Changeset 56b997e for GenericIO.cxx

Timestamp:

11/21/17 21:11:12 (6 years ago)

Author:

Hal Finkel <hfinkel@…>

Branches:

master, pympi

Children:

5e1952a, d6628a6

Parents:

9796d0a

git-author:

Hal Finkel <hfinkel@…> (11/21/17 21:11:12)

git-committer:

Hal Finkel <hfinkel@…> (11/21/17 21:11:12)

Message:

Work around MPI bug where MPI_Get_count does not return zero for zero count

File:

• GenericIO.cxx (modified) (2 diffs)

GenericIO.cxx

@@ -123 +123 @@
       throw runtime_error("Unable to write " + D + " to file: " + FileName);
 
-    int scount;
-    (void) MPI_Get_count(&status, MPI_BYTE, &scount);
+    int scount = 0;
+    // On some systems, MPI_Get_count will not return zero even when count is zero.
+    if (count > 0)
+      (void) MPI_Get_count(&status, MPI_BYTE, &scount);
 
     count -= scount;
@@ -141 +143 @@
       throw runtime_error("Unable to read " + D + " from file: " + FileName);
 
-    int scount;
-    (void) MPI_Get_count(&status, MPI_BYTE, &scount);
+    int scount = 0;
+    // On some systems, MPI_Get_count will not return zero even when count is zero.
+    if (count > 0)
+      (void) MPI_Get_count(&status, MPI_BYTE, &scount);
 
     count -= scount;