php:

<?
public class HttpServer : IDisposable
{
    readonly HttpListener http;
    readonly Semaphore govern =
        new Semaphore(8, 8);
    public bool IsListening 
        => http.IsListening;

    public HttpServer(
        string prefix,
        Action<
            HttpListenerRequest, 
            HttpListenerResponse> handler)
    {
        http = new HttpListener();
        http.Prefixes.Add(prefix);

        void Accept(IAsyncResult ar)
        {
            var c = http.EndGetContext(ar);
            Task.Factory.StartNew(() =>
            {
                using (var resp = c.Response)
                    handler(c.Request, c.Response);
            });
            govern.Release();
        }

        http.Start();

        new Thread(() =>
        {
            while (http.IsListening)
            {
                govern.WaitOne();
                http.BeginGetContext(Accept, null);
            }
        }).Start();
    }

    public void Dispose()
    {
        ((IDisposable)http).Dispose();
        govern.Dispose();
    }
}?>