Further simplify supervision protocols

syndicate/src/supervise.rs

@@ -15,12 +15,6 @@ use crate::schemas::service::State;
 
 pub type Boot = Arc<Mutex<Box<dyn Send + FnMut(&mut Activation) -> ActorResult>>>;
 
-#[derive(Debug)]
-enum Protocol {
-    SuperviseeStarted, // assertion
-    Retry, // message
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum RestartPolicy {
     Always,
@@ -36,9 +30,11 @@ pub struct SupervisorConfiguration {
     pub restart_policy: RestartPolicy,
 }
 
+#[derive(Debug)]
+struct StartNow;
+
 pub struct Supervisor {
-    self_ref: Arc<Ref<Protocol>>,
-    my_name: Name,
+    self_ref: Arc<Ref<StartNow>>,
     child_name: Name,
     config: SupervisorConfiguration,
     boot_fn: Boot,
@@ -68,17 +64,13 @@ impl SupervisorConfiguration {
     }
 }
 
-impl Entity<Protocol> for Supervisor
+impl Entity<StartNow> for Supervisor
 {
-    fn assert(&mut self, t: &mut Activation, m: Protocol, _h: Handle) -> ActorResult {
-        match m {
-            Protocol::SuperviseeStarted => t.set(&self.state, State::Started),
-            _ => Err(format!("Unexpected assertion: {:?}", m).as_str())?,
-        }
-        Ok(())
+    fn message(&mut self, t: &mut Activation, _m: StartNow) -> ActorResult {
+        self.start_now(t)
     }
 
-    fn retract(&mut self, t: &mut Activation, _h: Handle) -> ActorResult {
+    fn stop(&mut self, t: &mut Activation) -> ActorResult {
         let _entry = tracing::info_span!("supervisor", name = ?self.child_name).entered();
         let exit_status =
             self.ac_ref.take().expect("valid supervisee ActorRef")
@@ -114,29 +106,13 @@ impl Entity<Protocol> for Supervisor
                 };
                 t.after(wait_time, move |t| {
                     tracing::trace!("Sending retry trigger");
-                    t.message(&self_ref, Protocol::Retry);
+                    t.message(&self_ref, StartNow);
                     Ok(())
                 });
             },
         }
         Ok(())
     }
-
-    fn message(&mut self, t: &mut Activation, m: Protocol) -> ActorResult {
-        match m {
-            Protocol::Retry => {
-                self.start_now(t)
-            }
-            _ => Ok(())
-        }
-    }
-
-    fn stop(&mut self, _t: &mut Activation) -> ActorResult {
-        tracing::info!(name = ?self.my_name,
-                       self_ref = ?self.self_ref,
-                       "Supervisor terminating");
-        Ok(())
-    }
 }
 
 impl Supervisor {
@@ -156,7 +132,6 @@ impl Supervisor {
             |n| preserves::rec![AnyValue::symbol("supervisor"), n.clone()]);
         let mut supervisor = Supervisor {
             self_ref: Arc::clone(&self_ref),
-            my_name: my_name.clone(),
             child_name: name,
             config,
             boot_fn: Arc::new(Mutex::new(Box::new(boot_fn))),
@@ -172,14 +147,13 @@ impl Supervisor {
             state_cb(t, state)
         })?;
         self_ref.become_entity(supervisor);
-        t.on_stop_notify(&self_ref);
         Ok(())
     }
 
     fn start_now(&mut self, t: &mut Activation) -> ActorResult {
         let boot_cell = Arc::clone(&self.boot_fn);
         t.facet(|t: &mut Activation| {
-            t.assert(&self.self_ref, Protocol::SuperviseeStarted);
+            t.on_stop_notify(&self.self_ref);
             self.ac_ref = Some(t.spawn_link(
                 self.child_name.clone(),
                 move |t| boot_cell.lock().expect("Unpoisoned boot_fn mutex")(t)));
@@ -188,6 +162,7 @@ impl Supervisor {
                             "Supervisee started");
             Ok(())
         })?;
+        t.set(&self.state, State::Started);
         Ok(())
     }
 }