summaryrefslogtreecommitdiffstats
path: root/src/polypcore/core-subscribe.c
blob: 52babb7a373129a081071adec587876ee28b4ea5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/* $Id$ */

/***
  This file is part of polypaudio.
 
  polypaudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.
 
  polypaudio 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 Lesser General Public License
  along with polypaudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <assert.h>

#include <polyp/xmalloc.h>

#include <polypcore/queue.h>
#include <polypcore/log.h>

#include "core-subscribe.h"

/* The subscription subsystem may be used to be notified whenever an
 * entity (sink, source, ...) is created or deleted. Modules may
 * register a callback function that is called whenever an event
 * matching a subscription mask happens. The execution of the callback
 * function is postponed to the next main loop iteration, i.e. is not
 * called from within the stack frame the entity was created in. */

struct pa_subscription {
    pa_core *core;
    int dead;
    void (*callback)(pa_core *c, pa_subscription_event_type_t t, uint32_t index, void *userdata);
    void *userdata;
    pa_subscription_mask_t mask;

    pa_subscription *prev, *next;
};

struct pa_subscription_event {
    pa_subscription_event_type_t type;
    uint32_t index;
};

static void sched_event(pa_core *c);

/* Allocate a new subscription object for the given subscription mask. Use the specified callback function and user data */
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) {
    pa_subscription *s;
    assert(c);

    s = pa_xmalloc(sizeof(pa_subscription));
    s->core = c;
    s->dead = 0;
    s->callback = callback;
    s->userdata = userdata;
    s->mask = m;

    if ((s->next = c->subscriptions))
        s->next->prev = s;
    s->prev = NULL;
    c->subscriptions = s;
    return s;
}

/* Free a subscription object, effectively marking it for deletion */
void pa_subscription_free(pa_subscription*s) {
    assert(s && !s->dead);
    s->dead = 1;
    sched_event(s->core);
}

static void free_item(pa_subscription *s) {
    assert(s && s->core);

    if (s->prev)
        s->prev->next = s->next;
    else
        s->core->subscriptions = s->next;
            
    if (s->next)
        s->next->prev = s->prev;
    
    pa_xfree(s);
}

/* Free all subscription objects */
void pa_subscription_free_all(pa_core *c) {
    pa_subscription_event *e;
    assert(c);
    
    while (c->subscriptions)
        free_item(c->subscriptions);

    if (c->subscription_event_queue) {
        while ((e = pa_queue_pop(c->subscription_event_queue)))
            pa_xfree(e);
        
        pa_queue_free(c->subscription_event_queue, NULL, NULL);
        c->subscription_event_queue = NULL;
    }

    if (c->subscription_defer_event) {
        c->mainloop->defer_free(c->subscription_defer_event);
        c->subscription_defer_event = NULL;
    }
}

#if 0
static void dump_event(pa_subscription_event*e) {
    switch (e->type & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) {
        case PA_SUBSCRIPTION_EVENT_SINK:
            pa_log(__FILE__": SINK_EVENT");
            break;
        case PA_SUBSCRIPTION_EVENT_SOURCE:
            pa_log(__FILE__": SOURCE_EVENT");
            break;
        case PA_SUBSCRIPTION_EVENT_SINK_INPUT:
            pa_log(__FILE__": SINK_INPUT_EVENT");
            break;
        case PA_SUBSCRIPTION_EVENT_SOURCE_OUTPUT:
            pa_log(__FILE__": SOURCE_OUTPUT_EVENT");
            break;
        case PA_SUBSCRIPTION_EVENT_MODULE:
            pa_log(__FILE__": MODULE_EVENT");
            break;
        case PA_SUBSCRIPTION_EVENT_CLIENT:
            pa_log(__FILE__": CLIENT_EVENT");
            break;
        default:
            pa_log(__FILE__": OTHER");
            break;
    }

    switch (e->type & PA_SUBSCRIPTION_EVENT_TYPE_MASK) {
        case PA_SUBSCRIPTION_EVENT_NEW:
            pa_log(__FILE__":  NEW");
            break;
        case PA_SUBSCRIPTION_EVENT_CHANGE:
            pa_log(__FILE__":  CHANGE");
            break;
        case PA_SUBSCRIPTION_EVENT_REMOVE:
            pa_log(__FILE__":  REMOVE");
            break;
        default:
            pa_log(__FILE__":  OTHER");
            break;
    }

    pa_log(__FILE__":  %u", e->index);
}
#endif

/* Deferred callback for dispatching subscirption events */
static void defer_cb(pa_mainloop_api *m, pa_defer_event *de, void *userdata) {
    pa_core *c = userdata;
    pa_subscription *s;
    assert(c && c->subscription_defer_event == de && c->mainloop == m);

    c->mainloop->defer_enable(c->subscription_defer_event, 0);

    /* Dispatch queued events */
    
    if (c->subscription_event_queue) {
        pa_subscription_event *e;
        
        while ((e = pa_queue_pop(c->subscription_event_queue))) {

            for (s = c->subscriptions; s; s = s->next) {

                if (!s->dead && pa_subscription_match_flags(s->mask, e->type))
                    s->callback(c, e->type, e->index, s->userdata);
            }
            
            pa_xfree(e);
        }
    }

    /* Remove dead subscriptions */
    
    s = c->subscriptions;
    while (s) {
        pa_subscription *n = s->next;
        if (s->dead)
            free_item(s);
        s = n;
    }
}

/* Schedule an mainloop event so that a pending subscription event is dispatched */
static void sched_event(pa_core *c) {
    assert(c);

    if (!c->subscription_defer_event) {
        c->subscription_defer_event = c->mainloop->defer_new(c->mainloop, defer_cb, c);
        assert(c->subscription_defer_event);
    }
        
    c->mainloop->defer_enable(c->subscription_defer_event, 1);
}

/* Append a new subscription event to the subscription event queue and schedule a main loop event */
void pa_subscription_post(pa_core *c, pa_subscription_event_type_t t, uint32_t index) {
    pa_subscription_event *e;
    assert(c);

    e = pa_xmalloc(sizeof(pa_subscription_event));
    e->type = t;
    e->index = index;

    if (!c->subscription_event_queue) {
        c->subscription_event_queue = pa_queue_new();
        assert(c->subscription_event_queue);
    }
    
    pa_queue_push(c->subscription_event_queue, e);
    sched_event(c);
}