Merge pull request #357 from cunarist/dart-shutdown-await

Organize internal code

flutter_ffi_plugin/bin/src/message.dart

@@ -248,15 +248,9 @@ import 'package:rinf/rinf.dart';
 
 use crate::tokio;
 use prost::Message;
-use rinf::send_rust_signal;
-use rinf::DartSignal;
-use rinf::SharedCell;
-use std::cell::RefCell;
+use rinf::{send_rust_signal, DartSignal};
 use std::sync::Mutex;
-use std::sync::OnceLock;
-use tokio::sync::mpsc::unbounded_channel;
-use tokio::sync::mpsc::UnboundedReceiver;
-use tokio::sync::mpsc::UnboundedSender;
+use tokio::sync::mpsc::{unbounded_channel, UnboundedReceiver, UnboundedSender};
 ''',
           atFront: true,
         );
@@ -272,38 +266,32 @@ use tokio::sync::mpsc::UnboundedSender;
           await insertTextToFile(
             rustPath,
             '''
-type ${messageName}Cell = SharedCell<(
+type ${messageName}Cell = Mutex<Option<(
     Option<UnboundedSender<DartSignal<${normalizePascal(messageName)}>>>,
     Option<UnboundedReceiver<DartSignal<${normalizePascal(messageName)}>>>,
-)>;
+)>>;
 pub static ${snakeName.toUpperCase()}_CHANNEL: ${messageName}Cell =
-    OnceLock::new();
+    Mutex::new(None);
 
 impl ${normalizePascal(messageName)} {
     pub fn get_dart_signal_receiver() -> UnboundedReceiver<DartSignal<Self>> {
-        let cell = ${snakeName.toUpperCase()}_CHANNEL
-            .get_or_init(|| {
-                let (sender, receiver) = unbounded_channel();
-                Mutex::new(RefCell::new(Some((Some(sender), Some(receiver)))))
-            })
-            .lock()
-            .unwrap();
+        let mut guard = ${snakeName.toUpperCase()}_CHANNEL.lock().unwrap();
+        if guard.is_none() {
+            let (sender, receiver) = unbounded_channel();
+            guard.replace((Some(sender), Some(receiver)));
+        }
         #[cfg(debug_assertions)]
         {
             // After Dart's hot restart,
             // a sender from the previous run already exists
             // which is now closed.
-            let borrowed = cell.borrow();
-            let pair = borrowed.as_ref().unwrap();
-            let is_closed = pair.0.as_ref().unwrap().is_closed();
-            drop(borrowed);
-            if is_closed {
+            if guard.as_ref().unwrap().0.as_ref().unwrap().is_closed() {
                 let (sender, receiver) = unbounded_channel();
-                cell.replace(Some((Some(sender), Some(receiver))));
+                guard.replace((Some(sender), Some(receiver)));
             }
         }
-        let pair = cell.take().unwrap();
-        cell.replace(Some((pair.0, None)));
+        let pair = guard.take().unwrap();
+        guard.replace((pair.0, None));
         pair.1.expect("A receiver can be taken only once")
     }
 }
@@ -403,27 +391,24 @@ impl ${normalizePascal(messageName)} {
 
 use crate::tokio;
 use prost::Message;
-use rinf::debug_print;
 use rinf::DartSignal;
-use std::cell::RefCell;
 use std::collections::HashMap;
-use std::sync::Mutex;
 use std::sync::OnceLock;
 use tokio::sync::mpsc::unbounded_channel;
 
 type SignalHandlers =
-    OnceLock<Mutex<HashMap<i32, Box<dyn Fn(Vec<u8>, Vec<u8>) + Send>>>>;
+    OnceLock<HashMap<i32, Box<dyn Fn(Vec<u8>, Vec<u8>) + Send + Sync>>>;
 static SIGNAL_HANDLERS: SignalHandlers = OnceLock::new();
 
