Mercurial > hg > nginx-vendor-0-8
view src/core/ngx_spinlock.c @ 77:e6b3de2dc637
Added tag NGINX_0_1_38 for changeset da9a3b14312d
author | Igor Sysoev <http://sysoev.ru> |
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date | Fri, 08 Jul 2005 00:00:00 +0400 |
parents | 41ccba1aba45 |
children | 408f195b3482 |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> /* * TODO: the P4 optimized assembler version with the "pause" operation */ 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 }