From ddb3e73a902a33427779cc82e18317d49e159c9e Mon Sep 17 00:00:00 2001
From: Tarun <gtarun047@gmail.com>
Date: Sat, 25 Mar 2023 11:54:19 +0530
Subject: [PATCH 1/8] Initial Commit

---
 src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs   |  2 ++
 .../System.IO.Pipes/src/Resources/Strings.resx         |  3 +++
 .../src/System/IO/Pipes/NamedPipeServerStream.Unix.cs  |  5 +++++
 .../src/System/IO/Pipes/NamedPipeServerStream.cs       |  8 ++++----
 .../System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs |  6 +++++-
 .../tests/NamedPipeTests/NamedPipeTest.CreateServer.cs | 10 +++++++++-
 6 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
index a7432dbc5a217..92b38ed45de71 100644
--- a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
+++ b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
@@ -95,6 +95,8 @@ public enum PipeOptions
         None = 0,
         CurrentUserOnly = 536870912,
         Asynchronous = 1073741824,
+        [System.Runtime.Versioning.SupportedOSPlatformAttribute("windows")]
+        FirstPipeInstance = 524288
     }
     public abstract partial class PipeStream : System.IO.Stream
     {
diff --git a/src/libraries/System.IO.Pipes/src/Resources/Strings.resx b/src/libraries/System.IO.Pipes/src/Resources/Strings.resx
index ce20624ce4334..470ad29ab0d46 100644
--- a/src/libraries/System.IO.Pipes/src/Resources/Strings.resx
+++ b/src/libraries/System.IO.Pipes/src/Resources/Strings.resx
@@ -243,6 +243,9 @@
   <data name="PlatformNotSupported_MessageTransmissionMode" xml:space="preserve">
     <value>Message transmission mode is not supported on this platform.</value>
   </data>
+  <data name="PlatformNotSupported_PipeOptions_FirstPipeInstance" xml:space="preserve">
+    <value>First Pipe Instance option is not supported on this platform.</value>
+  </data>
   <data name="PlatformNotSupported_RemotePipes" xml:space="preserve">
     <value>Access to remote named pipes is not supported on this platform.</value>
   </data>
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
index 8544186c1c049..075345a80e33f 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
@@ -38,6 +38,11 @@ private void Create(string pipeName, PipeDirection direction, int maxNumberOfSer
                 throw new PlatformNotSupportedException(SR.PlatformNotSupported_MessageTransmissionMode);
             }
 
