AllocatedLock.cs

    public struct AllocatedLock : IDisposable
    {
        private readonly object _toLock;

        public AllocatedLock(object toLock)
        {
            _toLock = toLock;
        }

        public void Dispose()
        {
            Monitor.Exit(_toLock);
        }
    }
    public static AllocatedLock Lock(this object toLock, TimeSpan timeout)
    {
        if (Monitor.TryEnter(toLock, timeout))
        {
            return new AllocatedLock(toLock);
        }
        else
        {
            throw new TimeoutException(string.Format("Failed to get lock within {0}", timeout));
        }
    }