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MPI_Lookup_name(3) man page (version 1.8)

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Name


MPI_Lookup_name - Finds port associated with a service name

Syntax

C Syntax


#include <mpi.h>
int MPI_Lookup_name(const char *service_name, MPI_Info info,
    char *port_name)

Fortran Syntax


INCLUDE ’mpif.h’
MPI_LOOKUP_NAME(SERVICE_NAME, INFO, PORT_NAME, IERROR)
    CHARACTER*(*)    SERVICE_NAME, PORT_NAME
    INTEGER        INFO, IERROR

C++ Syntax


#include <mpi.h>
void MPI::Lookup_name(const char *service_name, const MPI::Info& info,
    char* port_name)

Input Parameters

service_name
A service name (string).
info
Options to the name service functions (handle).

Output Parameters

port_name
a port name (string).
IERROR
Fortran only: Error status (integer).

Description

This function retrieves a port_name published under service_name by a previous invocation of MPI_Publish_name. The application must supply a port_name buffer large enough to hold the largest possible port name (i.e., MPI_MAX_PORT_NAME bytes).

Info Arguments

The following keys for info are recognized:


Key                   Type      Description
---                   ----      -----------
ompi_lookup_order     char *    Resolution order for name lookup.

The ompi_lookup_order info key can specify one of four valid string values (see the NAME SCOPE section below for more information on name scopes):

local: Only search the local scope for name resolution.
global: Only search the global scope for name resolution.
local,global: Search the local scope for name resolution. If
not found, try searching the global scope for name resolution. This behavior is the default if the ompi_lookup_order info key is not specified.
global,local: Search the global scope for name resolution. If
not found, try searching the local scope for name resolution.

If no info key is provided, the search will first check to see if a global server has been specified and is available. If so, then the search will default to global scope first, followed by local. Otherwise, the search will default to local.

Name Scope

Open MPI supports two name scopes: global and local. Local scope values are placed in a data store located on the mpirun of the calling process’ job, while global scope values reside on a central server. Calls to MPI_Unpublish_name must correctly specify the scope to be used in finding the value to be removed. The function will return an error if the specified service name is not found on the indicated location.

For a more detailed description of scoping rules, please see the MPI_Publish_name man page.

Errors

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

See the MPI man page for a full list of MPI error codes.

See Also


MPI_Publish_name
MPI_Open_port

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