Index: openacs-4/packages/xotcl-core/tcl/cr-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/cr-procs.tcl,v
diff -u -r1.76.2.39 -r1.76.2.40
--- openacs-4/packages/xotcl-core/tcl/cr-procs.tcl	5 Feb 2021 14:19:52 -0000	1.76.2.39
+++ openacs-4/packages/xotcl-core/tcl/cr-procs.tcl	6 Feb 2021 20:43:14 -0000	1.76.2.40
@@ -1001,6 +1001,10 @@
     }
 
     ::xo::dc transaction {
+      #
+      # Provide a row-lock to protect against deadlocks during
+      # concurrent updates on the same item in different threads.
+      #
       ::xo::dc row_lock -for "no key update" -prepare integer item_lock {
         select item_id from cr_items where item_id = :item_id
       }
@@ -1751,7 +1755,7 @@
     # cache queries (and cache locks), since these lookups are
     # performed often many times per request.
     #
-    if {[acs::per_request_cache get -key xotcl-core.lookup($parent_id-$name) value]} {
+    if {[acs::per_request_cache get -key xotcl-core.lookup-$parent_id-$name value]} {
       return $value
     }
 
@@ -1763,7 +1767,7 @@
           # Not found, perform per-thread caching. This has to be
           # invalidated like the xotcl_object_type_cache.
           #
-          acs::per_request_cache eval -key xotcl-core.lookup($parent_id-$name) {set key 0}
+          acs::per_request_cache eval -key xotcl-core.lookup-$parent_id-$name {set key 0}
           #ns_log notice ".... lookup $parent_id-$name => 0 -> break and don't cache"
           break
         }
@@ -1857,7 +1861,7 @@
         ::xo::xotcl_object_cache flush $revision_id
       }
     }
-    acs::per_request_cache flush -pattern xotcl-core.lookup(${:parent_id}-${:name})
+    acs::per_request_cache flush -pattern xotcl-core.lookup-${:parent_id}-${:name}
   }
   CrCache::Item instproc update_attribute_from_slot args {
     set r [next]
@@ -1875,7 +1879,11 @@
   }
   CrCache::Item instproc save_new args {
     set item_id [next]
-    acs::per_request_cache flush -pattern xotcl-core.lookup(${:parent_id}-${:name})
+    ns_log notice "=====  save_new acs::per_request_cache flush -pattern xotcl-core.lookup-${:parent_id}-${:name}"
+    acs::per_request_cache flush -pattern xotcl-core.lookup-${:parent_id}-${:name}
+
+
+    
     return $item_id
   }
   CrCache::Item instproc delete args {
@@ -1889,12 +1897,12 @@
       ::xo::xotcl_object_cache flush [string trimleft [self] :]
     }
     xo::xotcl_object_type_cache flush -partition_key ${:parent_id} ${:parent_id}-${:name}
-    acs::per_request_cache flush -pattern xotcl-core.lookup(${:parent_id}-${:name})
+    acs::per_request_cache flush -pattern xotcl-core.lookup-${:parent_id}-${:name}
     next
   }
   CrCache::Item instproc rename {-old_name:required -new_name:required} {
     ::xo::xotcl_object_type_cache flush -partition_key ${:parent_id} ${:parent_id}-$old_name
-    acs::per_request_cache flush -pattern xotcl-core.lookup(${:parent_id}-$old_name)
+    acs::per_request_cache flush -pattern xotcl-core.lookup-${:parent_id}-$old_name
     next
   }