Mercurial > hg > nginx-vendor-0-7
diff src/core/ngx_spinlock.c @ 0:f0b350454894 NGINX_0_1_0
nginx 0.1.0
*) The first public version.
author | Igor Sysoev <http://sysoev.ru> |
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date | Mon, 04 Oct 2004 00:00:00 +0400 |
parents | |
children | 41ccba1aba45 |
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new file mode 100644 --- /dev/null +++ b/src/core/ngx_spinlock.c @@ -0,0 +1,48 @@ + +/* + * 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 + +}