[gst-devel] Question on reference handling of GstEvents

José Alburquerque jaalburquerque at cox.net
Thu Jan 3 20:14:56 CET 2008

Edward Hervey wrote:
> Hi,
> On Thu, 2008-01-03 at 09:53 +0000, Tim Müller wrote:
>> On Wed, 2008-01-02 at 22:33 -0500, José Alburquerque wrote:
>>> I'm trying to decide how to handle the referencing of GstEvents in the
>>>  bindings so I'm trying to get a sense of what happens with GstEvents. 
>>>  Any help will be greatly appreciated.
>> Generally, all functions that push or send events or buffers to another
>> pad or an element take ownership of that event or buffer.  Others do
>> usually not (with exceptions such as gst_adapter_push()).  This only
>> applies to events and buffers, but not for example queries, where the
>> called function never takes ownership (IIRC).
>   We had to do the same special handling with gst-python. If you look at
> gst-python/gst/*.defs you can see which parameters of which functions
> need to be handled like that (grep for "(keep-refcount)").
>   The way it's done in the python bindings is that we keep a refcount on
> GStreamer objects for as long as there's a corresponding python object.
>   So in the specials cases above, we INCREMENT the refcount of the
> argument before calling the given method. This means that after the
> function returns we guarantee that our python object still has a
> reference on the object (which will be dropped when python no longer
> uses that object).
>   Hope this helps.
>     Edward
It does, thanks.  From what Tim says it sounds as if keeping a refcount 
depends on which method (function) operates (is called) on the object 
(GstEvent).  I'm thinking of keeping a refcount of the object just 
before the "owner taking methods" are called.  Thanks so much for your 


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