[MPICH] MPICH2: Internal use of errno?

[James Frye]

Hi,

I've encountered something unusual with some MPI code I'm writing.  My
code is a communication layer that passes information between many
instances of a sequential program.  The sequential program is in wide use,
so I can at most make very limited changes to it.

The sequential program tests the C errno variable at various places.  When
I run it under MPICH2 (the mpd demon), it sees an errno=22 (Operation now
in progress), which seems to be coming from something MPICH is doing.  I
can get rid of the effects by setting errno in my code in each iteration.

So my questions are 1) Is this known? and 2) Is it something I need to be
concerned with?

Thanks,
James