closes #19: kill underlings with system level interrupts

scripts/engine.cm

@@ -512,8 +512,8 @@ $_.stop = function stop(actor) {
     throw new Error('Can only call stop on an actor.')
   if (!underlings.has(actor[ACTORDATA].id))
     throw new Error('Can only call stop on an underling or self.')
-    
-  sys_msg(actor, {kind:"stop"})
+
+  sys_msg(actor, "stop")
 }
 $_.stop[cell.DOC] = "The stop function stops an underling."
 
@@ -712,14 +712,13 @@ function handle_sysym(msg, from)
 {
   switch(msg.kind) {
     case 'stop':
-      if (from[ACTORDATA].id !== overling[ACTORDATA].id)
-        log.error(`Got a message from a random actor ${msg.id} to stop`)
-      else
-        disrupt("got stop message")
+      disrupt("got stop message")
       break
     case 'underling':
       var greeter = greeters[from[ACTORDATA].id]
       if (greeter) greeter(msg.message)
+      if (msg.message.type == 'disrupt')
+        underlings.delete(from[ACTORDATA].id)
       break
     case 'contact':
       if (portal_fn) {
@@ -810,10 +809,14 @@ var progContent = io.slurp(prog)
 
 var prog_script = `(function ${cell.args.program.name()}_start($_, arg) { var args = arg; ${progContent} })`
 
-var val = js.eval(cell.args.program, prog_script)($_, cell.args.arg)
-if (val)
-  throw new Error('Program must not return anything');
+// queue up its first turn instead of run immediately
 
-send_messages()
+var startfn = js.eval(cell.args.program, prog_script);
+$_.delay(_ => {
+  var val = startfn($_, cell.args.arg);
+  
+  if (val)
+    throw new Error('Program must not return anything');
+}, 0)
 
 })()