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Re: MPI-2.1 corrections, Batch 2 // Item 3



> I've added some text to the web page as well as included MPI_GET_ERRHANDLER 
> in the list.  
> In short, we did not explicitly say that after an 
> MPI_ERRHANDLER_GET the user should call MPI_ERRHANDLER_FREE, in the same 
> way that after MPI_COMM_GROUP, the user must call MPI_GROUP_FREE when the 
> group is no longer needed.  There was a long email discussion here, but the 
> consensus was the most of the implementations implemented what this 
> clarification says and that this is what users should expect.
> 
> Bill
> 

I propose to add some additional words to Bill's text:

 |  Page 61, after line 36. Add the following 
 |   
 |  MPI_ERRHANDLER_GET and MPI_{COMM,WIN,FILE}_GET_ERRHANDLER behave as if
 |  a new error handler object is created. That is, once the error handler is
 |  no longer needed, MPI_ERRHANDLER_FREE should be called with the error 
 |  handler returned from MPI_ERRHANDLER_GET or MPI_{COMM,WIN,FILE}_GET_ERRHANDLER
    to mark the error handler for deallocation. 
 |  This provides behavior similar to that of MPI_COMM_GROUP and MPI_GROUP_FREE. 
 |  
 |  Begin Rationale: This case was overlooked in the MPI-1 document. 
 |  It ensures that error handler objects behave with the same 
 |  reference-count semantics of other MPI objects. End of Rationale.  

Reason: with this words, it is obvious, that MPI_ERRHANDLER_FREE
has the same meaning for all error-handler handles, independent
of the way they are constructed: with ERRHANDLER_CREATE or
ERR_HANDLER_GET. The new wording is a shortcut of the wording in
MPI-1, page 196, lines 8-11.

Rolf 


Dr. Rolf Rabenseifner                      High Performance Computing
Parallel Computing                         Center Stuttgart    (HLRS)
Rechenzentrum Universitaet Stuttgart (RUS) Phone:    ++49 711 6855530
Allmandring 30                             FAX:      ++49 711 6787626
D-70550 Stuttgart                   rabenseifner@rus.uni-stuttgart.de
Germany                        http://www.hlrs.de/people/rabenseifner