 pub fn handle_dart_signal(
     message_id: i32,
     message_bytes: Vec<u8>,
     binary: Vec<u8>
 ) {    
-    let mutex = SIGNAL_HANDLERS.get_or_init(|| {
-        let mut hash_map =
+    let hash_map = SIGNAL_HANDLERS.get_or_init(|| {
+        let mut new_hash_map =
             HashMap
-            ::<i32, Box<dyn Fn(Vec<u8>, Vec<u8>) + Send + 'static>>
+            ::<i32, Box<dyn Fn(Vec<u8>, Vec<u8>) + Send + Sync>>
             ::new();
 ''';
   for (final entry in markedMessagesAll.entries) {
@@ -441,7 +426,7 @@ pub fn handle_dart_signal(
           var modulePath = subpath.replaceAll("/", "::");
           modulePath = modulePath == "::" ? "" : modulePath;
           rustReceiveScript += '''
-hash_map.insert(
+new_hash_map.insert(
     ${markedMessage.id},
     Box::new(|message_bytes: Vec<u8>, binary: Vec<u8>| {
         use super::$modulePath$filename::*;
@@ -452,29 +437,22 @@ hash_map.insert(
             message,
             binary,
         };
-        let cell = ${snakeName.toUpperCase()}_CHANNEL
-            .get_or_init(|| {
-                let (sender, receiver) = unbounded_channel();
-                Mutex::new(RefCell::new(Some((Some(sender), Some(receiver)))))
-            })
-            .lock()
-            .unwrap();
+        let mut guard = ${snakeName.toUpperCase()}_CHANNEL.lock().unwrap();
+        if guard.is_none() {
+            let (sender, receiver) = unbounded_channel();
+            guard.replace((Some(sender), Some(receiver)));
+        }
         #[cfg(debug_assertions)]
         {
             // After Dart's hot restart,
             // a sender from the previous run already exists
             // which is now closed.
-            let borrowed = cell.borrow();
-            let pair = borrowed.as_ref().unwrap();
-            let is_closed = pair.0.as_ref().unwrap().is_closed();
-            drop(borrowed);
-            if is_closed {
+            if guard.as_ref().unwrap().0.as_ref().unwrap().is_closed() {
                 let (sender, receiver) = unbounded_channel();
-                cell.replace(Some((Some(sender), Some(receiver))));
+                guard.replace((Some(sender), Some(receiver)));
             }
         }
-        let borrowed = cell.borrow();
-        let pair = borrowed.as_ref().unwrap();
+        let pair = guard.as_ref().unwrap();
         let sender = pair.0.as_ref().unwrap();
         let _ = sender.send(dart_signal);
     }),
@@ -485,11 +463,10 @@ hash_map.insert(
     }
   }
   rustReceiveScript += '''
-        Mutex::new(hash_map)
+        new_hash_map
     });
 
-    let guard = mutex.lock().unwrap();
-    let signal_handler = guard.get(&message_id).unwrap();
+    let signal_handler = hash_map.get(&message_id).unwrap();
     signal_handler(message_bytes, binary);
 }
 ''';
@@ -510,11 +487,6 @@ Future<void> initializeRust({String? compiledLibPath}) async {
   startRustLogic();
 }
 
-Future<void> finalizeRust() async {
-  stopRustLogic();
-  await Future.delayed(const Duration(milliseconds: 10));
-}
-
 final signalHandlers = <int, void Function(Uint8List, Uint8List)>{
 ''';
   for (final entry in markedMessagesAll.entries) {

flutter_ffi_plugin/example/ios/Runner.xcodeproj/project.pbxproj

@@ -215,7 +215,7 @@
 		97C146E61CF9000F007C117D /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 1430;
+				LastUpgradeCheck = 1510;
 				ORGANIZATIONNAME = "";
 				TargetAttributes = {
 					331C8080294A63A400263BE5 = {

flutter_ffi_plugin/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1430"
+   LastUpgradeVersion = "1510"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

flutter_ffi_plugin/example/lib/main.dart

@@ -1,4 +1,3 @@
-import 'dart:ui';
 import 'package:flutter/material.dart';
 import 'package:example_app/messages/generated.dart';
 import 'package:example_app/messages/counter_number.pb.dart';
@@ -7,31 +6,10 @@ import 'package:example_app/messages/fractal_art.pb.dart';
 void main() async {
   // Wait for Rust initialization to be completed first.
   await initializeRust();
-  runApp(const MyApp());
+  runApp(MyApp());
 }
 
-class MyApp extends StatefulWidget {
-  const MyApp({super.key});
-
-  @override
-  State<MyApp> createState() => _MyAppState();
-}
-
-class _MyAppState extends State<MyApp> {
-  final _appLifecycleListener = AppLifecycleListener(
-    onExitRequested: () async {
-      // Terminate Rust tasks before closing the Flutter app.
-      await finalizeRust();
-      return AppExitResponse.exit;
-    },
-  );
-
-  @override
-  void dispose() {
-    _appLifecycleListener.dispose();
-    super.dispose();
-  }
-
+class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(

flutter_ffi_plugin/example/macos/Runner.xcodeproj/project.pbxproj

@@ -259,7 +259,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0920;
-				LastUpgradeCheck = 1430;
+				LastUpgradeCheck = 1510;
 				ORGANIZATIONNAME = "";
 				TargetAttributes = {
 					331C80D4294CF70F00263BE5 = {

flutter_ffi_plugin/example/macos/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1430"
+   LastUpgradeVersion = "1510"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

