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: https://github.com/alsa-project/alsa-lib/issues/394
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/src/async.c b/src/async.c
index 76c6fb9e0077b38d995aaa029641aa8b348f4c2c..a003e44170ef1d012dba9eae1b5c133aca85cf26 100644 (file)
--- a/src/async.c
+++ b/src/async.c
@@ -149,12 +149,31 @@ 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");
@@ -162,27 +181,8 @@ int snd_async_del_handler(snd_async_handler_t *handler)
                }
                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;
 }
 
 /**