+            if ((options & PipeOptions.FirstPipeInstance) != 0)
+            {
+                throw new PlatformNotSupportedException(SR.PlatformNotSupported_PipeOptions_FirstPipeInstance);
+            }
+
             // We don't have a good way to enforce maxNumberOfServerInstances across processes; we only factor it in
             // for streams created in this process.  Between processes, we behave similarly to maxNumberOfServerInstances == 1,
             // in that the second process to come along and create a stream will find the pipe already in existence and will fail.
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
index 069ff0e0a930d..0e52e86ee05b3 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
@@ -60,10 +60,10 @@ public NamedPipeServerStream(string pipeName, PipeDirection direction, int maxNu
         /// Win32 note: this gets used for dwPipeMode. CreateNamedPipe allows you to specify PIPE_TYPE_BYTE/MESSAGE
         /// and PIPE_READMODE_BYTE/MESSAGE independently, but this sets type and readmode to match.
         /// </param>
-        /// <param name="options">PipeOption enum: None, Asynchronous, or Write-through
+        /// <param name="options">PipeOption enum: None, Asynchronous, or Write-through or FirstPipeInstance
         /// Win32 note: this gets passed in with dwOpenMode to CreateNamedPipe. Asynchronous corresponds to
-        /// FILE_FLAG_OVERLAPPED option. PipeOptions enum doesn't expose FIRST_PIPE_INSTANCE option because
-        /// this sets that automatically based on the number of instances specified.
+        /// FILE_FLAG_OVERLAPPED option. PipeOptions.FIRST_PIPE_INSTANCE
+        /// is automatically set based on the number of instances specified.
         /// </param>
         /// <param name="inBufferSize">Incoming buffer size, 0 or higher.
         /// Note: this size is always advisory; OS uses a suggestion.
@@ -103,7 +103,7 @@ private void ValidateParameters(
             {
                 throw new ArgumentOutOfRangeException(nameof(transmissionMode), SR.ArgumentOutOfRange_TransmissionModeByteOrMsg);
             }
-            if ((options & ~(PipeOptions.WriteThrough | PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly)) != 0)
+            if ((options & ~(PipeOptions.WriteThrough | PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly | PipeOptions.FirstPipeInstance)) != 0)
             {
                 throw new ArgumentOutOfRangeException(nameof(options), SR.ArgumentOutOfRange_OptionsInvalid);
             }
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
index 493ee5f675329..fd4547db69709 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.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.Runtime.Versioning;
+
 namespace System.IO.Pipes
 {
     [Flags]
@@ -9,6 +11,8 @@ public enum PipeOptions
         None = 0x0,
         WriteThrough = unchecked((int)0x80000000),
         Asynchronous = unchecked((int)0x40000000),  // corresponds to FILE_FLAG_OVERLAPPED
-        CurrentUserOnly = unchecked((int)0x20000000)
+        CurrentUserOnly = unchecked((int)0x20000000),
+        [SupportedOSPlatform("windows")]
+        FirstPipeInstance = unchecked((int)0x00080000)
     }
 }
diff --git a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
index d8afc8094a3de..4e93e227b602f 100644
--- a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
+++ b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
@@ -52,7 +52,8 @@ public static void ReservedPipeName_Throws_ArgumentOutOfRangeException(PipeDirec
             AssertExtensions.Throws<ArgumentOutOfRangeException>("pipeName", () => new NamedPipeServerStream(reservedName, direction, 1));
             AssertExtensions.Throws<ArgumentOutOfRangeException>("pipeName", () => new NamedPipeServerStream(reservedName, direction, 1, PipeTransmissionMode.Byte));
             AssertExtensions.Throws<ArgumentOutOfRangeException>("pipeName", () => new NamedPipeServerStream(reservedName, direction, 1, PipeTransmissionMode.Byte, PipeOptions.None));
-            AssertExtensions.Throws<ArgumentOutOfRangeException>("pipeName", () => new NamedPipeServerStream(reservedName, direction, 1, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0));}
+            AssertExtensions.Throws<ArgumentOutOfRangeException>("pipeName", () => new NamedPipeServerStream(reservedName, direction, 1, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0));
+        }
 
         [Fact]
         [SkipOnPlatform(TestPlatforms.LinuxBionic, "SElinux blocks UNIX sockets in our CI environment")]
@@ -254,5 +255,12 @@ public static void Windows_ServerCloneWithDifferentDirection_Throws_Unauthorized
                 Assert.Throws<UnauthorizedAccessException>(() => new NamedPipeServerStream(uniqueServerName, PipeDirection.Out));
             }
         }
+
+        [Fact]
+        [PlatformSpecific(TestPlatforms.AnyUnix)]
+        public static void Unix_PipeOptions_FirstPipeInstance_ThrowsPlatformNotSupportedException()
+        {
+            Assert.Throws<PlatformNotSupportedException>(() => new NamedPipeServerStream(PipeStreamConformanceTests.GetUniquePipeName(), PipeDirection.Out, 1, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance));
+        }
     }
 }

From 361eebe5e4138bceda793729e2b0ef90cbb66d14 Mon Sep 17 00:00:00 2001
From: Tarun <gtarun047@gmail.com>
Date: Sun, 26 Mar 2023 09:20:41 +0530
Subject: [PATCH 2/8] Update Code to remove SupportedOSPlatform Attribute

---
 src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs             | 1 -
 src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs | 1 -
 2 files changed, 2 deletions(-)

diff --git a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
index 92b38ed45de71..f7b404b93a502 100644
--- a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
+++ b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
@@ -95,7 +95,6 @@ public enum PipeOptions
         None = 0,
         CurrentUserOnly = 536870912,
         Asynchronous = 1073741824,
-        [System.Runtime.Versioning.SupportedOSPlatformAttribute("windows")]
         FirstPipeInstance = 524288
     }
     public abstract partial class PipeStream : System.IO.Stream
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
index fd4547db69709..28a65b2f9f550 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
@@ -12,7 +12,6 @@ public enum PipeOptions
         WriteThrough = unchecked((int)0x80000000),
         Asynchronous = unchecked((int)0x40000000),  // corresponds to FILE_FLAG_OVERLAPPED
         CurrentUserOnly = unchecked((int)0x20000000),
-        [SupportedOSPlatform("windows")]
         FirstPipeInstance = unchecked((int)0x00080000)
     }
 }

