0.9.2.35:

[sbcl.git] / src / code / thread.lisp

diff --git a/src/code/thread.lisp b/src/code/thread.lisp
index 19f14be..cd4ca4f 100644 (file)
--- a/src/code/thread.lisp
+++ b/src/code/thread.lisp
@@ -12,6 +12,10 @@
 (in-package "SB!THREAD")
 
 (sb!xc:defmacro with-mutex ((mutex &key value (wait-p t)) &body body)
+  #!+sb-doc
+  "Acquire MUTEX for the dynamic scope of BODY, setting it to
+NEW-VALUE or some suitable default value if NIL.  If WAIT-P is non-NIL
+and the mutex is in use, sleep until it is available"
   #!-sb-thread (declare (ignore mutex value wait-p))
   #!+sb-thread
   (with-unique-names (got)
@@ -28,14 +32,21 @@
   `(locally ,@body))
 
 (sb!xc:defmacro with-recursive-lock ((mutex) &body body)
+  #!+sb-doc
+  "Acquires MUTEX for the dynamic scope of BODY. Within that scope
+further recursive lock attempts for the same mutex succeed. However,
+it is an error to mix WITH-MUTEX and WITH-RECURSIVE-LOCK for the same
+mutex."
   #!-sb-thread (declare (ignore mutex))
   #!+sb-thread
-  (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)))))
+  (with-unique-names (cfp inner-lock)
+    `(let ((,cfp (sb!kernel:current-fp))
+           (,inner-lock
+            (and (mutex-value ,mutex)
+                 (sb!vm:control-stack-pointer-valid-p
+                  (sb!sys:int-sap
+                   (sb!kernel:get-lisp-obj-address (mutex-value ,mutex)))))))
+      (unless ,inner-lock
        ;; 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
@@ -46,10 +57,7 @@
        (get-mutex ,mutex (sb!kernel:make-lisp-obj (sb!sys:sap-int ,cfp))))
       (unwind-protect
           (locally ,@body)
-       (when (sb!sys:sap= (sb!sys:int-sap
-                           (sb!kernel:get-lisp-obj-address
-                            (mutex-value ,mutex)))
-                          ,cfp)
+        (unless ,inner-lock
          (release-mutex ,mutex)))))
   #!-sb-thread
   `(locally ,@body))