Sync up to latest code and cleanup.

src/libraries/Common/src/Interop/Windows/WinSock/Interop.WSAIoctl.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Net.Sockets;
 using System.Runtime.InteropServices;

src/libraries/Common/src/System/Net/ContextAwareResult.cs

@@ -1,8 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
+
 #nullable enable
-using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 
 namespace System.Net
@@ -159,7 +159,7 @@ internal ExecutionContext? ContextCopy
                     {
                         NetEventSource.Fail(this, "Must lock (StartPostingAsyncOp()) { ... FinishPostingAsyncOp(); } when calling ContextCopy (unless it's only called after FinishPostingAsyncOp).");
                     }
-                    lock (_lock) { }
+                    lock (_lock!) { }
                 }
 
                 if (InternalPeekCompleted)

src/libraries/Common/src/System/Net/DebugSafeHandleMinusOneIsInvalid.cs

@@ -1,8 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
-#nullable enable
 
+#nullable enable
 using Microsoft.Win32.SafeHandles;
 
 namespace System.Net
@@ -14,16 +14,16 @@ namespace System.Net
     //
     internal abstract class DebugSafeHandleMinusOneIsInvalid : SafeHandleMinusOneIsInvalid
     {
-        private string _trace;
+        private string _trace = null!; // initialized by helper called from ctor
 
         protected DebugSafeHandleMinusOneIsInvalid(bool ownsHandle) : base(ownsHandle)
         {
-            _trace = "WARNING! GC-ed  >>" + this.GetType().FullName + "<< (should be explicitly closed) \r\n";
             Trace();
         }
 
         private void Trace()
         {
+            _trace = "WARNING! GC-ed  >>" + this.GetType().FullName + "<< (should be explicitly closed) \r\n";
             if (NetEventSource.IsEnabled) NetEventSource.Info(this, "Creating SafeHandle");
 #if TRACE_VERBOSE
             string stacktrace = Environment.StackTrace;

src/libraries/Common/src/System/Net/Logging/NetEventSource.Common.cs

@@ -11,7 +11,6 @@
 #nullable enable
 using System.Collections;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Tracing;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -279,7 +278,6 @@ public static void Fail(object? thisOrContextObject, FormattableString formattab
         /// <param name="message">The message to be logged.</param>
         /// <param name="memberName">The calling member.</param>
         [NonEvent]
-        [DoesNotReturn]
         public static void Fail(object? thisOrContextObject, object message, [CallerMemberName] string? memberName = null)
         {
             // Don't call DebugValidateArg on args, as we expect Fail to be used in assert/failure situations

src/libraries/System.Net.Sockets/src/System/Net/Sockets/DisconnectOverlappedAsyncResult.cs

@@ -20,7 +20,7 @@ internal DisconnectOverlappedAsyncResult(Socket socket, object? asyncState, Asyn
             {
                 Socket socket = (Socket)AsyncObject;
                 socket.SetToDisconnected();
-                socket._remoteEndPoint = null!;//TODO:eerhardt
+                socket._remoteEndPoint = null;
             }
             return base.PostCompletion(numBytes);
         }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/MultipleConnectAsync.cs

@@ -261,7 +261,7 @@ private void InternalConnectCallback(object? sender, SocketAsyncEventArgs args)
                     NetEventSource.Fail(null, "attemptSocket is null!");
                 }
 
-                bool pending = attemptSocket.ConnectAsync(args);
+                bool pending = attemptSocket!.ConnectAsync(args);
                 if (!pending)
                 {
                     InternalConnectCallback(null, args);

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -840,7 +840,7 @@ public void Connect(string host, int port)
             // No need to call ValidateForMultiConnect(), as the validation
             // will be handled by the delegated Connect overloads.
 
-            IPAddress parsedAddress;
+            IPAddress? parsedAddress;
             if (IPAddress.TryParse(host, out parsedAddress))
             {
                 Connect(parsedAddress, port);
@@ -2089,7 +2089,7 @@ public IAsyncResult BeginConnect(string host, int port, AsyncCallback? requestCa
                 throw new SocketException((int)SocketError.IsConnected);
             }
 
-            IPAddress parsedAddress;
+            IPAddress? parsedAddress;
             if (IPAddress.TryParse(host, out parsedAddress))
             {
                 IAsyncResult r = BeginConnect(parsedAddress, port, requestCallback, state);

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncEngine.Unix.cs

@@ -159,7 +159,7 @@ private static void AllocateToken(SocketAsyncContext context, out SocketAsyncEng
                     // We minimize the number of engines on applications that have a low number of concurrent sockets.
                     for (int i = 0; i < s_allocateFromEngine; i++)
                     {
-                        SocketAsyncEngine? previousEngine = s_currentEngines[i];
+                        var previousEngine = s_currentEngines[i];
                         if (previousEngine == null || previousEngine.HasLowNumberOfSockets)
                         {
                             s_allocateFromEngine = i;

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncEventArgs.cs

@@ -573,7 +573,7 @@ internal void CancelConnectAsync()
                     {
                         NetEventSource.Fail(this, "CurrentSocket and MultipleConnect both null!");
                     }
-                    _currentSocket.Dispose();
+                    _currentSocket!.Dispose();
                 }
             }
         }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/TCPListener.cs

@@ -344,7 +344,7 @@ public static TcpListener Create(int port)
         }
 
         private void SetIPProtectionLevel(bool allowed)
-            => _serverSocket.SetIPProtectionLevel(allowed ? IPProtectionLevel.Unrestricted : IPProtectionLevel.EdgeRestricted);
+            => _serverSocket!.SetIPProtectionLevel(allowed ? IPProtectionLevel.Unrestricted : IPProtectionLevel.EdgeRestricted);
 
         private void CreateNewSocketIfNeeded()
         {