nginx 0.6.26 *) Bugfix: the "proxy_store" and "fastcgi_store" directives did not check a response length. *) Bugfix: a segmentation fault occurred in worker process, if big value was used in a "expires" directive. Thanks to Joaquin Cuenca Abela. *) Bugfix: nginx incorrectly detected cache line size on Pentium 4. Thanks to Gena Makhomed. *) Bugfix: in proxied or FastCGI subrequests a client original method was used instead of the GET method. *) Bugfix: socket leak in HTTPS mode if deferred accept was used. Thanks to Ben Maurer. *) Bugfix: nginx issued the bogus error message "SSL_shutdown() failed (SSL: )"; bug appeared in 0.6.23. *) Bugfix: in HTTPS mode requests might fail with the "bad write retry" error; bug appeared in 0.6.23.

/*
 * 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

}