nginx-0.1.2-RELEASE import *) Feature: the --user=USER, --group=GROUP, and --with-ld-opt=OPTIONS options in configure. *) Feature: the server_name directive supports *.domain.tld. *) Bugfix: the portability improvements. *) Bugfix: if configuration file was set in command line, the reconfiguration was impossible; the bug had appeared in 0.1.1. *) Bugfix: proxy module may get caught in an endless loop when sendfile is not used. *) Bugfix: with sendfile the response was not recoded according to the charset module directives; the bug had appeared in 0.1.1. *) Bugfix: very seldom bug in the kqueue processing. *) Bugfix: the gzip module compressed the proxied responses that was already compressed.

/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>


void ngx_spinlock(ngx_atomic_t *lock, ngx_uint_t spin)
{

#if (NGX_HAVE_ATOMIC_OPS)

    ngx_uint_t  tries;

    tries = 0;

    for ( ;; ) {

        if (*lock) {
            if (ngx_ncpu > 1 && tries++ < spin) {
                continue;
            }

            ngx_sched_yield();

            tries = 0;

        } else {
            if (ngx_atomic_cmp_set(lock, 0, 1)) {
                return;
            }
        }
    }

#else

#if (NGX_THREADS)

#error ngx_spinlock() or ngx_atomic_cmp_set() are not defined !

#endif

#endif

}