Cache: send conditional requests only for cached 200/206 responses. RFC7232 says: The 304 (Not Modified) status code indicates that a conditional GET or HEAD request has been received and would have resulted in a 200 (OK) response if it were not for the fact that the condition evaluated to false. which means that there is no reason to send requests with "If-None-Match" and/or "If-Modified-Since" headers for responses cached with other status codes. Also, sending conditional requests for responses cached with other status codes could result in a strange behavior, e.g. upstream server returning 304 Not Modified for cached 404 Not Found responses, etc. Signed-off-by: Piotr Sikora <piotr@cloudflare.com>

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>


ngx_queue_t  ngx_posted_accept_events;
ngx_queue_t  ngx_posted_events;


void
ngx_event_process_posted(ngx_cycle_t *cycle, ngx_queue_t *posted)
{
    ngx_queue_t  *q;
    ngx_event_t  *ev;

    while (!ngx_queue_empty(posted)) {

        q = ngx_queue_head(posted);
        ev = ngx_queue_data(q, ngx_event_t, queue);

        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                      "posted event %p", ev);

        ngx_delete_posted_event(ev);

        ev->handler(ev);
    }
}