Browser View

Using the Browser View

Before formally verifying an MPI C/C++ application, the number of processes needs to be set for the verification run. You will also need to know how to run GEM itself. The links below detail these processes:

When GEM has finished the verification of your MPI C/C++ application, the Console, Browser and Analyzer Views will all be opened and depending on what is specified in the GEM Preference Page, one of these views will be brought to the foreground and given the active focus.

Browser Overview

This highly functional view summarizes and categorically groups all of the errors and warnings found by GEM for a particular MPI verification run. The summary label (just above the tabs) gives the user a quick overview of problems found. Errors and warnings are mapped to the corresponding source code lines in the Eclipse editor. The Browser View's tabs help the user to quickly localize and fix MPI errors and warnings flagged by GEM within their source code.

The image below shows what the Browser View might look like followed by an explanation of its components.

Browser View Tabs

Below the GEM Browser View's summary label (the line above the tabs) is a section containing a tab for each category of error or warning that was found by GEM at runtime. By selecting a particular tab, the user is given detailed information on each occurrence of this error or warning in their MPI code. Clicking on any of these occurrences takes the user to the offending line of source code within the Eclipse editor. If there are no instances of the problem, then there is a short message indicating such. Furthermore, a user is shown which types of errors are presented via the icons of the tab (see icons directly below).

The following is a listing of all errors and warnings summarized by the GEM Browser View, each with a detailed description.

Deadlocks Tab

This tab allows the user to visit all calls that did not complete due to a detected deadlock.

Assertion Violations Tab

This tab lists all local assertion violations found. Clicking any one of these will take the user to the line of source code with the failed assertion.

Leaks Tab

Clicking any of these will take the user to the line of source code where the corresponding un-freed MPI resource was allocated (these are usually MPI communicators and MPI DataTypes).

Irrelevant Barriers Tab

This tab is reserved for Functionally Irrelevant Barriers. Clicking any these will take the user to the corresponding MPI_Barrier call itself, which can then be safely removed without changing the runtime behavior of the MPI application. This could potentially speed the application up with the absence of unnecessary synchronization.

Type Mismatches Tab

These are warnings about the send type not matching the receive type. In some cases this may be intentional, but often times it is a programming mistake.

Button Explanations

The drop down combo-box shows the current number of processes and lets the user conveniently choose a new value for the next GEM run.

This will re-run GEM on the current MPI project. This is equivalent to choosing "Formally Verify MPI Program" from the toolbar button drop-down and is provided for convenience.

Menu & Toolbar Options

     Terminate Operation - Forcibly terminates the current GEM operation
     Save to File - Saves a listing of all results to a local text file.
     Get Browser Help - Opens the Eclipse help topic related to the Browser View page.

Note: This same functionality can be obtained through the Browser View context and pull-down menus.

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