code.delx.au - pulseaudio/blob - src/polypcore/core-subscribe.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <stdio.h>
  27 #include <assert.h>
  28
  29 #include <polyp/xmalloc.h>
  30
  31 #include <polypcore/queue.h>
  32 #include <polypcore/log.h>
  33
  34 #include "core-subscribe.h"
  35
  36 /* The subscription subsystem may be used to be notified whenever an
  37  * entity (sink, source, ...) is created or deleted. Modules may
  38  * register a callback function that is called whenever an event
  39  * matching a subscription mask happens. The execution of the callback
  40  * function is postponed to the next main loop iteration, i.e. is not
  41  * called from within the stack frame the entity was created in. */
  42
  43 struct pa_subscription {
  44     pa_core *core;
  45     int dead;
  46     void (*callback)(pa_core *c, pa_subscription_event_type_t t, uint32_t index, void *userdata);
  47     void *userdata;
  48     pa_subscription_mask_t mask;
  49
  50     pa_subscription *prev, *next;
  51 };
  52
  53 struct pa_subscription_event {
  54     pa_subscription_event_type_t type;
  55     uint32_t index;
  56 };
  57
  58 static void sched_event(pa_core *c);
  59
  60 /* Allocate a new subscription object for the given subscription mask. Use the specified callback function and user data */
  61 pa_subscription* pa_subscription_new(pa_core *c, pa_subscription_mask_t m, void (*callback)(pa_core *c, pa_subscription_event_type_t t, uint32_t index, void *userdata), void *userdata) {
  62     pa_subscription *s;
  63     assert(c);
  64
  65     s = pa_xmalloc(sizeof(pa_subscription));
  66     s->core = c;
  67     s->dead = 0;
  68     s->callback = callback;
  69     s->userdata = userdata;
  70     s->mask = m;
  71
  72     if ((s->next = c->subscriptions))
  73         s->next->prev = s;
  74     s->prev = NULL;
  75     c->subscriptions = s;
  76     return s;
  77 }
  78
  79 /* Free a subscription object, effectively marking it for deletion */
  80 void pa_subscription_free(pa_subscription*s) {
  81     assert(s && !s->dead);
  82     s->dead = 1;
  83     sched_event(s->core);
  84 }
  85
  86 static void free_item(pa_subscription *s) {
  87     assert(s && s->core);
  88
  89     if (s->prev)
  90         s->prev->next = s->next;
  91     else
  92         s->core->subscriptions = s->next;
  93
  94     if (s->next)
  95         s->next->prev = s->prev;
  96
  97     pa_xfree(s);
  98 }
  99
 100 /* Free all subscription objects */
 101 void pa_subscription_free_all(pa_core *c) {
 102     pa_subscription_event *e;
 103     assert(c);
 104
 105     while (c->subscriptions)
 106         free_item(c->subscriptions);
 107
 108     if (c->subscription_event_queue) {
 109         while ((e = pa_queue_pop(c->subscription_event_queue)))
 110             pa_xfree(e);
 111
 112         pa_queue_free(c->subscription_event_queue, NULL, NULL);
 113         c->subscription_event_queue = NULL;
 114     }
 115
 116     if (c->subscription_defer_event) {
 117         c->mainloop->defer_free(c->subscription_defer_event);
 118         c->subscription_defer_event = NULL;
 119     }
 120 }
 121
 122 #if 0
 123 static void dump_event(pa_subscription_event*e) {
 124     switch (e->type & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) {
 125         case PA_SUBSCRIPTION_EVENT_SINK:
 126             pa_log(__FILE__": SINK_EVENT");
 127             break;
 128         case PA_SUBSCRIPTION_EVENT_SOURCE:
 129             pa_log(__FILE__": SOURCE_EVENT");
 130             break;
 131         case PA_SUBSCRIPTION_EVENT_SINK_INPUT:
 132             pa_log(__FILE__": SINK_INPUT_EVENT");
 133             break;
 134         case PA_SUBSCRIPTION_EVENT_SOURCE_OUTPUT:
 135             pa_log(__FILE__": SOURCE_OUTPUT_EVENT");
 136             break;
 137         case PA_SUBSCRIPTION_EVENT_MODULE:
 138             pa_log(__FILE__": MODULE_EVENT");
 139             break;
 140         case PA_SUBSCRIPTION_EVENT_CLIENT:
 141             pa_log(__FILE__": CLIENT_EVENT");
 142             break;
 143         default:
 144             pa_log(__FILE__": OTHER");
 145             break;
 146     }
 147
 148     switch (e->type & PA_SUBSCRIPTION_EVENT_TYPE_MASK) {
 149         case PA_SUBSCRIPTION_EVENT_NEW:
 150             pa_log(__FILE__":  NEW");
 151             break;
 152         case PA_SUBSCRIPTION_EVENT_CHANGE:
 153             pa_log(__FILE__":  CHANGE");
 154             break;
 155         case PA_SUBSCRIPTION_EVENT_REMOVE:
 156             pa_log(__FILE__":  REMOVE");
 157             break;
 158         default:
 159             pa_log(__FILE__":  OTHER");
 160             break;
 161     }
 162
 163     pa_log(__FILE__":  %u", e->index);
 164 }
 165 #endif
 166
 167 /* Deferred callback for dispatching subscirption events */
 168 static void defer_cb(pa_mainloop_api *m, pa_defer_event *de, void *userdata) {
 169     pa_core *c = userdata;
 170     pa_subscription *s;
 171     assert(c && c->subscription_defer_event == de && c->mainloop == m);
 172
 173     c->mainloop->defer_enable(c->subscription_defer_event, 0);
 174
 175     /* Dispatch queued events */
 176
 177     if (c->subscription_event_queue) {
 178         pa_subscription_event *e;
 179
 180         while ((e = pa_queue_pop(c->subscription_event_queue))) {
 181
 182             for (s = c->subscriptions; s; s = s->next) {
 183
 184                 if (!s->dead && pa_subscription_match_flags(s->mask, e->type))
 185                     s->callback(c, e->type, e->index, s->userdata);
 186             }
 187
 188             pa_xfree(e);
 189         }
 190     }
 191
 192     /* Remove dead subscriptions */
 193
 194     s = c->subscriptions;
 195     while (s) {
 196         pa_subscription *n = s->next;
 197         if (s->dead)
 198             free_item(s);
 199         s = n;
 200     }
 201 }
 202
 203 /* Schedule an mainloop event so that a pending subscription event is dispatched */
 204 static void sched_event(pa_core *c) {
 205     assert(c);
 206
 207     if (!c->subscription_defer_event) {
 208         c->subscription_defer_event = c->mainloop->defer_new(c->mainloop, defer_cb, c);
 209         assert(c->subscription_defer_event);
 210     }
 211
 212     c->mainloop->defer_enable(c->subscription_defer_event, 1);
 213 }
 214
 215 /* Append a new subscription event to the subscription event queue and schedule a main loop event */
 216 void pa_subscription_post(pa_core *c, pa_subscription_event_type_t t, uint32_t index) {
 217     pa_subscription_event *e;
 218     assert(c);
 219
 220     e = pa_xmalloc(sizeof(pa_subscription_event));
 221     e->type = t;
 222     e->index = index;
 223
 224     if (!c->subscription_event_queue) {
 225         c->subscription_event_queue = pa_queue_new();
 226         assert(c->subscription_event_queue);
 227     }
 228
 229     pa_queue_push(c->subscription_event_queue, e);
 230     sched_event(c);
 231 }
 232
 233