Sun MPI 4.0 User's Guide: With CRE

MPI_MAXREQHANDLES

The maximum number of Fortran request handles. MPI_MAXREQHANDLES specifies the upper limit on the number of concurrently allocated MPI request handles. Users must take care to free up request handles by properly completing requests. The default value is 1024. This variable is ignored in the default 32-bit library.