SEBWIN-301: Added unit tests for basic service functionality.

SafeExamBrowser.Service.UnitTests/Communication/ServiceHostTests.cs

@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Threading;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+using SafeExamBrowser.Contracts.Communication;
+using SafeExamBrowser.Contracts.Communication.Data;
+using SafeExamBrowser.Contracts.Communication.Events;
+using SafeExamBrowser.Contracts.Communication.Hosts;
+using SafeExamBrowser.Contracts.Configuration;
+using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Service.Communication;
+
+namespace SafeExamBrowser.Service.UnitTests.Communication
+{
+	[TestClass]
+	public class ServiceHostTests
+	{
+		private Mock<IHostObject> hostObject;
+		private Mock<IHostObjectFactory> hostObjectFactory;
+		private Mock<ILogger> logger;
+		private ServiceHost sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			hostObject = new Mock<IHostObject>();
+			hostObjectFactory = new Mock<IHostObjectFactory>();
+			logger = new Mock<ILogger>();
+
+			hostObjectFactory.Setup(f => f.CreateObject(It.IsAny<string>(), It.IsAny<ICommunication>())).Returns(hostObject.Object);
+
+			sut = new ServiceHost("net:pipe://some/address", hostObjectFactory.Object, logger.Object, 0);
+		}
+
+		[TestMethod]
+		public void Connect_MustAllowFirstConnnectionAndDenyFurtherRequests()
+		{
+			var response = sut.Connect();
+			var response2 = sut.Connect();
+			var response3 = sut.Connect();
+
+			Assert.IsTrue(response.ConnectionEstablished);
+			Assert.IsFalse(sut.AllowConnection);
+			Assert.IsFalse(response2.ConnectionEstablished);
+			Assert.IsFalse(response3.ConnectionEstablished);
+		}
+
+		[TestMethod]
+		public void Disconnect_MustDisconnectAndThenAllowNewConnection()
+		{
+			var connect = sut.Connect();
+			var disconnect = sut.Disconnect(new DisconnectionMessage { CommunicationToken = connect.CommunicationToken.Value, Interlocutor = Interlocutor.Runtime });
+
+			Assert.IsTrue(sut.AllowConnection);
+			Assert.IsTrue(disconnect.ConnectionTerminated);
+
+			var connect2 = sut.Connect();
+
+			Assert.IsFalse(sut.AllowConnection);
+			Assert.IsTrue(connect2.ConnectionEstablished);
+		}
+
+		[TestMethod]
+		public void Send_MustHandleSessionStartRequest()
+		{
+			var args = default(SessionStartEventArgs);
+			var sync = new AutoResetEvent(false);
+			var configuration = new ServiceConfiguration { SessionId = Guid.NewGuid() };
+			var sessionStartRequested = false;
+
+			sut.SessionStartRequested += (a) => { args = a; sessionStartRequested = true; sync.Set(); };
+
+			var token = sut.Connect().CommunicationToken.Value;
+			var message = new SessionStartMessage(configuration) { CommunicationToken = token };
+			var response = sut.Send(message);
+
+			sync.WaitOne();
+
+			Assert.IsTrue(sessionStartRequested);
+			Assert.IsNotNull(args);
+			Assert.IsNotNull(response);
+			Assert.IsInstanceOfType(response, typeof(SimpleResponse));
+			Assert.AreEqual(configuration.SessionId, args.Configuration.SessionId);
+			Assert.AreEqual(SimpleResponsePurport.Acknowledged, (response as SimpleResponse)?.Purport);
+		}
+
+		[TestMethod]
+		public void Send_MustHandleSessionStopRequest()
+		{
+			var args = default(SessionStopEventArgs);
+			var sync = new AutoResetEvent(false);
+			var sessionId = Guid.NewGuid();
+			var sessionStopRequested = false;
+
+			sut.SessionStopRequested += (a) => { args = a; sessionStopRequested = true; sync.Set(); };
+
+			var token = sut.Connect().CommunicationToken.Value;
+			var message = new SessionStopMessage(sessionId) { CommunicationToken = token };
+			var response = sut.Send(message);
+
+			sync.WaitOne();
+
+			Assert.IsTrue(sessionStopRequested);
+			Assert.IsNotNull(args);
+			Assert.IsNotNull(response);
+			Assert.IsInstanceOfType(response, typeof(SimpleResponse));
+			Assert.AreEqual(sessionId, args.SessionId);
+			Assert.AreEqual(SimpleResponsePurport.Acknowledged, (response as SimpleResponse)?.Purport);
+		}
+
+		[TestMethod]
+		public void Send_MustReturnUnknownMessageAsDefault()
+		{
+			var token = sut.Connect().CommunicationToken.Value;
+			var message = new TestMessage { CommunicationToken = token } as Message;
+			var response = sut.Send(message);
+
+			Assert.IsNotNull(response);
+			Assert.IsInstanceOfType(response, typeof(SimpleResponse));
+			Assert.AreEqual(SimpleResponsePurport.UnknownMessage, (response as SimpleResponse)?.Purport);
+
+			message = new SimpleMessage(default(SimpleMessagePurport)) { CommunicationToken = token };
+			response = sut.Send(message);
+
+			Assert.IsNotNull(response);
+			Assert.IsInstanceOfType(response, typeof(SimpleResponse));
+			Assert.AreEqual(SimpleResponsePurport.UnknownMessage, (response as SimpleResponse)?.Purport);
+		}
+
+		private class TestMessage : Message { };
+	}
+}

