[Core] Add ReaderWriterLockSlim extensions for disposable locking

2 files changed, 91 insertions, 0 deletions

diff --git a/main/src/core/MonoDevelop.Core/CoreExtensions.ReaderWriterLockSlim.cs b/main/src/core/MonoDevelop.Core/CoreExtensions.ReaderWriterLockSlim.cs
new file mode 100644
index 0000000000..b4805ff230
--- /dev/null
+++ b/main/src/core/MonoDevelop.Core/CoreExtensions.ReaderWriterLockSlim.cs
@@ -0,0 +1,90 @@
+//
+// CoreExtensions.ReaderWriterLockSlim.cs
+//
+// Author:
+//       Marius Ungureanu <maungu@microsoft.com>
+//
+// Copyright (c) 2019 Microsoft Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System;
+using System.Threading;
+
+namespace System
+{
+	public static partial class CoreExtensions
+	{
+		internal static ReadLockExiter Read (this ReaderWriterLockSlim @lock)
+			=> new ReadLockExiter (@lock);
+
+		internal readonly struct ReadLockExiter : IDisposable
+		{
+			readonly ReaderWriterLockSlim _lock;
+
+			internal ReadLockExiter (ReaderWriterLockSlim @lock)
+			{
+				_lock = @lock;
+				@lock.EnterReadLock ();
+			}
+
+			public void Dispose () => _lock.ExitReadLock ();
+		}
+
+		internal static UpgradeableReadLockExiter UpgradeableRead (this ReaderWriterLockSlim @lock)
+			=> new UpgradeableReadLockExiter (@lock);
+
+		internal readonly struct UpgradeableReadLockExiter : IDisposable
+		{
+			readonly ReaderWriterLockSlim _lock;
+
+			internal UpgradeableReadLockExiter (ReaderWriterLockSlim @lock)
+			{
+				_lock = @lock;
+				@lock.EnterUpgradeableReadLock ();
+			}
+
+			public void Dispose ()
+			{
+				if (_lock.IsWriteLockHeld) {
+					_lock.ExitWriteLock ();
+				}
+
+				_lock.ExitUpgradeableReadLock ();
+			}
+
+			public void EnterWrite () => _lock.EnterWriteLock ();
+		}
+
+		internal static WriteLockExiter Write (this ReaderWriterLockSlim @lock)
+			=> new WriteLockExiter (@lock);
+
+		internal readonly struct WriteLockExiter : IDisposable
+		{
+			readonly ReaderWriterLockSlim _lock;
+
+			internal WriteLockExiter (ReaderWriterLockSlim @lock)
+			{
+				_lock = @lock;
+				@lock.EnterWriteLock ();
+			}
+
+			public void Dispose () => _lock.ExitWriteLock ();
+		}
+	}
+}
diff --git a/main/src/core/MonoDevelop.Core/MonoDevelop.Core.csproj b/main/src/core/MonoDevelop.Core/MonoDevelop.Core.csproj
index e1ec35552d..63d61dadf9 100644
--- a/main/src/core/MonoDevelop.Core/MonoDevelop.Core.csproj
+++ b/main/src/core/MonoDevelop.Core/MonoDevelop.Core.csproj
@@ -741,6 +741,7 @@
     <Compile Include="CoreExtensions.Memoize.cs" />
     <Compile Include="CoreExtensions.EventHandlers.cs" />
     <Compile Include="CoreExtensions.Array.cs" />
+    <Compile Include="CoreExtensions.ReaderWriterLockSlim.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="BuildVariables.cs.in" />