Adjusting my debugger to work with NPTL

The subject says it all. I have Redhat 9 installed.

My specific needs/questions are how to.
1) stop and continue an individual thread. previously I used SIGSTOP and
SIGCONT with kill.
2) How are thread debug events received since wait returns "process"
signals. previously waitpid (possibly using __WCLONE) resulting in a
SIGTRAP was the catchall.

man ptrace
gives no information about anything new/changed so is there a new API.

I do use libthread_db, but of course it depends on me for the literal
work.

Best Regards,
Norman Black
Stony Brook Software