Files
Umbraco-CMS/src/Umbraco.Core/Extensions/WaitHandleExtensions.cs

44 lines
1.7 KiB
C#

// Copyright (c) Umbraco.
// See LICENSE for more details.
namespace Umbraco.Extensions;
public static class WaitHandleExtensions
{
// http://stackoverflow.com/questions/25382583/waiting-on-a-named-semaphore-with-waitone100-vs-waitone0-task-delay100
// http://blog.nerdbank.net/2011/07/c-await-for-waithandle.html
// F# has a AwaitWaitHandle method that accepts a time out... and seems pretty complex...
// version below should be OK
public static Task WaitOneAsync(this WaitHandle handle, int millisecondsTimeout = Timeout.Infinite)
{
var tcs = new TaskCompletionSource<object?>();
var callbackHandleInitLock = new Lock();
lock (callbackHandleInitLock)
{
RegisteredWaitHandle? callbackHandle = null;
// ReSharper disable once RedundantAssignment
callbackHandle = ThreadPool.RegisterWaitForSingleObject(
handle,
(state, timedOut) =>
{
// TODO: We aren't checking if this is timed out
tcs.SetResult(null);
// we take a lock here to make sure the outer method has completed setting the local variable callbackHandle.
lock (callbackHandleInitLock)
{
// ReSharper disable once PossibleNullReferenceException
// ReSharper disable once AccessToModifiedClosure
callbackHandle?.Unregister(null);
}
},
/*state:*/ null,
/*millisecondsTimeOutInterval:*/ millisecondsTimeout,
/*executeOnlyOnce:*/ true);
}
return tcs.Task;
}
}