Created attachment 353730 [details]
Deadlock callstacks

During dash playback there is an error between pad posting an event (which goes to decoebin2 on its pad) and decodebin2 trying to modify pad state.

From the dump (attached):

Thread 21:

+ Trace 237575

        /* lock order: STREAM_LOCK, LOCK, recheck flushing. */
        GST_OBJECT_UNLOCK (pad);
        GST_PAD_STREAM_LOCK (pad); <===== Lock taken here, as EOS event is serialized
        need_unlock = TRUE;
        GST_OBJECT_LOCK (pad);
        if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
          goto flushing;

        if (G_UNLIKELY (GST_PAD_IS_EOS (pad)))
          goto eos;
      }
      break;
  }

  /* now do the probe */
  PROBE_PUSH (pad,
      type | GST_PAD_PROBE_TYPE_PUSH |
      GST_PAD_PROBE_TYPE_BLOCK, event, probe_stopped);

  PROBE_PUSH (pad, type | GST_PAD_PROBE_TYPE_PUSH, event, probe_stopped);

  eventfullfunc = GST_PAD_EVENTFULLFUNC (pad);
  eventfunc = GST_PAD_EVENTFUNC (pad);
  if (G_UNLIKELY (eventfunc == NULL && eventfullfunc == NULL))
    goto no_function;

  ACQUIRE_PARENT (pad, parent, no_parent);
  GST_OBJECT_UNLOCK (pad);

  ret = pre_eventfunc_check (pad, event); <= executes this 

(gdb) print *event
$5 = {mini_object = {type = 3052471832, refcount = 54, lockstate = 0, flags = 0, copy = 0xb69c6751 <_gst_event_copy>, dispose = 0x0, free = 0xb69c68bd <_gst_event_free>, n_qdata = 0, qdata = 0x0}, type = GST_EVENT_EOS, timestamp = 18446744073709551615, seqnum = 8629}