view src/http/ngx_http_busy_lock.h @ 5569:462ae7eedc68 stable-1.4

Fixed TCP_DEFER_ACCEPT handling (ticket #353). Backed out 05a56ebb084a, as it turns out that kernel can return connections without any delay if syncookies are used. This basically means we can't assume anything about connections returned with deferred accept set. To solve original problem the 05a56ebb084a tried to solve, i.e. to don't wait longer than needed if a connection was accepted after deferred accept timeout, this patch changes a timeout set with setsockopt(TCP_DEFER_ACCEPT) to 1 second, unconditionally. This is believed to be enough for speed improvements, and doesn't imply major changes to timeouts used. Note that before 2.6.32 connections were dropped after a timeout. Though it is believed that 1s is still appropriate for kernels before 2.6.32, as previously tcp_synack_retries controlled the actual timeout and 1s results in more than 1 minute actual timeout by default.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 28 Jan 2014 15:40:46 +0400
parents d620f497c50f
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HTTP_BUSY_LOCK_H_INCLUDED_
#define _NGX_HTTP_BUSY_LOCK_H_INCLUDED_


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


typedef struct {
    u_char             *md5_mask;
    char               *md5;
    int                 cacheable;

    int                 busy;
    int                 max_busy;

    int                 waiting;
    int                 max_waiting;

    time_t              timeout;

    ngx_event_mutex_t  *mutex;
} ngx_http_busy_lock_t;


typedef struct {
    time_t         time;
    ngx_event_t   *event;
    void         (*event_handler)(ngx_event_t *ev);
    u_char        *md5;
    int            slot;
} ngx_http_busy_lock_ctx_t;


int ngx_http_busy_lock(ngx_http_busy_lock_t *bl, ngx_http_busy_lock_ctx_t *bc);
int ngx_http_busy_lock_cacheable(ngx_http_busy_lock_t *bl,
                                 ngx_http_busy_lock_ctx_t *bc, int lock);
void ngx_http_busy_unlock(ngx_http_busy_lock_t *bl,
                          ngx_http_busy_lock_ctx_t *bc);

char *ngx_http_set_busy_lock_slot(ngx_conf_t *cf, ngx_command_t *cmd,
                                  void *conf);


#endif /* _NGX_HTTP_BUSY_LOCK_H_INCLUDED_ */