[Mpi3-tools] Tools WG webex: tomorrow!

[Jeff Squyres (jsquyres)]

On Jul 1, 2013, at 1:24 PM, "David Goodell (dgoodell)" <dgoodell at cisco.com> wrote:

> ----8<----
>> 	• Jeff also brings up the idea of a callback (or some kind of MPI_T notification) to know when an MPI object is destroyed (per email conversation w/ Jeff, Kathryn, Martin).
>> 		• Marc-Andre will think about whether it will be useful for any tools to know when MPI objects get destroyed.
>> 		• Marc-Andre will also think about whether it would be useful for there to be an MPI_T mechanism to get some kind of unique ID for an MPI object (that will be durable after the handle is freed). This way, a tool can track the entire lifecycle of an object -- not just its handle.
> ----8<----
> 
> I was unable to attend the call, but why isn't attaching an attribute with a destructor callback to the object in question sufficient?  Is it because we have MPI opaque objects which do not support attributes (e.g., MPI_Op)?


Today's attribute calls give you a callback when MPI_*_FREE is invoked -- when is potentially not when the object is actually destroyed.

The Fab+Jeff idea was wondering if anyone cares about the difference between these two; are there any useful use cases where someone could benefit from knowing when the object was actually destroyed?

-- 
Jeff Squyres
jsquyres at cisco.com
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