A lock object (see make-lock).
The status of the current Lisp process, before
returns, that is, the status while the current process is waiting to timeout. This can be seen in the Process Browser.
A timeout interval, in seconds. If this is not given,
waits until the lock can be set by the current Lisp process. A process can set a lock more than once.
attempts to set a lock and returns
if successful, or
if timed out. If the lock is set and the owner of the lock is the value of
, then the lock's count is incremented by 1, and the lock is set to
. The Lisp process sleeps until the lock is claimed or the timeout period expires.