In the description of MPI_COMM_FREE we presently give the following advise
to implementors.
A reference-count mechanism may be used: the reference count is
incremented by each call to \func{MPI\_COMM\_DUP}, and decremented by
each call to \func{MPI\_COMM\_FREE}. The object is ultimately
deallocated when the count reaches zero.
I do not think it can ever be valid to implement MPI_COMM_DUP by simply
returning a new handle for an existing communicator object while bumping
its reference count because the output communicator must have a different
context than the original. Assuming I have not missed something, it seems
this advise is nonsense.
Is removing this the kind of change that should go on the MPI 2.2 list? I
will be surprised if anyone offers a rationale for keeping the advise but I
am also not quite comfortable that it fits within the "clean up" rules for
MPI 2.1 at this late stage.
Thoughts?
Dick
Dick Treumann - MPI Team/TCEM
IBM Systems & Technology Group
Dept 0lva / MS P963 -- 2455 South Road -- Poughkeepsie, NY 12601
Tele (845) 433-7846 Fax (845) 433-8363
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