Mercurial > hg > nginx
view src/core/ngx_rwlock.c @ 9162:f9845e4b5c14
QUIC: simplified setting close timer when closing connection.
Previously, the timer was never reset due to an explicit check. The check was
added in 36b59521a41c as part of connection close simplification. The reason
was to retain the earliest timeout. However, the timeouts are all the same
while QUIC handshake is in progress and resetting the timer for the same value
has no performance implications. After handshake completion there's only
application level. The change removes the check.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Thu, 14 Sep 2023 14:15:20 +0400 |
parents | 7752d8523066 |
children |
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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) { if (*lock == NGX_RWLOCK_WLOCK) { (void) ngx_atomic_cmp_set(lock, NGX_RWLOCK_WLOCK, 0); } else { (void) ngx_atomic_fetch_add(lock, -1); } } void ngx_rwlock_downgrade(ngx_atomic_t *lock) { if (*lock == NGX_RWLOCK_WLOCK) { *lock = 1; } } #else #if (NGX_HTTP_UPSTREAM_ZONE || NGX_STREAM_UPSTREAM_ZONE) #error ngx_atomic_cmp_set() is not defined! #endif #endif