From 5a8a508fdca9fde416eff8bde92af409b3816afb Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Fri, 24 Sep 2021 16:14:55 +0200
Subject: [PATCH] More general on_stop; the old behaviour is now at
 on_stop_notify

---
 syndicate/src/actor.rs     | 21 ++++++++++++++++++---
 syndicate/src/during.rs    |  2 +-
 syndicate/src/supervise.rs |  2 +-
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/syndicate/src/actor.rs b/syndicate/src/actor.rs
index 153eb77..44097fb 100644
--- a/syndicate/src/actor.rs
+++ b/syndicate/src/actor.rs
@@ -185,7 +185,7 @@ pub trait Entity<M>: Send {
     /// Optional callback for running actions when the entity's owning [Facet] terminates
     /// cleanly. Will not be called in case of abnormal shutdown (crash) of an actor.
     ///
-    /// Programs register an entity's stop hook with [Activation::on_stop].
+    /// Programs register an entity's stop hook with [Activation::on_stop_notify].
     ///
     /// The default implementation does nothing.
     fn stop(&mut self, turn: &mut Activation) -> ActorResult {
@@ -804,18 +804,27 @@ impl<'activation> Activation<'activation> {
     /// Registers the entity `r` in the list of stop actions for the active facet. If the facet
     /// terminates cleanly, `r`'s [`stop`][Entity::stop] will be called.
     ///
-    /// **Note.** If the actor crashes, the stop actions will *not* be called.
+    /// **Note.** If the actor crashes, stop actions will *not* be called.
     ///
     /// Use [`RunningActor::add_exit_hook`] to install a callback that will be called at the
     /// end of the lifetime of the *actor* rather than the facet. (Also, exit hooks are called
     /// no matter whether actor termination was normal or abnormal.)
-    pub fn on_stop<M: 'static + Send>(&mut self, r: &Arc<Ref<M>>) {
+    pub fn on_stop_notify<M: 'static + Send>(&mut self, r: &Arc<Ref<M>>) {
         if let Some(f) = self.active_facet() {
             let r = Arc::clone(r);
             f.stop_actions.push(Box::new(move |t| r.internal_with_entity(|e| e.stop(t))));
         }
     }
 
+    /// Registers `action` in the list of stop actions for the active facet. If the facet
+    /// terminates cleanly, `action` will be called. See also notes against
+    /// [`on_stop_notify`][Activation::on_stop_notify].
+    pub fn on_stop<F: 'static + Send + FnOnce(&mut Activation) -> ActorResult>(&mut self, action: F) {
+        if let Some(f) = self.active_facet() {
+            f.stop_actions.push(Box::new(action));
+        }
+    }
+
     /// Retrieve the [`Account`] against which actions are recorded.
     pub fn account(&self) -> &Arc<Account> {
         &self.pending.account
@@ -1921,6 +1930,12 @@ impl<M> Entity<M> for StopOnRetract {
     }
 }
 
+impl<F: Send + FnMut(&mut Activation) -> ActorResult> Entity<Synced> for F {
+    fn message(&mut self, t: &mut Activation, _m: Synced) -> ActorResult {
+        self(t)
+    }
+}
+
 /// A convenient Syndicate-enhanced variation on
 /// [`tracing::info_span`].
 ///
diff --git a/syndicate/src/during.rs b/syndicate/src/during.rs
index 410e4de..048be81 100644
--- a/syndicate/src/during.rs
+++ b/syndicate/src/during.rs
@@ -175,7 +175,7 @@ where
         let should_register_exit_hook = self.exit_handler.is_some();
         let r = t.create(self);
         if should_register_stop_action {
-            t.on_stop(&r);
+            t.on_stop_notify(&r);
         }
         if should_register_exit_hook {
             t.state.add_exit_hook(&r);
diff --git a/syndicate/src/supervise.rs b/syndicate/src/supervise.rs
index bec2f9b..815dea9 100644
--- a/syndicate/src/supervise.rs
+++ b/syndicate/src/supervise.rs
@@ -165,7 +165,7 @@ impl<Boot: 'static + Send + FnMut(&mut Activation) -> ActorResult> Supervisor<Bo
         };
         supervisor.ensure_started(t).unwrap();
         self_ref.become_entity(supervisor);
-        t.on_stop(&self_ref);
+        t.on_stop_notify(&self_ref);
     }
 
     fn enter_state(&mut self, supervisee: Supervisee) {