view src/os/unix/ngx_gcc_atomic_sparc64.h @ 8384:c61fcdc1b8e3 quic

UDP: extended datagram context. Sometimes it is required to process datagram properties at higher level (i.e. QUIC is interested in source address which may change and IP options). The patch adds ngx_udp_dgram_t structure used to pass packet-related information in c->udp.
author Vladimir Homutov <vl@nginx.com>
date Fri, 02 Apr 2021 18:58:19 +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()