Index: openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl,v
diff -u -r1.93.2.20 -r1.93.2.21
--- openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	14 Jul 2020 19:43:09 -0000	1.93.2.20
+++ openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	17 Jul 2020 13:03:38 -0000	1.93.2.21
@@ -808,21 +808,33 @@
   # after a request was processed (defined in this file).
   #
   ::xotcl::Object create ::xo::broadcast
+
   ::xo::broadcast proc send {-thread_pattern cmd} {
+
+    set tids {}
     foreach thread_info [ns_info threads] {
       set tn [lindex $thread_info 0]
+      set tid [lindex $thread_info 2]
+      dict set tids $tid 1
       if { [info exists thread_name] && ![string match $thread_pattern $tn] } {
         continue
       }
       switch -glob -- $tn {
         -conn:* -
         -sched:* {
-          set tid [lindex $thread_info 2]
           nsv_lappend broadcast $tid $cmd
         }
       }
     }
+
+    foreach tid [nsv_array names broadcast] {
+      if {![dict exists $tids $tid]} {
+        nsv_unset broadcast $tid
+        ns_log notice "xo::broadcast cleanup of TID $tid (thread does not exist anymore)"
+      }
+    }
   }
+
   ::xo::broadcast proc blueprint {cmd} {
     foreach t [::xotcl::THREAD info instances] {
       $t do eval $cmd