view src/mysql/ngx_http_mysql_test.c @ 6422:768e287a6f36

Fixed sendfile in threads (or with aio preload) and subrequests. If sendfile in threads is used, it is possible that multiple subrequests will trigger multiple ngx_linux_sendfile_thread() calls, as operations are only serialized in output chain based on r->aio, that is, on subrequest level. This resulted in "task #N already active" alerts, in particular, when running proxy_store.t with "aio threads; sendfile on;". Fix is to tolerate duplicate calls, with an additional safety check that the file is the same as previously used. The same problem also affects "aio on; sendfile on;" on FreeBSD (previously known as "aio sendfile;"), where aio->preload_handler() could be called multiple times due to similar reasons, resulting in "second aio post" alerts. Fix is the same as well. It is also believed that similar problems can arise if a filter calls the next body filter multiple times for some reason. These are mostly theoretical though.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 03 Mar 2016 21:14:12 +0300
parents d620f497c50f
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */

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


typedef struct {
    ngx_addr_t  *peers;
    ngx_uint_t   npeers;
} ngx_http_mysql_test_conf_t;


static void ngx_http_mysql_auth(ngx_mysql_t *m);
static void ngx_http_mysql_done(ngx_mysql_t *m);
static void *ngx_http_mysql_test_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_mysql_test(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);

static ngx_command_t  ngx_http_mysql_test_commands[] = {

    { ngx_string("mysql_test"),
      NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_mysql_test,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_mysql_test_module_ctx = {
    NULL,                          /* preconfiguration */
    NULL,                          /* postconfiguration */

    NULL,                          /* create main configuration */
    NULL,                          /* init main configuration */

    NULL,                          /* create server configuration */
    NULL,                          /* merge server configuration */

    ngx_http_mysql_test_create_loc_conf,  /* create location configuration */
    NULL                           /* merge location configuration */
};


ngx_module_t  ngx_http_mysql_test_module = {
    NGX_MODULE_V1,
    &ngx_http_mysql_test_module_ctx, /* module context */
    ngx_http_mysql_test_commands,   /* module directives */
    NGX_HTTP_MODULE,               /* module type */
    NULL,                          /* init master */
    NULL,                          /* init module */
    NULL,                          /* init process */
    NULL,                          /* init thread */
    NULL,                          /* exit thread */
    NULL,                          /* exit process */
    NULL,                          /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_str_t  ngx_mysql_login = ngx_string("root");
static ngx_str_t  ngx_mysql_passwd = ngx_string("tp");
static ngx_str_t  ngx_mysql_database = ngx_string("mysql");
static ngx_str_t  ngx_mysql_command_query =
    ngx_string("select * from user");


static ngx_int_t
ngx_http_mysql_test_handler(ngx_http_request_t *r)
{
    ngx_int_t                    rc;
    ngx_mysql_t                 *m;
    ngx_http_mysql_test_conf_t  *mtcf;

    mtcf = ngx_http_get_module_loc_conf(r, ngx_http_mysql_test_module);

    m = ngx_pcalloc(r->pool, sizeof(ngx_mysql_t));

    if (m == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    m->pool = r->pool;
    m->handler = ngx_http_mysql_auth;
    m->data = r;

    m->login = &ngx_mysql_login;
    m->passwd = &ngx_mysql_passwd;
    m->database = &ngx_mysql_database;

    /* STUB */
    m->peer.sockaddr = mtcf->peers[0].sockaddr;
    m->peer.socklen = mtcf->peers[0].socklen;
    m->peer.name = &mtcf->peers[0].name;
    m->peer.tries = mtcf->npeers;
    m->peer.get = ngx_event_get_peer;
    /**/
    m->peer.log = r->connection->log;
    m->peer.log_error = NGX_ERROR_ERR;

    rc = ngx_mysql_connect(m);

    if (rc == NGX_OK || rc == NGX_AGAIN) {
        return NGX_DONE;
    }

    return NGX_HTTP_INTERNAL_SERVER_ERROR;
}


static void
ngx_http_mysql_auth(ngx_mysql_t *m)
{
    ngx_http_request_t  *r;

    r = m->data;

    if (m->state != NGX_OK) {
        ngx_http_finalize_request(r, NGX_HTTP_NO_CONTENT);
        return;
    }

    m->query.len = NGX_MYSQL_CMDPKT_LEN + ngx_mysql_command_query.len;

    m->query.data = ngx_pnalloc(r->pool, m->query.len);
    if (m->query.data == NULL) {
        ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_memcpy(m->query.data + NGX_MYSQL_CMDPKT_LEN,
               ngx_mysql_command_query.data, ngx_mysql_command_query.len);

    m->handler = ngx_http_mysql_done;

    ngx_mysql_query(m);
}


static void
ngx_http_mysql_done(ngx_mysql_t *m)
{
    ngx_http_request_t  *r;

    r = m->data;

    ngx_http_finalize_request(r, NGX_HTTP_NO_CONTENT);
}


static void *
ngx_http_mysql_test_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_mysql_test_conf_t  *conf;

    conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_mysql_test_conf_t));
    if (conf == NULL) {
        return NGX_CONF_ERROR;
    }

    return conf;
}

static char *
ngx_http_mysql_test(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_mysql_test_conf_t  *mtcf = conf;

    ngx_str_t                 *value;
    ngx_url_t                  u;
    ngx_http_core_loc_conf_t  *clcf;

    clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
    clcf->handler = ngx_http_mysql_test_handler;

    value = cf->args->elts;

    ngx_memzero(&u, sizeof(ngx_url_t));

    u.url = value[1];
    u.default_port = 3306;

    if (ngx_parse_url(cf->pool, &u) != NGX_OK) {
        if (u.err) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "%s in upstream \"%V\"", u.err, &u.url);
        }

        return NGX_CONF_ERROR;
    }

    mtcf->peers = u.addrs;
    mtcf->npeers = u.naddrs;

    return NGX_CONF_OK;
}