nginx 0.6.36 *) Change: now the "Invalid argument" error returned by setsockopt(TCP_NODELAY) on Solaris, is ignored. *) Change: now POSTs without "Content-Length" header line are allowed. *) Feature: the "try_files" directive. *) Feature: the --with-pcre option in the configure. *) Feature: the "if_modified_since" directive. *) Feature: the "$cookie_..." variables. *) Feature: the "$arg_..." variables. *) Bugfix: compatibility with Tru64 UNIX. Thanks to Dustin Marquess. *) Bugfix: a "ssl_engine" directive did not use a SSL-accelerator for asymmetric ciphers. Thanks to Marcin Gozdalik. *) Bugfix: in a redirect rewrite directive original arguments were concatenated with new arguments by a "?" rather than an "&"; the bug had appeared in 0.1.18. Thanks to Maxim Dounin. *) Bugfix: nginx could not be built on AIX. *) Bugfix: a double response might be returned if the epoll or rtsig methods are used and a redirect was returned to a request with body. Thanks to Eden Li. *) Bugfix: a segmentation fault might occur in worker process if "resolver" directive was used in SMTP proxy. *) Bugfix: fastcgi_store stored files not always. *) Bugfix: nginx did not process a FastCGI server response, if the server send too many messages to stderr before 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

}