Version 0.4.0

CHANGELOG.md

@@ -1,10 +1,16 @@
+## 0.4.0
+
+* Added
+  * `stop` method in `SimContext`.
+  * Error handling.
+
 ## 0.3.0
 
 * Access the list of created resources.
 * Added
   * `runState` getter to determine whether the simulation has not started, is running, or has completed.
   * `stop` method to manually stop the simulation before it completes.
-  * Observer to receive data throughout the simulation.
+  * Listener to receive data throughout the simulation.
 
 ## 0.2.0
 

example/example.dart

@@ -1,7 +1,9 @@
+import 'dart:async';
+
 import 'package:simdart/simdart.dart';
 
 void main() async {
-  final SimDart sim = SimDart(observer: ConsoleEventObserver());
+  final SimDart sim = SimDart(listener: ConsoleEventListener());
 
   sim.process(event: _eventA, name: 'A');
 

lib/simdart.dart

@@ -1,7 +1,7 @@
 export 'src/event.dart';
 export 'src/interval.dart';
 export 'src/observable.dart';
-export 'src/sim_observer.dart';
+export 'src/sim_listener.dart';
 export 'src/event_phase.dart';
 export 'src/resources.dart' hide ResourcesFactory, ResourceStore;
 export 'src/simdart.dart' hide SimDartHelper;

lib/src/internal/completer_action.dart

@@ -12,7 +12,4 @@ class CompleterAction extends TimeAction {
   void execute() {
     complete.call();
   }
-
-  @override
-  void dispose() {}
 }

lib/src/internal/completer_interrupt.dart

@@ -0,0 +1,4 @@
+import 'package:meta/meta.dart';
+
+@internal
+class CompleterInterrupt {}

lib/src/internal/debug_listener.dart

@@ -0,0 +1,8 @@
+import 'package:meta/meta.dart';
+
+@internal
+abstract class DebugListener {
+  void onAddCompleter();
+
+  void onRemoveCompleter();
+}

lib/src/internal/event_action.dart

@@ -4,6 +4,8 @@ import 'package:meta/meta.dart';
 import 'package:simdart/src/event.dart';
 import 'package:simdart/src/event_phase.dart';
 import 'package:simdart/src/internal/completer_action.dart';
+import 'package:simdart/src/internal/completer_interrupt.dart';
+import 'package:simdart/src/internal/stop_action.dart';
 import 'package:simdart/src/internal/time_action.dart';
 import 'package:simdart/src/interval.dart';
 import 'package:simdart/src/resources.dart';
@@ -52,46 +54,49 @@ class EventAction extends TimeAction implements SimContext {
       throw StateError('This event is yielding');
     }
 
-    sim.observer?.onEvent(
+    sim.listener?.onEvent(
         name: eventName,
         time: sim.now,
         phase: EventPhase.called,
         executionHash: hashCode);
 
-    _runEvent().then((_) {
-      if (_eventCompleter != null) {
+    event(this).then((_) {
+      if (_eventCompleter != null && sim.runState == RunState.running) {
+        SimDartHelper.removeCompleter(
+            sim: sim, completer: _eventCompleter!.completer);
         SimDartHelper.error(
             sim: sim,
-            msg:
-                "Next event is being scheduled, but the current one is still paused waiting for continuation. Did you forget to use 'await'?");
+            error: StateError(
+                "Next event is being scheduled, but the current one is still paused waiting for continuation. Did you forget to use 'await'?"));
         return;
       }
-      sim.observer?.onEvent(
+      sim.listener?.onEvent(
           name: eventName,
           time: sim.now,
           phase: EventPhase.finished,
           executionHash: hashCode);
-
       SimDartHelper.scheduleNextAction(sim: sim);
-    }).catchError((e) {
-      // Sim already marked to finish. Let the last event finalize.
+    }).catchError((error) {
+      if (error is! CompleterInterrupt) {
+        SimDartHelper.error(sim: sim, error: error);
+        SimDartHelper.scheduleNextAction(sim: sim);
+      }
     });
   }
 
-  Future<void> _runEvent() async {
-    await event(this);
-  }
-
   @override
   Future<void> wait(int delay) async {
     if (_eventCompleter != null) {
+      SimDartHelper.removeCompleter(
+          sim: sim, completer: _eventCompleter!.completer);
       SimDartHelper.error(
           sim: sim,
-          msg: "The event is already waiting. Did you forget to use 'await'?");
+          error: StateError(
+              "The event is already waiting. Did you forget to use 'await'?"));
       return;
     }
 
-    sim.observer?.onEvent(
+    sim.listener?.onEvent(
         name: eventName,
         time: sim.now,
         phase: EventPhase.yielded,
@@ -106,8 +111,8 @@ class EventAction extends TimeAction implements SimContext {
             start: sim.now + delay,
             complete: _eventCompleter!.complete,
             order: order));
-    SimDartHelper.scheduleNextAction(sim: sim);
 
+    SimDartHelper.scheduleNextAction(sim: sim);
     await _eventCompleter!.future;
   }
 
@@ -133,6 +138,12 @@ class EventAction extends TimeAction implements SimContext {
         name: name);
   }
 
