.TH MPI_Type_get_name 3 "11/12/2019" " " "MPI"

.SH NAME

MPI_Type_get_name \-  Get the print name for a datatype 

.SH SYNOPSIS

.nf

int MPI_Type_get_name(MPI_Datatype datatype, char *type_name, int *resultlen)

.fi

.SH INPUT PARAMETERS

.PD 0

.TP

.B datatype 

- datatype whose name is to be returned (handle)

.PD 1

.SH OUTPUT PARAMETERS

.PD 0

.TP

.B type_name 

- the name previously stored on the datatype, or a empty string

if no such name exists (string)

.PD 1

.PD 0

.TP

.B resultlen 

- length of returned name (integer)

.PD 1

.SH 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 

.I 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.

.SH NULL HANDLES

The MPI 1.1 specification, in the section on opaque objects, explicitly

disallows freeing a null communicator.  The text from the standard is:

.nf

A null handle argument is an erroneous IN argument in MPI calls, unless an

exception is explicitly stated in the text that defines the function. Such

exception is allowed for handles to request objects in Wait and Test calls

(sections Communication Completion and Multiple Completions ). Otherwise, a

null handle can only be passed to a function that allocates a new object and

returns a reference to it in the handle.

.fi

.SH NOTES FOR FORTRAN

All MPI routines in Fortran (except for 

.I MPI_WTIME

and 

.I MPI_WTICK

) have

an additional argument 

.I ierr

at the end of the argument list.  

.I 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

.I call

statement.

All MPI objects (e.g., 

.I MPI_Datatype

, 

.I MPI_Comm

) are of type 

.I INTEGER

in Fortran.

.SH ERRORS

All MPI routines (except 

.I MPI_Wtime

and 

.I 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 

.I MPI_Comm_set_errhandler

(for communicators),

.I MPI_File_set_errhandler

(for files), and 

.I MPI_Win_set_errhandler

(for

RMA windows).  The MPI-1 routine 

.I MPI_Errhandler_set

may be used but

its use is deprecated.  The predefined error handler

.I MPI_ERRORS_RETURN

may be used to cause error values to be returned.

Note that MPI does 

.B not

guarentee that an MPI program can continue past

an error; however, MPI implementations will attempt to continue whenever

possible.

.PD 0

.TP

.B MPI_SUCCESS 

- No error; MPI routine completed successfully.

.PD 1

.PD 0

.TP

.B MPI_ERR_TYPE 

- Invalid datatype argument.  Additionally, this error can

occur if an uncommitted MPI_Datatype (see 

.I MPI_Type_commit

) is used

in a communication call.

.PD 1

.PD 0

.TP

.B MPI_ERR_ARG 

- Invalid argument.  Some argument is invalid and is not

identified by a specific error class (e.g., 

.I MPI_ERR_RANK

).

.PD 1