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MPI_Info_get_nkeys(3) MPI MPI_Info_get_nkeys(3)
MPI_Info_get_nkeys - Returns the number of currently defined keys in
#define FUNCNAME MPI_Info_get_nkeys
#define FCNAME MPIU_QUOTE(FUNCNAME)
int MPI_Info_get_nkeys( MPI_Info info, int *nkeys )
info - info object (handle)
nkeys - number of defined keys (integer)
THREAD AND INTERRUPT SAFETY
This routine is thread and interrupt safe only if no MPI routine that
updates or frees the same MPI_Info object may be called concurrently
with this routine.
The MPI standard defined a thread-safe interface but this does not mean
that all routines may be called without any thread locks. For example,
two threads must not attempt to change the contents of the same
MPI_Info object concurrently. The user is responsible in this case for
using some mechanism, such as thread locks, to ensure that only one
thread at a time makes use of this routine.
NOTES FOR FORTRAN
All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
an additional argument ierr at the end of the argument list. ierr is
an integer and has the same meaning as the return value of the routine
in C. In Fortran, MPI routines are subroutines, and are invoked with
the call statement.
All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
value; C routines as the value of the function and Fortran routines in
the last argument. Before the value is returned, the current MPI error
handler is called. By default, this error handler aborts the MPI job.
The error handler may be changed with MPI_Comm_set_errhandler (for
communicators), MPI_File_set_errhandler (for files), and
MPI_Win_set_errhandler (for RMA windows). The MPI-1 routine
MPI_Errhandler_set may be used but its use is deprecated. The
predefined error handler MPI_ERRORS_RETURN may be used to cause error
values to be returned. Note that MPI does not guarentee that an MPI
program can continue past an error; however, MPI implementations will
attempt to continue whenever possible.
- No error; MPI routine completed successfully.
- Other error; use MPI_Error_string to get more information
about this error code.