int MPI_Add_error_string(
  int errorcode,
  char *string
);

int MPI_Add_error_string(
  int errorcode,
  wchar_t *string
);

Parameters

errorcode

[in] error code or class (integer)

string

[in] text corresponding to errorcode (string)

Remarks

According to the MPI-2 standard, it is erroneous to call MPI_Add_error_string for an error code or class with a value less than or equal to MPI_ERR_LASTCODE. Thus, you cannot replace the predefined error messages with this routine.

If MPI_ERROR_STRING is called when no string has been set, it will return a empty string (all spaces in Fortran, "" in C and C++).

Thread and Interrupt Safety

This routine is thread-safe. This means that this routine may be safely used by multiple threads without the need for any user-provided thread locks. However, the routine is not interrupt safe. Typically, this is due to the use of memory allocation routines such as malloc or other non-MPICH runtime routines that are themselves not interrupt-safe.

Notes for Fortran

All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran.

Errors

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.

MPI_SUCCESS

No error; MPI routine completed successfully.

Example Code

The following sample code illustrates MPI_Add_error_string.

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

/* Create NCLASSES new classes, each with 5 codes (160 total) */
#define NCLASSES 32
#define NCODES 5

int main( int argc, char *argv[] )
{
    int errs = 0;
    char string[MPI_MAX_ERROR_STRING], outstring[MPI_MAX_ERROR_STRING];
    int newclass[NCLASSES], newcode[NCLASSES][NCODES];
    int i, j, slen, outclass;

    MPI_Init( &argc, &argv );
    /* Initialize the new codes */
    for (i=0; i<NCLASSES; i++) {
        MPI_Add_error_class( &newclass[i] );
        for (j=0; j<NCODES; j++) {
            MPI_Add_error_code( newclass[i], &newcode[i][j] );
            sprintf( string, "code for class %d code %d\n", i, j );
            MPI_Add_error_string( newcode[i][j], string );
        }
    }
    /* check the values */
    for (i=0; i<NCLASSES; i++) {
        MPI_Error_class( newclass[i], &outclass );
        if (outclass != newclass[i]) {
            errs++;
            printf( "Error class %d is not a valid error code %x %x\n", i,
                        outclass, newclass[i]);fflush(stdout);
        }
        for (j=0; j<NCODES; j++) {
            MPI_Error_class( newcode[i][j], &outclass );
            if (outclass != newclass[i]) {
                errs++;
                printf( "Class of code for %d is not correct %x %x\n", j,
                            outclass, newclass[i] );fflush(stdout);
            }
            MPI_Error_string( newcode[i][j], outstring, &slen );
            sprintf( string, "code for class %d code %d\n", i, j );
            if (strcmp( outstring, string )) {
                errs++;
                printf( "Error string is :%s: but should be :%s:\n",
                            outstring, string );fflush(stdout);
            }
        }
    }
    MPI_Finalize();
    return 0;
}