/* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*
*  Licensed to Elasticsearch B.V. under one or more contributor
*  license agreements. See the NOTICE file distributed with
*  this work for additional information regarding copyright
*  ownership. Elasticsearch B.V. licenses this file to you 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;
using System.Threading;

namespace OpenSearch.Net
{
	/// <summary>
	/// A convenience API for interacting with System.Threading.Timer in a way
	/// that doesn't capture the ExecutionContext. We should be using this (or equivalent)
	/// everywhere we use timers to avoid rooting any values stored in asynclocals.
	/// <para> https://github.com/dotnet/runtime/blob/master/src/libraries/Common/src/Extensions/ValueStopwatch/ValueStopwatch.cs </para>
	/// </summary>
	internal static class NonCapturingTimer
	{
		public static Timer Create(TimerCallback callback, object state, TimeSpan dueTime, TimeSpan period)
		{
			if (callback == null) throw new ArgumentNullException(nameof(callback));

			// Don't capture the current ExecutionContext and its AsyncLocals onto the timer
			var restoreFlow = false;
			try
			{
				if (ExecutionContext.IsFlowSuppressed()) return new Timer(callback, state, dueTime, period);

				ExecutionContext.SuppressFlow();
				restoreFlow = true;

				return new Timer(callback, state, dueTime, period);
			}
			finally
			{
				// Restore the current ExecutionContext
				if (restoreFlow) ExecutionContext.RestoreFlow();
			}
		}
	}
}