fwd: Improve `source' and `target' lifecycle management.

[fwd] / source.c

diff --git a/source.c b/source.c
index 96b7f816688b93f1a711f83ab80e57c85bb31544..f515ae28bd2910adc6bd716642dee014ab47ac52 100644 (file)
--- a/source.c
+++ b/source.c
@@ -45,11 +45,15 @@ static source *sources = 0;
 
 void source_add(source *s)
 {
+  assert(s->ops->shutdown);
+  assert(!(s->f&SF_ACTIVE));
   s->next = sources;
   s->prev = 0;
   if (sources)
     sources->prev = s;
   sources = s;
+  s->f |= SF_ACTIVE;
+  source_inc(s);
 }
 
 /* --- @source_remove@ --- *
@@ -63,12 +67,45 @@ void source_add(source *s)
 
 void source_remove(source *s)
 {
+  assert(s->f&SF_ACTIVE);
   if (s->next)
     s->next->prev = s->prev;
   if (s->prev)
     s->prev->next = s->next;
   else
     sources = s->next;
+  s->f &= ~SF_ACTIVE;
+  source_dec(s);
+}
+
+/* --- @source_inc@ --- *
+ *
+ * Arguments:  @source *s@ = pointer to a source
+ *
+ * Returns:    ---
+ *
+ * Use:                Increments a source's refcount.
+ */
+
+void source_inc(source *s) { s->ref++; }
+
+/* --- @source_dec@ --- *
+ *
+ * Arguments:  @source *s@ = pointer to a source
+ *
+ * Returns:    ---
+ *
+ * Use:                Decrements a source's refcount, destroying it if necessary.
+ */
+
+void source_dec(source *s)
+{
+  assert(s->ref > 0);
+  s->ref--;
+  if (!s->ref) {
+    if (s->f&SF_ACTIVE) s->ops->shutdown(s);
+    s->ops->destroy(s);
+  }
 }
 
 /* --- @source_killall@ --- *
@@ -86,7 +123,7 @@ void source_killall(void)
   while (s) {
     source *ss = s;
     s = s->next;
-    ss->ops->destroy(ss);
+    ss->ops->shutdown(ss);
   }
   sources = 0;
 }