Obsolete Socket.UseOnlyOverlappedIO (#52475)

close #47163

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

@@ -292,6 +292,8 @@ public Socket(System.Net.Sockets.SocketType socketType, System.Net.Sockets.Proto
  [System.ObsoleteAttribute("SupportsIPv6 is obsoleted for this type, please use OSSupportsIPv6 instead. https://go.microsoft.com/fwlink/?linkid=14202")]
  public static bool SupportsIPv6 { get { throw null; } }
  public short Ttl { get { throw null; } set { } }
+ [System.ObsoleteAttribute("This property has no effect in .NET 5+ and .NET Core.")]
+ [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
  public bool UseOnlyOverlappedIO { get { throw null; } set { } }
  public System.Net.Sockets.Socket Accept() { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.Socket> AcceptAsync() { throw null; }
@@ -505,6 +507,8 @@ public enum SocketInformationOptions
  NonBlocking = 1,
  Connected = 2,
  Listening = 4,
+ [System.ObsoleteAttribute("This flag has no effect in .NET 5+ and .NET Core.")]
+ [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
  UseOnlyOverlappedIO = 8,
  }
  public enum SocketOptionLevel

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

@@ -3,6 +3,7 @@
 
 using System.Collections;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
@@ -415,6 +416,8 @@ public bool Blocking
  // allowing calls to DuplicateAndClose() even after performing asynchronous IO.
  // .NET (Core) Windows sockets are entirely IOCP-based, and the concept of "overlapped IO"
  // does not exist on other platforms, therefore UseOnlyOverlappedIO is a dummy, compat-only property.
+ [Obsolete("This property has no effect in .NET 5+ and .NET Core.")]
+ [EditorBrowsable(EditorBrowsableState.Never)]
  public bool UseOnlyOverlappedIO
  {
  get { return false; }

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

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.ComponentModel;
+
 namespace System.Net.Sockets
 {
  [Flags]
@@ -11,6 +13,8 @@ public enum SocketInformationOptions
  //disconnect doesn't update getpeername to return a failure.
  Connected = 0x2,
  Listening = 0x4,
+ [Obsolete("This flag has no effect in .NET 5+ and .NET Core.")]
+ [EditorBrowsable(EditorBrowsableState.Never)]
  UseOnlyOverlappedIO = 0x8,
  }
 }

src/libraries/System.Net.Sockets/tests/FunctionalTests/CreateSocketTests.cs

@@ -379,7 +379,9 @@ public void Ctor_SafeHandle_BasicPropertiesPropagate_Success(AddressFamily addre
  Assert.Equal(orig.ReceiveTimeout, copy.ReceiveTimeout);
  Assert.Equal(orig.SendBufferSize, copy.SendBufferSize);
  Assert.Equal(orig.SendTimeout, copy.SendTimeout);
+#pragma warning disable 0618
  Assert.Equal(orig.UseOnlyOverlappedIO, copy.UseOnlyOverlappedIO);
+#pragma warning restore 0618
  }
 
  [Theory]
@@ -424,7 +426,6 @@ public async Task Ctor_SafeHandle_Tcp_SendReceive_Success(AddressFamily addressF
  Assert.Equal(orig.SendBufferSize, client.SendBufferSize);
  Assert.Equal(orig.SendTimeout, client.SendTimeout);
  Assert.Equal(orig.Ttl, client.Ttl);
- Assert.Equal(orig.UseOnlyOverlappedIO, client.UseOnlyOverlappedIO);
 
  // Validate setting various properties on the new instance and seeing them roundtrip back to the original.
  client.ReceiveTimeout = 42;

src/libraries/System.Net.Sockets/tests/FunctionalTests/SocketDuplicationTests.cs

@@ -32,9 +32,11 @@ public void UseOnlyOverlappedIO_AlwaysFalse()
  {
  using Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
 
+#pragma warning disable 0618
  Assert.False(s.UseOnlyOverlappedIO);
  s.UseOnlyOverlappedIO = true;
  Assert.False(s.UseOnlyOverlappedIO);
+#pragma warning restore 0618
  }
 
  [PlatformSpecific(TestPlatforms.Windows)]