From e589da1991dfd4f385695277cd25eb56dafb822b Mon Sep 17 00:00:00 2001
From: mainzelm <mainzelm>
Date: Wed, 13 Aug 2003 12:46:58 +0000
Subject: [PATCH] Add a counter to each process resource and use it to
 implement WITH-RESOURCES-ALIGNED by this partial order.

---
 scsh/resource.scm     | 16 +++++++++++++---
 scsh/scsh-package.scm |  2 +-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/scsh/resource.scm b/scsh/resource.scm
index 2b9e2d2..14feda0 100644
--- a/scsh/resource.scm
+++ b/scsh/resource.scm
@@ -1,12 +1,22 @@
+(define *resource-counter* 0)
+
 (define-record-type resource :resource
-  (make-resource align! lock)
+  (really-make-resource count align! lock)
   resource?
+  (count resource-count)
   (align! resource-align!)
   (lock resource-lock))
 
+(define (make-resource align! lock)
+  (set! *resource-counter* (+ *resource-counter* 1))
+  (really-make-resource *resource-counter* align! lock))
+
 (define (with-resources-aligned resources thunk)
-   (let ((locks (map resource-lock resources)))
-     (apply obtain-all-or-none locks)
+   (let ((locks (map resource-lock
+                     (sort-list resources (lambda (r1 r2)
+                                            (< (resource-count r1)
+                                               (resource-count r2)))))))
+     (for-each obtain-lock locks)
      (for-each
       (lambda (align!) (align!))
       (map resource-align! resources))
diff --git a/scsh/scsh-package.scm b/scsh/scsh-package.scm
index 99d657d..0335d2b 100644
--- a/scsh/scsh-package.scm
+++ b/scsh/scsh-package.scm
@@ -38,7 +38,7 @@
 	define-record-types
 	handle
 	locks
-	scsh-utilities)
+	sort)
   (files resource))
 
 (define-structure weak-tables weak-tables-interface