Synopsis

int MPI_Comm_set_attr(MPI_Comm comm, int comm_keyval, void *attribute_val)

Input Parameters

comm

communicator to which attribute will be attached (handle)

keyval

key value, as returned by MPI_Comm_create_keyval (integer)

attribute_val

attribute value

Notes

The type of the attribute value depends on whether C, C++, or Fortran is being used. In C and C++, an attribute value is a pointer (void *); in Fortran, it is an address-sized integer.

If an attribute is already present, the delete function (specified when the corresponding keyval was created) will be called.

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.

MPI_ERR_COMM

Invalid communicator. A common error is to use a null communicator in a call (not even allowed in MPI_Comm_rank).

MPI_ERR_KEYVAL

Invalid keyval

MPI_ERR_ARG

This error class is associated with an error code that indicates that an attempt was made to free one of the permanent keys.

See Also

Location:comm_set_attr.c