srt: avoid srtsrc segfault upon downward state change

... when it has not yet been connected to.

Also, a condition variable is not a semaphore, so a lock/wait/unlock
sequence is inherently racy without any state checking.  So switch to
a different lock and check the intended state.
This commit is contained in:
Mark Nauwelaerts 2019-05-01 19:01:03 +02:00
parent cc11a7f9d7
commit dbab2f9498
2 changed files with 20 additions and 25 deletions

View file

@ -189,7 +189,6 @@ gst_srt_object_new (GstElement * element)
srtobject->listener_poll_id = SRT_ERROR;
srtobject->sent_headers = FALSE;
g_mutex_init (&srtobject->sock_lock);
g_cond_init (&srtobject->sock_cond);
return srtobject;
}
@ -204,7 +203,6 @@ gst_srt_object_destroy (GstSRTObject * srtobject)
srtobject->poll_id = SRT_ERROR;
}
g_mutex_clear (&srtobject->sock_lock);
g_cond_clear (&srtobject->sock_cond);
GST_DEBUG_OBJECT (srtobject->element, "Destroying srtobject");
@ -683,11 +681,8 @@ idle_listen_source_cb (gpointer data)
GST_OBJECT_LOCK (srtobject->element);
srtobject->callers = g_list_append (srtobject->callers, caller);
GST_OBJECT_UNLOCK (srtobject->element);
g_mutex_lock (&srtobject->sock_lock);
g_cond_signal (&srtobject->sock_cond);
g_mutex_unlock (&srtobject->sock_lock);
GST_OBJECT_UNLOCK (srtobject->element);
/* notifying caller-added */
if (srtobject->caller_added_closure != NULL) {
@ -1096,17 +1091,23 @@ static gboolean
gst_srt_object_wait_caller (GstSRTObject * srtobject,
GCancellable * cancellable, GError ** errorj)
{
gboolean ret = FALSE;
GST_DEBUG_OBJECT (srtobject->element, "Waiting connection from caller");
if (g_cancellable_is_cancelled (cancellable)) {
return FALSE;
GST_OBJECT_LOCK (srtobject->element);
while (!g_cancellable_is_cancelled (cancellable)) {
ret = g_list_length (srtobject->callers) >= 1;
if (ret)
break;
g_cond_wait (&srtobject->sock_cond,
GST_OBJECT_GET_LOCK (srtobject->element));
}
GST_OBJECT_UNLOCK (srtobject->element);
g_mutex_lock (&srtobject->sock_lock);
g_cond_wait (&srtobject->sock_cond, &srtobject->sock_lock);
g_mutex_unlock (&srtobject->sock_lock);
GST_DEBUG_OBJECT (srtobject->element, "got %s connection", ret ? "a" : "no");
return TRUE;
return ret;
}
gssize
@ -1129,11 +1130,8 @@ gst_srt_object_read (GstSRTObject * srtobject,
if (connection_mode == GST_SRT_CONNECTION_MODE_LISTENER) {
SRTCaller *caller;
if (g_list_length (srtobject->callers) < 1) {
if (!gst_srt_object_wait_caller (srtobject, cancellable, error)) {
return -1;
}
}
if (!gst_srt_object_wait_caller (srtobject, cancellable, error))
return -1;
caller = srtobject->callers->data;
poll_id = caller->poll_id;
@ -1228,9 +1226,9 @@ gst_srt_object_wakeup (GstSRTObject * srtobject)
GST_TYPE_SRT_CONNECTION_MODE, (gint *) & connection_mode);
if (connection_mode == GST_SRT_CONNECTION_MODE_LISTENER) {
g_mutex_lock (&srtobject->sock_lock);
GST_OBJECT_LOCK (srtobject->element);
g_cond_signal (&srtobject->sock_cond);
g_mutex_unlock (&srtobject->sock_lock);
GST_OBJECT_UNLOCK (srtobject->element);
}
}
@ -1428,11 +1426,9 @@ gst_srt_object_write (GstSRTObject * srtobject,
GST_TYPE_SRT_CONNECTION_MODE, (gint *) & connection_mode);
if (connection_mode == GST_SRT_CONNECTION_MODE_LISTENER) {
if (g_list_length (srtobject->callers) < 1) {
if (!gst_srt_object_wait_caller (srtobject, cancellable, error)) {
return -1;
}
}
if (!gst_srt_object_wait_caller (srtobject, cancellable, error))
return -1;
len =
gst_srt_object_write_to_callers (srtobject, headers, mapinfo,
cancellable, error);

View file

@ -55,7 +55,6 @@ struct _GstSRTObject
gint poll_id;
gboolean sent_headers;
GMutex sock_lock;
GCond sock_cond;
GTask *listener_task;