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Diffstat (limited to 'thirdparty/internal/refcount.h')
| -rw-r--r-- | thirdparty/internal/refcount.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/thirdparty/internal/refcount.h b/thirdparty/internal/refcount.h new file mode 100644 index 00000000..7412d62f --- /dev/null +++ b/thirdparty/internal/refcount.h @@ -0,0 +1,178 @@ +/* + * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the Apache License 2.0 (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ +#ifndef OSSL_INTERNAL_REFCOUNT_H +# define OSSL_INTERNAL_REFCOUNT_H +# pragma once + +# include <openssl/e_os2.h> +# include <openssl/trace.h> + +# ifndef OPENSSL_DEV_NO_ATOMICS +# if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L \ + && !defined(__STDC_NO_ATOMICS__) +# include <stdatomic.h> +# define HAVE_C11_ATOMICS +# endif + +# if defined(HAVE_C11_ATOMICS) && defined(ATOMIC_INT_LOCK_FREE) \ + && ATOMIC_INT_LOCK_FREE > 0 + +# define HAVE_ATOMICS 1 + +typedef _Atomic int CRYPTO_REF_COUNT; + +static inline int CRYPTO_UP_REF(_Atomic int *val, int *ret, + ossl_unused void *lock) +{ + *ret = atomic_fetch_add_explicit(val, 1, memory_order_relaxed) + 1; + return 1; +} + +/* + * Changes to shared structure other than reference counter have to be + * serialized. And any kind of serialization implies a release fence. This + * means that by the time reference counter is decremented all other + * changes are visible on all processors. Hence decrement itself can be + * relaxed. In case it hits zero, object will be destructed. Since it's + * last use of the object, destructor programmer might reason that access + * to mutable members doesn't have to be serialized anymore, which would + * otherwise imply an acquire fence. Hence conditional acquire fence... + */ +static inline int CRYPTO_DOWN_REF(_Atomic int *val, int *ret, + ossl_unused void *lock) +{ + *ret = atomic_fetch_sub_explicit(val, 1, memory_order_relaxed) - 1; + if (*ret == 0) + atomic_thread_fence(memory_order_acquire); + return 1; +} + +# elif defined(__GNUC__) && defined(__ATOMIC_RELAXED) && __GCC_ATOMIC_INT_LOCK_FREE > 0 + +# define HAVE_ATOMICS 1 + +typedef int CRYPTO_REF_COUNT; + +static __inline__ int CRYPTO_UP_REF(int *val, int *ret, ossl_unused void *lock) +{ + *ret = __atomic_fetch_add(val, 1, __ATOMIC_RELAXED) + 1; + return 1; +} + +static __inline__ int CRYPTO_DOWN_REF(int *val, int *ret, + ossl_unused void *lock) +{ + *ret = __atomic_fetch_sub(val, 1, __ATOMIC_RELAXED) - 1; + if (*ret == 0) + __atomic_thread_fence(__ATOMIC_ACQUIRE); + return 1; +} +# elif defined(__ICL) && defined(_WIN32) +# define HAVE_ATOMICS 1 +typedef volatile int CRYPTO_REF_COUNT; + +static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, + ossl_unused void *lock) +{ + *ret = _InterlockedExchangeAdd((void *)val, 1) + 1; + return 1; +} + +static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, + ossl_unused void *lock) +{ + *ret = _InterlockedExchangeAdd((void *)val, -1) - 1; + return 1; +} + +# elif defined(_MSC_VER) && _MSC_VER>=1200 + +# define HAVE_ATOMICS 1 + +typedef volatile int CRYPTO_REF_COUNT; + +# if (defined(_M_ARM) && _M_ARM>=7 && !defined(_WIN32_WCE)) || defined(_M_ARM64) +# include <intrin.h> +# if defined(_M_ARM64) && !defined(_ARM_BARRIER_ISH) +# define _ARM_BARRIER_ISH _ARM64_BARRIER_ISH +# endif + +static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, + ossl_unused void *lock) +{ + *ret = _InterlockedExchangeAdd_nf(val, 1) + 1; + return 1; +} + +static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, + ossl_unused void *lock) +{ + *ret = _InterlockedExchangeAdd_nf(val, -1) - 1; + if (*ret == 0) + __dmb(_ARM_BARRIER_ISH); + return 1; +} +# else +# if !defined(_WIN32_WCE) +# pragma intrinsic(_InterlockedExchangeAdd) +# else +# if _WIN32_WCE >= 0x600 + extern long __cdecl _InterlockedExchangeAdd(long volatile*, long); +# else + /* under Windows CE we still have old-style Interlocked* functions */ + extern long __cdecl InterlockedExchangeAdd(long volatile*, long); +# define _InterlockedExchangeAdd InterlockedExchangeAdd +# endif +# endif + +static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, + ossl_unused void *lock) +{ + *ret = _InterlockedExchangeAdd(val, 1) + 1; + return 1; +} + +static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, + ossl_unused void *lock) +{ + *ret = _InterlockedExchangeAdd(val, -1) - 1; + return 1; +} +# endif + +# endif +# endif /* !OPENSSL_DEV_NO_ATOMICS */ + +/* + * All the refcounting implementations above define HAVE_ATOMICS, so if it's + * still undefined here (such as when OPENSSL_DEV_NO_ATOMICS is defined), it + * means we need to implement a fallback. This fallback uses locks. + */ +# ifndef HAVE_ATOMICS + +typedef int CRYPTO_REF_COUNT; + +# define CRYPTO_UP_REF(val, ret, lock) CRYPTO_atomic_add(val, 1, ret, lock) +# define CRYPTO_DOWN_REF(val, ret, lock) CRYPTO_atomic_add(val, -1, ret, lock) + +# endif + +# if !defined(NDEBUG) && !defined(OPENSSL_NO_STDIO) +# define REF_ASSERT_ISNT(test) \ + (void)((test) ? (OPENSSL_die("refcount error", __FILE__, __LINE__), 1) : 0) +# else +# define REF_ASSERT_ISNT(i) +# endif + +# define REF_PRINT_EX(text, count, object) \ + OSSL_TRACE3(REF_COUNT, "%p:%4d:%s\n", (object), (count), (text)); +# define REF_PRINT_COUNT(text, object) \ + REF_PRINT_EX(text, object->references, (void *)object) + +#endif |