view src/os/unix/ngx_sunpro_atomic_sparc64.h @ 8551:c35b255d80dc quic

HTTP/3: close connection on keepalive_requests * 2. After receiving GOAWAY, client is not supposed to create new streams. However, until client reads this frame, we allow it to create new streams, which are gracefully rejected. To prevent client from abusing this algorithm, a new limit is introduced. Upon reaching keepalive_requests * 2, server now closes the entire QUIC connection claiming excessive load.
author Roman Arutyunyan <arut@nginx.com>
date Thu, 29 Jul 2021 16:01:37 +0300
parents d620f497c50f
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#if (NGX_PTR_SIZE == 4)
#define NGX_CASA  ngx_casa
#else
#define NGX_CASA  ngx_casxa
#endif


ngx_atomic_uint_t
ngx_casa(ngx_atomic_uint_t set, ngx_atomic_uint_t old, ngx_atomic_t *lock);

ngx_atomic_uint_t
ngx_casxa(ngx_atomic_uint_t set, ngx_atomic_uint_t old, ngx_atomic_t *lock);

/* the code in src/os/unix/ngx_sunpro_sparc64.il */


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)
{
    set = NGX_CASA(set, old, lock);

    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;

        res = NGX_CASA(res, old, value);

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

        old = res;
    }
}


#define ngx_memory_barrier()                                                  \
        __asm (".volatile");                                                  \
        __asm ("membar #LoadLoad | #LoadStore | #StoreStore | #StoreLoad");   \
        __asm (".nonvolatile")

#define ngx_cpu_pause()