features are available as options to the set thread-checkcommand. The syntax for the set thread-checkcommand is as follows:

set thread check { [onoff] [option] [onoff] [option] [num]}

The set thread-check [onoff] command enables or disables advanced thread debugging. This feature is off by default. The set thread-check [onoff] command must be enabled prior to running the application under the debugger, to force the underlying runtime system to collect information on pthread primitives.

The advanced thread debugging features can be enabled only if the set thread-check [on] command is enabled. The following advanced thread debugging options are available for the set thread-checkcommand:

recursive-relock [onoff] This set thread-check recursive-relock

[onoff] command checks if a thread has attempted to acquire a non-recursive mutex that it currently holds. Re-locking a non-recursive mutex results in a deadlock. At run-time, the debugger keeps track of each mutex in the application and the thread that currently holds each mutex. When a thread attempts to acquire a lock on a non-recursive mutex, the debugger checks if the thread currently holds the lock object for the mutex. The debugger transfers the execution control to the user and prints a warning message when this condition is detected.

unlock-not-own [onoff] The set thread-check unlock-not-own

[onoff] command checks if a thread has attempted to unlock a mutex or a read-write lock that it has not acquired. The debugger transfers the execution control to the user and prints a warning message when this condition is detected.

mixed-sched-policy [onoff] The set thread-check

mixed-sched-policy [onoff] command checks if a thread is waiting (blocked) on a mutex or a read-write lock that is held by a thread with a different scheduling policy. This is not an application error and does not always result in deadlock. However, it degrades the application performance. The debugger transfers the execution control to the user and prints a warning message when this condition is detected.

cv-multiple-mxs [onoff] The set thread-check cv-multiple-mxs

[onoff] command checks if an application

184 HP-UX Configuration-Specific Information