Pull ConcurrentList<T> from ArchiBot

Previous implementation of ConcurrentSortedHashSet was prone to deadlocks and very suboptimal, on top of no guarantee to do what it claimed to.

ArchiSteamFarm/Collections/ConcurrentList.cs

@@ -0,0 +1,122 @@
+//     _                _      _  ____   _                           _____
+//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
+//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
+//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
+// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
+// |
+// Copyright 2015-2019 Łukasz "JustArchi" Domeradzki
+// Contact: JustArchi@JustArchi.net
+// |
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// |
+// http://www.apache.org/licenses/LICENSE-2.0
+// |
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using JetBrains.Annotations;
+using Nito.AsyncEx;
+
+namespace ArchiSteamFarm.Collections {
+	internal sealed class ConcurrentList<T> : IList<T>, IReadOnlyList<T> {
+		public bool IsReadOnly => false;
+
+		internal int Count {
+			get {
+				using (Lock.ReaderLock()) {
+					return BackingCollection.Count;
+				}
+			}
+		}
+
+		private readonly List<T> BackingCollection = new List<T>();
+		private readonly AsyncReaderWriterLock Lock = new AsyncReaderWriterLock();
+
+		int ICollection<T>.Count => Count;
+		int IReadOnlyCollection<T>.Count => Count;
+
+		public T this[int index] {
+			get {
+				using (Lock.ReaderLock()) {
+					return BackingCollection[index];
+				}
+			}
+
+			set {
+				using (Lock.WriterLock()) {
+					BackingCollection[index] = value;
+				}
+			}
+		}
+
+		public void Add(T item) {
+			using (Lock.WriterLock()) {
+				BackingCollection.Add(item);
+			}
+		}
+
+		public void Clear() {
+			using (Lock.WriterLock()) {
+				BackingCollection.Clear();
+			}
+		}
+
+		public bool Contains(T item) {
+			using (Lock.ReaderLock()) {
+				return BackingCollection.Contains(item);
+			}
+		}
+
+		public void CopyTo(T[] array, int arrayIndex) {
+			using (Lock.ReaderLock()) {
+				BackingCollection.CopyTo(array, arrayIndex);
+			}
+		}
+
+		[NotNull]
+		[SuppressMessage("ReSharper", "AnnotationRedundancyInHierarchy")]
+		public IEnumerator<T> GetEnumerator() => new ConcurrentEnumerator<T>(BackingCollection, Lock.ReaderLock());
+
+		public int IndexOf(T item) {
+			using (Lock.ReaderLock()) {
+				return BackingCollection.IndexOf(item);
+			}
+		}
+
+		public void Insert(int index, T item) {
+			using (Lock.WriterLock()) {
+				BackingCollection.Insert(index, item);
+			}
+		}
+
+		public bool Remove(T item) {
+			using (Lock.WriterLock()) {
+				return BackingCollection.Remove(item);
+			}
+		}
+
+		public void RemoveAt(int index) {
+			using (Lock.WriterLock()) {
+				BackingCollection.RemoveAt(index);
+			}
+		}
+
+		[NotNull]
+		[SuppressMessage("ReSharper", "AnnotationRedundancyInHierarchy")]
+		IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+		internal void AddRange([NotNull] IEnumerable<T> collection) {
+			using (Lock.WriterLock()) {
+				BackingCollection.AddRange(collection);
+			}
+		}
+	}
+}