feat(core): Remove the connection lock

packages/moxxmpp/lib/src/connection.dart

@@ -114,6 +114,7 @@ class XmppConnection {
 
   /// A policy on how to reconnect
   final ReconnectionPolicy _reconnectionPolicy;
+  ReconnectionPolicy get reconnectionPolicy => _reconnectionPolicy;
 
   /// The class responsible for preventing errors on initial connection due
   /// to no network.
@@ -173,34 +174,9 @@ class XmppConnection {
   /// The logger for the class
   final Logger _log = Logger('XmppConnection');
 
-  /// A value indicating whether a connection attempt is currently running or not
-  bool _isConnectionRunning = false;
-  final Lock _connectionRunningLock = Lock();
-
   /// Flag indicating whether reconnection should be enabled after a successful connection.
   bool _enableReconnectOnSuccess = false;
 
-  /// Enters the critical section for accessing [XmppConnection._isConnectionRunning]
-  /// and does the following:
-  /// - if _isConnectionRunning is false, set it to true and return false.
-  /// - if _isConnectionRunning is true, return true.
-  Future<bool> _testAndSetIsConnectionRunning() async =>
-      _connectionRunningLock.synchronized(() {
-        if (!_isConnectionRunning) {
-          _isConnectionRunning = true;
-          return false;
-        }
-
-        return true;
-      });
-
-  /// Enters the critical section for accessing [XmppConnection._isConnectionRunning]
-  /// and sets it to false.
-  Future<void> _resetIsConnectionRunning() async =>
-      _connectionRunningLock.synchronized(() => _isConnectionRunning = false);
-
-  ReconnectionPolicy get reconnectionPolicy => _reconnectionPolicy;
-
   bool get isAuthenticated => _isAuthenticated;
 
   /// Return the registered feature negotiator that has id [id]. Returns null if
@@ -364,13 +340,6 @@ class XmppConnection {
 
   /// Attempts to reconnect to the server by following an exponential backoff.
   Future<void> _attemptReconnection() async {
-    if (await _testAndSetIsConnectionRunning()) {
-      _log.warning(
-        '_attemptReconnection is called but connection attempt is already running. Ignoring...',
-      );
-      return;
-    }
-
     _log.finest('_attemptReconnection: Setting state to notConnected');
     await _setConnectionState(XmppConnectionState.notConnected);
     _log.finest('_attemptReconnection: Done');
@@ -615,7 +584,6 @@ class XmppConnection {
   /// Called when we timeout during connecting
   Future<void> _onConnectingTimeout() async {
     _log.severe('Connection stuck in "connecting". Causing a reconnection...');
-    await _resetIsConnectionRunning();
     await handleError(TimeoutError());
   }
 
@@ -844,7 +812,6 @@ class XmppConnection {
   /// a disco sweep among other things.
   Future<void> _onNegotiationsDone() async {
     // Set the connection state
-    await _resetIsConnectionRunning();
     await _setConnectionState(XmppConnectionState.connected);
 
     // Enable reconnections
@@ -880,14 +847,12 @@ class XmppConnection {
       // We failed before authenticating
       if (!_isAuthenticated) {
         _log.severe('No negotiator could be picked while unauthenticated');
-        await _resetIsConnectionRunning();
         await handleError(NoMatchingAuthenticationMechanismAvailableError());
         return;
       } else {
         _log.severe(
           'No negotiator could be picked while negotiations are not done',
         );
-        await _resetIsConnectionRunning();
         await handleError(NoAuthenticatorAvailableError());
         return;
       }
@@ -896,7 +861,6 @@ class XmppConnection {
     final result = await _currentNegotiator!.negotiate(nonza);
     if (result.isType<NegotiatorError>()) {
       _log.severe('Negotiator returned an error');
-      await _resetIsConnectionRunning();
       await handleError(result.get<NegotiatorError>());
       return;
     }
@@ -919,7 +883,6 @@ class XmppConnection {
               !_isNegotiationPossible(_streamFeatures)) {
             _log.finest('Negotiations done!');
             _updateRoutingState(RoutingState.handleStanzas);
-            await _resetIsConnectionRunning();
             await _onNegotiationsDone();
           } else {
             _currentNegotiator = getNextNegotiator(_streamFeatures);
@@ -943,7 +906,6 @@ class XmppConnection {
           _log.finest('Negotiations done!');
 
