Chapter 14 Manipulating Processes and Threads

Totalview® for HPC User Guide : PART II Debugging Tools and Tasks : Chapter 14 Manipulating Processes and Threads

This chapter illustrates some foundational parallel debugging tasks and is based on the shipped program, wave_extended_threads, located in the directory installdir/toolworks/totalview.version/platform/examples. This is a simple program that creates an array and then increments its values to simulate a wave form which can then be viewed using the Visualizer. The program requires user input to provide the number of times to increment.

The first steps when debugging programs with TotalView are similar to those using other debuggers:

• Use the -g option to compile the program. (Compiling is not discussed here. Please see "Compiling Programs".)

• Start the program under TotalView control.

• Start the debugging process, including setting breakpoints and examining your program’s data.

When working with multi-process, multi-threaded programs, you have many options for controlling thread and process execution, viewing specific threads and processes, and organizing processes in to groups in order to better view the various elements of your program. This chapter includes:

• "Viewing Process and Thread States"

• "Using the Toolbar to Select a Target"

• "Stopping Processes and Threads"

• "Using the Processes/Ranks and Threads Tabs"

• "Updating Process Information"

• "Holding and Releasing Processes and Threads"

• "Using Barrier Points"

• "Barrier Point Illustration"

• "Examining Groups"

• "Placing Processes in Groups"

• "Starting Processes and Threads"

• "Creating a Process Without Starting It"