From 08837e98ffbe39f9e06429d19d99a00ce87ae741 Mon Sep 17 00:00:00 2001
From: "Gudipati.Tarun" <Gudipati.Tarun@wisetechglobal.com>
Date: Sun, 9 Apr 2023 20:54:08 +0530
Subject: [PATCH 3/8] Address Review Comments

---
 .../System.IO.Pipes/ref/System.IO.Pipes.cs          |  1 +
 .../System/IO/Pipes/NamedPipeServerStream.Unix.cs   |  2 ++
 .../src/System/IO/Pipes/NamedPipeServerStream.cs    |  7 ++++---
 .../src/System/IO/Pipes/PipeOptions.cs              |  1 +
 .../NamedPipeTests/NamedPipeTest.CreateServer.cs    | 13 +++++++++++++
 5 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
index f7b404b93a502..92b38ed45de71 100644
--- a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
+++ b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
@@ -95,6 +95,7 @@ public enum PipeOptions
         None = 0,
         CurrentUserOnly = 536870912,
         Asynchronous = 1073741824,
+        [System.Runtime.Versioning.SupportedOSPlatformAttribute("windows")]
         FirstPipeInstance = 524288
     }
     public abstract partial class PipeStream : System.IO.Stream
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
index 075345a80e33f..7c34d9940f82c 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
@@ -38,7 +38,9 @@ private void Create(string pipeName, PipeDirection direction, int maxNumberOfSer
                 throw new PlatformNotSupportedException(SR.PlatformNotSupported_MessageTransmissionMode);
             }
 
+#pragma warning disable CA1416
             if ((options & PipeOptions.FirstPipeInstance) != 0)
+#pragma warning restore CA1416
             {
                 throw new PlatformNotSupportedException(SR.PlatformNotSupported_PipeOptions_FirstPipeInstance);
             }
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
index 0e52e86ee05b3..8d7ba073c7222 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Win32.SafeHandles;
@@ -60,7 +59,7 @@ public NamedPipeServerStream(string pipeName, PipeDirection direction, int maxNu
         /// Win32 note: this gets used for dwPipeMode. CreateNamedPipe allows you to specify PIPE_TYPE_BYTE/MESSAGE
         /// and PIPE_READMODE_BYTE/MESSAGE independently, but this sets type and readmode to match.
         /// </param>
-        /// <param name="options">PipeOption enum: None, Asynchronous, or Write-through or FirstPipeInstance
+        /// <param name="options">PipeOption enum: None, Asynchronous, Write-through, or FirstPipeInstance
         /// Win32 note: this gets passed in with dwOpenMode to CreateNamedPipe. Asynchronous corresponds to
         /// FILE_FLAG_OVERLAPPED option. PipeOptions.FIRST_PIPE_INSTANCE
         /// is automatically set based on the number of instances specified.
@@ -103,7 +102,9 @@ private void ValidateParameters(
             {
                 throw new ArgumentOutOfRangeException(nameof(transmissionMode), SR.ArgumentOutOfRange_TransmissionModeByteOrMsg);
             }
+#pragma warning disable CA1416
             if ((options & ~(PipeOptions.WriteThrough | PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly | PipeOptions.FirstPipeInstance)) != 0)
+#pragma warning restore CA1416
             {
                 throw new ArgumentOutOfRangeException(nameof(options), SR.ArgumentOutOfRange_OptionsInvalid);
             }
@@ -161,7 +162,7 @@ public Task WaitForConnectionAsync()
             return WaitForConnectionAsync(CancellationToken.None);
         }
 
-        public System.IAsyncResult BeginWaitForConnection(AsyncCallback? callback, object? state) =>
+        public IAsyncResult BeginWaitForConnection(AsyncCallback? callback, object? state) =>
             TaskToAsyncResult.Begin(WaitForConnectionAsync(), callback, state);
 
         public void EndWaitForConnection(IAsyncResult asyncResult) =>
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
index 28a65b2f9f550..fd4547db69709 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
@@ -12,6 +12,7 @@ public enum PipeOptions
         WriteThrough = unchecked((int)0x80000000),
         Asynchronous = unchecked((int)0x40000000),  // corresponds to FILE_FLAG_OVERLAPPED
         CurrentUserOnly = unchecked((int)0x20000000),
+        [SupportedOSPlatform("windows")]
         FirstPipeInstance = unchecked((int)0x00080000)
     }
 }
diff --git a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
index 4e93e227b602f..44f6bd5b91333 100644
--- a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
+++ b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Net.NetworkInformation;
 using Microsoft.Win32.SafeHandles;
 using Xunit;
 
