Using a counter to prioritize between microtask and delayed.

lib/simdart.dart

@@ -1,8 +1,8 @@
 export 'src/event.dart';
-export 'src/execution_priority.dart';
 export 'src/interval.dart';
 export 'src/observable.dart';
 export 'src/resource_configurator.dart' hide ResourcesConfiguratorHelper;
 export 'src/simdart.dart' hide SimDartHelper;
 export 'src/simulation_track.dart';
 export 'src/start_time_handling.dart';
+export 'src/sim_result.dart';

lib/src/event.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:math';
 
 import 'package:simdart/src/internal/event_scheduler_interface.dart';
 
@@ -20,4 +21,9 @@ abstract interface class EventContext implements EventSchedulerInterface {
   ///
   /// Throws an [ArgumentError] if the delay is negative.
   Future<void> wait(int delay);
+
+  /// The instance of the random number generator used across the simulation.
+  /// It is initialized once and reused to improve performance, avoiding the need to
+  /// instantiate a new `Random` object for each event.
+  Random get random;
 }

lib/src/internal/event_action.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:math';
 
 import 'package:meta/meta.dart';
 import 'package:simdart/src/event.dart';
@@ -32,6 +33,9 @@ class EventAction extends TimeAction implements EventContext {
 
   final SimDart _sim;
 
+  @override
+  Random get random => _sim.random;
+
   /// The resource id required by the event.
   final String? resourceId;
 

lib/src/internal/sim_configuration_interface.dart

@@ -1,20 +1,11 @@
 import 'package:meta/meta.dart';
-import 'package:simdart/src/execution_priority.dart';
 import 'package:simdart/src/start_time_handling.dart';
 
 @internal
 abstract interface class SimConfigurationInterface {
   /// Specifies how the simulation handles start times in the past.
   StartTimeHandling get startTimeHandling;
 
-  /// Defines the priority of task execution in the simulation.
-  ///
-  /// - `highPriority`: Uses `Future.microtask` for immediate execution, prioritizing
-  ///   processing without blocking the UI.
-  /// - `lowPriority`: Uses `Future.delayed(Duration.zero)` to ensure non-blocking
-  ///   execution, allowing the UI to remain responsive.
-  ExecutionPriority get executionPriority;
-
   /// Determines whether simulation tracks should be included in the simulation result.
   ///
   /// When set to `true`, the simulation will collect and return a list of [SimulationTrack]
@@ -23,4 +14,11 @@ abstract interface class SimConfigurationInterface {
   ///
   /// Default: `false`
   bool get includeTracks;
+
+  /// Determines how often `Future.delayed` is used instead of `microtask` during event execution.
+  ///
+  /// - `0`: Always uses `microtask`.
+  /// - `1`: Alternates between `microtask` and `Future.delayed`.
+  /// - `N > 1`: Executes `N` events with `microtask` before using `Future.delayed`.
+  int get executionPriorityCounter;
 }

lib/src/internal/time_loop.dart

@@ -1,8 +1,8 @@
 import 'dart:async';
+import 'dart:math' as math;
 
 import 'package:collection/collection.dart';
 import 'package:meta/meta.dart';
-import 'package:simdart/src/execution_priority.dart';
 import 'package:simdart/src/internal/now_interface.dart';
 import 'package:simdart/src/internal/sim_result_interface.dart';
 import 'package:simdart/src/internal/time_action.dart';
@@ -19,19 +19,18 @@ class TimeLoop
       {required int? now,
       required this.beforeRun,
       required this.includeTracks,
-      required this.executionPriority,
-      required this.startTimeHandling}) {
-    _now = now ?? 0;
-    _priorityScheduler = executionPriority == ExecutionPriority.high
-        ? _highPrioritySchedule
-        : _lowPrioritySchedule;
-  }
+      required int executionPriorityCounter,
+      required this.startTimeHandling})
+      : executionPriorityCounter = math.max(executionPriorityCounter, 0),
+        _now = now ?? 0;
 
   @override
   final StartTimeHandling startTimeHandling;
 
   @override
-  final ExecutionPriority executionPriority;
+  final int executionPriorityCounter;
+
+  int _executionCount = 0;
 
   final Function beforeRun;
 
@@ -57,8 +56,6 @@ class TimeLoop
   int? get duration => _duration;
   int? _duration;
 
-  late final Function _priorityScheduler;
-
   bool _nextEventScheduled = false;
 
   late int? _until;
@@ -106,15 +103,14 @@ class TimeLoop
   void _scheduleNextEvent() {
     assert(!_nextEventScheduled, 'Multiple schedules for the next event.');
     _nextEventScheduled = true;
-    _priorityScheduler.call();
-  }
-
-  void _highPrioritySchedule() {
-    Future.microtask(_consumeFirstEvent);
-  }
-
-  void _lowPrioritySchedule() {
-    Future.delayed(Duration.zero, _consumeFirstEvent);
+    if (executionPriorityCounter == 0 ||
+        _executionCount < executionPriorityCounter) {
+      _executionCount++;
+      Future.microtask(_consumeFirstEvent);
+    } else {
+      _executionCount = 0;
+      Future.delayed(Duration.zero, _consumeFirstEvent);
+    }
   }
 
   void addAction(TimeAction action) {

lib/src/simdart.dart

@@ -4,7 +4,6 @@ import 'dart:math';
 
 import 'package:meta/meta.dart';
 import 'package:simdart/src/event.dart';
-import 'package:simdart/src/execution_priority.dart';
 import 'package:simdart/src/internal/event_action.dart';
 import 'package:simdart/src/internal/event_scheduler_interface.dart';
 import 'package:simdart/src/internal/now_interface.dart';
@@ -48,19 +47,22 @@ class SimDart
       int? now,
       this.secondarySortByName = false,
       this.includeTracks = false,
-      ExecutionPriority executionPriority = ExecutionPriority.high,
+      this.executionPriorityCounter = 0,
       int? seed})
       : random = Random(seed) {
     _loop = TimeLoop(
         now: now,
         includeTracks: includeTracks,
         beforeRun: _beforeRun,
-        executionPriority: executionPriority,
+        executionPriorityCounter: executionPriorityCounter,
         startTimeHandling: startTimeHandling);
   }
 
   late final TimeLoop _loop;
 
+  @override
+  final int executionPriorityCounter;
+
   @override
   final bool includeTracks;
 
@@ -202,9 +204,6 @@ class SimDart
     }
   }
 
-  @override
-  ExecutionPriority get executionPriority => _loop.executionPriority;
-
   @override
   int get now => _loop.now;
 

test/time_loop_test.dart

@@ -21,7 +21,7 @@ void main() {
       TimeLoop loop = TimeLoop(
           includeTracks: true,
           now: null,
-          executionPriority: ExecutionPriority.high,
+          executionPriorityCounter: 0,
           beforeRun: () {},
           startTimeHandling: StartTimeHandling.throwErrorIfPast);