[WIP][GSoC] CoreRT changes to import filestream into mono

src/System.Private.CoreLib/shared/Interop/Unix/Interop.IOErrors.cs

@@ -3,7 +3,11 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+#if MONO
+using System.Diagnostics.Private;
+#else
 using System.Diagnostics;
+#endif
 using System.IO;
 using System.Runtime.InteropServices;
 using Microsoft.Win32.SafeHandles;

src/System.Private.CoreLib/shared/Microsoft/Win32/SafeHandles/SafeFileHandle.Unix.cs

@@ -3,6 +3,11 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+#if MONO
+using System.Diagnostics.Private;
+#else
+using System.Diagnostics;
+#endif
 using System.Diagnostics;
 using System.Runtime.InteropServices;
 

src/System.Private.CoreLib/shared/System/Buffers/ArrayPool.cs

@@ -34,7 +34,9 @@ public abstract class ArrayPool<T>
         /// The shared pool instance is created lazily on first access.
         /// </remarks>
         public static ArrayPool<T> Shared { get; } =
+#if !MONO
             typeof(T) == typeof(byte) || typeof(T) == typeof(char) ? new TlsOverPerCoreLockedStacksArrayPool<T>() :
+#endif
             Create();
 
         /// <summary>

src/System.Private.CoreLib/shared/System/Buffers/Utilities.cs

@@ -3,6 +3,9 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
+#if MONO
+using System.Diagnostics.Private;
+#endif
 using System.Runtime.CompilerServices;
 
 namespace System.Buffers

src/System.Private.CoreLib/shared/System/IO/FileStream.Unix.cs

@@ -4,6 +4,9 @@
 
 using Microsoft.Win32.SafeHandles;
 using System.Diagnostics;
+#if MONO
+using System.Diagnostics.Private;
+#endif
 using System.Threading;
 using System.Threading.Tasks;
 

src/System.Private.CoreLib/shared/System/IO/FileStream.cs

@@ -5,6 +5,9 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Win32.SafeHandles;
+#if MONO
+using System.Diagnostics.Private;
+#endif
 using System.Diagnostics;
 
 namespace System.IO
@@ -161,7 +164,8 @@ public FileStream(string path, FileMode mode, FileAccess access, FileShare share
                 throw new ArgumentOutOfRangeException(badArg, SR.ArgumentOutOfRange_Enum);
 
             // NOTE: any change to FileOptions enum needs to be matched here in the error validation
-            if (options != FileOptions.None && (options & ~(FileOptions.WriteThrough | FileOptions.Asynchronous | FileOptions.RandomAccess | FileOptions.DeleteOnClose | FileOptions.SequentialScan | FileOptions.Encrypted | (FileOptions)0x20000000 /* NoBuffering */)) != 0)
+            if (options != FileOptions.None && (options & ~(FileOptions.WriteThrough | FileOptions.Asynchronous | FileOptions.RandomAccess | FileOptions.DeleteOnClose 
+                        | FileOptions.SequentialScan | FileOptions.Encrypted | (FileOptions)0x20000000 /* NoBuffering */ | (FileOptions)1)) != 0)
                 throw new ArgumentOutOfRangeException(nameof(options), SR.ArgumentOutOfRange_Enum);
 
             if (bufferSize <= 0)

src/System.Private.CoreLib/shared/System/IO/PathInternal.Unix.cs

@@ -3,6 +3,9 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
+#if MONO
+using System.Diagnostics.Private;
+#endif
 using System.Text;
 
 namespace System.IO

src/System.Private.CoreLib/shared/System/IO/PathInternal.cs

@@ -3,6 +3,9 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
+#if MONO
+using System.Diagnostics.Private;
+#endif
 using System.Text;
 
 namespace System.IO

src/System.Private.CoreLib/src/System/IO/Stream.cs

@@ -3,6 +3,10 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
+#if MONO
+using System.Diagnostics.Private;
+using System.Runtime.ExceptionServices;
+#endif
 using System.Diagnostics.Contracts;
 using System.Threading;
 using System.Threading.Tasks;
@@ -738,5 +742,90 @@ public override void EndWrite(IAsyncResult asyncResult)
                     _stream.EndWrite(asyncResult);
             }
         }
+
+#if MONO
+        /// <summary>Used as the IAsyncResult object when using asynchronous IO methods on the base Stream class.</summary>
+        internal sealed class SynchronousAsyncResult : IAsyncResult {
+
+            private readonly Object _stateObject;            
+            private readonly bool _isWrite;
+            private ManualResetEvent _waitHandle;
+            private ExceptionDispatchInfo _exceptionInfo;
+
+            private bool _endXxxCalled;
+            private Int32 _bytesRead;
+
+            internal SynchronousAsyncResult(Int32 bytesRead, Object asyncStateObject) {
+                _bytesRead = bytesRead;
+                _stateObject = asyncStateObject;
+                //_isWrite = false;
+            }
+
+            internal SynchronousAsyncResult(Object asyncStateObject) {
+                _stateObject = asyncStateObject;
+                _isWrite = true;
+            }
+
+            internal SynchronousAsyncResult(Exception ex, Object asyncStateObject, bool isWrite) {
+                _exceptionInfo = ExceptionDispatchInfo.Capture(ex);
+                _stateObject = asyncStateObject;
+                _isWrite = isWrite;                
+            }
+
+            public bool IsCompleted {
+                // We never hand out objects of this type to the user before the synchronous IO completed:
+                get { return true; }
+            }
+
+            public WaitHandle AsyncWaitHandle {
+                get {
+                    return LazyInitializer.EnsureInitialized(ref _waitHandle, () => new ManualResetEvent(true));                    
+                }
+            }
+
+            public Object AsyncState {
+                get { return _stateObject; }
+            }
+
+            public bool CompletedSynchronously {
+                get { return true; }
+            }
+
+            internal void ThrowIfError() {
+                if (_exceptionInfo != null)
+                    _exceptionInfo.Throw();
+            }                        
+
+            internal static Int32 EndRead(IAsyncResult asyncResult) {
+
+                SynchronousAsyncResult ar = asyncResult as SynchronousAsyncResult;
+                if (ar == null || ar._isWrite)
+                    __Error.WrongAsyncResult();
+
+                if (ar._endXxxCalled)
+                    __Error.EndReadCalledTwice();
+
+                ar._endXxxCalled = true;
+
+                ar.ThrowIfError();
+                return ar._bytesRead;
+            }
+
+            internal static void EndWrite(IAsyncResult asyncResult) {
+
+                SynchronousAsyncResult ar = asyncResult as SynchronousAsyncResult;
+                if (ar == null || !ar._isWrite)
+                    __Error.WrongAsyncResult();
+
+                if (ar._endXxxCalled)
+                    __Error.EndWriteCalledTwice();
+
+                ar._endXxxCalled = true;
+
+                ar.ThrowIfError();
+            }
+        }   // class SynchronousAsyncResult
+#endif
+
     }
 }