DDT/MAP provides an options window (Preferences on Mac OS X), which allows you to quickly edit the settings in the configuration wizard, as well as other non-essential preferences. These options are outlined briefly below.
24.4.1 System
MPI Implementation: Allows you to tell DDT/MAP which MPI implementation you are using. Note: If you are not using DDT to debug MPI programs select none.
Override default mpirun path: Allows you to override the path to the mpirun (or equivalent) command.
Select Debugger: Tells DDT/MAP which underlying debugger it should use. This should almost always be left as Automatic.
Create Root and Workers groups automatically: If this option is checked DDT will automatically create a Root group for rank 0 and a Workers group for ranks 1... n when you start a new MPI session. Use Shared Symbol Cache: The shared symbol cache is a file that contains all the symbols in your program in a format that can be used directly by the debugger. Rather than loading and converting the symbols itself, every debugger shares the same cache file. This significantly reduces the amount of memory used on each node by the debuggers. For large programs there may be a delay starting a job while the cache file is created as it may be quite large. The cache files are stored in
$HOME/.allinea/symbols. We recommend only turning this option on if you are running out of memory on compute nodes when debugging programs with DDT.
Heterogeneous system support: DDT has support for running heterogeneous MPMD MPI applications where some nodes use one architecture and other nodes use another architecture. This requires a little preparation of your DDT installation. You must have a separate installation of DDT for each architecture. The architecture of the machine running the DDT GUI is called the host architecture. You must create symbolic links from the host architecture installation of DDT to the other installations for the other architectures. For example with a 64-bit x86_64 host architecture (running the GUI) and some compute nodes running the 32-bit i686 architecture:
ln -s /path/to/ddt-i686/bin/ddt-debugger /path/to/ddt-x86_64/bin/ddt- debugger.i686
Enable CUDA software pre-emption (CUDA 5.5+): Allows debugging of CUDA kernels on a workstation with a single GPU.
Default groups file: Entering a file here allows you to customise the groups displayed by DDT when starting an MPI job. If you do not specify a file DDT will create the default Root and Workers groups if the previous option is checked.
Note: A groups file can be created by right clicking the process groups panel and selecting Save groups... while running your program.
Attach hosts file: When attaching, DDT will fetch a list of processes for each of the hosts listed in this file. See section 4.8 Attaching To Running Programs for more details.
24.4.2 Job Submission
This section allows you to configure DDT/MAP to use a custom mpirun command, or submit your jobs to a queuing system. For more information on this, see section 24.2 Integration With Queuing
Systems.
24.4.3 Code Viewer Settings
This allows you to configure the appearance of the DDT/MAP code viewer (used to display your source code while debugging)
Tab size : Sets the width of a tab character in the source code display. (A width of 8 means that a tab character will have the same width as 8 space characters.)
Font name: The name of the font used to display your source code. It is recommended that you use a fixed width font.
Editor : This is the program DDT/MAP will execute if you right click the code viewer and choose
Open file in editor. This command should launch a graphical editor. If no editor is specified,
DDT/MAP will attempt to launch a default editor (as configured in your desktop environment). Colour Scheme: Colour palette to use for the code viewer's background, text and syntax highlighting. Defined in Kate syntax definition format in the resource/styles directory of the DDT/MAP install.
Visualize Whitespace: Enables or disables this display of sybols to represent whitespace. Useful for distinguishing between space and tab characters.
Warn about potential programming errors: This setting enables or disables the use of static analysis tools that are included with the Allinea DDT installation. These tools support F77, C and C+ +, and analyse the source code of viewed source files to discover common errors, but can cause heavy CPU usage on the system running the DDT user interface. You can disable this by unchecking this option.
24.4.4 Appearance
This section allows you to configure the graphical style of DDT/MAP, as well fonts and tab settings for the code viewer.
Look and Feel: This determines the general graphical style of DDT/MAP. This includes the appearance of buttons, context menus.
Override System Font Settings: This setting can be used to change the font and size of all components in DDT/MAP (except the code viewer).
24.4.5 VisIt
Allow the use of VisIt with DDT: When ticked DDT will launch VisIt whenever a Vispoint is hit, or on demand.
VisIt launch command: The full path to the VisIt binary (visit). Custom Arguments: Any extra arguments to pass to VisIt.
Launch VisIt with small viewer: Launches VisIt with a smaller viewer window. Use Hardware Acceleration: Enable hardware acceleration (uses GPU for rendering).
Raise DDT window when a 'DDT pick' is made in VisIt: When enabled, selecting an cell/zone with the DDT pick tool within VisIt will cause DDT to attempt to raise its window to the top of your desktop. Note that this may not be successful as many window managers prevent applications from raising themselves in this way.
Close VisIt when the DDT session ends: It is not possible to interact with a VisIt visualization once DDT has ended the session (the program containing the arrays to visualize no longer exists). To avoid confusion and prevent problems when next viewing a VisIt visualization it is recommended VisIt be closed when the DDT session ends, and a fresh VisIt instance launched as needed for the next visualization.
Enable vispoints: When a visualization breakpoint is hit DDT transfers control to VisIt where you can visualise a given array from your program. Vispoints do not work with programs that are already instrumented for use with VisIt (see section 16.9 Using DDT with a pre-instrumented program). Automatically create Pseudocolour plots for variables: When a new vispoint is hit the vispoint's array variables will automatically be plotted (using pseudocolour plots) within VisIt. When there are multiple array variables to visualize each will be plotted in a viewer window. Note that this feature
uses the VisIt CLI and that whilst the viewer windows are being created and configured a CLI terminal window will be briefly visible.
If you see a dialog “VisIt is waiting for a CLI to launch” for more than 10 seconds it is likely VisIt is unable to provide a CLI on your system. On Linux systems the program xterm is required to use VisIt's CLI.
VisIt launch command on compute nodes: The full path to the VisIt binary on the compute nodes (if different from the frontend).
25 The Licence Server
The licence server supplied with DDT/MAP is capable of serving clients for several different licences, enabling one server to serve all Allinea software in an organization. There is no need to run separate licence servers for DDT and MAP – one combined licence server provides licences for both products.