<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=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Feb 10, 2022, at 6:00 PM, Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div dir="ltr" class="">On Thu, Feb 10, 2022 at 9:17 AM Medane TCHAKOROM <<a href="mailto:medane.tchakorom@univ-fcomte.fr" class="">medane.tchakorom@univ-fcomte.fr</a>> wrote:<br class=""></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div class=""><p class="">Hello ,</p><p class="">Sorry if this question does not belong to this mailling list,
i'am using Petsc , but with some</p><p class="">MPI parts code, when dealing with communication.<br class="">
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<div style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;width:659px" class=""><p style="margin-top:0px;margin-right:0px;margin-left:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both" class="">If
a make two consecutive MPI_Isend requests, and if the
destination processor has not yet receive the message
inbetween the two calls, will the buffer be updated ? I mean
if I send message "1" for the first request, then send "0" as
the second message. Will the receiver receive "0" as message ?
I not, how can I do to update the message ?</p></div></div></div></blockquote><div class="">I believe that MPI guarantees in-order message delivery from a source to a target, so if you send 1 before 0, the receiver</div><div class="">should get them in that order. However, someone here should know for sure.</div></div></div></div></blockquote><div><br class=""></div>I don’t think so. You should use tags to flag the proper operation and wait for it if you need the value to arrive.</div><div><br class=""></div><div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_quote"><div class=""><br class=""></div><div class=""> Thanks,</div><div class=""><br class=""></div><div class=""> Matt</div><div class=""> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class=""><div class=""><div style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;width:659px" class=""><div style="margin: 0px; padding: 0px; border: 0px; font-style: inherit; font-variant-ligatures: inherit; font-variant-position: inherit; font-variant-caps: inherit; font-variant-numeric: inherit; font-variant-alternates: inherit; font-variant-east-asian: inherit; font-weight: inherit; font-stretch: inherit; line-height: inherit; font-family: inherit; font-size: 15px; vertical-align: baseline; box-sizing: inherit; clear: both;" class="">Thanks</div>
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</blockquote></div><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div dir="ltr" class="gmail_signature"><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class="">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br class="">-- Norbert Wiener</div><div class=""><br class=""></div><div class=""><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank" class="">https://www.cse.buffalo.edu/~knepley/</a><br class=""></div></div></div></div></div></div></div></div>
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