3193

Bugfix: 'restart' should never restart completed routines. They will
often have nothing to run.

I ran into this while considering whether 'read' on channels to return
true on success or failure. Switching from 'fail?' to 'success?'
crashed. But now that it's fixed I think I'll keep things the way they
are. No reason to be consistent with 'next-ingredient' and have the
status be true to signal success.

1 files changed, 19 insertions, 1 deletions

diff --git a/073wait.cc b/073wait.cc
index 147d442a..78a5c46f 100644
--- a/073wait.cc
+++ b/073wait.cc
@@ -328,6 +328,8 @@ int some_other_running_routine() {
   return 0;
 }
 
+//: helper for restarting blocking routines in tests
+
 :(before "End Primitive Recipe Declarations")
 RESTART,
 :(before "End Primitive Recipe Numbers")
@@ -349,9 +351,25 @@ case RESTART: {
   int id = ingredients.at(0).at(0);
   for (int i = 0; i < SIZE(Routines); ++i) {
     if (Routines.at(i)->id == id) {
-      Routines.at(i)->state = RUNNING;
+      if (Routines.at(i)->state == WAITING)
+        Routines.at(i)->state = RUNNING;
       break;
     }
   }
   break;
 }
+
+:(scenario cannot_restart_completed_routine)
+% Scheduling_interval = 1;
+def main [
+  local-scope
+  r:number/routine-id <- start-running f
+  x:number <- copy 0  # wait for f to be scheduled
+  # r is COMPLETED by this point
+  restart r  # should have no effect
+  x:number <- copy 0  # give f time to be scheduled (though it shouldn't be)
+]
+def f [
+  1:number/raw <- copy 1
+]
+# shouldn't crash