add subscription subsystem

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@112 fefdeb5f-60dc-0310-8127-8f9354f1896f

polyp/subscribe.c

@@ -0,0 +1,152 @@
+#include <stdio.h>
+#include <assert.h>
+
+#include "queue.h"
+#include "subscribe.h"
+#include "xmalloc.h"
+
+struct pa_subscription {
+    struct pa_core *core;
+    int dead;
+    void (*callback)(struct pa_core *c, enum pa_subscription_event_type t, uint32_t index, void *userdata);
+    void *userdata;
+    enum pa_subscription_mask mask;
+
+    struct pa_subscription *prev, *next;
+};
+
+struct pa_subscription_event {
+    enum pa_subscription_event_type type;
+    uint32_t index;
+};
+
+static void sched_event(struct pa_core *c);
+
+struct pa_subscription* pa_subscription_new(struct pa_core *c, enum pa_subscription_mask m, void (*callback)(struct pa_core *c, enum pa_subscription_event_type t, uint32_t index, void *userdata), void *userdata) {
+    struct pa_subscription *s;
+    assert(c);
+
+    s = pa_xmalloc(sizeof(struct 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 NULL;
+}
+
+void pa_subscription_free(struct pa_subscription*s) {
+    assert(s && !s->dead);
+    s->dead = 1;
+    sched_event(s->core);
+}
+
+static void free_item(struct 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);
+}
+
+void pa_subscription_free_all(struct pa_core *c) {
+    struct 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;
+    }
+}
+
+static void defer_cb(struct pa_mainloop_api *m, struct pa_defer_event *e, void *userdata) {
+    struct pa_core *c = userdata;
+    struct pa_subscription *s;
+    assert(c && c->subscription_defer_event == e && c->mainloop == m);
+
+    c->mainloop->defer_enable(c->subscription_defer_event, 0);
+
+
+    /* Dispatch queued events */
+    
+    if (c->subscription_event_queue) {
+        struct pa_subscription_event *e;
+        
+        while ((e = pa_queue_pop(c->subscription_event_queue))) {
+            struct pa_subscription *s;
+
+            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) {
+        struct pa_subscription *n = s->next;
+        if (s->dead)
+            free_item(s);
+        s = n;
+    }
+}
+
+static void sched_event(struct 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);
+}
+
+
+void pa_subscription_post(struct pa_core *c, enum pa_subscription_event_type t, uint32_t index) {
+    struct pa_subscription_event *e;
+    assert(c);
+
+    e = pa_xmalloc(sizeof(struct 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);
+}
+
+
+int pa_subscription_match_flags(enum pa_subscription_mask m, enum pa_subscription_event_type t) {
+    return !!(m & (1 >> (t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK)));
+}