1 (in-package "SB!THREAD")
3 (sb!xc:defmacro with-recursive-lock ((mutex) &body body)
5 (with-unique-names (cfp)
6 `(let ((,cfp (sb!kernel:current-fp)))
7 (unless (and (mutex-value ,mutex)
8 (sb!vm:control-stack-pointer-valid-p
10 (sb!kernel:get-lisp-obj-address (mutex-value ,mutex)))))
11 ;; this punning with MAKE-LISP-OBJ depends for its safety on
12 ;; the frame pointer being a lispobj-aligned integer. While
13 ;; it is, then MAKE-LISP-OBJ will always return a FIXNUM, so
14 ;; we're safe to do that. Should this ever change, this
15 ;; MAKE-LISP-OBJ could return something that looks like a
16 ;; pointer, but pointing into neverneverland, which will
17 ;; confuse GC completely. -- CSR, 2003-06-03
18 (get-mutex ,mutex (sb!kernel:make-lisp-obj (sb!sys:sap-int ,cfp))))
21 (when (sb!sys:sap= (sb!sys:int-sap
22 (sb!kernel:get-lisp-obj-address
23 (mutex-value ,mutex)))
25 (release-mutex ,mutex)))))