *prev; unsigned long flags; int count; int prior; if (snd_BUG_ON(!f || !cell)) return -EINVAL; /* check flags */ prior = (cell->event.flags & SNDRV_SEQ_PRIORITY_MASK); spin_lock_irqsave(&f->lock, flags); /* check if this element needs to inserted at the end (ie. ordered data is inserted) This will be very likeley if a sequencer application or midi file player is feeding us (sequential) data */ if (f->tail && !prior) { if (compare_timestamp(&cell->event, &f->tail->event)) { /* add new cell to tail of the fifo */ f->tail->next = cell; f->tail = cell; cell->next = NULL; f->cells++; spin_unlock_irqrestore(&f->lock, flags); return 0; } } /* traverse list of elements to find the place where the new cell is to be inserted... Note that this is a order n process ! */ prev = NULL; /* previous cell */ cur = f->head; /* cursor */ count = 10000; /* FIXME: enough big, isn't it? */ while (cur != NULL) { /* compare timestamps */ int rel = compare_timestamp_rel(&cell->event, &cur->event); if (rel < 0) /* new cell has earlier schedule time, */ break; else if (rel == 0 && prior) /* equal schedule time and prior to others */ break; /* new cell has equal or larger schedule time, */ /* move cursor to next cell */ prev = cur; cur = cur->next; if (! --count) { spin_unlock_irqrestore(&f->lock, flags); pr_err("ALSA: seq: cannot find a pointer.. infinite loop?\n"); return -EINVAL; } } /* insert it before cursor */ if (prev != NULL) prev->next = cell; cell->next = cur; if (f->head == cur) /* this is the first cell, set head to it */ f->head = cell; if (cur == NULL) /* reached end of the list */ f->tail = cell; f->cells++; spin_unlock_irqrestore(&f->lock, flags); return 0; } /* dequeue cell from prioq */ struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f) { struct snd_seq_event_cell *cell; unsigned long flags; if (f == NULL) { pr_debug("ALSA: seq: snd_seq_prioq_cell_in() called with NULL prioq\n"); return NULL; } spin_lock_irqsave(&f->lock, flags); cell = f->head; if (cell) { f->head = cell->next; /* reset tail if this was the last element */ if (f->tail == cell) f->tail = NULL; cell->next = NULL; f->cells--; } spin_unlock_irqrestore(&f->lock, flags); return cell; } /* return number of events available in prioq */ int snd_seq_prioq_avail(struct snd_seq_prioq * f) { if (f == NULL) { pr_debug("ALSA: seq: snd_seq_prioq_cell_in() called with NULL prioq\n"); return 0; } return f->cells; } /* peek at cell at the head of the prioq */ struct snd_seq_event_cell *snd_seq_prioq_cell_peek(struct snd_seq_prioq * f) { if (f == NULL) { pr_debug("ALSA: seq: snd_seq_prioq_cell_in() called with NULL prioq\n"); return NULL; } return f->head; } static inline int prioq_match(struct snd_seq_event_cell *cell, int client, int timestamp) { if (cell->event.source.client == client || cell->event.dest.client == client) return 1; if (!timestamp) return 0; switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) { case SNDRV_SEQ_TIME_STAMP_TICK: if (cell->event.time.tick) return 1; break; case SNDRV_SEQ_TIME_STAMP_REAL: if (cell->event.time.time.tv_sec || cell->event.time.time.tv_nsec) return 1; break; } return 0; } /* remove cells for left client */ void snd_seq_prioq_leave(struct snd_seq_prioq * f, int client, int timestamp) { register struct snd_seq_event_cell *cell, *next; unsigned long flags; struct snd_seq_event_cell *prev = NULL; struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext; /* collect all removed cells */ spin_lock_irqsave(&f->lock, flags); cell = f->head; while (cell) { next = cell->next; if (prioq_match(cell, client, timestamp)) { /* remove cell from prioq */ if (cell == f->head) { f->head = cell->next; } else { prev->next = cell->next; } if (cell == f->tail) f->tail = cell->next; f->cells--; /* add cell to free list */ cell->next = NULL; if (freefirst == NULL) { freefirst = cell; } else { freeprev->next = cell; } freeprev = cell; } else { #if 0 pr_debug("ALSA: seq: type = %i, source = %i, dest = %i, " "client = %i\n", cell->event.type, cell->event.source.client, cell->event.dest.client, client); #endif prev = cell; } cell = next; } spin_unlock_irqrestore(&f->lock, flags); /* remove selected cells */ while (freefirst) { freenext = freefirst->next; snd_seq_cell_free(freefirst); freefirst = freenext; } } static int prioq_remove_match(struct snd_seq_remove_events *info, struct snd_seq_event *ev) { int res; if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) { if (ev->dest.client != info->dest.client || ev->dest.port != info->dest.port) return 0; } if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST_CHANNEL) { if (! snd_seq_ev_is_channel_type(ev)) return 0; /* data.note.channel and data.control.channel are identical */ if (ev->data.note.channel != info->channel) return 0; } if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_AFTER) { if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK) res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick); else res = snd_seq_compare_real_time(&ev->time.time, &info->time.time); if (!res) return 0; } if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_BEFORE) { if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK) res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick); else res = snd_seq_compare_real_time(&ev->time.time, &info->time.time); if (res) return 0; } if (info->remove_mode & SNDRV_SEQ_REMOVE_EVENT_TYPE) { if (ev->type != info->type) return 0; } if (info->remove_mode & SNDRV_SEQ_REMOVE_IGNORE_OFF) { /* Do not remove off events */ switch (ev->type) { case SNDRV_SEQ_EVENT_NOTEOFF: /* case SNDRV_SEQ_EVENT_SAMPLE_STOP: */ return 0; default: break; } } if (info->remove_mode & SNDRV_SEQ_REMOVE_TAG_MATCH) { if (info->tag != ev->tag) return 0; } return 1; } /* remove cells matching remove criteria */ void snd_seq_prioq_remove_events(struct snd_seq_prioq * f, int client, struct snd_seq_remove_events *info) { struct snd_seq_event_cell *cell, *next; unsigned long flags; struct snd_seq_event_cell *prev = NULL; struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext; /* collect all removed cells */ spin_lock_irqsave(&f->lock, flags); cell = f->head; while (cell) { next = cell->next; if (cell->event.source.client == client && prioq_remove_match(info, &cell->event)) { /* remove cell from prioq */ if (cell == f->head) { f->head = cell->next; } else { prev->next = cell->next; } if (cell == f->tail) f->tail = cell->next; f->cells--; /* add cell to free list */ cell->next = NULL; if (freefirst == NULL) { freefirst = cell; } else { freeprev->next = cell; } freeprev = cell; } else { prev = cell; } cell = next; } spin_unlock_irqrestore(&f->lock, flags); /* remove selected cells */ while (freefirst) { freenext = freefirst->next; snd_seq_cell_free(freefirst); freefirst = freenext; } }