@@ -262,5 +263,17 @@ public static void Unix_PipeOptions_FirstPipeInstance_ThrowsPlatformNotSupported
         {
             Assert.Throws<PlatformNotSupportedException>(() => new NamedPipeServerStream(PipeStreamConformanceTests.GetUniquePipeName(), PipeDirection.Out, 1, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance));
         }
+
+        [Fact]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public static void Windows_PipeOptions_FirstPipeInstanceWithSameNameReuse_Throws_UnauthorizedAccessException()
+        {
+            string uniqueServerName = PipeStreamConformanceTests.GetUniquePipeName();
+            using (NamedPipeServerStream server = new NamedPipeServerStream(uniqueServerName, PipeDirection.In, 2, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance))
+            {
+                Assert.Throws<UnauthorizedAccessException>(() => new NamedPipeServerStream(uniqueServerName, PipeDirection.In, 2, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance));
+            }
+        }
+
     }
 }

From 951984aea84232e290acaee5d98873880c5872c6 Mon Sep 17 00:00:00 2001
From: "Gudipati.Tarun" <Gudipati.Tarun@wisetechglobal.com>
Date: Sun, 9 Apr 2023 20:59:12 +0530
Subject: [PATCH 4/8] Remove Unused Imports

---
 .../tests/NamedPipeTests/NamedPipeTest.CreateServer.cs           | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
index 44f6bd5b91333..2aee831ee3485 100644
--- a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
+++ b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Net.NetworkInformation;
 using Microsoft.Win32.SafeHandles;
 using Xunit;
 

From c335ebcb399806740c0ceeff01432aed3c29211d Mon Sep 17 00:00:00 2001
From: Tarun <gtarun047@gmail.com>
Date: Sat, 20 May 2023 12:57:05 +0530
Subject: [PATCH 5/8] WIP Commmit

---
 .../System.IO.Pipes/ref/System.IO.Pipes.cs    |  1 -
 .../src/Resources/Strings.resx                | 57 +++++++++----------
 .../IO/Pipes/NamedPipeServerStream.Unix.cs    | 32 +++++------
 .../System/IO/Pipes/NamedPipeServerStream.cs  |  2 -
 .../src/System/IO/Pipes/PipeOptions.cs        |  1 -
 .../NamedPipeTest.CreateServer.cs             | 10 +---
 6 files changed, 44 insertions(+), 59 deletions(-)

diff --git a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
index 92b38ed45de71..f7b404b93a502 100644
--- a/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
+++ b/src/libraries/System.IO.Pipes/ref/System.IO.Pipes.cs
@@ -95,7 +95,6 @@ public enum PipeOptions
         None = 0,
         CurrentUserOnly = 536870912,
         Asynchronous = 1073741824,
-        [System.Runtime.Versioning.SupportedOSPlatformAttribute("windows")]
         FirstPipeInstance = 524288
     }
     public abstract partial class PipeStream : System.IO.Stream
diff --git a/src/libraries/System.IO.Pipes/src/Resources/Strings.resx b/src/libraries/System.IO.Pipes/src/Resources/Strings.resx
index 470ad29ab0d46..8910eb4d7ac45 100644
--- a/src/libraries/System.IO.Pipes/src/Resources/Strings.resx
+++ b/src/libraries/System.IO.Pipes/src/Resources/Strings.resx
@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
-    Microsoft ResX Schema 
-    
+  <!--
+    Microsoft ResX Schema
+
     Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
-    There are any number of "resheader" rows that contain simple 
+
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -243,9 +243,6 @@
   <data name="PlatformNotSupported_MessageTransmissionMode" xml:space="preserve">
     <value>Message transmission mode is not supported on this platform.</value>
   </data>
-  <data name="PlatformNotSupported_PipeOptions_FirstPipeInstance" xml:space="preserve">
-    <value>First Pipe Instance option is not supported on this platform.</value>
-  </data>
   <data name="PlatformNotSupported_RemotePipes" xml:space="preserve">
     <value>Access to remote named pipes is not supported on this platform.</value>
   </data>
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
index 7c34d9940f82c..97c6d3eaeb583 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
@@ -6,7 +6,6 @@
 using System.Diagnostics;
 using System.Net.Sockets;
 using System.Runtime.InteropServices;
-using System.Security;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -38,19 +37,12 @@ private void Create(string pipeName, PipeDirection direction, int maxNumberOfSer
                 throw new PlatformNotSupportedException(SR.PlatformNotSupported_MessageTransmissionMode);
             }
 
