code.delx.au - pulseaudio/blob - src/polypcore/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 "queue.h"
  30 #include "subscribe.h"
  31 #include "xmalloc.h"
  32 #include "log.h"
  33
  34 /* The subscription subsystem may be used to be notified whenever an
  35  * entity (sink, source, ...) is created or deleted. Modules may
  36  * register a callback function that is called whenever an event
  37  * matching a subscription mask happens. The execution of the callback
  38  * function is postponed to the next main loop iteration, i.e. is not
  39  * called from within the stack frame the entity was created in. */
  40
  41 struct pa_subscription {
  42     pa_core *core;
  43     int dead;
  44     void (*callback)(pa_core *c, pa_subscription_event_type_t t, uint32_t index, void *userdata);
  45     void *userdata;
  46     pa_subscription_mask_t mask;
  47
  48     pa_subscription *prev, *next;
  49 };
  50
  51 struct pa_subscription_event {
  52     pa_subscription_event_type_t type;
  53     uint32_t index;
  54 };
  55
  56 static void sched_event(pa_core *c);
  57
  58 /* Allocate a new subscription object for the given subscription mask. Use the specified callback function and user data */
  59 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) {
  60     pa_subscription *s;
  61     assert(c);
  62
  63     s = pa_xmalloc(sizeof(pa_subscription));
  64     s->core = c;
  65     s->dead = 0;
  66     s->callback = callback;
  67     s->userdata = userdata;
  68     s->mask = m;
  69
  70     if ((s->next = c->subscriptions))
  71         s->next->prev = s;
  72     s->prev = NULL;
  73     c->subscriptions = s;
  74     return s;
  75 }
  76
  77 /* Free a subscription object, effectively marking it for deletion */
  78 void pa_subscription_free(pa_subscription*s) {
  79     assert(s && !s->dead);
  80     s->dead = 1;
  81     sched_event(s->core);
  82 }
  83
  84 static void free_item(pa_subscription *s) {
  85     assert(s && s->core);
  86
  87     if (s->prev)
  88         s->prev->next = s->next;
  89     else
  90         s->core->subscriptions = s->next;
  91
  92     if (s->next)
  93         s->next->prev = s->prev;
  94
  95     pa_xfree(s);
  96 }
  97
  98 /* Free all subscription objects */
  99 void pa_subscription_free_all(pa_core *c) {
 100     pa_subscription_event *e;
 101     assert(c);
 102
 103     while (c->subscriptions)
 104         free_item(c->subscriptions);
 105
 106     if (c->subscription_event_queue) {
 107         while ((e = pa_queue_pop(c->subscription_event_queue)))
 108             pa_xfree(e);
 109
 110         pa_queue_free(c->subscription_event_queue, NULL, NULL);
 111         c->subscription_event_queue = NULL;
 112     }
 113
 114     if (c->subscription_defer_event) {
 115         c->mainloop->defer_free(c->subscription_defer_event);
 116         c->subscription_defer_event = NULL;
 117     }
 118 }
 119
 120 /*static void dump_event(pa_subscription_event*e) {
 121     switch (e->type & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) {
 122         case PA_SUBSCRIPTION_EVENT_SINK:
 123             pa_log(__FILE__": SINK_EVENT");
 124             break;
 125         case PA_SUBSCRIPTION_EVENT_SOURCE:
 126             pa_log(__FILE__": SOURCE_EVENT");
 127             break;
 128         case PA_SUBSCRIPTION_EVENT_SINK_INPUT:
 129             pa_log(__FILE__": SINK_INPUT_EVENT");
 130             break;
 131         case PA_SUBSCRIPTION_EVENT_SOURCE_OUTPUT:
 132             pa_log(__FILE__": SOURCE_OUTPUT_EVENT");
 133             break;
 134         case PA_SUBSCRIPTION_EVENT_MODULE:
 135             pa_log(__FILE__": MODULE_EVENT");
 136             break;
 137         case PA_SUBSCRIPTION_EVENT_CLIENT:
 138             pa_log(__FILE__": CLIENT_EVENT");
 139             break;
 140         default:
 141             pa_log(__FILE__": OTHER");
 142             break;
 143     }
 144
 145     switch (e->type & PA_SUBSCRIPTION_EVENT_TYPE_MASK) {
 146         case PA_SUBSCRIPTION_EVENT_NEW:
 147             pa_log(__FILE__":  NEW");
 148             break;
 149         case PA_SUBSCRIPTION_EVENT_CHANGE:
 150             pa_log(__FILE__":  CHANGE");
 151             break;
 152         case PA_SUBSCRIPTION_EVENT_REMOVE:
 153             pa_log(__FILE__":  REMOVE");
 154             break;
 155         default:
 156             pa_log(__FILE__":  OTHER");
 157             break;
 158     }
 159
 160     pa_log(__FILE__":  %u\n", e->index);
 161 }*/
 162
 163 /* Deferred callback for dispatching subscirption events */
 164 static void defer_cb(pa_mainloop_api *m, pa_defer_event *de, void *userdata) {
 165     pa_core *c = userdata;
 166     pa_subscription *s;
 167     assert(c && c->subscription_defer_event == de && c->mainloop == m);
 168
 169     c->mainloop->defer_enable(c->subscription_defer_event, 0);
 170
 171
 172     /* Dispatch queued events */
 173
 174     if (c->subscription_event_queue) {
 175         pa_subscription_event *e;
 176
 177         while ((e = pa_queue_pop(c->subscription_event_queue))) {
 178
 179             for (s = c->subscriptions; s; s = s->next) {
 180
 181                 if (!s->dead && pa_subscription_match_flags(s->mask, e->type))
 182                     s->callback(c, e->type, e->index, s->userdata);
 183             }
 184
 185             pa_xfree(e);
 186         }
 187     }
 188
 189     /* Remove dead subscriptions */
 190
 191     s = c->subscriptions;
 192     while (s) {
 193         pa_subscription *n = s->next;
 194         if (s->dead)
 195             free_item(s);
 196         s = n;
 197     }
 198 }
 199
 200 /* Schedule an mainloop event so that a pending subscription event is dispatched */
 201 static void sched_event(pa_core *c) {
 202     assert(c);
 203
 204     if (!c->subscription_defer_event) {
 205         c->subscription_defer_event = c->mainloop->defer_new(c->mainloop, defer_cb, c);
 206         assert(c->subscription_defer_event);
 207     }
 208
 209     c->mainloop->defer_enable(c->subscription_defer_event, 1);
 210 }
 211
 212 /* Append a new subscription event to the subscription event queue and schedule a main loop event */
 213 void pa_subscription_post(pa_core *c, pa_subscription_event_type_t t, uint32_t index) {
 214     pa_subscription_event *e;
 215     assert(c);
 216
 217     e = pa_xmalloc(sizeof(pa_subscription_event));
 218     e->type = t;
 219     e->index = index;
 220
 221     if (!c->subscription_event_queue) {
 222         c->subscription_event_queue = pa_queue_new();
 223         assert(c->subscription_event_queue);
 224     }
 225
 226     pa_queue_push(c->subscription_event_queue, e);
 227     sched_event(c);
 228 }
 229
 230