view src/stream/ngx_stream_upstream.h @ 6133:af7eba90645d

Win32: shared memory base addresses and remapping. Two mechanisms are implemented to make it possible to store pointers in shared memory on Windows, in particular on Windows Vista and later versions with ASLR: - The ngx_shm_remap() function added to allow remapping of a shared memory zone to the address originally used for it in the master process. While important, it doesn't solve the problem by itself as in many cases it's not possible to use the address because of conflicts with other allocations. - We now create mappings at the same address in all processes by starting mappings at predefined addresses normally unused by newborn processes. These two mechanisms combined allow to use shared memory on Windows almost without problems, including reloads. Based on the patch by Sergey Brester: http://mailman.nginx.org/pipermail/nginx-devel/2015-April/006836.html
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 27 Apr 2015 18:25:42 +0300
parents 61d7ae76647d
children fa663739e115
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_STREAM_UPSTREAM_H_INCLUDED_
#define _NGX_STREAM_UPSTREAM_H_INCLUDED_


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


#define NGX_STREAM_UPSTREAM_CREATE        0x0001
#define NGX_STREAM_UPSTREAM_WEIGHT        0x0002
#define NGX_STREAM_UPSTREAM_MAX_FAILS     0x0004
#define NGX_STREAM_UPSTREAM_FAIL_TIMEOUT  0x0008
#define NGX_STREAM_UPSTREAM_DOWN          0x0010
#define NGX_STREAM_UPSTREAM_BACKUP        0x0020


typedef struct {
    ngx_array_t                        upstreams;
                                           /* ngx_stream_upstream_srv_conf_t */
} ngx_stream_upstream_main_conf_t;


typedef struct ngx_stream_upstream_srv_conf_s  ngx_stream_upstream_srv_conf_t;


typedef ngx_int_t (*ngx_stream_upstream_init_pt)(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us);
typedef ngx_int_t (*ngx_stream_upstream_init_peer_pt)(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us);


typedef struct {
    ngx_stream_upstream_init_pt        init_upstream;
    ngx_stream_upstream_init_peer_pt   init;
    void                              *data;
} ngx_stream_upstream_peer_t;


typedef struct {
    ngx_str_t                          name;
    ngx_addr_t                        *addrs;
    ngx_uint_t                         naddrs;
    ngx_uint_t                         weight;
    ngx_uint_t                         max_fails;
    time_t                             fail_timeout;

    unsigned                           down:1;
    unsigned                           backup:1;
} ngx_stream_upstream_server_t;


struct ngx_stream_upstream_srv_conf_s {
    ngx_stream_upstream_peer_t         peer;
    void                             **srv_conf;

    ngx_array_t                       *servers;
                                              /* ngx_stream_upstream_server_t */

    ngx_uint_t                         flags;
    ngx_str_t                          host;
    u_char                            *file_name;
    ngx_uint_t                         line;
    in_port_t                          port;
    ngx_uint_t                         no_port;  /* unsigned no_port:1 */

#if (NGX_STREAM_UPSTREAM_ZONE)
    ngx_shm_zone_t                    *shm_zone;
#endif
};


typedef struct {
    ngx_peer_connection_t              peer;
    ngx_buf_t                          downstream_buf;
    ngx_buf_t                          upstream_buf;
    off_t                              received;
#if (NGX_STREAM_SSL)
    ngx_str_t                          ssl_name;
#endif
} ngx_stream_upstream_t;


ngx_stream_upstream_srv_conf_t *ngx_stream_upstream_add(ngx_conf_t *cf,
    ngx_url_t *u, ngx_uint_t flags);


#define ngx_stream_conf_upstream_srv_conf(uscf, module)                       \
    uscf->srv_conf[module.ctx_index]


extern ngx_module_t  ngx_stream_upstream_module;


#endif /* _NGX_STREAM_UPSTREAM_H_INCLUDED_ */