z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

dbx: threads
threads: Thread Display and Control
Usage Note
Example
If execution is stopped for any one thread, the entire process and all other threads
in the process also stop. The dbx events such as breakpoints are not specific to
any one thread. If one thread hits a breakpoint, all threads and the process stop. An
automatic way to ensure that other threads do not hit breakpoints set by next(i) or
step(i) is to set the variable $hold_next. dbx will then hold all threads except the
current thread during those operations, then unhold all threads after the operation is
complete. Holding all threads, or holding a thread that may release a mutex will
cause the user program to deadlock. Conditional breakpoints can be used to
specify breakpoints for any one particular thread by checking the execution state of
the thread.
’stop at 42 if $t2==$current’ will set a breakpoint at line 42 only for thread two.
Related Information
For thread display and control, see the condition, mutex, readwritelock, and
thread commands. For manipulation of thread-oriented dbx variables ($c,
$t, $l, $current, $hold_next, $cv_events, $mv_events, $tv_events, and
$lv_events), see the assign, print, set, and whatis commands.
usage: Basic Command Usage
Usage Note
Basic dbx command usage:
run begin or restart execution of the program
print
print the value of the expression
where print currently active functions (stack trace)
stop at
set a breakpoint at the line
stop in
set a breakpoint when a particular function is called
cont continue execution
step single step one line
next step to next line (skip over calls)
trace
trace execution of the line
trace
trace calls to the procedure
trace
trace changes to the variable
trace at
print when is reached
940 z/OS V1R9.0 UNIX System Services Command Reference