[gstreamer-bugs] [Bug 502891] New: deterministic realtime behaviour

[GStreamer (bugzilla.gnome.org)]

If you have any questions why you received this email, please see the text at
the end of this email. Replies to this email are NOT read, please see the text
at the end of this email. You can add comments to this bug at:
  http://bugzilla.gnome.org/show_bug.cgi?id=502891

  GStreamer | gstreamer (core) | Ver: HEAD CVS
           Summary: deterministic realtime behaviour
           Product: GStreamer
           Version: HEAD CVS
          Platform: Other
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: Normal
         Component: gstreamer (core)
        AssignedTo: gstreamer-bugs at lists.sourceforge.net
        ReportedBy: ensonic at sonicpulse.de
         QAContact: gstreamer-bugs at lists.sourceforge.net
     GNOME version: Unspecified
   GNOME milestone: Unspecified


This is a tracker bug to design what it need to make gstreamer behave
deterministicly during GST_STATE_PLAYING. This is especially important when
assigning realtime privileges to threads (see Bug 501239). Right now gstreamer
is e.g. allocating and freeing memory at playing time. The libc allocator is
not suited for realtime criteria. Smaller allocation are done from pools and
releasing them can cause trimming pools. The later can cause significant
delays.

GSlice is not an option as it uses thread local pools that require locking when
freeing buffers allocated from different threads.

What options are there:
1.) switching off trimming using mallopt()
    http://www.zeroc.com/faq/largeRequests.html
    http://www.linuxjournal.com/article/6390

2.) reuse objects
    example in Bug 500653

3.) use a different allocator
   http://rtportal.upv.es/rtmalloc/
   http://goog-perftools.sourceforge.net/doc/tcmalloc.html

Some further links:
http://en.wikipedia.org/wiki/Malloc#External_links


-- 
See http://bugzilla.gnome.org/page.cgi?id=email.html for more info about why you received
this email, why you can't respond via email, how to stop receiving
emails (or reduce the number you receive), and how to contact someone
if you are having problems with the system.

You can add comments to this bug at http://bugzilla.gnome.org/show_bug.cgi?id=502891.