Index: openacs-4/packages/acs-tcl/tcl/acs-cache-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/acs-cache-procs.tcl,v
diff -u -N -r1.10.2.8 -r1.10.2.9
--- openacs-4/packages/acs-tcl/tcl/acs-cache-procs.tcl	6 Jun 2020 09:24:43 -0000	1.10.2.8
+++ openacs-4/packages/acs-tcl/tcl/acs-cache-procs.tcl	22 Jul 2020 12:28:42 -0000	1.10.2.9
@@ -426,6 +426,14 @@
             }
             return [set $cache_key]
         }
+
+        :public method flush {
+           {-pattern *}
+        } {
+            set pattern ${:prefix}${pattern}
+            unset -nocomplain {*}[info vars $pattern]
+        }
+
         #
         # The per-thread cache uses namespaced Tcl variables, identified
         # by the prefix "::acs:cache::"
Index: openacs-4/packages/acs-tcl/tcl/acs-permissions-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/acs-permissions-procs.tcl,v
diff -u -N -r1.47.2.3 -r1.47.2.4
--- openacs-4/packages/acs-tcl/tcl/acs-permissions-procs.tcl	19 May 2020 19:15:36 -0000	1.47.2.3
+++ openacs-4/packages/acs-tcl/tcl/acs-permissions-procs.tcl	22 Jul 2020 12:28:42 -0000	1.47.2.4
@@ -173,7 +173,7 @@
 ad_proc -private permission::permission_thread_cache_flush {} {
     Flush thread cache
 } {
-    array unset ::permission__permission_p__cache
+    acs::per_request_cache flush -pattern acs-tcl.permission_p__cache*
 }
 
 ad_proc -public permission::require_permission {