xlcb Graphical Browser:
User Manual

Invocation Syntax
Overview Graph View
Call Graph Graph View
Culprit Only View
Find Routine Dialog
Summary of xlcb Functions

Invocation Syntax

The graphical version of LCB, xlcb, is invoked with a single argument, naming the lightweight corefile to be used as input:

     xlcb <lightweight-corefile-name> &

For example:

     xlcb vector_manipulation.lcb &

The initial window that comes up is the Overview Graph. It presents the calling structure of the program as a tree, or call graph. Each node in the graph represents a routine in the call stack of one or more processes, with each node colored according to the number of active processes associated with it at the time of program termination. The node colored in red indicates the location of the culprit process.

To get more information on a routine, select its corresponding node by clicking on it. When selected, the node is highlighted (it shows up as white in the pictures below) and the message area displays the number of processes active in the corresponding routine.

A Color Key window also appears within the Overview Graph view when xlcb starts up. It provides the legend for the node colors, and its message field displays the executable name, culprit process identifier, the reason for failure and the location of failure. You can show or hide this window at will via the Options menu.

Click here to see the names of the different areas in the Overview Graph view.

Call Graph View

By clicking the Call Graph button at the bottom of the Overview Graph view, you can change to a more detailed representation of the program's calling structure. This view gives a zoomed-in version of the call graph, where each node displays the routine name.

The Call Graph view shown below includes a Routine Detail window, which supplies process id number and last recorded source location for each process that was executing in the selected routine. This window appears when a node is selected for the first time in the Call Graph and Overview Graph views. You can hide or show this window at will via the Options menu.

Culprit Only View

By clicking the Culprit Only button at the bottom of the Overview Graph view, you see the display of the call stack of just the culprit process.

Find Routine Dialog

By clicking the Find Routine... button at the bottom of the Overview Graph view, you get an alphabetic list of all routines represented in the current view. You can then select any routine in the list, and the corresponding node in the current view will be highlighted.

Summary of xlcb Functions

To see an overall picture of the calling structure of a parallel program when it failed, select the Overview Graph view by clicking its button in the controls area.
To change the layout of the call graph, choose the Horizontal Layout or Vertical Layout entry in the Options menu.
To see a zoomed-in version of the call graph showing the routine names, select the Call Graph view by clicking on that button in the controls area.
To see the call graph of only the culprit process, select the Culprit Only view by clicking on that button in the controls area.
To find all occurrences of a particular routine in the current graph, use the Find Routine dialog. If the dialog is not present, select the Find Routine... button in the controls area. Scroll the list if necessary to find the desired routine and select it. The corresponding node will be highlighted; the display will scroll to reveal the node, if it is not visible already. To find other occurrences of the same routine, keep "selecting" it by clicking on the routine name.
To find the number of processes that were active in a given routine, click on a node corresponding to the routine in either the Overview or Call Graph view. The message area will display the required information.
To find the caller-callee information about a given routine, click on the corresponding node in the Culprit Only view. The message area will display the required information.
To hide the Color Key window, choose the "Hide Color Key" entry in the Options menu.
To find information about each process present in a specific routine, use the Routine Detail window. If the window is not present, select the Show Detail Window entry in the Options menu. This window displays each process identifier and its source location in the routine. (This window is available only in the Overview Graph and Call Graph views.)
To trace the calling sequence that led to the culprit's failure, follow the path from the root of the graph (corresponding to the main program module) to the culprit process in the any of the three views. This gives the sequence of calls leading to the culprit routine. In Culprit Only view, selecting each node in turn will also provide specifics on the calling location within the routine.
To view the executable name or the reason for failure, use the Color Key window. If the window is not currently visible, select the Show Color Key Window entry in the Options menu. The text in the window provides the desired information. It also displays the culprit process identifier and the source location of the failure.

Parallel Tools at OSU home page
Parallel Tools Consortium home page

This document was last updated 2 Aug. '95.

For further information, contact ptools-questions@nero.net.

xlcb Graphical Browser: User Manual