open fun afterConcurrentHandlingStarted(request: HttpServletRequest, response: HttpServletResponse, handler: Any): Unit
Called instead of postHandle and afterCompletion when the handler is being executed concurrently.
Implementations may use the provided request and response but should avoid modifying them in ways that would conflict with the concurrent execution of the handler. A typical use of this method would be to clean up thread-local variables.
response - the current response
handler - the handler (or HandlerMethod) that started async execution, for type and/or instance examination