Changes between Initial Version and Version 1 of bgas-user:bgas-manpages:jb_am_i_irank0

Timestamp:

09/30/14 20:25:08 (10 years ago)

Author:

foszczynski

Comment:

--

bgas-user:bgas-manpages:jb_am_i_irank0

@@ +1 @@
+= jb_am_i_irank0 =
+
+== Name ==
+
+//jb_am_i_irank0// - singles out one compute node process per BGAS IO node.
+
+== Synopsis ==
+{{{
+#include <mpi.h>
+#include "jbcnl.h"
+
+int jb_am_i_irank0();
+}}}
+
+Include with //-I/bgsys/local/bgas/jbrt/jbcn/include//, link with //-L/bgsys/local/bgas/jbrt/jbcn/lib -ljbcn//.
+
+== Description ==
+
+//jb_am_i_irank0()// chooses one compute node process (i.e. MPI task) out of the set of processes living on compute nodes connected to a given IO node. That is, for each IO node, there is exactly one MPI task which lives on a compute node connected to it and on which //jb_am_i_irank0()// returns TRUE (1).
+
+== Return value ==
+
+//jb_am_i_irank0()// returns 1 if and only if the caller's MPI rank is lowest among the MPI ranks of tasks connected to the same IO node as the caller, 0 else.
+
+== Errors ==
+
+None.
+
+== Thread safety ==
+
+//jb_am_i_irank0()// is thread-safe.