flutter_ffi_plugin/example/native/hub/Cargo.toml

@@ -14,6 +14,7 @@ crate-type = ["lib", "cdylib", "staticlib"]
 [dependencies]
 rinf = "6.11.1"
 prost = "0.12.6"
+# tokio = { version = "1", features = ["sync"] }
 wasm-bindgen = "0.2.92"                     # Uncomment this line to target the web
 tokio_with_wasm = "0.4.4"                   # Uncomment this line to target the web
 sample_crate = { path = "../sample_crate" }

flutter_ffi_plugin/example/web/index.html

@@ -31,29 +31,8 @@
 
   <title>example</title>
   <link rel="manifest" href="manifest.json">
-
-  <script>
-    // The value below is injected by flutter build, do not touch.
-    var serviceWorkerVersion = null;
-  </script>
-  <!-- This script adds the flutter initialization JS code -->
-  <script src="flutter.js" defer></script>
 </head>
 <body>
-  <script>
-    window.addEventListener('load', function(ev) {
-      // Download main.dart.js
-      _flutter.loader.loadEntrypoint({
-        serviceWorker: {
-          serviceWorkerVersion: serviceWorkerVersion,
-        },
-        onEntrypointLoaded: function(engineInitializer) {
-          engineInitializer.initializeEngine().then(function(appRunner) {
-            appRunner.runApp();
-          });
-        }
-      });
-    });
-  </script>
+  <script src="flutter_bootstrap.js" async></script>
 </body>
 </html>

flutter_ffi_plugin/lib/rinf.dart

@@ -13,28 +13,18 @@ export 'src/interface.dart' show RustSignal;
 /// This function might not be necessary for major platforms
 /// but can be useful when the app runs on embedded devices.
 void setCompiledLibPath(String? path) {
-  setCompiledLibPathExtern(path);
+  setCompiledLibPathReal(path);
 }
 
 /// Prepares the native interface
 /// needed to communicate with Rust.
 Future<void> prepareInterface(HandleRustSignal handleRustSignal) async {
-  await prepareInterfaceExtern(handleRustSignal);
+  await prepareInterfaceReal(handleRustSignal);
 }
 
 /// Starts the `main` function in Rust.
 void startRustLogic() async {
-  startRustLogicExtern();
-}
-
-/// Terminates all Rust tasks.
-/// Calling this function before closing the Flutter app
-/// can prevent potential resource leaks that may occur
-/// if the Rust side is abruptly terminated.
-/// Please note that on the web, this function does not have any effect,
-/// as tasks are managed by the JavaScript runtime, not Rust.
-void stopRustLogic() async {
-  stopRustLogicExtern();
+  startRustLogicReal();
 }
 
 /// Sends a signal to Rust.
@@ -43,7 +33,7 @@ void sendDartSignal(
   Uint8List messageBytes,
   Uint8List binary,
 ) async {
-  sendDartSignalExtern(
+  sendDartSignalReal(
     messageId,
     messageBytes,
     binary,

flutter_ffi_plugin/lib/src/interface_os.dart

@@ -7,11 +7,11 @@ import 'dart:isolate';
 import 'interface.dart';
 import 'dart:convert';
 
-void setCompiledLibPathExtern(String? path) {
+void setCompiledLibPathReal(String? path) {
   setDynamicLibPath(path);
 }
 
-Future<void> prepareInterfaceExtern(
+Future<void> prepareInterfaceReal(
   HandleRustSignal handleRustSignal,
 ) async {
   /// This should be called once at startup
@@ -53,27 +53,19 @@ Future<void> prepareInterfaceExtern(
   });
 
   // Make Rust prepare its isolate to send data to Dart.
-  prepareIsolateExtern(rustSignalPort.sendPort.nativePort);
+  prepareIsolateReal(rustSignalPort.sendPort.nativePort);
 }
 
-void startRustLogicExtern() {
+void startRustLogicReal() {
   final rustFunction =
       rustLibrary.lookupFunction<Void Function(), void Function()>(
     'start_rust_logic_extern',
   );
   rustFunction();
 }
 
-void stopRustLogicExtern() {
-  final rustFunction =
-      rustLibrary.lookupFunction<Void Function(), void Function()>(
-    'stop_rust_logic_extern',
-  );
-  rustFunction();
-}
-
 /// Sends bytes to Rust.
-Future<void> sendDartSignalExtern(
+Future<void> sendDartSignalReal(
   int messageId,
   Uint8List messageBytes,
   Uint8List binary,
@@ -112,7 +104,7 @@ Future<void> sendDartSignalExtern(
   malloc.free(binaryMemory);
 }
 
-void prepareIsolateExtern(int port) {
+void prepareIsolateReal(int port) {
   final rustFunction = rustLibrary.lookupFunction<
       Void Function(
         IntPtr,