view src/core/ngx_spinlock.c @ 564:da3c99095432 NGINX_0_8_34

nginx 0.8.34 *) Bugfix: nginx did not support all ciphers and digests used in client certificates. Thanks to Innocenty Enikeew. *) Bugfix: nginx cached incorrectly FastCGI responses if there was large stderr output before response. *) Bugfix: nginx did not support HTTPS referrers. *) Bugfix: nginx/Windows might not find file if path in configuration was given in other character case; the bug had appeared in 0.8.34. *) Bugfix: the $date_local variable has an incorrect value, if the "%s" format was used. Thanks to Maxim Dounin. *) Bugfix: if ssl_session_cache was not set or was set to "none", then during client certificate verify the error "session id context uninitialized" might occur; the bug had appeared in 0.7.1. *) Bugfix: a geo range returned default value if the range included two or more /16 networks and did not begin at /16 network boundary. *) Bugfix: a block used in a "stub" parameter of an "include" SSI directive was output with "text/plain" MIME type. *) Bugfix: $r->sleep() did not work; the bug had appeared in 0.8.11.
author Igor Sysoev <http://sysoev.ru>
date Wed, 03 Mar 2010 00:00:00 +0300
parents 73e8476f9142
children d0f7a625f27c
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 */


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


void
ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin)
{

#if (NGX_HAVE_ATOMIC_OPS)

    ngx_uint_t  i, n;

    for ( ;; ) {

        if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
            return;
        }

        if (ngx_ncpu > 1) {

            for (n = 1; n < spin; n <<= 1) {

                for (i = 0; i < n; i++) {
                    ngx_cpu_pause();
                }

                if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
                    return;
                }
            }
        }

        ngx_sched_yield();
    }

#else

#if (NGX_THREADS)

#error ngx_spinlock() or ngx_atomic_cmp_set() are not defined !

#endif

#endif

}