- (with-unique-names (cfp)
- `(let ((,cfp (sb!kernel:current-fp)))
- (unless (and (mutex-value ,mutex)
- (sb!vm:control-stack-pointer-valid-p
- (sb!sys:int-sap
- (sb!kernel:get-lisp-obj-address (mutex-value ,mutex)))))
- ;; this punning with MAKE-LISP-OBJ depends for its safety on
- ;; the frame pointer being a lispobj-aligned integer. While
- ;; it is, then MAKE-LISP-OBJ will always return a FIXNUM, so
- ;; we're safe to do that. Should this ever change, this
- ;; MAKE-LISP-OBJ could return something that looks like a
- ;; pointer, but pointing into neverneverland, which will
- ;; confuse GC completely. -- CSR, 2003-06-03
- (get-mutex ,mutex (sb!kernel:make-lisp-obj (sb!sys:sap-int ,cfp))))
- (unwind-protect
- (progn ,@body)
- (when (sb!sys:sap= (sb!sys:int-sap
- (sb!kernel:get-lisp-obj-address
- (mutex-value ,mutex)))
- ,cfp)
- (release-mutex ,mutex)))))
+ (with-unique-names (got mutex1)
+ `(let ((,mutex1 ,mutex)
+ ,got)
+ (unwind-protect
+ ;; FIXME: async unwind in SETQ form
+ (when (setq ,got (get-mutex ,mutex1 ,value ,wait-p))
+ (locally
+ ,@body))
+ (when ,got
+ (release-mutex ,mutex1)))))
+ ;; KLUDGE: this separate expansion for (NOT SB-THREAD) is not
+ ;; strictly necessary; GET-MUTEX and RELEASE-MUTEX are implemented.
+ ;; However, there would be a (possibly slight) performance hit in
+ ;; using them.