Mercurial > hg > nginx
view src/core/ngx_rwlock.c @ 6804:2c7a2d75938a
Configure: honor dependencies of dynamic modules.
Dependencies of dynamic modules are added to NGX_ADDON_DEPS (and
it is now used for dynamic modules) to be in line with what happens
in case of static compilation.
To avoid duplication, MAIL_DEPS and STREAM_DEPS are no longer passed
to auto/module when these modules are compiled as dynamic ones. Mail
and stream dependencies are handled explicitly via corresponding
variables.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 21 Nov 2016 16:49:19 +0300 |
parents | e769cc88f996 |
children | 12efcdcb8a4b |
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/* * Copyright (C) Ruslan Ermilov * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_HAVE_ATOMIC_OPS) #define NGX_RWLOCK_SPIN 2048 #define NGX_RWLOCK_WLOCK ((ngx_atomic_uint_t) -1) void ngx_rwlock_wlock(ngx_atomic_t *lock) { ngx_uint_t i, n; for ( ;; ) { if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, NGX_RWLOCK_WLOCK)) { return; } if (ngx_ncpu > 1) { for (n = 1; n < NGX_RWLOCK_SPIN; n <<= 1) { for (i = 0; i < n; i++) { ngx_cpu_pause(); } if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, NGX_RWLOCK_WLOCK)) { return; } } } ngx_sched_yield(); } } void ngx_rwlock_rlock(ngx_atomic_t *lock) { ngx_uint_t i, n; ngx_atomic_uint_t readers; for ( ;; ) { readers = *lock; if (readers != NGX_RWLOCK_WLOCK && ngx_atomic_cmp_set(lock, readers, readers + 1)) { return; } if (ngx_ncpu > 1) { for (n = 1; n < NGX_RWLOCK_SPIN; n <<= 1) { for (i = 0; i < n; i++) { ngx_cpu_pause(); } readers = *lock; if (readers != NGX_RWLOCK_WLOCK && ngx_atomic_cmp_set(lock, readers, readers + 1)) { return; } } } ngx_sched_yield(); } } void ngx_rwlock_unlock(ngx_atomic_t *lock) { ngx_atomic_uint_t readers; readers = *lock; if (readers == NGX_RWLOCK_WLOCK) { *lock = 0; return; } for ( ;; ) { if (ngx_atomic_cmp_set(lock, readers, readers - 1)) { return; } readers = *lock; } } #else #if (NGX_HTTP_UPSTREAM_ZONE || NGX_STREAM_UPSTREAM_ZONE) #error ngx_atomic_cmp_set() is not defined! #endif #endif