merge r2897, r2898, r2899, r2901, r2902, r2904, r2905, r2906, r2907, r2909, r2910, r2922, r2923, r2924, r2925, r2929: various win32 fixes: *) use no-threads for Unix builds only *) Win32 returns ERROR_PATH_NOT_FOUND instead of ERROR_FILE_NOT_FOUND *) add trailing zero to a file name in ngx_win32_rename_file() *) fix logging in ngx_win32_rename_file() *) allow shared memory segments more than 4G *) fix memory leak in successful case *) log shared memory name in failure case *) test that zone has the same addresses in different processes *) add drive letter for Win32 root path *) log GetExitCodeProcess()'s errno *) test premature process termination *) fix debug logging *) exit if no workers could not be started *) do not quit old workers if no new workers could not be started *) a signaller process should stop configuration processing just after it is able to get pid file, this allows to not open log files, etc. *) win32 master process had aready closed listening sockets

/*
 * 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

}