view src/os/unix/ngx_gcc_atomic_sparc64.h @ 9306:e46e1ea89ccd default tip

Upstream: $upstream_cache_age variable. The variable reflects response age, including the time spent in the cache and the upstream response age as obtained from the "Age" header. If the response wasn't cached, the variable reflects the "Age" header of the upstream response. If the intended use case is to cache responses as per HTTP/1.1 caching model, the $upstream_cache_age variable can be used to provide the "Age" header with the "add_header" directive, such as: add_header Age $upstream_cache_age; This now removes the "Age" header if it was present. Further, the "expires" directives now removes the "Age" header if it was present in the response, as the "expires" directive assumes zero age when it adds "Expires" and "Cache-Control" headers.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 18 Jul 2024 19:39:45 +0300
parents 67653855682e
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


/*
 * "casa   [r1] 0x80, r2, r0"  and
 * "casxa  [r1] 0x80, r2, r0"  do the following:
 *
 *     if ([r1] == r2) {
 *         swap(r0, [r1]);
 *     } else {
 *         r0 = [r1];
 *     }
 *
 * so "r0 == r2" means that the operation was successful.
 *
 *
 * The "r" means the general register.
 * The "+r" means the general register used for both input and output.
 */


#if (NGX_PTR_SIZE == 4)
#define NGX_CASA  "casa"
#else
#define NGX_CASA  "casxa"
#endif


static ngx_inline ngx_atomic_uint_t
ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old,
    ngx_atomic_uint_t set)
{
    __asm__ volatile (

    NGX_CASA " [%1] 0x80, %2, %0"

    : "+r" (set) : "r" (lock), "r" (old) : "memory");

    return (set == old);
}


static ngx_inline ngx_atomic_int_t
ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add)
{
    ngx_atomic_uint_t  old, res;

    old = *value;

    for ( ;; ) {

        res = old + add;

        __asm__ volatile (

        NGX_CASA " [%1] 0x80, %2, %0"

        : "+r" (res) : "r" (value), "r" (old) : "memory");

        if (res == old) {
            return res;
        }

        old = res;
    }
}


#if (NGX_SMP)
#define ngx_memory_barrier()                                                  \
            __asm__ volatile (                                                \
            "membar #LoadLoad | #LoadStore | #StoreStore | #StoreLoad"        \
            ::: "memory")
#else
#define ngx_memory_barrier()   __asm__ volatile ("" ::: "memory")
#endif

#define ngx_cpu_pause()