Merge pull request #2875 from ianhays/pipes_serverinstances

Removed the Unix restriction on MaxNumberOfServerInstances

Author: Ian Hays

src/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Unix.cs

@@ -31,7 +31,7 @@ private void Create(string pipeName, PipeDirection direction, int maxNumberOfSer
             Debug.Assert(direction >= PipeDirection.In && direction <= PipeDirection.InOut, "invalid pipe direction");
             Debug.Assert(inBufferSize >= 0, "inBufferSize is negative");
             Debug.Assert(outBufferSize >= 0, "outBufferSize is negative");
-            Debug.Assert((maxNumberOfServerInstances >= 1 && maxNumberOfServerInstances <= 254) || (maxNumberOfServerInstances == MaxAllowedServerInstances), "maxNumberOfServerInstances is invalid");
+            Debug.Assert((maxNumberOfServerInstances >= 1) || (maxNumberOfServerInstances == MaxAllowedServerInstances), "maxNumberOfServerInstances is invalid");
             Debug.Assert(transmissionMode >= PipeTransmissionMode.Byte && transmissionMode <= PipeTransmissionMode.Message, "transmissionMode is out of range");
 
             if (transmissionMode == PipeTransmissionMode.Message)
@@ -132,6 +132,16 @@ public String GetImpersonationUserName()
             throw new PlatformNotSupportedException();
         }
 
+        private void ValidateMaxNumberOfServerInstances(int maxNumberOfServerInstances)
+        {
+            // Since Unix has no notion of Max allowed Server Instances per named pipe, we don't enforce an
+            // upper bound on maxNumberOfServerInstances.
+            if ((maxNumberOfServerInstances < 1) && (maxNumberOfServerInstances != MaxAllowedServerInstances))
+            {
+                throw new ArgumentOutOfRangeException("maxNumberOfServerInstances", SR.ArgumentOutOfRange_MaxNumServerInstances);
+            }
+        }
+
         // -----------------------------
         // ---- PAL layer ends here ----
         // -----------------------------

src/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.Windows.cs

@@ -298,5 +298,15 @@ private void CheckConnectOperationsServerWithHandle()
             }
             CheckConnectOperationsServer();
         }
+
+        private void ValidateMaxNumberOfServerInstances(int maxNumberOfServerInstances)
+        {
+            // win32 allows fixed values of 1-254 or 255 to mean max allowed by system. We expose 255 as -1 (unlimited)
+            // through the MaxAllowedServerInstances constant. This is consistent e.g. with -1 as infinite timeout, etc
+            if ((maxNumberOfServerInstances < 1 || maxNumberOfServerInstances > 254) && (maxNumberOfServerInstances != MaxAllowedServerInstances))
+            {
+                throw new ArgumentOutOfRangeException("maxNumberOfServerInstances", SR.ArgumentOutOfRange_MaxNumServerInstances);
+            }
+        }
     }
 }

src/System.IO.Pipes/src/System/IO/Pipes/NamedPipeServerStream.cs

@@ -61,8 +61,8 @@ public NamedPipeServerStream(String pipeName, PipeDirection direction, int maxNu
         /// Win32 note: this gets OR'd into dwOpenMode to CreateNamedPipe
         /// </param>
         /// <param name="maxNumberOfServerInstances">Maximum number of server instances. Specify a fixed value between 
-        /// 1 and 254, or use NamedPipeServerStream.MaxAllowedServerInstances to use the maximum amount allowed by 
-        /// system resources.</param>
+        /// 1 and 254 (Windows)/greater than 1 (Unix), or use NamedPipeServerStream.MaxAllowedServerInstances to use the 
+        /// maximum amount allowed by system resources.</param>
         /// <param name="transmissionMode">Byte mode or message mode.
         /// 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.
@@ -102,12 +102,7 @@ private NamedPipeServerStream(String pipeName, PipeDirection direction, int maxN
             {
                 throw new ArgumentOutOfRangeException("inBufferSize", SR.ArgumentOutOfRange_NeedNonNegNum);
             }
-            // win32 allows fixed values of 1-254 or 255 to mean max allowed by system. We expose 255 as -1 (unlimited)
-            // through the MaxAllowedServerInstances constant. This is consistent e.g. with -1 as infinite timeout, etc
-            if ((maxNumberOfServerInstances < 1 || maxNumberOfServerInstances > 254) && (maxNumberOfServerInstances != MaxAllowedServerInstances))
-            {
-                throw new ArgumentOutOfRangeException("maxNumberOfServerInstances", SR.ArgumentOutOfRange_MaxNumServerInstances);
-            }
+            ValidateMaxNumberOfServerInstances(maxNumberOfServerInstances);
             // inheritability will always be None since this private constructor is only called from other constructors from which
             // inheritability is always set to None. Desktop has a public constructor to allow setting it to something else, but Core
             // doesnt.

src/System.IO.Pipes/tests/NamedPipeTests/NamedPipeTest.CreateServer.cs

@@ -89,16 +89,42 @@ public static void InvalidPipeDirection_Throws_ArgumentOutOfRangeException()
             Assert.Throws<ArgumentOutOfRangeException>("direction", () => new NamedPipeServerStream("tempx", (PipeDirection)123, 1, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0));
         }
 
+        [Theory]
+        [InlineData(0)]
+        [InlineData(-2)]
+        public static void InvalidServerInstances_Throws_ArgumentOutOfRangeException(int numberOfServerInstances)
+        {
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", PipeDirection.In, numberOfServerInstances));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", PipeDirection.In, numberOfServerInstances, PipeTransmissionMode.Byte));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", PipeDirection.In, numberOfServerInstances, PipeTransmissionMode.Byte, PipeOptions.None));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", PipeDirection.In, numberOfServerInstances, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0));
+        }
+
         [Theory]
         [InlineData(PipeDirection.In)]
         [InlineData(PipeDirection.InOut)]
         [InlineData(PipeDirection.Out)]
-        public static void InvalidServerInstances_Throws_ArgumentOutOfRangeException(PipeDirection direction)
+        [PlatformSpecific(PlatformID.AnyUnix)]
+        public static void Unix_ServerInstancesOver254_Allowed(PipeDirection direction)
+        {
+            // MaxNumberOfServerInstances has functionality on Unix and as such is not upper bound.
+            new NamedPipeServerStream(GetUniquePipeName(), direction, 255).Dispose();
+            new NamedPipeServerStream(GetUniquePipeName(), direction, 255, PipeTransmissionMode.Byte).Dispose();
+            new NamedPipeServerStream(GetUniquePipeName(), direction, 255, PipeTransmissionMode.Byte, PipeOptions.None).Dispose();
+            new NamedPipeServerStream(GetUniquePipeName(), direction, 255, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0).Dispose();
+        }
+
+        [Theory]
+        [InlineData(PipeDirection.In)]
+        [InlineData(PipeDirection.InOut)]
+        [InlineData(PipeDirection.Out)]
+        [PlatformSpecific(PlatformID.Windows)]
+        public static void Windows_ServerInstancesOver254_Throws_ArgumentOutOfRangeException(PipeDirection direction)
         {
-            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 0));
-            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 0, PipeTransmissionMode.Byte));
-            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 0, PipeTransmissionMode.Byte, PipeOptions.None));
-            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 0, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 255));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 255, PipeTransmissionMode.Byte));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 255, PipeTransmissionMode.Byte, PipeOptions.None));
+            Assert.Throws<ArgumentOutOfRangeException>("maxNumberOfServerInstances", () => new NamedPipeServerStream("temp3", direction, 255, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0));
         }
 
         [Theory]