nginx 0.1.18 *) Workaround: the default values of the devpoll_events and the devpoll_changes directives changed from 512 to 32 to be compatible with Solaris 10. *) Bugfix: the proxy_set_x_var and fastcgi_set_var directives were not inherited. *) Bugfix: in the redirect rewrite directive the arguments were concatenated with URI by the "&" rather than the "?". *) Bugfix: the lines without trailing ";" in the file being included by the ngx_http_geo_module were silently ignored. *) Feature: the ngx_http_stub_status_module. *) Bugfix: the unknown log format in the access_log directive caused the segmentation fault. *) Feature: the new "document_root" parameter of the fastcgi_params directive. *) Feature: the fastcgi_redirect_errors directive. *) Feature: the new "break" modifier of the "rewrite" directive allows to stop the rewrite/location cycle and sets the current configuration to the request.

/*
 * Copyright (C) Igor Sysoev
 */


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


void ngx_spinlock(ngx_atomic_t *lock, ngx_uint_t spin)
{

#if (NGX_HAVE_ATOMIC_OPS)

    ngx_uint_t  tries;

    tries = 0;

    for ( ;; ) {

        if (*lock) {
            if (ngx_ncpu > 1 && tries++ < spin) {
                continue;
            }

            ngx_sched_yield();

            tries = 0;

        } else {
            if (ngx_atomic_cmp_set(lock, 0, 1)) {
                return;
            }
        }
    }

#else

#if (NGX_THREADS)

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

#endif

#endif

}