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Fix the Q_ATOMIC_xxx_IS_www_NATIVE macros with C++11

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When I introduced this code in Qt 5.0, I made INT and POINTER be
SOMETIMES_NATIVE, but then later I made the specific sizes be
ALWAYS_NATIVE. That doesn't make sense.

Instead, use the macros from the C++11 <atomic> header.

Note that the member isXxxxNative() functions should not have been
constexpr. That's a defect I introduced in Qt 5.0.

Task-number: QTBUG-51315
Change-Id: I0c94a5c2846b48c8aea7ffff1436013e8686c153
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
This commit is contained in:
Thiago Macieira 2016-02-24 14:28:17 -08:00
parent 5c46d07a7c
commit aca0e367be
1 changed files with 156 additions and 31 deletions
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187
src/corelib/arch/qatomic_cxx11.h
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@ -53,44 +53,168 @@ QT_END_NAMESPACE
#pragma qt_sync_stop_processing #pragma qt_sync_stop_processing
#endif #endif
#define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE /* Attempt to detect whether the atomic operations exist in hardware
#define Q_ATOMIC_INT_TEST_AND_SET_IS_SOMETIMES_NATIVE * or whether they are emulated by way of a lock.
#define Q_ATOMIC_INT_FETCH_AND_STORE_IS_SOMETIMES_NATIVE *
#define Q_ATOMIC_INT_FETCH_AND_ADD_IS_SOMETIMES_NATIVE * 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() Q_DECL_NOTHROW; };
#define Q_ATOMIC_INT32_IS_SUPPORTED #define Q_ATOMIC_INT32_IS_SUPPORTED
#define Q_ATOMIC_INT32_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE #if ATOMIC_INT_LOCK_FREE == 2
#define Q_ATOMIC_INT32_TEST_AND_SET_IS_SOMETIMES_NATIVE # define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_ALWAYS_NATIVE
#define Q_ATOMIC_INT32_FETCH_AND_STORE_IS_SOMETIMES_NATIVE # define Q_ATOMIC_INT_TEST_AND_SET_IS_ALWAYS_NATIVE
#define Q_ATOMIC_INT32_FETCH_AND_ADD_IS_SOMETIMES_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
#define Q_ATOMIC_POINTER_REFERENCE_COUNTING_IS_SOMETIMES_NATIVE template <> Q_DECL_CONSTEXPR inline bool QAtomicTraits<4>::isLockFree() Q_DECL_NOTHROW
#define Q_ATOMIC_POINTER_TEST_AND_SET_IS_SOMETIMES_NATIVE { return true; }
#define Q_ATOMIC_POINTER_FETCH_AND_STORE_IS_SOMETIMES_NATIVE #elif ATOMIC_INT_LOCK_FREE == 1
#define Q_ATOMIC_POINTER_FETCH_AND_ADD_IS_SOMETIMES_NATIVE # 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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ return false; }
#endif
#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<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_IS_SUPPORTED
#define Q_ATOMIC_INT8_REFERENCE_COUNTING_IS_ALWAYS_NATIVE #if ATOMIC_CHAR_LOCK_FREE == 2
#define Q_ATOMIC_INT8_TEST_AND_SET_IS_ALWAYS_NATIVE # define Q_ATOMIC_INT8_REFERENCE_COUNTING_IS_ALWAYS_NATIVE
#define Q_ATOMIC_INT8_FETCH_AND_STORE_IS_ALWAYS_NATIVE # define Q_ATOMIC_INT8_TEST_AND_SET_IS_ALWAYS_NATIVE
#define Q_ATOMIC_INT8_FETCH_AND_ADD_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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ return false; }
#endif
template<> struct QAtomicOpsSupport<2> { enum { IsSupported = 1 }; };
#define Q_ATOMIC_INT16_IS_SUPPORTED #define Q_ATOMIC_INT16_IS_SUPPORTED
#define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_ALWAYS_NATIVE #if ATOMIC_SHORT_LOCK_FREE == 2
#define Q_ATOMIC_INT16_TEST_AND_SET_IS_ALWAYS_NATIVE # define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_ALWAYS_NATIVE
#define Q_ATOMIC_INT16_FETCH_AND_STORE_IS_ALWAYS_NATIVE # define Q_ATOMIC_INT16_TEST_AND_SET_IS_ALWAYS_NATIVE
#define Q_ATOMIC_INT16_FETCH_AND_ADD_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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ return false; }
#endif
#ifndef QT_NO_STD_ATOMIC64 #ifndef QT_NO_STD_ATOMIC64
template<> struct QAtomicOpsSupport<8> { enum { IsSupported = 1 }; };
# define Q_ATOMIC_INT64_IS_SUPPORTED # define Q_ATOMIC_INT64_IS_SUPPORTED
# define Q_ATOMIC_INT64_REFERENCE_COUNTING_IS_ALWAYS_NATIVE # if ATOMIC_LLONG_LOCK_FREE == 2
# define Q_ATOMIC_INT64_TEST_AND_SET_IS_ALWAYS_NATIVE # define Q_ATOMIC_INT16_REFERENCE_COUNTING_IS_ALWAYS_NATIVE
# define Q_ATOMIC_INT64_FETCH_AND_STORE_IS_ALWAYS_NATIVE # define Q_ATOMIC_INT16_TEST_AND_SET_IS_ALWAYS_NATIVE
# define Q_ATOMIC_INT64_FETCH_AND_ADD_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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ 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() Q_DECL_NOTHROW
{ return false; }
# endif
#endif #endif
template <typename X> struct QAtomicOps template <typename X> struct QAtomicOps
@ -133,7 +257,7 @@ template <typename X> struct QAtomicOps
_q_value.store(newValue, std::memory_order_release); _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; } static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() Q_DECL_NOTHROW { return false; }
template <typename T> template <typename T>
static inline bool ref(std::atomic<T> &_q_value) static inline bool ref(std::atomic<T> &_q_value)
@ -147,7 +271,8 @@ template <typename X> struct QAtomicOps
return --_q_value != 0; 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; } static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return false; }
template <typename T> template <typename T>
@ -186,7 +311,7 @@ template <typename X> struct QAtomicOps
return tmp; 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; } static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return false; }
template <typename T> template <typename T>
@ -213,7 +338,7 @@ template <typename X> struct QAtomicOps
return _q_value.exchange(newValue, std::memory_order_acq_rel); 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; } static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return false; }
template <typename T> static inline template <typename T> static inline