view src/event/ngx_event_mutex.c @ 5405:620808518349

SPDY: ignore priority when queuing blocked frames. With this change all such frames will be added in front of the output queue, and will be sent first. It prevents HOL blocking when response with higher priority is blocked by response with lower priority in the middle of the queue because the order of their SYN_REPLY frames cannot be changed. Proposed by Yury Kirpichev.
author Valentin Bartenev <vbart@nginx.com>
date Tue, 01 Oct 2013 00:14:37 +0400
parents d620f497c50f
children 3377f9459e99
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


ngx_int_t ngx_event_mutex_timedlock(ngx_event_mutex_t *m, ngx_msec_t timer,
                                    ngx_event_t *ev)
{
    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
                   "lock event mutex %p lock:%XD", m, m->lock);

    if (m->lock) {

        if (m->events == NULL) {
            m->events = ev;

        } else {
            m->last->next = ev;
        }

        m->last = ev;
        ev->next = NULL;

#if (NGX_THREADS0)
        ev->light = 1;
#endif

        ngx_add_timer(ev, timer);

        return NGX_AGAIN;
    }

    m->lock = 1;

    return NGX_OK;
}


ngx_int_t ngx_event_mutex_unlock(ngx_event_mutex_t *m, ngx_log_t *log)
{
    ngx_event_t  *ev;

    if (m->lock == 0) {
        ngx_log_error(NGX_LOG_ALERT, log, 0,
                      "tring to unlock the free event mutex %p", m);
        return NGX_ERROR;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, log, 0,
                   "unlock event mutex %p, next event: %p", m, m->events);

    m->lock = 0;

    if (m->events) {
        ev = m->events;
        m->events = ev->next;

        ev->next = (ngx_event_t *) ngx_posted_events;
        ngx_posted_events = ev;
    }

    return NGX_OK;
}