SafeExamBrowser.Service.UnitTests/Operations/EventStub.cs

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System.Threading;
+
+namespace SafeExamBrowser.Service.UnitTests.Operations
+{
+	internal class EventStub : EventWaitHandle
+	{
+		public bool IsClosed { get; set; }
+
+		public EventStub() : base(false, EventResetMode.AutoReset)
+		{
+		}
+
+		public override void Close()
+		{
+			IsClosed = true;
+		}
+	}
+}

SafeExamBrowser.Service.UnitTests/Operations/ServiceEventCleanupOperationTests.cs

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System.Threading;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+using SafeExamBrowser.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Service.Operations;
+
+namespace SafeExamBrowser.Service.UnitTests.Operations
+{
+	[TestClass]
+	public class ServiceEventCleanupOperationTests
+	{
+		private Mock<ILogger> logger;
+		private SessionContext sessionContext;
+		private ServiceEventCleanupOperation sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			logger = new Mock<ILogger>();
+			sessionContext = new SessionContext();
+
+			sut = new ServiceEventCleanupOperation(logger.Object, sessionContext);
+		}
+
+		[TestMethod]
+		public void Perform_MustDoNothing()
+		{
+			var serviceEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
+
+			sessionContext.ServiceEvent = serviceEvent;
+
+			var result = sut.Perform();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.AreSame(serviceEvent, sessionContext.ServiceEvent);
+		}
+
+		[TestMethod]
+		public void Revert_MustCloseEvent()
+		{
+			var serviceEvent = new EventStub();
+
+			sessionContext.ServiceEvent = serviceEvent;
+
+			var result = sut.Revert();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.IsTrue(serviceEvent.IsClosed);
+		}
+
+		[TestMethod]
+		public void Revert_MustNotFailIfEventNull()
+		{
+			var result = sut.Revert();
+
+			Assert.AreEqual(OperationResult.Success, result);
+		}
+	}
+}

SafeExamBrowser.Service.UnitTests/Operations/SessionActivationOperationTests.cs

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+using SafeExamBrowser.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Service.Operations;
+
+namespace SafeExamBrowser.Service.UnitTests.Operations
+{
+	[TestClass]
+	public class SessionActivationOperationTests
+	{
+		private Mock<ILogger> logger;
+		private SessionContext sessionContext;
+		private SessionActivationOperation sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			logger = new Mock<ILogger>();
+			sessionContext = new SessionContext();
+
+			sut = new SessionActivationOperation(logger.Object, sessionContext);
+		}
+
+		[TestMethod]
+		public void Perform_MustSetServiceEvent()
+		{
+			sessionContext.ServiceEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
+
+			var wasSet = false;
+			var task = Task.Run(() => wasSet = sessionContext.ServiceEvent.WaitOne(1000));
+			var result = sut.Perform();
+
+			task.Wait();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.IsTrue(wasSet);
+		}
+
+		[TestMethod]
+		public void Revert_MustDoNothing()
+		{
+			var result = sut.Revert();
+
+			Assert.AreEqual(OperationResult.Success, result);
+		}
+	}
+}

