Workaround for "configuration file test failed" under OpenVZ. If nginx was used under OpenVZ and a container with nginx was suspended and resumed, configuration tests started to fail because of EADDRINUSE returned from listen() instead of bind(): # nginx -t nginx: the configuration file /etc/nginx/nginx.conf syntax is ok nginx: [emerg] listen() to 0.0.0.0:80, backlog 511 failed (98: Address already in use) nginx: configuration file /etc/nginx/nginx.conf test failed With this change EADDRINUSE errors returned by listen() are handled similarly to errors returned by bind(), and configuration tests work fine in the same environment: # nginx -t nginx: the configuration file /etc/nginx/nginx.conf syntax is ok nginx: configuration file /etc/nginx/nginx.conf test is successful More details about OpenVZ suspend/resume bug: https://bugzilla.openvz.org/show_bug.cgi?id=2470

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


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


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


/* 32-bit crc16 */

static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
    uint32_t  sum;

    for (sum = 0; len; len--) {

        /*
         * gcc 2.95.2 x86 and icc 7.1.006 compile
         * that operator into the single "rol" opcode,
         * msvc 6.0sp2 compiles it into four opcodes.
         */
        sum = sum >> 1 | sum << 31;

        sum += *data++;
    }

    return sum;
}


#endif /* _NGX_CRC_H_INCLUDED_ */