Factored locking primitives out to their own implementation-dependend

files.  Part of the porting effort to LispWorks.

src/cmu-locking.cl

@@ -0,0 +1,28 @@
+;;;; CLASH --- The Common Lisp Adaptable Simple HTTP server
+;;;; This is copyrighted software.  See documentation for terms.
+;;;; 
+;;;; cmu-locking.cl --- Platform independent locking primitives
+;;;; 
+;;;; Checkout Tag: $Name$
+;;;; $Id$
+
+(in-package :CLASH)
+
+;;;; %File Description:
+;;;; 
+;;;; 
+;;;; 
+
+;;; Locking primitives for CMUCL
+
+(defmacro pop-atomically (place)
+  #+MP
+  `(mp:atomic-pop ,place)
+  #-MP
+  `(pop ,place))
+
+(defmacro push-atomically (value place)
+  #+MP
+  `(mp:atomic-push ,value ,place)
+  #-MP
+  `(push ,value ,place))

src/lwl-locking.cl

@@ -0,0 +1,24 @@
+;;;; CLASH --- The Common Lisp Adaptable Simple HTTP server
+;;;; This is copyrighted software.  See documentation for terms.
+;;;; 
+;;;; lwl-locking.cl --- Platform independent locking primitives
+;;;; 
+;;;; Checkout Tag: $Name$
+;;;; $Id$
+
+(in-package :CLASH)
+
+;;;; %File Description:
+;;;; 
+;;;; 
+;;;; 
+
+;;; Locking primitives for LWL
+
+(defmacro pop-atomically (place)
+  `(mp:without-preemption
+    (pop ,place)))
+
+(defmacro push-atomically (value place)
+  `(mp:without-preemption
+    (push ,value ,place)))

src/main/buffer.cl

@@ -29,21 +29,14 @@ server needs.")
 with `release-io-buffer', to enable it to be recycled.  Otherwise it
 will just be GC'ed as usual."
   (or
-   #+(and :CMU :MP)
+   (pop-atomically *io-buffers*)
-   (mp:atomic-pop *io-buffers*)
-   #-(and :CMU :MP)
-   (pop *io-buffers*)
-   
    ;; No ready-made buffer, so we create a new one
    (make-new-buffer)))
 
 (defun release-io-buffer (buffer)
   "Return a buffer allocated by `get-io-buffer' to the buffer pool for
 re-use."
-  #+(and :CMU :MP)
+  (push-atomically buffer *io-buffers*)
-  (mp:atomic-push buffer *io-buffers*)
-  #-(and :CMU :MP)
-  (push buffer *io-buffers*)
   t)
 
 (defmacro with-io-buffer ((var) &body body)