           _updateRoutingState(RoutingState.handleStanzas);
-          await _resetIsConnectionRunning();
           await _onNegotiationsDone();
         } else {
           _log.finest('Picking new negotiator...');
@@ -962,7 +924,6 @@ class XmppConnection {
         );
 
         _updateRoutingState(RoutingState.handleStanzas);
-        await _resetIsConnectionRunning();
         await _onNegotiationsDone();
         break;
     }
@@ -1052,7 +1013,6 @@ class XmppConnection {
   /// To be called when we lost the network connection.
   Future<void> _onNetworkConnectionLost() async {
     _socket.close();
-    await _resetIsConnectionRunning();
     await _setConnectionState(XmppConnectionState.notConnected);
   }
 
@@ -1112,22 +1072,8 @@ class XmppConnection {
     bool enableReconnectOnSuccess = true,
     bool ignoreLock = false,
   }) async {
-    if (!ignoreLock) {
-      if (await _testAndSetIsConnectionRunning()) {
-        _log.fine(
-          'Cancelling this connection attempt as one appears to be already running.',
-        );
-        return Future.value(
-          Result(
-            ConnectionAlreadyRunningError(),
-          ),
-        );
-      }
-
-      await _resetIsConnectionRunning();
-    } else {
-      _log.fine('Ignoring connection lock as ignoreLock = true');
-    }
+    // Kill a possibly existing connection
+    _socket.close();
 
     if (waitUntilLogin) {
       _log.finest('Setting up completer for awaiting completed login');

packages/moxxmpp/lib/src/connection_errors.dart

@@ -4,12 +4,6 @@ import 'package:moxxmpp/src/negotiators/negotiator.dart';
 /// The reason a call to `XmppConnection.connect` failed.
 abstract class XmppConnectionError extends XmppError {}
 
-/// Returned by `XmppConnection.connect` when a connection is already active.
-class ConnectionAlreadyRunningError extends XmppConnectionError {
-  @override
-  bool isRecoverable() => true;
-}
-
 /// Returned by `XmppConnection.connect` when a negotiator returned an unrecoverable
 /// error. Only returned when waitUntilLogin is true.
 class NegotiatorReturnedError extends XmppConnectionError {

packages/moxxmpp/test/helpers/xmpp.dart

@@ -139,6 +139,11 @@ class StubTCPSocket extends BaseSocketWrapper {
   Stream<XmppSocketEvent> getEventStream() =>
       _eventStream.stream.asBroadcastStream();
 
+  /// "Closes" the socket unexpectedly
+  void injectSocketFault() {
+    _eventStream.add(XmppSocketClosureEvent(false));
+  }
+      
   /// Let the "connection" receive [data].
   void injectRawXml(String data) {
     // ignore: avoid_print

