0.pre8.85

[sbcl.git] / src / code / target-unithread.lisp

diff --git a/src/code/target-unithread.lisp b/src/code/target-unithread.lisp
index c684a3c..e11ec9d 100644 (file)
--- a/src/code/target-unithread.lisp
+++ b/src/code/target-unithread.lisp
@@ -91,8 +91,15 @@
      (setf old-value t1))))
 
 (defmacro with-mutex ((mutex &key value (wait-p t))  &body body)
-  (declare (ignore mutex value wait-p))
-  `(progn ,@body))
+  (cond ((not wait-p)
+        `(unless (mutex-value ,mutex)
+          (unwind-protect
+               (progn
+                 (setf (mutex-value ,mutex) (or ,value t))
+                 ,@body)
+            (setf (mutex-value ,mutex) nil))))
+       (t 
+        `(progn ,@body))))
 
 ;;; what's the best thing to do with these on unithread?
 #+NIl