TotalView Users Guide - CI Wiki

Understanding
Process/Thread
Sets
Setting Process and Thread Focus
When you select a scope modifier, you are telling TotalView that when you
press one of the remaining buttons on the toolbar, this element names the
focus on which TotalView acts. For example, if you select a thread and then
select Step, TotalView steps the current thread. If Process (workers) is
selected and you select Halt, TotalView halts all processes associated with
the current threads workers group. If you were running a multi-process program,
other processes continue to execute.
The Processes/Ranks Tab shows you which processes or ranks are members
of the group. For more information, see “Using the Toolbar to Select a Target”
on page 228.
Setting Process and Thread Focus
The previous sections emphasize the GUI; this section and the ones that follow emphasize
the CLI. Here you will find information on how to have full asynchronous debugging
control over your program. Fortunately, having this level of control is seldom necessary.
In other words, don’t read the rest of this chapter unless you have to.
When TotalView executes a command, it must decide which processes and
threads to act on. Most commands have a default set of threads and processes
and, in most cases, you won’t want to change the default. In the GUI,
the default is the process and thread in the current Process Window. In the
CLI, this default is indicated by the focus, which is shown in the CLI prompt.
There are times, however, when you need to change this default. This section
begins a rather intensive look at how you tell TotalView what processes
and threads to use as the target of a command.
Topics in this section are:
� “Understanding Process/Thread Sets” on page 257
� “Specifying Arenas” on page 259
� “Specifying Processes and Threads” on page 259
All TotalView commands operate on a set of processes and threads. This set
is called a Process/Thread (P/T) set. The right-hand text box in windows that
contain P/T set controls lets you construct these sets. In the CLI, you specify
a P/T set as an argument to a command such as dfocus. If you’re using the
GUI, TotalView creates this list for you based on which Process Window has
focus.
Unlike a serial debugger in which each command clearly applies to the only
executing thread, TotalView can control and monitor many threads with
their PCs at many different locations. The P/T set indicates the groups, processes,
and threads that are the target of the CLI command. No limitation
exists on the number of groups, processes, and threads in a set.
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