[Sugar-devel] [ASLO] Release Clock-17

James Cameron quozl at laptop.org
Tue May 12 18:21:26 EDT 2015

On Tue, May 12, 2015 at 06:22:42PM -0300, Gonzalo Odiard wrote:
> I think I found the problem. 
> Could you confirm replacing the attached file in the activity dir?

Thanks, that's much better.  The warning about rate and the delay
before speaking have been fixed.

Rarely, about one in 10 times, it doesn't speak, and reports in log

(sugar-activity:2492): GStreamer-CRITICAL **: gst_memory_new_wrapped: assertion `offset + size <= maxsize' failed

(sugar-activity:2492): GStreamer-CRITICAL **: gst_buffer_insert_memory: assertion `mem != NULL' failed

Rarely, about one in 5 times, it does segmentation fault.  I've
captured two core dumps by adding "ulimit -c unlimited" to
~/.sugar/debug.  Both showed similar stack traces; a thread busy doing
an fts_open and fts_sort at the same time as the main thread doing
something else.


Speculation: the Gst.init() in src/sugar3/speech.py creates a thread
which is racing with something in the main thread.  fts_open and
fts_sort are necessary calls for scanning plugins.

Sometimes the race condition corrupts pointers and we get the silence
with GStreamer-CRITICAL messages.  Sometimes the corruption causes a
segmentation fault.

Perhaps _GstSpeechPlayer should wait for good Gst.State before the
next call into Gst?

I remember recent work on GStreamer plugin scan initialisation in
Sugar, but I can't find it yet.

James Cameron

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