view src/core/ngx_spinlock.c @ 452:23fb87bddda1 release-0.1.1

nginx-0.1.1-RELEASE import *) Feature: the gzip_types directive. *) Feature: the tcp_nodelay directive. *) Feature: the send_lowat directive is working not only on OSes that support kqueue NOTE_LOWAT, but also on OSes that support SO_SNDLOWAT. *) Feature: the setproctitle() emulation for Linux and Solaris. *) Bugfix: the "Location" header rewrite bug fixed while the proxying. *) Bugfix: the ngx_http_chunked_module module may get caught in an endless loop. *) Bugfix: the /dev/poll module bugs fixed. *) Bugfix: the responses were corrupted when the temporary files were used while the proxying. *) Bugfix: the unescaped requests were passed to the backend. *) Bugfix: while the build configuration on Linux 2.4 the --with-poll_module parameter was required.
author Igor Sysoev <igor@sysoev.ru>
date Mon, 11 Oct 2004 15:07:03 +0000
parents 42d11f017717
children 975f62e77f02
line wrap: on
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/*
 * 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

}