nginx 0.6.21 *) Change: if variable values used in a "proxy_pass" directive contain IP-addresses only, then a "resolver" directive is not mandatory. resolver *) Bugfix: a segmentation fault might occur in worker process if a "proxy_pass" directive with URI-part was used; bug appeared in 0.6.19. *) Bugfix: if resolver was used on platform that does not support kqueue, then nginx issued an alert "name is out of response". Thanks to Andrei Nigmatulin. *) Bugfix: if the $server_protocol was used in FastCGI parameters and a request line length was near to the "client_header_buffer_size" directive value, then nginx issued an alert "fastcgi: the request record is too big". *) Bugfix: if a plain text HTTP/0.9 version request was made to HTTPS server, then nginx returned usual response.

/*
 * 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

}