SafeExamBrowser.Service.UnitTests/Operations/SessionInitializationOperationTests.cs

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+using SafeExamBrowser.Contracts.Communication.Hosts;
+using SafeExamBrowser.Contracts.Configuration;
+using SafeExamBrowser.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Service.Operations;
+
+namespace SafeExamBrowser.Service.UnitTests.Operations
+{
+	[TestClass]
+	public class SessionInitializationOperationTests
+	{
+		private Mock<ILogger> logger;
+		private Mock<Func<string, ILogObserver>> logWriterFactory;
+		private Mock<IServiceHost> serviceHost;
+		private Mock<Func<string, EventWaitHandle>> serviceEventFactory;
+		private SessionContext sessionContext;
+		private SessionInitializationOperation sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			logger = new Mock<ILogger>();
+			logWriterFactory = new Mock<Func<string, ILogObserver>>();
+			serviceHost = new Mock<IServiceHost>();
+			serviceEventFactory = new Mock<Func<string, EventWaitHandle>>();
+			sessionContext = new SessionContext();
+
+			logWriterFactory.Setup(f => f.Invoke(It.IsAny<string>())).Returns(new Mock<ILogObserver>().Object);
+			serviceEventFactory.Setup(f => f.Invoke(It.IsAny<string>())).Returns(new EventStub());
+			sessionContext.Configuration = new ServiceConfiguration
+			{
+				AppConfig = new AppConfig { ServiceEventName = $"{nameof(SafeExamBrowser)}-{nameof(SessionInitializationOperationTests)}" }
+			};
+
+			sut = new SessionInitializationOperation(logger.Object, logWriterFactory.Object, serviceEventFactory.Object, serviceHost.Object, sessionContext);
+		}
+
+		[TestMethod]
+		public void Perform_MustDisableNewConnections()
+		{
+			var result = sut.Perform();
+
+			serviceHost.VerifySet(h => h.AllowConnection = false, Times.Once);
+
+			Assert.AreEqual(OperationResult.Success, result);
+		}
+
+		[TestMethod]
+		public void Perform_MustInitializeServiceEvent()
+		{
+			var result = sut.Perform();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.IsInstanceOfType(sessionContext.ServiceEvent, typeof(EventWaitHandle));
+		}
+
+		[TestMethod]
+		public void Revert_MustSetServiceEvent()
+		{
+			sessionContext.ServiceEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
+
+			var wasSet = false;
+			var task = Task.Run(() => wasSet = sessionContext.ServiceEvent.WaitOne(1000));
+			var result = sut.Revert();
+
+			task.Wait();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.IsTrue(wasSet);
+		}
+
+		[TestMethod]
+		public void Revert_MustDeleteConfiguration()
+		{
+			sessionContext.Configuration = new ServiceConfiguration();
+			sessionContext.ServiceEvent = new EventStub();
+
+			var result = sut.Revert();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.IsNull(sessionContext.Configuration);
+		}
+
+		[TestMethod]
+		public void Revert_MustEnableNewConnections()
+		{
+			sessionContext.ServiceEvent = new EventStub();
+
+			var result = sut.Revert();
+
+			serviceHost.VerifySet(h => h.AllowConnection = true, Times.Once);
+			Assert.AreEqual(OperationResult.Success, result);
+		}
+	}
+}

SafeExamBrowser.Service.UnitTests/SafeExamBrowser.Service.UnitTests.csproj

@@ -80,6 +80,11 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Communication\ServiceHostTests.cs" />
+    <Compile Include="Operations\EventStub.cs" />
+    <Compile Include="Operations\ServiceEventCleanupOperationTests.cs" />
+    <Compile Include="Operations\SessionActivationOperationTests.cs" />
+    <Compile Include="Operations\SessionInitializationOperationTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ServiceControllerTests.cs" />
   </ItemGroup>
@@ -87,6 +92,10 @@
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\SafeExamBrowser.Communication\SafeExamBrowser.Communication.csproj">
+      <Project>{c9416a62-0623-4d38-96aa-92516b32f02f}</Project>
+      <Name>SafeExamBrowser.Communication</Name>
+    </ProjectReference>
     <ProjectReference Include="..\SafeExamBrowser.Contracts\SafeExamBrowser.Contracts.csproj">
       <Project>{47da5933-bef8-4729-94e6-abde2db12262}</Project>
       <Name>SafeExamBrowser.Contracts</Name>
@@ -96,10 +105,7 @@
       <Name>SafeExamBrowser.Service</Name>
     </ProjectReference>
   </ItemGroup>
-  <ItemGroup>
-    <Folder Include="Communication\" />
-    <Folder Include="Operations\" />
-  </ItemGroup>
+  <ItemGroup />
   <Import Project="$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets" Condition="Exists('$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets')" />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">

