.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)