nginx 0.6.25 *) Change: now the "server_name_in_redirect" directive is used instead of the "server_name" directive's special "*" parameter. *) Change: now wildcard and regex names can be used as main name in a "server_name" directive. *) Change: the "satisfy_any" directive was replaced by the "satisfy" directive. *) Workaround: old worker processes might hog CPU after reconfiguration if they was run under Linux OpenVZ. *) Feature: the "min_delete_depth" directive. *) Bugfix: the COPY and MOVE methods did not work with single files. *) Bugfix: the ngx_http_gzip_static_module did not allow the ngx_http_dav_module to work; bug appeared in 0.6.23. *) Bugfix: socket leak in HTTPS mode if deferred accept was used. Thanks to Ben Maurer. *) Bugfix: nginx could not be built without PCRE library; bug appeared in 0.6.23.

/*
 * 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

}