SafeExamBrowser.Service.UnitTests/ServiceControllerTests.cs

@@ -6,8 +6,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Moq;
+using SafeExamBrowser.Contracts.Communication.Events;
 using SafeExamBrowser.Contracts.Communication.Hosts;
 using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Core.OperationModel;
@@ -21,7 +23,7 @@ namespace SafeExamBrowser.Service.UnitTests
 		private Mock<ILogger> logger;
 		private Mock<IOperationSequence> bootstrapSequence;
 		private SessionContext sessionContext;
-		private Mock<IRepeatableOperationSequence> sessionSequence;
+		private Mock<IOperationSequence> sessionSequence;
 		private Mock<IServiceHost> serviceHost;
 		private ServiceController sut;
 
@@ -31,12 +33,86 @@ namespace SafeExamBrowser.Service.UnitTests
 			logger = new Mock<ILogger>();
 			bootstrapSequence = new Mock<IOperationSequence>();
 			sessionContext = new SessionContext();
-			sessionSequence = new Mock<IRepeatableOperationSequence>();
+			sessionSequence = new Mock<IOperationSequence>();
 			serviceHost = new Mock<IServiceHost>();
 
 			sut = new ServiceController(logger.Object, bootstrapSequence.Object, sessionSequence.Object, serviceHost.Object, sessionContext);
 		}
 
+		[TestMethod]
+		public void Communication_MustStartNewSessionUponRequest()
+		{
+			var args = new SessionStartEventArgs { Configuration = new ServiceConfiguration { SessionId = Guid.NewGuid() } };
+
+			bootstrapSequence.Setup(b => b.TryPerform()).Returns(OperationResult.Success);
+			sessionSequence.Setup(b => b.TryPerform()).Returns(OperationResult.Success);
+
+			sut.TryStart();
+			serviceHost.Raise(h => h.SessionStartRequested += null, args);
+
+			sessionSequence.Verify(s => s.TryPerform(), Times.Once);
+
+			Assert.IsNotNull(sessionContext.Configuration);
+			Assert.AreEqual(args.Configuration.SessionId, sessionContext.Configuration.SessionId);
+		}
+
+		[TestMethod]
+		public void Communication_MustNotAllowNewSessionDuringActiveSession()
+		{
+			var args = new SessionStartEventArgs { Configuration = new ServiceConfiguration { SessionId = Guid.NewGuid() } };
+
+			bootstrapSequence.Setup(b => b.TryPerform()).Returns(OperationResult.Success);
+			sessionContext.Configuration = new ServiceConfiguration { SessionId = Guid.NewGuid() };
+
+			sut.TryStart();
+			serviceHost.Raise(h => h.SessionStartRequested += null, args);
+
+			sessionSequence.Verify(s => s.TryPerform(), Times.Never);
+
+			Assert.AreNotEqual(args.Configuration.SessionId, sessionContext.Configuration.SessionId);
+		}
+
+		[TestMethod]
+		public void Communication_MustStopActiveSessionUponRequest()
+		{
+			var args = new SessionStopEventArgs { SessionId = Guid.NewGuid() };
+
+			bootstrapSequence.Setup(b => b.TryPerform()).Returns(OperationResult.Success);
+			sessionContext.Configuration = new ServiceConfiguration { SessionId = args.SessionId };
+
+			sut.TryStart();
+			serviceHost.Raise(h => h.SessionStopRequested += null, args);
+
+			sessionSequence.Verify(s => s.TryRevert(), Times.Once);
+		}
+
+		[TestMethod]
+		public void Communication_MustNotStopSessionWithWrongId()
+		{
+			var args = new SessionStopEventArgs { SessionId = Guid.NewGuid() };
+
+			bootstrapSequence.Setup(b => b.TryPerform()).Returns(OperationResult.Success);
+			sessionContext.Configuration = new ServiceConfiguration { SessionId = Guid.NewGuid() };
+
+			sut.TryStart();
+			serviceHost.Raise(h => h.SessionStopRequested += null, args);
+
+			sessionSequence.Verify(s => s.TryRevert(), Times.Never);
+		}
+
+		[TestMethod]
+		public void Communication_MustNotStopSessionWithoutActiveSession()
+		{
+			var args = new SessionStopEventArgs { SessionId = Guid.NewGuid() };
+
+			bootstrapSequence.Setup(b => b.TryPerform()).Returns(OperationResult.Success);
+
+			sut.TryStart();
+			serviceHost.Raise(h => h.SessionStopRequested += null, args);
+
+			sessionSequence.Verify(s => s.TryRevert(), Times.Never);
+		}
+
 		[TestMethod]
 		public void Start_MustOnlyPerformBootstrapSequence()
 		{
@@ -49,7 +125,6 @@ namespace SafeExamBrowser.Service.UnitTests
 			bootstrapSequence.Verify(b => b.TryPerform(), Times.Once);
 			bootstrapSequence.Verify(b => b.TryRevert(), Times.Never);
 			sessionSequence.Verify(b => b.TryPerform(), Times.Never);
-			sessionSequence.Verify(b => b.TryRepeat(), Times.Never);
 			sessionSequence.Verify(b => b.TryRevert(), Times.Never);
 
