<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Yes, but every time the MPI Forum breaks backwards compatibility, an angel loses its wings, so we can’t fix design flaws like this.  Everyone must suffer forever.<div class=""><br class=""></div><div class="">More seriously, Lisandro pointer out that we’d need allocate and deallocate functions for status if they were handles to hidden state, so we can’t just fix this by making Status opaque.</div><div class=""><br class=""></div><div class="">I guess we have no choice but to standardize the MPI_Status object size and layout.<br class=""><div class=""><div class=""><br class=""></div><div class="">Jeff</div><div class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 21Nov 2022, at 2:43 PM, Skjellum, Anthony <<a href="mailto:tony-skjellum@utc.edu" class="">tony-skjellum@utc.edu</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">

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It should be an opaque object :-) <br class="">
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<div dir="ltr" class="">Anthony Skjellum, PhD
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<div class="">205-807-4968</div>
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On Nov 21, 2022, at 7:29 AM, Jeff Hammond via mpi-forum <<a href="mailto:mpi-forum@lists.mpi-forum.org" class="">mpi-forum@lists.mpi-forum.org</a>> wrote:<br class="">
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<div dir="ltr" class="">I assume that MPI_Status is not opaque because somebody asserted that function call overhead was too much for some use cases.  Was there more to it than this?
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<div class="">Why does the standard say there is an opaque part for elements and cancelled, but not make those visible?  The lack of consistency here doesn't make a lot of sense to me.</div>
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<div class="">MPI_Status not being opaque was a horrible mistake but I would like to be less mad about it by learning what possible reasons for it existed in 1995.</div>
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<div class="">Thanks,</div>
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<div class="">Jeff <br clear="all" class="">
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<div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">Jeff Hammond<br class="">
<a href="mailto:jeff.science@gmail.com" target="_blank" class="">jeff.science@gmail.com</a><br class="">
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