packages/moxxmpp/test/xmpp_test.dart

@@ -427,4 +427,115 @@ void main() {
       true,
     );
   });
+
+  test('Test losing the connection while negotiation', () async {
+    final fakeSocket = StubTCPSocket(
+      [
+        StringExpectation(
+          "<stream:stream xmlns='jabber:client' version='1.0' xmlns:stream='http://etherx.jabber.org/streams' to='example.org' from='testuser@example.org' xml:lang='en'>",
+          '''
+<stream:stream
+    xmlns="jabber:client"
+    version="1.0"
+    xmlns:stream="http://etherx.jabber.org/streams"
+    from="test.server"
+    xml:lang="en">
+  <stream:features xmlns="http://etherx.jabber.org/streams">
+    <mechanisms xmlns="urn:ietf:params:xml:ns:xmpp-sasl">
+      <mechanism>PLAIN</mechanism>
+    </mechanisms>
+  </stream:features>''',
+        ),
+        StringExpectation(
+          "<auth xmlns='urn:ietf:params:xml:ns:xmpp-sasl' mechanism='PLAIN'>AHRlc3R1c2VyAGFiYzEyMw==</auth>",
+          '',
+        ),
+        StringExpectation(
+          "<stream:stream xmlns='jabber:client' version='1.0' xmlns:stream='http://etherx.jabber.org/streams' to='example.org' from='testuser@example.org' xml:lang='en'>",
+          '''
+<stream:stream
+    xmlns="jabber:client"
+    version="1.0"
+    xmlns:stream="http://etherx.jabber.org/streams"
+    from="test.server"
+    xml:lang="en">
+  <stream:features xmlns="http://etherx.jabber.org/streams">
+    <mechanisms xmlns="urn:ietf:params:xml:ns:xmpp-sasl">
+      <mechanism>PLAIN</mechanism>
+    </mechanisms>
+  </stream:features>''',
+        ),
+        StringExpectation(
+          "<auth xmlns='urn:ietf:params:xml:ns:xmpp-sasl' mechanism='PLAIN'>AHRlc3R1c2VyAGFiYzEyMw==</auth>",
+          '<success xmlns="urn:ietf:params:xml:ns:xmpp-sasl" />',
+        ),
+        StringExpectation(
+          "<stream:stream xmlns='jabber:client' version='1.0' xmlns:stream='http://etherx.jabber.org/streams' to='example.org' from='testuser@example.org' xml:lang='en'>",
+          '''
+<stream:stream
+    xmlns="jabber:client"
+    version="1.0"
+    xmlns:stream="http://etherx.jabber.org/streams"
+    from="test.server"
+    xml:lang="en">
+  <stream:features xmlns="http://etherx.jabber.org/streams">
+    <bind xmlns="urn:ietf:params:xml:ns:xmpp-bind">
+      <required/>
+    </bind>
+  </stream:features>''',
+        ),
+        StanzaExpectation(
+          '<iq xmlns="jabber:client" type="set" id="a"><bind xmlns="urn:ietf:params:xml:ns:xmpp-bind"/></iq>',
+          '<iq xmlns="jabber:client" type="result" id="a"><bind xmlns="urn:ietf:params:xml:ns:xmpp-bind"><jid>testuser@example.org/MU29eEZn</jid></bind></iq>',
+        ignoreId: true,
+        ),
+      ],
+    );
+
+    final conn = XmppConnection(
+      TestingReconnectionPolicy(),
+      AlwaysConnectedConnectivityManager(),
+      fakeSocket,
+    );
+    await conn.registerManagers([
+      RosterManager(TestingRosterStateManager('', [])),
+      DiscoManager([]),
+    ]);
+    await conn.registerFeatureNegotiators([
+      SaslPlainNegotiator(),
+      ResourceBindingNegotiator(),
+    ]);
+    conn.setConnectionSettings(
+      ConnectionSettings(
+        jid: JID.fromString('testuser@example.org'),
+        password: 'abc123',
+        useDirectTLS: false,
+      ),
+    );
+
+    final result1 = conn.connect(
+      waitUntilLogin: true,
+    );
+    await Future<void>.delayed(const Duration(seconds: 2));
+
+    // Inject a fault
+    fakeSocket.injectSocketFault();
+    expect(
+      (await result1).isType<bool>(),
+      false,
+    );
+
+    // Try to connect again
+    final result2 = await conn.connect(
+      waitUntilLogin: true,
+    );
+    expect(
+      fakeSocket.getState(),
+      6,
+    );
+    expect(
+      result2.isType<bool>(),
+      true,
+    );
+  });
 }