nginx 0.6.7 *) Change: now the paths specified in the "include", "auth_basic_user_file", "perl_modules", "ssl_certificate", "ssl_certificate_key", and "ssl_client_certificate" directives are relative to directory of nginx configuration file nginx.conf, but not to nginx prefix directory. *) Change: the --sysconfdir=PATH option in configure was canceled. *) Change: the special make target "upgrade1" was defined for online upgrade of 0.1.x versions. *) Feature: the "server_name" and "valid_referers" directives support regular expressions. *) Feature: the "server" directive in the "upstream" context supports the "backup" parameter. *) Feature: the ngx_http_perl_module supports the $r->discard_request_body. *) Feature: the "add_header Last-Modified ..." directive changes the "Last-Modified" response header line. *) Bugfix: if an response different than 200 was returned to an request with body and connection went to the keep-alive state after the request, then nginx returned 400 for the next request. *) Bugfix: a segmentation fault occurred in worker process if invalid address was set in the "auth_http" directive. *) Bugfix: now nginx uses default listen backlog value 511 on all platforms except FreeBSD. Thanks to Jiang Hong. *) Bugfix: a worker process may got caught in an endless loop, if an "server" inside "upstream" block was marked as "down"; bug appeared in 0.6.6. *) Bugfix: now Solaris sendfilev() is not used to transfer the client request body to FastCGI-server via the unix domain socket.

/*
 * 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

}