view src/os/win32/ngx_atomic.h @ 7702:7015f26aef90

Cache: ignore stale-if-error for 4xx and 5xx codes. Previously the stale-if-error extension of the Cache-Control upstream header triggered the return of a stale response for all error conditions that can be specified in the proxy_cache_use_stale directive. The list of these errors includes both network/timeout/format errors, as well as some HTTP codes like 503, 504, 403, 429 etc. The latter prevented a cache entry from being updated by a response with any of these HTTP codes during the stale-if-error period. Now stale-if-error only works for network/timeout/format errors and ignores the upstream HTTP code. The return of a stale response for certain HTTP codes is still possible using the proxy_cache_use_stale directive. This change also applies to the stale-while-revalidate extension of the Cache-Control header, which triggers stale-if-error if it is missing. Reported at http://mailman.nginx.org/pipermail/nginx/2020-July/059723.html.
author Roman Arutyunyan <arut@nginx.com>
date Wed, 29 Jul 2020 13:28:04 +0300
parents 2cd019520210
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_ATOMIC_H_INCLUDED_
#define _NGX_ATOMIC_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


#define NGX_HAVE_ATOMIC_OPS   1

typedef int32_t                     ngx_atomic_int_t;
typedef uint32_t                    ngx_atomic_uint_t;
typedef volatile ngx_atomic_uint_t  ngx_atomic_t;
#define NGX_ATOMIC_T_LEN            (sizeof("-2147483648") - 1)


#if defined( __WATCOMC__ ) || defined( __BORLANDC__ ) || defined(__GNUC__)    \
    || ( _MSC_VER >= 1300 )

/* the new SDK headers */

#define ngx_atomic_cmp_set(lock, old, set)                                    \
    ((ngx_atomic_uint_t) InterlockedCompareExchange((long *) lock, set, old)  \
                         == old)

#else

/* the old MS VC6.0SP2 SDK headers */

#define ngx_atomic_cmp_set(lock, old, set)                                    \
    (InterlockedCompareExchange((void **) lock, (void *) set, (void *) old)   \
     == (void *) old)

#endif


#define ngx_atomic_fetch_add(p, add) InterlockedExchangeAdd((long *) p, add)


#define ngx_memory_barrier()


#if defined( __BORLANDC__ ) || ( __WATCOMC__ < 1230 )

/*
 * Borland C++ 5.5 (tasm32) and Open Watcom C prior to 1.3
 * do not understand the "pause" instruction
 */

#define ngx_cpu_pause()
#else
#define ngx_cpu_pause()       __asm { pause }
#endif


void ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin);

#define ngx_trylock(lock)  (*(lock) == 0 && ngx_atomic_cmp_set(lock, 0, 1))
#define ngx_unlock(lock)    *(lock) = 0


#endif /* _NGX_ATOMIC_H_INCLUDED_ */