NAME

odtunlock − release lock on a tty line

SYNOPSIS

odtunlock [ −cclass ] [ −lx ]

DESCRIPTION

Odtunlock releases the caller’s currently reserved microcomputer, making it available for others to use.  Mutual exclusion locks are created automatically by odt and download, and are reported by lusers.  Reservations may expire after some idle time even if odtunlock is not used (see default timeout values set in Xinu-directory/lib/machines). 

Without arguments, odtunlock removes the reservation on the tty line most recently accessed by the caller.  Argument −c can be used to specify a class, in which case odtunlock removes the user’s most recently held reservation in that class.  Argument −lx forces odtunlock to cancel the reservation on line number x within the selected class. 

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. 

FILES

/dev/CLASS.itty lines for a particular class. 
/tmp/xinu/ulock.user records current line allocated by user
/tmp/xinu/cname.i Lock file for line i in class cname. 
{Xinu-directory}/lib/machines database listing parameters for all machines

SEE ALSO

lusers(1), odt(1), download(1), upload(1)

December 01, 1986  —  Xinu Programmer’s Manual