 			Assert.IsTrue(success);
@@ -76,7 +151,6 @@ namespace SafeExamBrowser.Service.UnitTests
 			bootstrapSequence.Verify(b => b.TryPerform(), Times.Never);
 			bootstrapSequence.Verify(b => b.TryRevert(), Times.Once);
 			sessionSequence.Verify(b => b.TryPerform(), Times.Never);
-			sessionSequence.Verify(b => b.TryRepeat(), Times.Never);
 			sessionSequence.Verify(b => b.TryRevert(), Times.Once);
 
 			Assert.AreEqual(1, session);
@@ -104,7 +178,6 @@ namespace SafeExamBrowser.Service.UnitTests
 			bootstrapSequence.Verify(b => b.TryPerform(), Times.Never);
 			bootstrapSequence.Verify(b => b.TryRevert(), Times.Once);
 			sessionSequence.Verify(b => b.TryPerform(), Times.Never);
-			sessionSequence.Verify(b => b.TryRepeat(), Times.Never);
 			sessionSequence.Verify(b => b.TryRevert(), Times.Never);
 
 			Assert.AreEqual(0, session);

SafeExamBrowser.Service/CompositionRoot.cs

@@ -9,6 +9,9 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Security.AccessControl;
+using System.Security.Principal;
+using System.Threading;
 using SafeExamBrowser.Communication.Hosts;
 using SafeExamBrowser.Communication.Proxies;
 using SafeExamBrowser.Contracts.Core.OperationModel;
@@ -42,13 +45,10 @@ namespace SafeExamBrowser.Service
 			var bootstrapOperations = new Queue<IOperation>();
 			var sessionOperations = new Queue<IOperation>();
 
-			// TODO: bootstrapOperations.Enqueue(new RestoreOperation());
 			bootstrapOperations.Enqueue(new CommunicationHostOperation(serviceHost, logger));
 			bootstrapOperations.Enqueue(new ServiceEventCleanupOperation(logger, sessionContext));
 
-			sessionOperations.Enqueue(new SessionInitializationOperation(logger, CreateLogWriter, serviceHost, sessionContext));
-			// TODO: sessionOperations.Enqueue(new RegistryOperation());
-			//       sessionOperations.Enqueue(new WindowsUpdateOperation());
+			sessionOperations.Enqueue(new SessionInitializationOperation(logger, LogWriterFactory, ServiceEventFactory, serviceHost, sessionContext));
 			sessionOperations.Enqueue(new SessionActivationOperation(logger, sessionContext));
 
 			var bootstrapSequence = new OperationSequence(logger, bootstrapOperations);
@@ -82,7 +82,7 @@ namespace SafeExamBrowser.Service
 			logFileWriter.Initialize();
 		}
 
