15.2.6.4 Atomic plist update

Old:

(without-interrupts

 (setf (getf *global-plist* key) value))

     (without-interrupts

      (getf *global-plist* key))

New: use a lock, because a plist consists of more than one object so cannot be updated with low level atomic operations.

(defvar *global-plist-lock* (mp:make-lock :name "Global Plist"))

(mp:with-lock (*global-plist-lock*)

	      (setf (getf *global-plist* key) value))

(mp:with-lock (*global-plist-lock*)

	      (getf *global-plist* key))

LispWorks User Guide and Reference Manual - 21 Dec 2011