nginx 0.8.20 *) Change: now default SSL ciphers are "HIGH:!ADH:!MD5". *) Bugfix: the ngx_http_autoindex_module did not show the trailing slash in links to a directory; the bug had appeared in 0.7.15. *) Bugfix: nginx did not close a log file set by the --error-log-path configuration option; the bug had appeared in 0.7.53. *) Bugfix: nginx did not treat a comma as separator in the "Cache-Control" backend response header line. *) Bugfix: nginx/Windows might not create temporary file, a cache file, or "proxy/fastcgi_store"d file if a worker has no enough access rights for top level directories. *) Bugfix: the "Set-Cookie" and "P3P" FastCGI response header lines were not hidden while caching if no "fastcgi_hide_header" directives were used with any parameters. *) Bugfix: nginx counted incorrectly disk cache size.

/*
 * 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

}