-#pragma warning disable CA1416
-            if ((options & PipeOptions.FirstPipeInstance) != 0)
-#pragma warning restore CA1416
-            {
-                throw new PlatformNotSupportedException(SR.PlatformNotSupported_PipeOptions_FirstPipeInstance);
-            }
-
             // We don't have a good way to enforce maxNumberOfServerInstances across processes; we only factor it in
             // for streams created in this process.  Between processes, we behave similarly to maxNumberOfServerInstances == 1,
             // in that the second process to come along and create a stream will find the pipe already in existence and will fail.
             _instance = SharedServer.Get(
                 GetPipePath(".", pipeName),
-                (maxNumberOfServerInstances == MaxAllowedServerInstances) ? int.MaxValue : maxNumberOfServerInstances);
+                (maxNumberOfServerInstances == MaxAllowedServerInstances) ? int.MaxValue : maxNumberOfServerInstances, options);
 
             _direction = direction;
             _options = options;
@@ -256,7 +248,7 @@ private sealed class SharedServer
             /// <summary>The concurrent number of concurrent streams using this instance.</summary>
             private int _currentCount;
 
-            internal static SharedServer Get(string path, int maxCount)
+            internal static SharedServer Get(string path, int maxCount, PipeOptions pipeOptions)
             {
                 Debug.Assert(!string.IsNullOrEmpty(path));
                 Debug.Assert(maxCount >= 1);
@@ -283,7 +275,7 @@ internal static SharedServer Get(string path, int maxCount)
                     else
                     {
                         // No instance exists yet for this path. Create one a new.
-                        server = new SharedServer(path, maxCount);
+                        server = new SharedServer(path, maxCount, pipeOptions);
                         s_servers.Add(path, server);
                     }
 
@@ -318,12 +310,20 @@ internal void Dispose(bool disposing)
                 }
             }
 
-            private SharedServer(string path, int maxCount)
+            private SharedServer(string path, int maxCount, PipeOptions pipeOptions)
             {
-                // Binding to an existing path fails, so we need to remove anything left over at this location.
-                // There's of course a race condition here, where it could be recreated by someone else between this
-                // deletion and the bind below, in which case we'll simply let the bind fail and throw.
-                Interop.Sys.Unlink(path); // ignore any failures
+                bool firstPipeInstance = (pipeOptions & PipeOptions.FirstPipeInstance) != 0;
+                if (!firstPipeInstance)
+                {
+                    // Binding to an existing path fails, so we need to remove anything left over at this location.
+                    // There's of course a race condition here, where it could be recreated by someone else between this
+                    // deletion and the bind below, in which case we'll simply let the bind fail and throw.
+                    Interop.Sys.Unlink(path); // ignore any failures
+                }
+                else
+                {
+                    throw new ArgumentException();
+                }
 
                 // Start listening for connections on the path.
                 var socket = new Socket(AddressFamily.Unix, SocketType.Stream, ProtocolType.Unspecified);
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
index 8d7ba073c7222..1995823a9b858 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
@@ -102,9 +102,7 @@ private void ValidateParameters(
             {
                 throw new ArgumentOutOfRangeException(nameof(transmissionMode), SR.ArgumentOutOfRange_TransmissionModeByteOrMsg);
             }
-#pragma warning disable CA1416
             if ((options & ~(PipeOptions.WriteThrough | PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly | PipeOptions.FirstPipeInstance)) != 0)
-#pragma warning restore CA1416
             {
                 throw new ArgumentOutOfRangeException(nameof(options), SR.ArgumentOutOfRange_OptionsInvalid);
             }
diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
index fd4547db69709..28a65b2f9f550 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/PipeOptions.cs
@@ -12,7 +12,6 @@ public enum PipeOptions
         WriteThrough = unchecked((int)0x80000000),
         Asynchronous = unchecked((int)0x40000000),  // corresponds to FILE_FLAG_OVERLAPPED
         CurrentUserOnly = unchecked((int)0x20000000),
-        [SupportedOSPlatform("windows")]
         FirstPipeInstance = unchecked((int)0x00080000)
     }
 }
diff --git a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
index 2aee831ee3485..6d7e83b4f0499 100644
--- a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
+++ b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs
@@ -257,15 +257,7 @@ public static void Windows_ServerCloneWithDifferentDirection_Throws_Unauthorized
         }
 
