From: Arnaud Giersch <arnaud.giersch@univ-fcomte.fr>
Date: Sun, 6 Jun 2021 10:03:26 +0000 (+0200)
Subject: Correctly remember buffer between persistent communications.
X-Git-Tag: v3.28~139
X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/30b3c775fe9258b3589999070db57a618a614538

Correctly remember buffer between persistent communications.

Fixes lots of Petsc tests, especially vec/is/sf/tests/ex14.c.

The buffer was lost after the first communication, and no more data could
be transfered effectively.
---

diff --git a/src/smpi/mpi/smpi_request.cpp b/src/smpi/mpi/smpi_request.cpp
index 2526f7c4a8..72c4f99e74 100644
--- a/src/smpi/mpi/smpi_request.cpp
+++ b/src/smpi/mpi/smpi_request.cpp
@@ -39,6 +39,7 @@ namespace smpi{
 Request::Request(const void* buf, int count, MPI_Datatype datatype, aid_t src, aid_t dst, int tag, MPI_Comm comm,
                  unsigned flags, MPI_Op op)
     : buf_(const_cast<void*>(buf))
+    , old_buf_(buf_)
     , type_(datatype)
     , size_(datatype->size() * count)
     , src_(src)
@@ -158,22 +159,20 @@ bool Request::match_common(MPI_Request req, MPI_Request sender, MPI_Request rece
 }
 
 void Request::init_buffer(int count){
-  void *old_buf = nullptr;
 // FIXME Handle the case of a partial shared malloc.
   // This part handles the problem of non-contiguous memory (for the unserialization at the reception)
   if ((((flags_ & MPI_REQ_RECV) != 0) && ((flags_ & MPI_REQ_ACCUMULATE) != 0)) || (type_->flags() & DT_FLAG_DERIVED)) {
     // This part handles the problem of non-contiguous memory
-    old_buf = buf_;
+    old_buf_ = buf_;
     if (count==0){
       buf_ = nullptr;
     }else {
       buf_ = xbt_malloc(count*type_->size());
       if ((type_->flags() & DT_FLAG_DERIVED) && ((flags_ & MPI_REQ_SEND) != 0)) {
-        type_->serialize(old_buf, buf_, count);
+        type_->serialize(old_buf_, buf_, count);
       }
     }
   }
-  old_buf_  = old_buf;
 }
 
 bool Request::match_recv(void* a, void* b, simgrid::kernel::activity::CommImpl*)