nginx 0.6.23 *) Change: the "off" parameter in the "ssl_session_cache" directive; now this is default parameter. *) Change: the "open_file_cache_retest" directive was renamed to the "open_file_cache_valid". *) Feature: the "open_file_cache_min_uses" directive. *) Feature: the ngx_http_gzip_static_module. *) Feature: the "gzip_disable" directive. *) Feature: the "memcached_pass" directive may be used inside the "if" block. *) Bugfix: a segmentation fault occurred in worker process, if the "memcached_pass" and "if" directives were used in the same location. *) Bugfix: if a "satisfy_any on" directive was used and not all access and auth modules directives were set, then other given access and auth directives were not tested; *) Bugfix: regex parameters in a "valid_referers" directive were not inherited from previous level. *) Bugfix: a "post_action" directive did run if a request was completed with 499 status code. *) Bugfix: optimization of 16K buffer usage in a SSL connection. Thanks to Ben Maurer. *) Bugfix: the STARTTLS in SMTP mode did not work. Thanks to Oleg Motienko. *) Bugfix: in HTTPS mode requests might fail with the "bad write retry" error; bug appeared in 0.5.13.

/*
 * 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

}