X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4eeff47d092d58bdcdc789c683bcb6ec9873e5c9..cd701c7e68bbf6598c9350e19389c0b6952bdeef:/src/smpi/smpi_base.c

diff --git a/src/smpi/smpi_base.c b/src/smpi/smpi_base.c
index 73fe79ad64..8afbcae3cb 100644
--- a/src/smpi/smpi_base.c
+++ b/src/smpi/smpi_base.c
@@ -1298,3 +1298,56 @@ void smpi_mpi_scan(void *sendbuf, void *recvbuf, int count,
   xbt_free(tmpbufs);
   xbt_free(requests);
 }
+
+void smpi_mpi_exscan(void *sendbuf, void *recvbuf, int count,
+                   MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
+{
+  int system_tag = 888;
+  int rank, size, other, index;
+  MPI_Aint lb = 0, dataext = 0;
+  MPI_Request *requests;
+  void **tmpbufs;
+  int recvbuf_is_empty=1;
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+
+  // FIXME: check for errors
+  smpi_datatype_extent(datatype, &lb, &dataext);
+
+  // Send/Recv buffers to/from others;
+  requests = xbt_new(MPI_Request, size - 1);
+  tmpbufs = xbt_new(void *, rank);
+  index = 0;
+  for(other = 0; other < rank; other++) {
+    // FIXME: possibly overkill we we have contiguous/noncontiguous data
+    // mapping...
+    tmpbufs[index] = xbt_malloc(count * dataext);
+    requests[index] =
+      smpi_irecv_init(tmpbufs[index], count, datatype, other, system_tag,
+                      comm);
+    index++;
+  }
+  for(other = rank + 1; other < size; other++) {
+    requests[index] =
+      smpi_isend_init(sendbuf, count, datatype, other, system_tag, comm);
+    index++;
+  }
+  // Wait for completion of all comms.
+  smpi_mpi_startall(size - 1, requests);
+  for(other = 0; other < size - 1; other++) {
+    index = smpi_mpi_waitany(size - 1, requests, MPI_STATUS_IGNORE);
+    if(index == MPI_UNDEFINED) {
+      break;
+    }
+    if(index < rank) {
+      if(recvbuf_is_empty)  smpi_datatype_copy(tmpbufs[index], count, datatype, recvbuf, count, datatype);
+      // #Request is below rank: it's a irecv
+      else smpi_op_apply(op, tmpbufs[index], recvbuf, &count, &datatype);
+    }
+  }
+  for(index = 0; index < rank; index++) {
+    xbt_free(tmpbufs[index]);
+  }
+  xbt_free(tmpbufs);
+  xbt_free(requests);
+}