In HttpProtocol, we have the following thread-unsafe fields:

	// FIXME the following fields need to be made thread-safe
	private String inputId = null;
	private MultiPartFormDataParser multiPartFormDataParser = null;
	private String encoding = null;
	private String requestFormat = null;
	private String requestCharset = null;
	private boolean headRequest = false;

This is a problem when isThreadSafe() == true because of data races when dealing with concurrent HTTP requests.

@mwallnoefer would it be possible to at least group all of these parameters into an enclosing object (a private HttpExchangeContext class or something like that?). That way we can start either:

• Deactivating content negotiation & co. when isThreadSafe() == true; or, even better,
• Have a concurrent hashmap to keep track of these context objects per request id.