view src/os/unix/ngx_gcc_atomic_sparc64.h @ 6929:3069dd358ba2

Cancelable timers are now preserved if there are other timers. There is no need to cancel timers early if there are other timers blocking shutdown anyway. Preserving such timers allows nginx to continue some periodic work till the shutdown is actually possible. With the new approach, timers with ev->cancelable are simply ignored when checking if there are any timers left during shutdown.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 07 Mar 2017 18:51:15 +0300
parents 67653855682e
children
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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()