Mercurial > hg > nginx-vendor-0-8
view src/core/ngx_spinlock.c @ 303:8b5bc9ef5e54
Added tag NGINX_0_5_21 for changeset 9b7db0df50f0
author | Igor Sysoev <http://sysoev.ru> |
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date | Mon, 28 May 2007 00:00:00 +0400 |
parents | 73e8476f9142 |
children |
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/* * 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 }