Mercurial > hg > nginx-quic
view src/os/win32/ngx_atomic.h @ 8945:043006e5a0b1
SSL: optimized rotation of session ticket keys.
Instead of syncing keys with shared memory on each ticket operation,
the code now does this only when the worker is going to change expiration
of the current key, or going to switch to a new key: that is, usually
at most once per second.
To do so without races, the code maintains 3 keys: current, previous,
and next. If a worker will switch to the next key earlier, other workers
will still be able to decrypt new tickets, since they will be encrypted
with the next key.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Wed, 12 Oct 2022 20:14:55 +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_ */