Cancel ongoing ngx_http_request_t (no replies)

So I'm continuing to work on my simple timeout module: http://forum.nginx.org/read.php?2,259019

Now, when timer elapses, I want to cancel ongoing http request, here's my timer handler:

static void simple_timeout_handler(ngx_event_t* timeout_event)
{
ngx_http_request_t* request = (ngx_http_request_t*)timeout_event->data;

ngx_log_debug0(NGX_LOG_DEBUG_HTTP, timeout_event->log, 0,
"SIMPLE TIMEOUT TIMER END");

ngx_http_finalize_request(request, NGX_HTTP_REQUEST_TIME_OUT); // this does not seem to work,
// as request stays in progress
}

This does not work as request still continues to be in progress. Is it possible to terminate it immediately, and return http timeout response?