1/* 2 * Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9#ifndef OSSL_INTERNAL_REFCOUNT_H 10# define OSSL_INTERNAL_REFCOUNT_H 11 12/* Used to checking reference counts, most while doing perl5 stuff :-) */ 13# if defined(OPENSSL_NO_STDIO) 14# if defined(REF_PRINT) 15# error "REF_PRINT requires stdio" 16# endif 17# endif 18 19# if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L \ 20 && !defined(__STDC_NO_ATOMICS__) 21# include <stdatomic.h> 22# define HAVE_C11_ATOMICS 23# endif 24 25# if defined(HAVE_C11_ATOMICS) && defined(ATOMIC_INT_LOCK_FREE) \ 26 && ATOMIC_INT_LOCK_FREE > 0 27 28# define HAVE_ATOMICS 1 29 30typedef _Atomic int CRYPTO_REF_COUNT; 31 32static inline int CRYPTO_UP_REF(_Atomic int *val, int *ret, void *lock) 33{ 34 *ret = atomic_fetch_add_explicit(val, 1, memory_order_relaxed) + 1; 35 return 1; 36} 37 38/* 39 * Changes to shared structure other than reference counter have to be 40 * serialized. And any kind of serialization implies a release fence. This 41 * means that by the time reference counter is decremented all other 42 * changes are visible on all processors. Hence decrement itself can be 43 * relaxed. In case it hits zero, object will be destructed. Since it's 44 * last use of the object, destructor programmer might reason that access 45 * to mutable members doesn't have to be serialized anymore, which would 46 * otherwise imply an acquire fence. Hence conditional acquire fence... 47 */ 48static inline int CRYPTO_DOWN_REF(_Atomic int *val, int *ret, void *lock) 49{ 50 *ret = atomic_fetch_sub_explicit(val, 1, memory_order_relaxed) - 1; 51 if (*ret == 0) 52 atomic_thread_fence(memory_order_acquire); 53 return 1; 54} 55 56# elif defined(__GNUC__) && defined(__ATOMIC_RELAXED) && __GCC_ATOMIC_INT_LOCK_FREE > 0 57 58# define HAVE_ATOMICS 1 59 60typedef int CRYPTO_REF_COUNT; 61 62static __inline__ int CRYPTO_UP_REF(int *val, int *ret, void *lock) 63{ 64 *ret = __atomic_fetch_add(val, 1, __ATOMIC_RELAXED) + 1; 65 return 1; 66} 67 68static __inline__ int CRYPTO_DOWN_REF(int *val, int *ret, void *lock) 69{ 70 *ret = __atomic_fetch_sub(val, 1, __ATOMIC_RELAXED) - 1; 71 if (*ret == 0) 72 __atomic_thread_fence(__ATOMIC_ACQUIRE); 73 return 1; 74} 75 76# elif defined(_MSC_VER) && _MSC_VER>=1200 77 78# define HAVE_ATOMICS 1 79 80typedef volatile int CRYPTO_REF_COUNT; 81 82# if (defined(_M_ARM) && _M_ARM>=7 && !defined(_WIN32_WCE)) || defined(_M_ARM64) 83# include <intrin.h> 84# if defined(_M_ARM64) && !defined(_ARM_BARRIER_ISH) 85# define _ARM_BARRIER_ISH _ARM64_BARRIER_ISH 86# endif 87 88static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, void *lock) 89{ 90 *ret = _InterlockedExchangeAdd_nf(val, 1) + 1; 91 return 1; 92} 93 94static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, void *lock) 95{ 96 *ret = _InterlockedExchangeAdd_nf(val, -1) - 1; 97 if (*ret == 0) 98 __dmb(_ARM_BARRIER_ISH); 99 return 1; 100} 101# else 102# if !defined(_WIN32_WCE) 103# pragma intrinsic(_InterlockedExchangeAdd) 104# else 105# if _WIN32_WCE >= 0x600 106 extern long __cdecl _InterlockedExchangeAdd(long volatile*, long); 107# else 108 /* under Windows CE we still have old-style Interlocked* functions */ 109 extern long __cdecl InterlockedExchangeAdd(long volatile*, long); 110# define _InterlockedExchangeAdd InterlockedExchangeAdd 111# endif 112# endif 113 114static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, void *lock) 115{ 116 *ret = _InterlockedExchangeAdd(val, 1) + 1; 117 return 1; 118} 119 120static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, void *lock) 121{ 122 *ret = _InterlockedExchangeAdd(val, -1) - 1; 123 return 1; 124} 125# endif 126 127# else 128 129typedef int CRYPTO_REF_COUNT; 130 131# define CRYPTO_UP_REF(val, ret, lock) CRYPTO_atomic_add(val, 1, ret, lock) 132# define CRYPTO_DOWN_REF(val, ret, lock) CRYPTO_atomic_add(val, -1, ret, lock) 133 134# endif 135 136# if !defined(NDEBUG) && !defined(OPENSSL_NO_STDIO) 137# define REF_ASSERT_ISNT(test) \ 138 (void)((test) ? (OPENSSL_die("refcount error", __FILE__, __LINE__), 1) : 0) 139# else 140# define REF_ASSERT_ISNT(i) 141# endif 142 143# ifdef REF_PRINT 144# define REF_PRINT_COUNT(a, b) \ 145 fprintf(stderr, "%p:%4d:%s\n", b, b->references, a) 146# else 147# define REF_PRINT_COUNT(a, b) 148# endif 149 150#endif 151