.TH ODTUNLOCK 1 .SH NAME odtunlock \- release lock on a tty line .SH SYNOPSIS .B odtunlock [ \f3\-c\f1class ] [ \f3\-l\f1x ] .SH DESCRIPTION .I Odtunlock releases the caller's currently reserved microcomputer, making it available for others to use. Mutual exclusion locks are created automatically by \f2odt\f1 and \f2download\f1, and are reported by \f2lusers\f1. Reservations may expire after some idle time even if \f2odtunlock\f1 is not used (see default timeout values set in Xinu-directory/lib/machines). .PP Without arguments, \f2odtunlock\f1 removes the reservation on the tty line most recently accessed by the caller. Argument \f3\-c\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. Argument \f3\-l\f1x forces \f2odtunlock\f1 to cancel the reservation on line number \f2x\f1 within the selected class. .PP Xinu's tty reservation system is a friendly, cooperative mutual-exclusion mechanism. All software that accesses tty lines for communicating with back-end microcomputers 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 /dev/CLASS.i tty lines for a particular class. .br /tmp/xinu/ulock.\f2user\f1 records current line allocated by \f2user\f1 .br /tmp/xinu/\f2cname.i\f1 Lock file for line \f2i\f1 in class \f2cname\f1. .br {Xinu-directory}/lib/machines database listing parameters for all machines .SH "SEE ALSO" lusers(1), odt(1), download(1), upload(1)