view src/os/win32/ngx_atomic.h @ 8099:b4ef79ef1c23 quic

QUIC: refined the "c->quic->initialized" flag usage. The flag is tied to the initial secret creation. The presence of c->quic pointer is sufficient to enable execution of ngx_quic_close_quic(). The ngx_quic_new_connection() function now returns the allocated quic connection object and the c->quic pointer is set by the caller. If an early error occurs before secrets initialization (i.e. in cases of invalid retry token or nginx exiting), it is still possible to generate an error response by trying to initialize secrets directly in the ngx_quic_send_cc() function. Before the change such early errors failed to send proper connection close message and logged an error. An auxilliary ngx_quic_init_secrets() function is introduced to avoid verbose call to ngx_quic_set_initial_secret() requiring local variable.
author Vladimir Homutov <vl@nginx.com>
date Wed, 30 Sep 2020 21:27:52 +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_ */