Make plugin API async (#940)

* Make plugin API async

Pave way for #824

* Fix formatting

* Make stop blocking and non-throwing

Author: yim-lee

Sources/ActorSingletonPlugin/ActorSingletonPlugin.swift

@@ -77,18 +77,14 @@ extension ActorSingletonPlugin: _Plugin {
         Self.pluginKey
     }
 
-    public func start(_ system: ClusterSystem) -> Result<Void, Error> {
-        .success(())
-    }
+    public func start(_ system: ClusterSystem) async throws {}
 
-    // TODO: Future; TODO2: no need for this at all now since we have async await
-    public func stop(_ system: ClusterSystem) -> Result<Void, Error> {
+    public func stop(_ system: ClusterSystem) {
         self.singletonsLock.withLock {
             for (_, singleton) in self.singletons {
                 singleton.stop(system)
             }
         }
-        return .success(())
     }
 }
 

Sources/DistributedActors/ClusterSystem.swift

@@ -380,7 +380,7 @@ public class ClusterSystem: DistributedActorSystem, @unchecked Sendable {
         lazyNodeDeathWatcher?.wakeUp()
 
         /// Starts plugins after the system is fully initialized
-        self.settings.plugins.startAll(self)
+        await self.settings.plugins.startAll(self)
 
         self.log.info("ClusterSystem [\(self.name)] initialized, listening on: \(self.settings.uniqueBindNode)")
         if settings.enabled {

Sources/DistributedActors/Plugins/ActorSystem+Plugins.swift

@@ -17,12 +17,10 @@
 
 public protocol _AnyPlugin {
     /// Starts the plugin.
-    // TODO: move to async function
-    func start(_ system: ClusterSystem) -> Result<Void, Error>
+    func start(_ system: ClusterSystem) async throws
 
     /// Stops the plugin.
-    // TODO: move to async function
-    func stop(_ system: ClusterSystem) -> Result<Void, Error>
+    func stop(_ system: ClusterSystem)
 }
 
 /// A plugin provides specific features and capabilities (e.g., singleton) to a `ClusterSystem`.
@@ -50,11 +48,11 @@ internal struct BoxedPlugin: _AnyPlugin {
         return unwrapped
     }
 
-    func start(_ system: ClusterSystem) -> Result<Void, Error> {
-        self.underlying.start(system)
+    func start(_ system: ClusterSystem) async throws {
+        try await self.underlying.start(system)
     }
 
-    func stop(_ system: ClusterSystem) -> Result<Void, Error> {
+    func stop(_ system: ClusterSystem) {
         self.underlying.stop(system)
     }
 }

Sources/DistributedActors/Plugins/ActorSystemSettings+Plugins.swift

@@ -41,9 +41,11 @@ public struct PluginsSettings {
     }
 
     /// Starts all plugins in the same order as they were added.
-    internal func startAll(_ system: ClusterSystem) {
+    internal func startAll(_ system: ClusterSystem) async {
         for plugin in self.plugins {
-            if case .failure(let error) = plugin.start(system) {
+            do {
+                try await plugin.start(system)
+            } catch {
                 fatalError("Failed to start plugin \(plugin.key)! Error: \(error)")
             }
         }
@@ -54,9 +56,7 @@ public struct PluginsSettings {
     internal func stopAll(_ system: ClusterSystem) {
         // Shut down in reversed order so plugins with the fewest dependencies are stopped first!
         for plugin in self.plugins.reversed() {
-            if case .failure(let error) = plugin.stop(system) {
-                fatalError("Failed to stop plugin \(plugin.key)! Error: \(error)")
-            }
+            plugin.stop(system)
         }
     }