-		private ILogObserver CreateLogWriter(string filePath)
+		private ILogObserver LogWriterFactory(string filePath)
 		{
 			var writer = new LogFileWriter(new DefaultLogFormatter(), filePath);
 
@@ -90,5 +90,16 @@ namespace SafeExamBrowser.Service
 
 			return writer;
 		}
+
+		private EventWaitHandle ServiceEventFactory(string eventName)
+		{
+			var securityIdentifier = new SecurityIdentifier(WellKnownSidType.BuiltinUsersSid, null);
+			var accessRule = new EventWaitHandleAccessRule(securityIdentifier, EventWaitHandleRights.Synchronize, AccessControlType.Allow);
+			var security = new EventWaitHandleSecurity();
+
+			security.AddAccessRule(accessRule);
+
+			return new EventWaitHandle(false, EventResetMode.AutoReset, eventName, out _, security);
+		}
 	}
 }

SafeExamBrowser.Service/Operations/SessionInitializationOperation.cs

@@ -7,8 +7,6 @@
  */
 
 using System;
-using System.Security.AccessControl;
-using System.Security.Principal;
 using System.Threading;
 using SafeExamBrowser.Contracts.Communication.Hosts;
 using SafeExamBrowser.Contracts.Core.OperationModel;
@@ -19,18 +17,21 @@ namespace SafeExamBrowser.Service.Operations
 	internal class SessionInitializationOperation : SessionOperation
 	{
 		private ILogger logger;
-		private Func<string, ILogObserver> createLogWriter;
+		private Func<string, ILogObserver> logWriterFactory;
+		private Func<string, EventWaitHandle> serviceEventFactory;
 		private IServiceHost serviceHost;
 		private ILogObserver sessionWriter;
 
 		public SessionInitializationOperation(
 			ILogger logger,
-			Func<string, ILogObserver> createLogWriter,
+			Func<string, ILogObserver> logWriterFactory,
+			Func<string, EventWaitHandle> serviceEventFactory,
 			IServiceHost serviceHost,
 			SessionContext sessionContext) : base(sessionContext)
 		{
 			this.logger = logger;
-			this.createLogWriter = createLogWriter;
+			this.logWriterFactory = logWriterFactory;
+			this.serviceEventFactory = serviceEventFactory;
 			this.serviceHost = serviceHost;
 		}
 
@@ -80,12 +81,6 @@ namespace SafeExamBrowser.Service.Operations
 
 		private void InitializeServiceEvent()
 		{
-			var securityIdentifier = new SecurityIdentifier(WellKnownSidType.BuiltinUsersSid, null);
-			var accessRule = new EventWaitHandleAccessRule(securityIdentifier, EventWaitHandleRights.Synchronize, AccessControlType.Allow);
-			var security = new EventWaitHandleSecurity();
-
-			security.AddAccessRule(accessRule);
-
 			if (Context.ServiceEvent != null)
 			{
 				logger.Info("Closing service event from previous session...");
@@ -94,13 +89,13 @@ namespace SafeExamBrowser.Service.Operations
 			}
 
 			logger.Info("Attempting to create new service event...");
-			Context.ServiceEvent = new EventWaitHandle(false, EventResetMode.AutoReset, Context.Configuration.AppConfig.ServiceEventName, out _, security);
+			Context.ServiceEvent = serviceEventFactory.Invoke(Context.Configuration.AppConfig.ServiceEventName);
 			logger.Info("Service event successfully created.");
 		}
 
 		private void InitializeSessionWriter()
 		{
-			sessionWriter = createLogWriter.Invoke(Context.Configuration.AppConfig.ServiceLogFilePath);
+			sessionWriter = logWriterFactory.Invoke(Context.Configuration.AppConfig.ServiceLogFilePath);
 			logger.Subscribe(sessionWriter);
 		}
 	}

SafeExamBrowser.Service/ServiceController.cs

@@ -160,7 +160,14 @@ namespace SafeExamBrowser.Service
 		{
 			if (SessionIsRunning)
 			{
-				StopSession();
+				if (Session.SessionId == args.SessionId)
+				{
+					StopSession();
+				}
+				else
+				{
+					logger.Warn("Received session stop request with wrong session ID!");
+				}
 			}
 			else
 			{