The Great and Terrible implementation of MPI-2

function index


Set the error handler for an MPI file
int MPI_File_set_errhandler(
  MPI_File file,
  MPI_Errhandler errhandler


[in] MPI file (handle)
[in] new error handler for file (handle)


Attaches a new error handler to a file. The error handler must be either a predefined error handler (MPI_ERRORS_RETURN, MPI_ERRORS_ARE_FATAL), or an error handler created by a call to MPI_FILE_CREATE_ERRHANDLER.

Thread and Interrupt Safety

This routine is thread and interrupt safe only if no MPI routine that updates or frees the same MPI 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 Fortran.


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.

Example Code

The following sample code illustrates MPI_File_set_errhandler.

#include "mpi.h"
#include <stdio.h>
#include <string.h>

static int ncalls = 0;
void efn( MPI_File *fh, int *code, ... );
void efn( MPI_File *fh, int *code, ... )
    ncalls ++;
    *code = MPI_SUCCESS;

int main( int argc, char *argv[] )
    MPI_File fh;
    MPI_Errhandler eh;
    char filename[10];
int errs = 0, toterrs, rank, rc;

    MPI_Init( &argc, &argv );
/* Test that the default error handler is errors return for files */
strncpy( filename, "t1", sizeof(filename) );
    rc = MPI_File_open( MPI_COMM_WORLD, filename, MPI_MODE_RDWR, MPI_INFO_NULL, &fh );
    if (!rc) {
        printf( "Did not get error from open for writing without CREATE\n" );fflush(stdout);
    /* Test that we can change the default error handler by changing the error handler on MPI_FILE_NULL. */
MPI_File_create_errhandler( efn, &eh );
    MPI_File_set_errhandler( MPI_FILE_NULL, eh );
    rc = MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_RDWR, MPI_INFO_NULL, &fh );
if (rc) {
        printf( "Returned error from open (should have called error handler instead)\n");fflush(stdout);
    if (ncalls != 1) {
        printf( "Did not invoke error handler when opening a non-existent file for writing and reading (without MODE_CREATE)\n" );fflush(stdout);
return errs;