async: snd_async_del_handler - move clear signal using sigaction as last

Improve the shutdown order for the asynchronous users. There may be
unhandled signals, because the signal is reset before signal deactivation
using fnctl (O_ASYNC).

Closes: #394
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

src/async.c

@@ -149,40 +149,40 @@ int snd_async_add_handler(snd_async_handler_t **handler, int fd,
  */
 int snd_async_del_handler(snd_async_handler_t *handler)
 {
-	int err = 0;
-	int was_empty = list_empty(&snd_async_handlers);
+	int err = 0, err2 = 0;
+	int was_empty;
 	assert(handler);
+	if (handler->type != SND_ASYNC_HANDLER_GENERIC) {
+		if (!list_empty(&handler->hlist))
+			list_del(&handler->hlist);
+		if (!list_empty(&handler->hlist))
+			goto _glist;
+		switch (handler->type) {
+#ifdef BUILD_PCM
+		case SND_ASYNC_HANDLER_PCM:
+			err2 = snd_pcm_async(handler->u.pcm, -1, 1);
+			break;
+#endif
+		case SND_ASYNC_HANDLER_CTL:
+			err2 = snd_ctl_async(handler->u.ctl, -1, 1);
+			break;
+		default:
+			assert(0);
+		}
+	}
+ _glist:
+	was_empty = list_empty(&snd_async_handlers);
 	list_del(&handler->glist);
-	if (!was_empty
-	 && list_empty(&snd_async_handlers)) {
+	if (!was_empty && list_empty(&snd_async_handlers)) {
 		err = sigaction(snd_async_signo, &previous_action, NULL);
 		if (err < 0) {
 			SYSERR("sigaction");
 			return -errno;
 		}
 		memset(&previous_action, 0, sizeof(previous_action));
 	}
-	if (handler->type == SND_ASYNC_HANDLER_GENERIC)
-		goto _end;
-	if (!list_empty(&handler->hlist))
-		list_del(&handler->hlist);
-	if (!list_empty(&handler->hlist))
-		goto _end;
-	switch (handler->type) {
-#ifdef BUILD_PCM
-	case SND_ASYNC_HANDLER_PCM:
-		err = snd_pcm_async(handler->u.pcm, -1, 1);
-		break;
-#endif
-	case SND_ASYNC_HANDLER_CTL:
-		err = snd_ctl_async(handler->u.ctl, -1, 1);
-		break;
-	default:
-		assert(0);
-	}
- _end:
 	free(handler);
-	return err;
+	return err ? err : err2;
 }
 
 /**