comparison src/core/ngx_spinlock.c @ 160:73e8476f9142 NGINX_0_3_27

nginx 0.3.27 *) Change: the "variables_hash_max_size" and "variables_hash_bucket_size" directives. *) Feature: the $body_bytes_sent variable can be used not only in the "log_format" directive. *) Feature: the $ssl_protocol and $ssl_cipher variables. *) Feature: the cache line size detection for widespread CPUs at start time. *) Feature: now the "accept_mutex" directive is supported using fcntl(2) on platforms different from i386, amd64, sparc64, and ppc. *) Feature: the "lock_file" directive and the --with-lock-path=PATH autoconfiguration directive. *) Bugfix: if the HTTPS protocol was used in the "proxy_pass" directive then the requests with the body was not transferred.
author Igor Sysoev <http://sysoev.ru>
date Wed, 08 Feb 2006 00:00:00 +0300
parents 408f195b3482
children d0f7a625f27c
comparison
equal deleted inserted replaced
159:25c27e983933 160:73e8476f9142
6 6
7 #include <ngx_config.h> 7 #include <ngx_config.h>
8 #include <ngx_core.h> 8 #include <ngx_core.h>
9 9
10 10
11 /*
12 * TODO: the P4 optimized assembler version with the "pause" operation
13 */
14
15 void 11 void
16 ngx_spinlock(ngx_atomic_t *lock, ngx_uint_t spin) 12 ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin)
17 { 13 {
18 14
19 #if (NGX_HAVE_ATOMIC_OPS) 15 #if (NGX_HAVE_ATOMIC_OPS)
20 16
21 ngx_uint_t tries; 17 ngx_uint_t i, n;
22
23 tries = 0;
24 18
25 for ( ;; ) { 19 for ( ;; ) {
26 20
27 if (*lock) { 21 if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
28 if (ngx_ncpu > 1 && tries++ < spin) { 22 return;
29 continue; 23 }
30 }
31 24
32 ngx_sched_yield(); 25 if (ngx_ncpu > 1) {
33 26
34 tries = 0; 27 for (n = 1; n < spin; n <<= 1) {
35 28
36 } else { 29 for (i = 0; i < n; i++) {
37 if (ngx_atomic_cmp_set(lock, 0, 1)) { 30 ngx_cpu_pause();
38 return; 31 }
32
33 if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
34 return;
35 }
39 } 36 }
40 } 37 }
38
39 ngx_sched_yield();
41 } 40 }
42 41
43 #else 42 #else
44 43
45 #if (NGX_THREADS) 44 #if (NGX_THREADS)