88ffc8dea4
This implementation is referenced to https://www.boost.org/doc/libs/1_69_0/boost/detail/interlocked.hpp Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/8596)
159 lines
4.6 KiB
C
159 lines
4.6 KiB
C
/*
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* Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#ifndef HEADER_INTERNAL_REFCOUNT_H
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# define HEADER_INTERNAL_REFCOUNT_H
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/* Used to checking reference counts, most while doing perl5 stuff :-) */
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# if defined(OPENSSL_NO_STDIO)
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# if defined(REF_PRINT)
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# error "REF_PRINT requires stdio"
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# endif
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# endif
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# ifndef OPENSSL_DEV_NO_ATOMICS
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# if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L \
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&& !defined(__STDC_NO_ATOMICS__)
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# include <stdatomic.h>
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# define HAVE_C11_ATOMICS
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# endif
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# if defined(HAVE_C11_ATOMICS) && defined(ATOMIC_INT_LOCK_FREE) \
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&& ATOMIC_INT_LOCK_FREE > 0
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# define HAVE_ATOMICS 1
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typedef _Atomic int CRYPTO_REF_COUNT;
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static inline int CRYPTO_UP_REF(_Atomic int *val, int *ret, void *lock)
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{
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*ret = atomic_fetch_add_explicit(val, 1, memory_order_relaxed) + 1;
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return 1;
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}
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/*
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* Changes to shared structure other than reference counter have to be
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* serialized. And any kind of serialization implies a release fence. This
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* means that by the time reference counter is decremented all other
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* changes are visible on all processors. Hence decrement itself can be
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* relaxed. In case it hits zero, object will be destructed. Since it's
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* last use of the object, destructor programmer might reason that access
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* to mutable members doesn't have to be serialized anymore, which would
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* otherwise imply an acquire fence. Hence conditional acquire fence...
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*/
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static inline int CRYPTO_DOWN_REF(_Atomic int *val, int *ret, void *lock)
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{
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*ret = atomic_fetch_sub_explicit(val, 1, memory_order_relaxed) - 1;
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if (*ret == 0)
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atomic_thread_fence(memory_order_acquire);
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return 1;
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}
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# elif defined(__GNUC__) && defined(__ATOMIC_RELAXED) && __GCC_ATOMIC_INT_LOCK_FREE > 0
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# define HAVE_ATOMICS 1
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typedef int CRYPTO_REF_COUNT;
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static __inline__ int CRYPTO_UP_REF(int *val, int *ret, void *lock)
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{
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*ret = __atomic_fetch_add(val, 1, __ATOMIC_RELAXED) + 1;
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return 1;
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}
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static __inline__ int CRYPTO_DOWN_REF(int *val, int *ret, void *lock)
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{
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*ret = __atomic_fetch_sub(val, 1, __ATOMIC_RELAXED) - 1;
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if (*ret == 0)
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__atomic_thread_fence(__ATOMIC_ACQUIRE);
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return 1;
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}
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# elif defined(_MSC_VER) && _MSC_VER>=1200
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# define HAVE_ATOMICS 1
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typedef volatile int CRYPTO_REF_COUNT;
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# if (defined(_M_ARM) && _M_ARM>=7 && !defined(_WIN32_WCE)) || defined(_M_ARM64)
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# include <intrin.h>
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# if defined(_M_ARM64) && !defined(_ARM_BARRIER_ISH)
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# define _ARM_BARRIER_ISH _ARM64_BARRIER_ISH
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# endif
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static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, void *lock)
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{
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*ret = _InterlockedExchangeAdd_nf(val, 1) + 1;
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return 1;
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}
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static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, void *lock)
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{
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*ret = _InterlockedExchangeAdd_nf(val, -1) - 1;
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if (*ret == 0)
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__dmb(_ARM_BARRIER_ISH);
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return 1;
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}
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# else
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# if !defined(_WIN32_WCE)
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# pragma intrinsic(_InterlockedExchangeAdd)
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# else
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# if _WIN32_WCE >= 0x600
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extern long __cdecl _InterlockedExchangeAdd(long volatile*, long);
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# else
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// under Windows CE we still have old-style Interlocked* functions
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extern long __cdecl InterlockedExchangeAdd(long volatile*, long);
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# define _InterlockedExchangeAdd InterlockedExchangeAdd
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# endif
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# endif
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static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, void *lock)
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{
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*ret = _InterlockedExchangeAdd(val, 1) + 1;
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return 1;
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}
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static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, void *lock)
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{
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*ret = _InterlockedExchangeAdd(val, -1) - 1;
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return 1;
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}
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# endif
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# endif
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# endif /* !OPENSSL_DEV_NO_ATOMICS */
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/*
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* All the refcounting implementations above define HAVE_ATOMICS, so if it's
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* still undefined here (such as when OPENSSL_DEV_NO_ATMOICS is defined), it
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* means we need to implement a fallback. This fallback uses locks.
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*/
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# ifndef HAVE_ATOMICS
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typedef int CRYPTO_REF_COUNT;
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# define CRYPTO_UP_REF(val, ret, lock) CRYPTO_atomic_add(val, 1, ret, lock)
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# define CRYPTO_DOWN_REF(val, ret, lock) CRYPTO_atomic_add(val, -1, ret, lock)
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# endif
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# if !defined(NDEBUG) && !defined(OPENSSL_NO_STDIO)
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# define REF_ASSERT_ISNT(test) \
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(void)((test) ? (OPENSSL_die("refcount error", __FILE__, __LINE__), 1) : 0)
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# else
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# define REF_ASSERT_ISNT(i)
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# endif
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# ifdef REF_PRINT
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# define REF_PRINT_COUNT(a, b) \
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fprintf(stderr, "%p:%4d:%s\n", b, b->references, a)
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# else
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# define REF_PRINT_COUNT(a, b)
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# endif
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#endif
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