+  @override
+  void stop() {
+    SimDartHelper.addAction(
+        sim: sim, action: StopAction(start: sim.now, sim: sim));
+  }
+
   @override
   SimCounter counter(String name) {
     return sim.counter(name);
@@ -142,29 +153,29 @@ class EventAction extends TimeAction implements SimContext {
   SimNum num(String name) {
     return sim.num(name);
   }
-
-  @override
-  void dispose() {
-    _eventCompleter?.complete();
-  }
 }
 
 class EventCompleter {
-  EventCompleter({required this.event});
+  EventCompleter({required this.event}) {
+    SimDartHelper.addCompleter(sim: event.sim, completer: completer);
+  }
 
-  final Completer<void> _completer = Completer();
+  final Completer<void> completer = Completer();
 
   final EventAction event;
 
-  Future<void> get future => _completer.future;
+  Future<void> get future {
+    return completer.future;
+  }
 
   void complete() {
-    event.sim.observer?.onEvent(
+    event.sim.listener?.onEvent(
         name: event.eventName,
         time: event.sim.now,
         phase: EventPhase.resumed,
         executionHash: hashCode);
-    _completer.complete();
+    completer.complete();
     event._eventCompleter = null;
+    SimDartHelper.removeCompleter(sim: event.sim, completer: completer);
   }
 }

lib/src/internal/repeat_event_action.dart

@@ -45,7 +45,4 @@ class RepeatEventAction extends TimeAction {
     }
     SimDartHelper.scheduleNextAction(sim: sim);
   }
-
-  @override
-  void dispose() {}
 }

lib/src/internal/stop_action.dart

@@ -0,0 +1,16 @@
+import 'package:meta/meta.dart';
+import 'package:simdart/src/internal/time_action.dart';
+import 'package:simdart/src/simdart.dart';
+
+@internal
+class StopAction extends TimeAction {
+  StopAction({required super.start, super.order = -1, required this.sim});
+
+  final SimDart sim;
+
+  @override
+  void execute() {
+    SimDartHelper.stop(sim: sim);
+    SimDartHelper.scheduleNextAction(sim: sim);
+  }
+}

lib/src/internal/time_action.dart

@@ -14,6 +14,4 @@ abstract class TimeAction {
   final int order;
 
   void execute();
-
-  void dispose();
 }

lib/src/resources.dart

@@ -153,17 +153,20 @@ class ResourcesContext extends Resources {
   /// - Returns: A [Future] that completes when the resource is acquired.
   Future<void> acquire(String name) async {
     if (_event.eventCompleter != null) {
+      SimDartHelper.removeCompleter(
+          sim: _sim, completer: _event.eventCompleter!.completer);
+      //TODO method or throw?
       SimDartHelper.error(
           sim: _sim,
-          msg:
-              "This event should be waiting for the resource to be released. Did you forget to use 'await'?");
+          error: StateError(
+              "This event should be waiting. Did you forget to use 'await'?"));
       return;
     }
     _ResourceImpl? resource = _store._map[name];
     if (resource != null) {
       bool acquired = resource.acquire(_event);
       if (!acquired) {
-        _sim.observer?.onEvent(
+        _sim.listener?.onEvent(
             name: _event.eventName,
             time: _sim.now,
             phase: EventPhase.yielded,
@@ -185,14 +188,15 @@ class ResourcesContext extends Resources {
     if (resource != null) {
       if (resource.release(_sim, _event)) {
         if (resource._waiting.isNotEmpty) {
-          EventAction other = resource._waiting.removeAt(0);
+          EventAction waitingEvent = resource._waiting.removeAt(0);
           // Schedule a complete to resume this event in the future.
           SimDartHelper.addAction(
               sim: _sim,
               action: CompleterAction(
                   start: _sim.now,
-                  complete: other.eventCompleter!.complete,
-                  order: other.order));
+                  complete: waitingEvent.eventCompleter!.complete,
+                  order: waitingEvent.order));
+          //TODO need?
           SimDartHelper.scheduleNextAction(sim: _sim);
         }
       }

lib/src/sim_context.dart

@@ -13,4 +13,6 @@ abstract interface class SimContext implements SimDartInterface {
   String get eventName;
 
   ResourcesContext get resources;
+
+  void stop();
 }

lib/src/sim_observer.dart → lib/src/sim_listener.dart

@@ -1,7 +1,7 @@
 import 'package:simdart/src/event_phase.dart';
 
-/// A base class for observing simulation.
-abstract class SimObserver {
+/// A base class for listening simulation.
+abstract class SimListener {
   /// Called when there is a change in resource usage.
   ///
   /// [name] - The name of the resource whose usage is being reported.
@@ -21,11 +21,15 @@ abstract class SimObserver {
       required int executionHash});
 
   void onStart() {}
+
+  void onError(String error);
 }
 
-mixin SimObserverMixin implements SimObserver {
+mixin SimListenerMixin implements SimListener {
   @override
   void onStart() {}
+  @override
+  void onError(String error) {}
   //@override
   //void onResourceUsage({required String name, required double usage}) {}
   @override
@@ -36,8 +40,8 @@ mixin SimObserverMixin implements SimObserver {
       required int executionHash}) {}
 }
 
-class ConsoleEventObserver with SimObserverMixin {
-  ConsoleEventObserver();
+class ConsoleEventListener with SimListenerMixin {
+  ConsoleEventListener();
 
   @override
   void onEvent(
@@ -47,4 +51,9 @@ class ConsoleEventObserver with SimObserverMixin {
       required int executionHash}) {
     print('[time:$time][event:$name][phase:${phase.name}]');
   }
+
+  @override
+  void onError(String error) {
+    print('Error: $error');
+  }
 }