         [Fact]
-        [PlatformSpecific(TestPlatforms.AnyUnix)]
-        public static void Unix_PipeOptions_FirstPipeInstance_ThrowsPlatformNotSupportedException()
-        {
-            Assert.Throws<PlatformNotSupportedException>(() => new NamedPipeServerStream(PipeStreamConformanceTests.GetUniquePipeName(), PipeDirection.Out, 1, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance));
-        }
-
-        [Fact]
-        [PlatformSpecific(TestPlatforms.Windows)]
-        public static void Windows_PipeOptions_FirstPipeInstanceWithSameNameReuse_Throws_UnauthorizedAccessException()
+        public static void PipeOptions_FirstPipeInstanceWithSameNameReuse_Throws_UnauthorizedAccessException()
         {
             string uniqueServerName = PipeStreamConformanceTests.GetUniquePipeName();
             using (NamedPipeServerStream server = new NamedPipeServerStream(uniqueServerName, PipeDirection.In, 2, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance))

From 6f12df42691816bad57386442e405a0628392286 Mon Sep 17 00:00:00 2001
From: Tarun <gtarun047@gmail.com>
Date: Sat, 20 May 2023 14:48:23 +0530
Subject: [PATCH 6/8] Finalize Implementation on Unix

---
 .../IO/Pipes/NamedPipeServerStream.Unix.cs    | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
index 97c6d3eaeb583..8a2970d8f0bf1 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
@@ -256,6 +256,7 @@ internal static SharedServer Get(string path, int maxCount, PipeOptions pipeOpti
                 lock (s_servers)
                 {
                     SharedServer? server;
+                    bool isFirstPipeInstance = (pipeOptions & PipeOptions.FirstPipeInstance) != 0;
                     if (s_servers.TryGetValue(path, out server))
                     {
                         // On Windows, if a subsequent server stream is created for the same pipe and with a different
@@ -267,7 +268,7 @@ internal static SharedServer Get(string path, int maxCount, PipeOptions pipeOpti
                         {
                             throw new IOException(SR.IO_AllPipeInstancesAreBusy);
                         }
-                        else if (server._currentCount == maxCount)
+                        else if (server._currentCount == maxCount || isFirstPipeInstance)
                         {
                             throw new UnauthorizedAccessException(SR.Format(SR.UnauthorizedAccess_IODenied_Path, path));
                         }
@@ -275,7 +276,7 @@ internal static SharedServer Get(string path, int maxCount, PipeOptions pipeOpti
                     else
                     {
                         // No instance exists yet for this path. Create one a new.
-                        server = new SharedServer(path, maxCount, pipeOptions);
+                        server = new SharedServer(path, maxCount, isFirstPipeInstance);
                         s_servers.Add(path, server);
                     }
 
@@ -310,20 +311,15 @@ internal void Dispose(bool disposing)
                 }
             }
 
-            private SharedServer(string path, int maxCount, PipeOptions pipeOptions)
+            private SharedServer(string path, int maxCount, bool isFirstPipeInstance)
             {
-                bool firstPipeInstance = (pipeOptions & PipeOptions.FirstPipeInstance) != 0;
-                if (!firstPipeInstance)
+                if (!isFirstPipeInstance)
                 {
                     // Binding to an existing path fails, so we need to remove anything left over at this location.
                     // There's of course a race condition here, where it could be recreated by someone else between this
                     // deletion and the bind below, in which case we'll simply let the bind fail and throw.
                     Interop.Sys.Unlink(path); // ignore any failures
                 }
-                else
-                {
-                    throw new ArgumentException();
-                }
 
                 // Start listening for connections on the path.
                 var socket = new Socket(AddressFamily.Unix, SocketType.Stream, ProtocolType.Unspecified);
@@ -332,6 +328,11 @@ private SharedServer(string path, int maxCount, PipeOptions pipeOptions)
                     socket.Bind(new UnixDomainSocketEndPoint(path));
                     socket.Listen(int.MaxValue);
                 }
+                catch (SocketException) when (isFirstPipeInstance)
+                {
+                    socket.Dispose();
+                    throw new UnauthorizedAccessException(SR.Format(SR.UnauthorizedAccess_IODenied_Path, path));
+                }
                 catch
                 {
                     socket.Dispose();

