view src/core/ngx_connection.h @ 6153:4f6efabcb09b

The "reuseport" option of the "listen" directive. When configured, an individual listen socket on a given address is created for each worker process. This allows to reduce in-kernel lock contention on configurations with high accept rates, resulting in better performance. As of now it works on Linux and DragonFly BSD. Note that on Linux incoming connection requests are currently tied up to a specific listen socket, and if some sockets are closed, connection requests will be reset, see https://lwn.net/Articles/542629/. With nginx, this may happen if the number of worker processes is reduced. There is no such problem on DragonFly BSD. Based on previous work by Sepherosa Ziehau and Yingqi Lu.
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 20 May 2015 15:51:56 +0300
parents 187aa751ad62
children 5e6142609e48
line wrap: on
line source


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


#ifndef _NGX_CONNECTION_H_INCLUDED_
#define _NGX_CONNECTION_H_INCLUDED_


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


typedef struct ngx_listening_s  ngx_listening_t;

struct ngx_listening_s {
    ngx_socket_t        fd;

    struct sockaddr    *sockaddr;
    socklen_t           socklen;    /* size of sockaddr */
    size_t              addr_text_max_len;
    ngx_str_t           addr_text;

    int                 type;

    int                 backlog;
    int                 rcvbuf;
    int                 sndbuf;
#if (NGX_HAVE_KEEPALIVE_TUNABLE)
    int                 keepidle;
    int                 keepintvl;
    int                 keepcnt;
#endif

    /* handler of accepted connection */
    ngx_connection_handler_pt   handler;

    void               *servers;  /* array of ngx_http_in_addr_t, for example */

    ngx_log_t           log;
    ngx_log_t          *logp;

    size_t              pool_size;
    /* should be here because of the AcceptEx() preread */
    size_t              post_accept_buffer_size;
    /* should be here because of the deferred accept */
    ngx_msec_t          post_accept_timeout;

    ngx_listening_t    *previous;
    ngx_connection_t   *connection;

    ngx_uint_t          worker;

    unsigned            open:1;
    unsigned            remain:1;
    unsigned            ignore:1;

    unsigned            bound:1;       /* already bound */
    unsigned            inherited:1;   /* inherited from previous process */
    unsigned            nonblocking_accept:1;
    unsigned            listen:1;
    unsigned            nonblocking:1;
    unsigned            shared:1;    /* shared between threads or processes */
    unsigned            addr_ntop:1;

#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
    unsigned            ipv6only:1;
#endif
#if (NGX_HAVE_REUSEPORT)
    unsigned            reuseport:1;
    unsigned            add_reuseport:1;
#endif
    unsigned            keepalive:2;

#if (NGX_HAVE_DEFERRED_ACCEPT)
    unsigned            deferred_accept:1;
    unsigned            delete_deferred:1;
    unsigned            add_deferred:1;
#ifdef SO_ACCEPTFILTER
    char               *accept_filter;
#endif
#endif
#if (NGX_HAVE_SETFIB)
    int                 setfib;
#endif

#if (NGX_HAVE_TCP_FASTOPEN)
    int                 fastopen;
#endif

};


typedef enum {
     NGX_ERROR_ALERT = 0,
     NGX_ERROR_ERR,
     NGX_ERROR_INFO,
     NGX_ERROR_IGNORE_ECONNRESET,
     NGX_ERROR_IGNORE_EINVAL
} ngx_connection_log_error_e;


typedef enum {
     NGX_TCP_NODELAY_UNSET = 0,
     NGX_TCP_NODELAY_SET,
     NGX_TCP_NODELAY_DISABLED
} ngx_connection_tcp_nodelay_e;


typedef enum {
     NGX_TCP_NOPUSH_UNSET = 0,
     NGX_TCP_NOPUSH_SET,
     NGX_TCP_NOPUSH_DISABLED
} ngx_connection_tcp_nopush_e;


#define NGX_LOWLEVEL_BUFFERED  0x0f
#define NGX_SSL_BUFFERED       0x01
#define NGX_SPDY_BUFFERED      0x02


struct ngx_connection_s {
    void               *data;
    ngx_event_t        *read;
    ngx_event_t        *write;

    ngx_socket_t        fd;

    ngx_recv_pt         recv;
    ngx_send_pt         send;
    ngx_recv_chain_pt   recv_chain;
    ngx_send_chain_pt   send_chain;

    ngx_listening_t    *listening;

    off_t               sent;

    ngx_log_t          *log;

    ngx_pool_t         *pool;

    struct sockaddr    *sockaddr;
    socklen_t           socklen;
    ngx_str_t           addr_text;

    ngx_str_t           proxy_protocol_addr;

#if (NGX_SSL)
    ngx_ssl_connection_t  *ssl;
#endif

    struct sockaddr    *local_sockaddr;
    socklen_t           local_socklen;

    ngx_buf_t          *buffer;

    ngx_queue_t         queue;

    ngx_atomic_uint_t   number;

    ngx_uint_t          requests;

    unsigned            buffered:8;

    unsigned            log_error:3;     /* ngx_connection_log_error_e */

    unsigned            unexpected_eof:1;
    unsigned            timedout:1;
    unsigned            error:1;
    unsigned            destroyed:1;

    unsigned            idle:1;
    unsigned            reusable:1;
    unsigned            close:1;

    unsigned            sendfile:1;
    unsigned            sndlowat:1;
    unsigned            tcp_nodelay:2;   /* ngx_connection_tcp_nodelay_e */
    unsigned            tcp_nopush:2;    /* ngx_connection_tcp_nopush_e */

    unsigned            need_last_buf:1;

#if (NGX_HAVE_IOCP)
    unsigned            accept_context_updated:1;
#endif

#if (NGX_HAVE_AIO_SENDFILE)
    unsigned            busy_count:2;
#endif

#if (NGX_THREADS)
    ngx_thread_task_t  *sendfile_task;
#endif
};


#define ngx_set_connection_log(c, l)                                         \
                                                                             \
    c->log->file = l->file;                                                  \
    c->log->next = l->next;                                                  \
    c->log->writer = l->writer;                                              \
    c->log->wdata = l->wdata;                                                \
    if (!(c->log->log_level & NGX_LOG_DEBUG_CONNECTION)) {                   \
        c->log->log_level = l->log_level;                                    \
    }


ngx_listening_t *ngx_create_listening(ngx_conf_t *cf, void *sockaddr,
    socklen_t socklen);
ngx_int_t ngx_clone_listening(ngx_conf_t *cf, ngx_listening_t *ls);
ngx_int_t ngx_set_inherited_sockets(ngx_cycle_t *cycle);
ngx_int_t ngx_open_listening_sockets(ngx_cycle_t *cycle);
void ngx_configure_listening_sockets(ngx_cycle_t *cycle);
void ngx_close_listening_sockets(ngx_cycle_t *cycle);
void ngx_close_connection(ngx_connection_t *c);
ngx_int_t ngx_connection_local_sockaddr(ngx_connection_t *c, ngx_str_t *s,
    ngx_uint_t port);
ngx_int_t ngx_connection_error(ngx_connection_t *c, ngx_err_t err, char *text);

ngx_connection_t *ngx_get_connection(ngx_socket_t s, ngx_log_t *log);
void ngx_free_connection(ngx_connection_t *c);

void ngx_reusable_connection(ngx_connection_t *c, ngx_uint_t reusable);

#endif /* _NGX_CONNECTION_H_INCLUDED_ */