// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the MIT license. // See the LICENSE file in the project root for more information. using System; using System.Threading; using Microsoft.CodeAnalysis; namespace Roslyn.Utilities { internal static class ReaderWriterLockSlimExtensions { internal static ReadLockExiter DisposableRead(this ReaderWriterLockSlim @lock) { return new ReadLockExiter(@lock); } [NonCopyable] internal readonly struct ReadLockExiter : IDisposable { private readonly ReaderWriterLockSlim _lock; internal ReadLockExiter(ReaderWriterLockSlim @lock) { _lock = @lock; @lock.EnterReadLock(); } public void Dispose() { _lock.ExitReadLock(); } } internal static UpgradeableReadLockExiter DisposableUpgradeableRead(this ReaderWriterLockSlim @lock) { return new UpgradeableReadLockExiter(@lock); } [NonCopyable] internal readonly struct UpgradeableReadLockExiter : IDisposable { private 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 DisposableWrite(this ReaderWriterLockSlim @lock) { return new WriteLockExiter(@lock); } [NonCopyable] internal readonly struct WriteLockExiter : IDisposable { private readonly ReaderWriterLockSlim _lock; internal WriteLockExiter(ReaderWriterLockSlim @lock) { _lock = @lock; @lock.EnterWriteLock(); } public void Dispose() { _lock.ExitWriteLock(); } } internal static void AssertCanRead(this ReaderWriterLockSlim @lock) { if (!@lock.IsReadLockHeld && !@lock.IsUpgradeableReadLockHeld && !@lock.IsWriteLockHeld) { throw new InvalidOperationException(); } } internal static void AssertCanWrite(this ReaderWriterLockSlim @lock) { if (!@lock.IsWriteLockHeld) { throw new InvalidOperationException(); } } } } |