view src/core/ngx_list.h @ 7142:b9d919b53593 stable-1.12

Stream: relaxed next upstream condition (ticket #1317). When switching to a next upstream, some buffers could be stuck in the middle of the filter chain. A condition existed that raised an error when this happened. As it turned out, this condition prevented switching to a next upstream if ssl preread was used with the TCP protocol (see the ticket). In fact, the condition does not make sense for TCP, since after successful connection to an upstream switching to another upstream never happens. As for UDP, the issue with stuck buffers is unlikely to happen, but is still possible. Specifically, if a filter delays sending data to upstream. The condition can be relaxed to only check the "buffered" bitmask of the upstream connection. The new condition is simpler and fixes the ticket issue as well. Additionally, the upstream_out chain is now reset for UDP prior to connecting to a new upstream to prevent repeating the client data twice.
author Roman Arutyunyan <arut@nginx.com>
date Mon, 11 Sep 2017 15:32:31 +0300
parents d620f497c50f
children
line wrap: on
line source


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


#ifndef _NGX_LIST_H_INCLUDED_
#define _NGX_LIST_H_INCLUDED_


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


typedef struct ngx_list_part_s  ngx_list_part_t;

struct ngx_list_part_s {
    void             *elts;
    ngx_uint_t        nelts;
    ngx_list_part_t  *next;
};


typedef struct {
    ngx_list_part_t  *last;
    ngx_list_part_t   part;
    size_t            size;
    ngx_uint_t        nalloc;
    ngx_pool_t       *pool;
} ngx_list_t;


ngx_list_t *ngx_list_create(ngx_pool_t *pool, ngx_uint_t n, size_t size);

static ngx_inline ngx_int_t
ngx_list_init(ngx_list_t *list, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{
    list->part.elts = ngx_palloc(pool, n * size);
    if (list->part.elts == NULL) {
        return NGX_ERROR;
    }

    list->part.nelts = 0;
    list->part.next = NULL;
    list->last = &list->part;
    list->size = size;
    list->nalloc = n;
    list->pool = pool;

    return NGX_OK;
}


/*
 *
 *  the iteration through the list:
 *
 *  part = &list.part;
 *  data = part->elts;
 *
 *  for (i = 0 ;; i++) {
 *
 *      if (i >= part->nelts) {
 *          if (part->next == NULL) {
 *              break;
 *          }
 *
 *          part = part->next;
 *          data = part->elts;
 *          i = 0;
 *      }
 *
 *      ...  data[i] ...
 *
 *  }
 */


void *ngx_list_push(ngx_list_t *list);


#endif /* _NGX_LIST_H_INCLUDED_ */