4.3 Charm Debugging Related Options

When using the charm debugger to launch your application, it will automatically set these to defaults appropriate for most situations.

+cpd

Triggers application freeze at startup for debugger.

++charmdebug

Triggers charmrun to provide some information about the executable, as well as provide an interface to gdb for querying.

+debugger

Which debuggers to use.

++debug

Run each node under gdb in an xterm window, prompting the user to begin execution.

++debug-no-pause

Run each node under gdb in an xterm window immediately (i.e. without prompting the user to begin execution).

Note: If you're using the charm debugger it will probably be best to control the sequential (i.e. gdb) debuggers from within its GUI interface.

++DebugDisplay

X Display for xterm

++server-port

Port to listen for CCS requests

++server

Enable client-server (CCS) mode

+record

Use the recordreplay tracemode to record the exact event/message sequence for later use.

+replay

Force the use of recorded log of events/messages to exactly reproduce a previous run.

The preceding pair of commands +record +replay are used to produce the ``instant replay'' feature. This feature is valuable for catching errors which only occur sporadically. Such bugs which arise from the nondeterminacy of parallel execution can be fiendishly difficult to replicate in a debugging environment. Typical usage is to keep running the application with +record until the bug occurs. Then run the application under the debugger with the +replay option.