Changed lock-region to use proc objects instead of pids, and fixed a

bug in UNLOCK-REGION.

scsh/flock.scm

@@ -51,7 +51,7 @@
   start			; integer
   len			; Positive integer or #f
   whence		; seek/set, seek/delta, or seek/end.
-  pid      		; Process holding lock
+  proc      		; Process holding lock
   )
 
 (define lock-region?               %lock-region?)
@@ -59,16 +59,24 @@
 (define lock-region:whence         %lock-region:whence)
 (define lock-region:start          %lock-region:start)
 (define lock-region:len            %lock-region:len)
-(define lock-region:pid            %lock-region:pid)
+(define lock-region:proc           %lock-region:proc)
 (define set-lock-region:exclusive? set-%lock-region:exclusive?)
 (define set-lock-region:whence     set-%lock-region:whence)
 (define set-lock-region:start      set-%lock-region:start)
 (define set-lock-region:len        set-%lock-region:len)
-(define set-lock-region:pid        set-%lock-region:pid)
+(define set-lock-region:proc       set-%lock-region:proc)
+
+;;; Backwards compatibility for one or two releases.
+(define lock-region:pid
+  (deprecated-proc (lambda (lr)
+		     (cond ((lock-region:proc lr) => proc:pid)
+			   (else #f)))
+		   'lock-region:pid
+		   "Use lock-region:proc instead."))
 
 (define (make-lock-region exclusive? start len . maybe-whence)
   (let ((whence (:optional maybe-whence seek/set)))
-    (make-%lock-region exclusive? start len whence 0)))
+    (make-%lock-region exclusive? start len whence #f)))
 
 
 ;;; Internal middleman routine
@@ -95,26 +103,31 @@
 (define (lock-region/no-block fdes lock)
   (cond ((call-lock-region %set-lock fcntl/set-record-lock-noblock fdes lock) 
          => (lambda (errno)
-	      (cond ((= errno errno/again) #f)
+	      (cond ((or (= errno errno/again) (= errno errno/acces)) #f)
 		    ((= errno errno/intr) (lock-region/no-block fdes lock))
 		    (else (errno-error errno lock-region/no-block fdes lock)))))
 	(else #t)))
 
 
-;;; Return first lock overlapping LOCK; if none, return #f.
+;;; Return first lock that conflicts w/LOCK; if none, return #f.
 
 (define (get-lock-region fdes lock)
   (receive (err type whence start len pid)
            (call-lock-region %get-lock fcntl/get-record-lock fdes lock)
     (cond ((not err)
 	   (and (not (= type lock/release))
-		(make-%lock-region (= type lock/write) start len whence pid)))
+		(make-%lock-region (= type lock/write) start len whence
+				   (pid->proc pid 'create))))
 	  ((= err errno/intr) (get-lock-region fdes lock))
 	  (else (errno-error err get-lock-region fdes lock)))))
 
 
 (define-errno-syscall (unlock-region fdes lock)
-  (lambda (fdes lock) (call-lock-region %set-lock lock/release fdes lock)))
+  (lambda (fdes lock)
+    (%set-lock fdes fcntl/set-record-lock lock/release
+	       (lock-region:whence lock)
+	       (lock-region:start lock)
+	       (lock-region:len lock))))
 
 
 ;;; Locks with dynamic extent -- with and without sugar