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 lock
if successful, or
if timed out. If
is already locked and the owner of the lock is the value of *current-process*, then
remains locked and an internal count is incremented. The Lisp process sleeps until the lock is claimed or the timeout period expires.