Xinu7/contrib/distodt/man/odtunlock.1

.TH ODTUNLOCK 1
.SH NAME
odtunlock \- release lock on a backend machine
.SH SYNOPSIS
.B odtunlock
[ \f3\-c\f2CLASS\f1 ]
[ \f3\-m\f2MACH\f1 ]
[ \f3\-r\f1 ]
.SH DESCRIPTION
.I Odtunlock
releases the caller's currently reserved SUN,
making it available for others to use.
Mutual exclusion locks are created automatically by
\f2odt\f1 and \f2download\f1, and are reported by \f2busers\f1 and
\f2status\f1.
Reservations may expire after some idle time even if
\f2odtunlock\f1 is not used.  \f2Odt\f1 or \f2download\f1 may reclaim a
backend SUN if the reservation has expired.
.PP
Reservations are recorded in two places: once with the BED in charge of the
specified backend, and once on the user's local machine.  The reservation
on the BED's frontend is the \f2official\f1 reservation.  The reservation
recorded on the user's local machine is simply a \f2hint\f1 that tells which
backend machine the user \f2probably\f1 has reserved.  \f2Odtunlock\f1
removes the reservation on the BED's frontend, however, by default it does
not remove the local reservation.  The next time the user uses \f2odt\f1 or
\f2download\f1 it will check the local reservation and then try to connect
to the same backend the user used the last time.  If that backend is not
available, \f2odt\f1 and \f2download\f1 will then find a new free backend
and change the local reservation to the new backend.  The \f3\-r\f1
argument causes the local reservation to be removed as well as the
reservation on the BED's frontend.
.PP
Without arguments, \f2odtunlock\f1 removes the reservation on the
backend machine
most recently accessed by the caller.
.PP
Argument \f3\-c\f2CLASS\f1 can be used to specify a \f2CLASS\f1, in which
case \f2odtunlock\f1 removes the user's most recently held reservation in
that class.
.PP
Argument \f3\-m\f2MACH\f1 forces \f2odtunlock\f1 to cancel the reservation
for machine \f2MACH\f1 within the selected class.
.PP
Argument \f3\-r\f1 removes the local reservation lock.
.PP
Xinu's reservation system is a friendly, cooperative mutual-exclusion
mechanism.
All software that accesses backend SUNs
is expected to adhere to the reservation system to
prevent multiple users from trying to access the same machine
simultaneously.
.SH FILES
.ta 1.4i
/tmp/xinu/*   Local lock files. Named by user's login id
.SH "SEE ALSO"
busers(1), odt(1), download(1)