diff options
Diffstat (limited to 'src/corelib/arch/qatomic_cxx11.h')
| -rw-r--r-- | src/corelib/arch/qatomic_cxx11.h | 220 |
1 files changed, 176 insertions, 44 deletions
diff --git a/src/corelib/arch/qatomic_cxx11.h b/src/corelib/arch/qatomic_cxx11.h index baa3d65faf..63b23b71ab 100644 --- a/src/corelib/arch/qatomic_cxx11.h +++ b/src/corelib/arch/qatomic_cxx11.h @@ -1,31 +1,38 @@ /**************************************************************************** ** ** Copyright (C) 2011 Thiago Macieira <thiago@kde.org> -** Contact: http://www.qt.io/licensing/ +** Copyright (C) 2016 Intel Corporation. +** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtCore module of the Qt Toolkit. ** -** $QT_BEGIN_LICENSE:LGPL21$ +** $QT_BEGIN_LICENSE:LGPL$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms -** and conditions see http://www.qt.io/terms-conditions. For further -** information use the contact form at http://www.qt.io/contact-us. +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 2.1 or version 3 as published by the Free -** Software Foundation and appearing in the file LICENSE.LGPLv21 and -** LICENSE.LGPLv3 included in the packaging of this file. Please review the -** following information to ensure the GNU Lesser General Public License -** requirements will be met: https://www.gnu.org/licenses/lgpl.html and -** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. ** -** As a special exception, The Qt Company gives you certain additional -** rights. These rights are described in The Qt Company LGPL Exception -** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. ** ** $QT_END_LICENSE$ ** @@ -46,44 +53,168 @@ QT_END_NAMESPACE #pragma qt_sync_stop_processing #endif -#define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_INT_TEST_AND_SET_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_INT_FETCH_AND_STORE_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_INT_FETCH_AND_ADD_IS_SOMETIMES_NATIVE +/* Attempt to detect whether the atomic operations exist in hardware + * or whether they are emulated by way of a lock. + * + * C++11 29.4 [atomics.lockfree] p1 says + * + * The ATOMIC_..._LOCK_FREE macros indicate the lock-free property of the + * corresponding atomic types, with the signed and unsigned variants grouped + * together. The properties also apply to the corresponding (partial) + * specializations of the atomic template. A value of 0 indicates that the + * types are never lock-free. A value of 1 indicates that the types are + * sometimes lock-free. A value of 2 indicates that the types are always + * lock-free. + * + * We have a problem when the value is 1: we'd need to check at runtime, but + * QAtomicInteger requires a constexpr answer (defect introduced in Qt 5.0). So + * we'll err in the side of caution and say it isn't. + */ + +// ### Qt 6: make non-constexpr (see above) +template <int N> struct QAtomicTraits +{ static Q_DECL_CONSTEXPR inline bool isLockFree(); }; #define Q_ATOMIC_INT32_IS_SUPPORTED -#define Q_ATOMIC_INT32_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_INT32_TEST_AND_SET_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_INT32_FETCH_AND_STORE_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_INT32_FETCH_AND_ADD_IS_SOMETIMES_NATIVE +#if ATOMIC_INT_LOCK_FREE == 2 +# define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT_TEST_AND_SET_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT_FETCH_AND_STORE_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT_FETCH_AND_ADD_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT32_REFERENCE_COUNTING_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT32_TEST_AND_SET_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT32_FETCH_AND_STORE_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT32_FETCH_AND_ADD_IS_ALWAYS_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<4>::isLockFree() +{ return true; } +#elif ATOMIC_INT_LOCK_FREE == 1 +# define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT_TEST_AND_SET_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT_FETCH_AND_STORE_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT_FETCH_AND_ADD_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT32_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT32_TEST_AND_SET_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT32_FETCH_AND_STORE_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT32_FETCH_AND_ADD_IS_SOMETIMES_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<4>::isLockFree() +{ return false; } +#else +# define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_NEVER_NATIVE +# define Q_ATOMIC_INT_TEST_AND_SET_IS_NEVER_NATIVE +# define Q_ATOMIC_INT_FETCH_AND_STORE_IS_NEVER_NATIVE +# define Q_ATOMIC_INT_FETCH_AND_ADD_IS_NEVER_NATIVE +# define Q_ATOMIC_INT32_REFERENCE_COUNTING_IS_NEVER_NATIVE +# define Q_ATOMIC_INT32_TEST_AND_SET_IS_NEVER_NATIVE +# define Q_ATOMIC_INT32_FETCH_AND_STORE_IS_NEVER_NATIVE +# define Q_ATOMIC_INT32_FETCH_AND_ADD_IS_NEVER_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<4>::isLockFree() +{ return false; } +#endif -#define Q_ATOMIC_POINTER_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_POINTER_TEST_AND_SET_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_POINTER_FETCH_AND_STORE_IS_SOMETIMES_NATIVE -#define Q_ATOMIC_POINTER_FETCH_AND_ADD_IS_SOMETIMES_NATIVE +#if ATOMIC_POINTER_LOCK_FREE == 2 +# define Q_ATOMIC_POINTER_REFERENCE_COUNTING_IS_ALWAYS_NATIVE +# define Q_ATOMIC_POINTER_TEST_AND_SET_IS_ALWAYS_NATIVE +# define Q_ATOMIC_POINTER_FETCH_AND_STORE_IS_ALWAYS_NATIVE +# define Q_ATOMIC_POINTER_FETCH_AND_ADD_IS_ALWAYS_NATIVE +#elif ATOMIC_POINTER_LOCK_FREE == 1 +# define Q_ATOMIC_POINTER_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_POINTER_TEST_AND_SET_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_POINTER_FETCH_AND_STORE_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_POINTER_FETCH_AND_ADD_IS_SOMETIMES_NATIVE +#else +# define Q_ATOMIC_POINTER_REFERENCE_COUNTING_IS_NEVER_NATIVE +# define Q_ATOMIC_POINTER_TEST_AND_SET_IS_NEVER_NATIVE +# define Q_ATOMIC_POINTER_FETCH_AND_STORE_IS_NEVER_NATIVE +# define Q_ATOMIC_POINTER_FETCH_AND_ADD_IS_NEVER_NATIVE +#endif template<> struct QAtomicOpsSupport<1> { enum { IsSupported = 1 }; }; -template<> struct QAtomicOpsSupport<2> { enum { IsSupported = 1 }; }; -template<> struct QAtomicOpsSupport<8> { enum { IsSupported = 1 }; }; - #define Q_ATOMIC_INT8_IS_SUPPORTED -#define Q_ATOMIC_INT8_REFERENCE_COUNTING_IS_ALWAYS_NATIVE -#define Q_ATOMIC_INT8_TEST_AND_SET_IS_ALWAYS_NATIVE -#define Q_ATOMIC_INT8_FETCH_AND_STORE_IS_ALWAYS_NATIVE -#define Q_ATOMIC_INT8_FETCH_AND_ADD_IS_ALWAYS_NATIVE +#if ATOMIC_CHAR_LOCK_FREE == 2 +# define Q_ATOMIC_INT8_REFERENCE_COUNTING_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT8_TEST_AND_SET_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT8_FETCH_AND_STORE_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT8_FETCH_AND_ADD_IS_ALWAYS_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<1>::isLockFree() +{ return true; } +#elif ATOMIC_CHAR_LOCK_FREE == 1 +# define Q_ATOMIC_INT8_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT8_TEST_AND_SET_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT8_FETCH_AND_STORE_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT8_FETCH_AND_ADD_IS_SOMETIMES_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<1>::isLockFree() +{ return false; } +#else +# define Q_ATOMIC_INT8_REFERENCE_COUNTING_IS_NEVER_NATIVE +# define Q_ATOMIC_INT8_TEST_AND_SET_IS_NEVER_NATIVE +# define Q_ATOMIC_INT8_FETCH_AND_STORE_IS_NEVER_NATIVE +# define Q_ATOMIC_INT8_FETCH_AND_ADD_IS_NEVER_NATIVE +template <> Q_DECL_CONSTEXPR bool QAtomicTraits<1>::isLockFree() +{ return false; } +#endif + +template<> struct QAtomicOpsSupport<2> { enum { IsSupported = 1 }; }; #define Q_ATOMIC_INT16_IS_SUPPORTED -#define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_ALWAYS_NATIVE -#define Q_ATOMIC_INT16_TEST_AND_SET_IS_ALWAYS_NATIVE -#define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_ALWAYS_NATIVE -#define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_ALWAYS_NATIVE +#if ATOMIC_SHORT_LOCK_FREE == 2 +# define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT16_TEST_AND_SET_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_ALWAYS_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<2>::isLockFree() +{ return false; } +#elif ATOMIC_SHORT_LOCK_FREE == 1 +# define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT16_TEST_AND_SET_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_SOMETIMES_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<2>::isLockFree() +{ return false; } +#else +# define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_NEVER_NATIVE +# define Q_ATOMIC_INT16_TEST_AND_SET_IS_NEVER_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_NEVER_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_NEVER_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<2>::isLockFree() +{ return false; } +#endif #ifndef QT_NO_STD_ATOMIC64 +template<> struct QAtomicOpsSupport<8> { enum { IsSupported = 1 }; }; # define Q_ATOMIC_INT64_IS_SUPPORTED -# define Q_ATOMIC_INT64_REFERENCE_COUNTING_IS_ALWAYS_NATIVE -# define Q_ATOMIC_INT64_TEST_AND_SET_IS_ALWAYS_NATIVE -# define Q_ATOMIC_INT64_FETCH_AND_STORE_IS_ALWAYS_NATIVE -# define Q_ATOMIC_INT64_FETCH_AND_ADD_IS_ALWAYS_NATIVE +# if ATOMIC_LLONG_LOCK_FREE == 2 +# define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT16_TEST_AND_SET_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_ALWAYS_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_ALWAYS_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<8>::isLockFree() +{ return true; } +# elif ATOMIC_LLONG_LOCK_FREE == 1 +# define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT16_TEST_AND_SET_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_SOMETIMES_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_SOMETIMES_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<8>::isLockFree() +{ return false; } +# else +# define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_NEVER_NATIVE +# define Q_ATOMIC_INT16_TEST_AND_SET_IS_NEVER_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_NEVER_NATIVE +# define Q_ATOMIC_INT16_FETCH_AND_ADD_IS_NEVER_NATIVE + +template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<8>::isLockFree() +{ return false; } +# endif #endif template <typename X> struct QAtomicOps @@ -126,7 +257,7 @@ template <typename X> struct QAtomicOps _q_value.store(newValue, std::memory_order_release); } - static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() Q_DECL_NOTHROW { return true; } + static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() Q_DECL_NOTHROW { return isTestAndSetNative(); } static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() Q_DECL_NOTHROW { return false; } template <typename T> static inline bool ref(std::atomic<T> &_q_value) @@ -140,7 +271,8 @@ template <typename X> struct QAtomicOps return --_q_value != 0; } - static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW { return false; } + static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW + { return QAtomicTraits<sizeof(X)>::isLockFree(); } static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return false; } template <typename T> @@ -179,7 +311,7 @@ template <typename X> struct QAtomicOps return tmp; } - static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return false; } + static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return isTestAndSetNative(); } static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return false; } template <typename T> @@ -206,7 +338,7 @@ template <typename X> struct QAtomicOps return _q_value.exchange(newValue, std::memory_order_acq_rel); } - static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return false; } + static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return isTestAndSetNative(); } static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return false; } template <typename T> static inline |