TotalView Users Guide - CI Wiki

Debugging UPC Programs
Debugging UPC Programs
TotalView lets you debug UPC programs that were compiled using the HP
Compaq Alpha UPC 2.0 and the Intrepid (SGI gcc UPC) compilers. This section
only discusses the UPC-specific features of TotalView. It is not an introduction
to the UPC Language. For an introduction to the UPC language, go
to http://www.gwu.edu/~upc.
When debugging UPC code, TotalView requires help from a UPC assistant library that
your compiler vendor provides. You need to include the location of this library in your
LD_LIBRARY_PATH environment variable. TotalView Technologies also provides assistants
that you can use. You can find these assistants at http://www.totalviewtech.com/Products/TotalView/developers/index.html.
Topics in this section are:
� “Invoking TotalView” on page 158
� “Viewing Shared Objects” on page 158
� “Displaying Pointer to Shared Variables” on page 160
Invoking TotalView
The way in which you invoke TotalView on a UPC program is straight-forward.
However, this procedure depends on the computer upon which the
program is executing:
� When running on an SGI system using the gcc UPC compiler, invoke
TotalView on your UPC program in the same way as you would invoke it
on most other programs; for example:
totalview prog_upc -a prog_upc_args
� When running on Linux and HP Compaq SC computers, debug UPC code
in the same way that you would debug other kinds of parallel code; for
example:
totalview prun -a -n node_count prog_upc prog_upc_args
Viewing Shared Objects
TotalView displays UPC shared objects, and fetches data from the UPC
thread with which it has an affinity. For example, TotalView always fetches
shared scalar variables from thread 0.
The upper-left screen in Figure 108 on page 159 displays elements of a
large shared array. You can manipulate and examine shared arrays the same
as any other array. For example, you can slice, filter, obtain statistical information,
and so on. (For more information on displaying array data, see
Chapter 15, “Examining Arrays,” on page 333.) The lower-right screen shows
a slice of this array.
158 Chapter 7: Setting Up Parallel Debugging Sessions