From d42615ea4df237b9569ac1d0ddbd3cb6446dc76b Mon Sep 17 00:00:00 2001
From: Tarun <gtarun047@gmail.com>
Date: Mon, 29 May 2023 19:55:38 +0530
Subject: [PATCH 7/8] Add tests for cross process creation of named pipes

---
 .../IO/Pipes/NamedPipeServerStream.Unix.cs       |  4 +++-
 .../NamedPipeTests/NamedPipeTest.CrossProcess.cs | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
index 8a2970d8f0bf1..2d8e934030ab1 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs
@@ -321,14 +321,16 @@ private SharedServer(string path, int maxCount, bool isFirstPipeInstance)
                     Interop.Sys.Unlink(path); // ignore any failures
                 }
 
+                bool isSocketBound = false;
                 // Start listening for connections on the path.
                 var socket = new Socket(AddressFamily.Unix, SocketType.Stream, ProtocolType.Unspecified);
                 try
                 {
                     socket.Bind(new UnixDomainSocketEndPoint(path));
+                    isSocketBound = true;
                     socket.Listen(int.MaxValue);
                 }
-                catch (SocketException) when (isFirstPipeInstance)
+                catch (SocketException) when (isFirstPipeInstance && !isSocketBound)
                 {
                     socket.Dispose();
                     throw new UnauthorizedAccessException(SR.Format(SR.UnauthorizedAccess_IODenied_Path, path));
diff --git a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CrossProcess.cs b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CrossProcess.cs
index b94f6771f07d4..e01f42f9d27e5 100644
--- a/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CrossProcess.cs
+++ b/src/libraries/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CrossProcess.cs
@@ -103,6 +103,22 @@ public async Task PingPong_Async()
             }
         }
 
+        [ConditionalFact(typeof(RemoteExecutor), nameof(RemoteExecutor.IsSupported))]
+        [SkipOnPlatform(TestPlatforms.LinuxBionic, "SElinux blocks UNIX sockets in our CI environment")]
+        public void NamedPipeOptionsFirstPipeInstance_Throws_WhenNameIsUsedAcrossProcesses()
+        {
+            var uniqueServerName = PipeStreamConformanceTests.GetUniquePipeName();
+            using (var firstServer = new NamedPipeServerStream(uniqueServerName, PipeDirection.In, 2, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance))
+            {
+                RemoteExecutor.Invoke(new Action<string>(CreateFirstPipeInstance_OtherProcess), uniqueServerName).Dispose();
+            }
+        }
+
+        private static void CreateFirstPipeInstance_OtherProcess(string uniqueServerName)
+        {
+            Assert.Throws<UnauthorizedAccessException>(() => new NamedPipeServerStream(uniqueServerName, PipeDirection.In, 2, PipeTransmissionMode.Byte, PipeOptions.FirstPipeInstance));
+        }
+
         private static void PingPong_OtherProcess(string inName, string outName)
         {
             // Create pipes with the supplied names

From 719dbcc17e2eb2526b7eed1fb7436e80178a07d2 Mon Sep 17 00:00:00 2001
From: Tarun047 <32017154+Tarun047@users.noreply.github.com>
Date: Mon, 29 May 2023 19:56:50 +0530
Subject: [PATCH 8/8] Update
 src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs

Co-authored-by: Adam Sitnik <adam.sitnik@gmail.com>
---
 .../src/System/IO/Pipes/NamedPipeServerStream.cs               | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
index 1995823a9b858..04e61475ecc8e 100644
--- a/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
+++ b/src/libraries/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs
@@ -61,8 +61,7 @@ public NamedPipeServerStream(string pipeName, PipeDirection direction, int maxNu
         /// </param>
         /// <param name="options">PipeOption enum: None, Asynchronous, Write-through, or FirstPipeInstance
         /// Win32 note: this gets passed in with dwOpenMode to CreateNamedPipe. Asynchronous corresponds to
-        /// FILE_FLAG_OVERLAPPED option. PipeOptions.FIRST_PIPE_INSTANCE
-        /// is automatically set based on the number of instances specified.
+        /// FILE_FLAG_OVERLAPPED option.
         /// </param>
         /// <param name="inBufferSize">Incoming buffer size, 0 or higher.
         /// Note: this size is always advisory; OS uses a suggestion.