Re: Multiplexing SUGUSR1

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> To set or clear the flag from PGPROC, to send or handle a signal, we 
> have to acquire ProcArrayLock. Is that safe to do in a signal handler? 

No.  If it's trying to do that then it's broken.  In fact, if it's
trying to do much of anything beyond setting a "volatile" flag variable
in a signal handler, it's broken --- unless there are special provisions
to limit where the signal trap can occur, which would be pretty much
unacceptable for a multiplexed-signal implementation.
        regards, tom lane