nginx 1.1.9 *) Change: now double quotes are encoded in an "echo" SSI-command output. Thanks to Zaur Abasmirzoev. *) Feature: the "valid" parameter of the "resolver" directive. By default TTL returned by a DNS server is used. Thanks to Kirill A. Korinskiy. *) Bugfix: nginx might hang after a worker process abnormal termination. *) Bugfix: a segmentation fault might occur in a worker process if SNI was used; the bug had appeared in 1.1.2. *) Bugfix: in the "keepalive_disable" directive; the bug had appeared in 1.1.8. Thanks to Alexander Usov. *) Bugfix: SIGWINCH signal did not work after first binary upgrade; the bug had appeared in 1.1.1. *) Bugfix: backend responses with length not matching "Content-Length" header line are no longer cached. *) Bugfix: in the "scgi_param" directive, if complex parameters were used. *) Bugfix: in the "epoll" event method. Thanks to Yichun Zhang. *) Bugfix: in the ngx_http_flv_module. Thanks to Piotr Sikora. *) Bugfix: in the ngx_http_mp4_module. *) Bugfix: IPv6 addresses are now handled properly in a request line and in a "Host" request header line. *) Bugfix: "add_header" and "expires" directives did not work if a request was proxied and response status code was 206. *) Bugfix: nginx could not be built on FreeBSD 10. *) Bugfix: nginx could not be built on AIX.

/*
 * 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

}