Locks (Spooler)

A lock is a software security feature for the application to run correctly. There are four locks specifically associated with the spooler:

form
input
master
printer element (or entry)

If a lock is not set, the literal ### displays in the location. If a lock is set, the port number of the process holding the lock is displayed by the list-locks command.

fq	Form queue lock is locked whenever a form queue is attached to a printer.
iq	Input queue lock indicates the maximum number of jobs that may be open at once. The limit is about 650 permanent (hold-type) entries.
mq	Master queue lock is locked by the spooler process when altering any of its tables, such as when a printer is being started.
peq	Printer element queue lock is locked briefly by each user as the first byte of a spooler entry is produced.