MPI Programming Guide

MP_MARKER, mpc_marker

Purpose

Passes numeric and text data to the Program Marker Array.

Library

libmpi.a

libmpi_r.a

C synopsis

#include <mp_marker.h>
void mpc_marker(int light, int color, char *string);

FORTRAN synopsis

MP_MARKER(INTEGER LIGHT, INTEGER COLOR,
          CHARACTER STRING)

Parameters

light

is the light number to be colored. The lights in each task row are numbered, left to right, from 0 to one less than the number of lights. The row on which the light is colored is that of the calling task.

If the value of light is out of range, the parameter is ignored. No light is colored by the subroutine. Setting the light to a negative number lets you update the string only.

color

is the color you want to make the light. Supported values range from 0 to 102. The range 0 to 99 is, roughly, a spectrum starting with black and going through brown, green, blue, purple, red, orange, yellow, and ending with white. 100, 101, and 102 are three shades of gray growing increasingly dark. These are approximations, as the actual colors used are requested from the default X-Windows color map. If the X-Server is not capable of providing the colors in the RGB intensities requested, it colors the light with a close approximation.

If the value of color is out of range, the parameter is ignored. The subroutine does not give the light a new color.

string

is the output string to be passed to the Program Marker Array. In C programs, the string must be null-terminated. This is not necessary in FORTRAN programs. The string can be any length, although only the first 80 characters can display. A null string can be passed.

Description

This parallel utility subroutine requests that the numeric and text data passed in the call be forwarded to the Program Marker Array for display. This call waits for a specific acknowledgement from the Partition Manager if the number of lights (specified by the MP_PMLIGHTS environment variable) is positive. The program returns only after the message has been acknowledged by the POE home node. Hence, this call will slow down the user's application and synchronize it approximately with the Program Marker Array.

If MP_PMLIGHTS is set to 0, no message is sent.

Notes

• Creates a trace record (marker event).
• Sends a message only if PMLIGHTS is greater than 0. Each call waits for an acknowledgement from the home node.
• The Program Marker Array X-Windows display routine is distributed as a sample program.
• This subroutine is not supported with threads programs.

Examples

C Example

The C statement:

#include <mp_marker.h>
mpc_marker(2, 0, "Starting task 2");

gives the third light of the calling task the color black and after the lights on that task's row, prints the string "Starting task 2".

FORTRAN Example

The FORTRAN statement:

CALL MP_MARKER(2, 0, 'Starting task 2')

gives the third light of the calling task the color black and after the lights on that task's row, prints the string 'Starting task 2'.

Related information

Commands: pmarray

Subroutines: MP_NLIGHTS, mpc_nlights