From 1cd6e20de6e40ead3795087811f151f00b06e016 Mon Sep 17 00:00:00 2001 From: amacleod Date: Sun, 6 Nov 2011 14:55:48 +0000 Subject: Check in patch/merge from cxx-mem-model Branch git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181031 138bc75d-0d04-0410-961f-82ee72b054a4 --- libstdc++-v3/include/bits/atomic_base.h | 675 ++++++++++++++++++++++++++++---- 1 file changed, 600 insertions(+), 75 deletions(-) (limited to 'libstdc++-v3/include/bits/atomic_base.h') diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h index ebb7d58ac72..2e4a6a1894a 100644 --- a/libstdc++-v3/include/bits/atomic_base.h +++ b/libstdc++-v3/include/bits/atomic_base.h @@ -83,86 +83,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return __ret; } - /** - * @brief Base type for atomic_flag. - * - * Base type is POD with data, allowing atomic_flag to derive from - * it and meet the standard layout type requirement. In addition to - * compatibilty with a C interface, this allows different - * implementations of atomic_flag to use the same atomic operation - * functions, via a standard conversion to the __atomic_flag_base - * argument. - */ - _GLIBCXX_BEGIN_EXTERN_C + /// Lock-free Property - struct __atomic_flag_base - { - bool _M_i; - }; +#define LOCKFREE_PROP(T) (__atomic_always_lock_free (sizeof (T), 0) ? 2 : 1) - _GLIBCXX_END_EXTERN_C - -#define ATOMIC_FLAG_INIT { false } +#define ATOMIC_CHAR_LOCK_FREE LOCKFREE_PROP (char) +#define ATOMIC_CHAR16_T_LOCK_FREE LOCKFREE_PROP (char16_t) +#define ATOMIC_CHAR32_T_LOCK_FREE LOCKFREE_PROP (char32_t) +#define ATOMIC_WCHAR_T_LOCK_FREE LOCKFREE_PROP (wchar_t) +#define ATOMIC_SHORT_LOCK_FREE LOCKFREE_PROP (short) +#define ATOMIC_INT_LOCK_FREE LOCKFREE_PROP (int) +#define ATOMIC_LONG_LOCK_FREE LOCKFREE_PROP (long) +#define ATOMIC_LLONG_LOCK_FREE LOCKFREE_PROP (long long) // Base types for atomics. - // - // Three nested namespaces for atomic implementation details. - // - // The nested namespace inlined into std:: is determined by the value - // of the _GLIBCXX_ATOMIC_PROPERTY macro and the resulting - // ATOMIC_*_LOCK_FREE macros. - // - // 0 == __atomic0 == Never lock-free - // 1 == __atomic1 == Best available, sometimes lock-free - // 2 == __atomic2 == Always lock-free - - namespace __atomic0 - { - struct atomic_flag; - - template - struct __atomic_base; - } - - namespace __atomic2 - { - struct atomic_flag; - - template - struct __atomic_base; - } - - namespace __atomic1 - { - using __atomic2::atomic_flag; - using __atomic0::__atomic_base; - } - - /// Lock-free Property -#if defined(_GLIBCXX_ATOMIC_BUILTINS_1) && defined(_GLIBCXX_ATOMIC_BUILTINS_2) \ - && defined(_GLIBCXX_ATOMIC_BUILTINS_4) && defined(_GLIBCXX_ATOMIC_BUILTINS_8) -# define _GLIBCXX_ATOMIC_PROPERTY 2 -# define _GLIBCXX_ATOMIC_NAMESPACE __atomic2 -#elif defined(_GLIBCXX_ATOMIC_BUILTINS_1) -# define _GLIBCXX_ATOMIC_PROPERTY 1 -# define _GLIBCXX_ATOMIC_NAMESPACE __atomic1 -#else -# define _GLIBCXX_ATOMIC_PROPERTY 0 -# define _GLIBCXX_ATOMIC_NAMESPACE __atomic0 -#endif - -#define ATOMIC_CHAR_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_CHAR16_T_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_CHAR32_T_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_WCHAR_T_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_SHORT_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_INT_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_LONG_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY -#define ATOMIC_LLONG_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY - - inline namespace _GLIBCXX_ATOMIC_NAMESPACE { } - + template + struct __atomic_base; /// atomic_char typedef __atomic_base atomic_char; @@ -287,6 +224,594 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template struct atomic<_Tp*>; + + /** + * @brief Base type for atomic_flag. + * + * Base type is POD with data, allowing atomic_flag to derive from + * it and meet the standard layout type requirement. In addition to + * compatibilty with a C interface, this allows different + * implementations of atomic_flag to use the same atomic operation + * functions, via a standard conversion to the __atomic_flag_base + * argument. + */ + _GLIBCXX_BEGIN_EXTERN_C + + struct __atomic_flag_base + { + bool _M_i; + }; + + _GLIBCXX_END_EXTERN_C + +#define ATOMIC_FLAG_INIT { false } + + /// atomic_flag + struct atomic_flag : public __atomic_flag_base + { + atomic_flag() noexcept = default; + ~atomic_flag() noexcept = default; + atomic_flag(const atomic_flag&) = delete; + atomic_flag& operator=(const atomic_flag&) = delete; + atomic_flag& operator=(const atomic_flag&) volatile = delete; + + // Conversion to ATOMIC_FLAG_INIT. + atomic_flag(bool __i) noexcept : __atomic_flag_base({ __i }) { } + + bool + test_and_set(memory_order __m = memory_order_seq_cst) noexcept + { + return __atomic_exchange_n(&_M_i, 1, __m); + } + + bool + test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept + { + return __atomic_exchange_n(&_M_i, 1, __m); + } + + void + clear(memory_order __m = memory_order_seq_cst) noexcept + { + __glibcxx_assert(__m != memory_order_consume); + __glibcxx_assert(__m != memory_order_acquire); + __glibcxx_assert(__m != memory_order_acq_rel); + + __atomic_store_n(&_M_i, 0, __m); + } + + void + clear(memory_order __m = memory_order_seq_cst) volatile noexcept + { + __glibcxx_assert(__m != memory_order_consume); + __glibcxx_assert(__m != memory_order_acquire); + __glibcxx_assert(__m != memory_order_acq_rel); + + __atomic_store_n(&_M_i, 0, __m); + } + }; + + + /// Base class for atomic integrals. + // + // For each of the integral types, define atomic_[integral type] struct + // + // atomic_bool bool + // atomic_char char + // atomic_schar signed char + // atomic_uchar unsigned char + // atomic_short short + // atomic_ushort unsigned short + // atomic_int int + // atomic_uint unsigned int + // atomic_long long + // atomic_ulong unsigned long + // atomic_llong long long + // atomic_ullong unsigned long long + // atomic_char16_t char16_t + // atomic_char32_t char32_t + // atomic_wchar_t wchar_t + // + // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or + // 8 bytes, since that is what GCC built-in functions for atomic + // memory access expect. + template + struct __atomic_base + { + private: + typedef _ITp __int_type; + + __int_type _M_i; + + public: + __atomic_base() noexcept = default; + ~__atomic_base() noexcept = default; + __atomic_base(const __atomic_base&) = delete; + __atomic_base& operator=(const __atomic_base&) = delete; + __atomic_base& operator=(const __atomic_base&) volatile = delete; + + // Requires __int_type convertible to _M_i. + constexpr __atomic_base(__int_type __i) noexcept : _M_i (__i) { } + + operator __int_type() const noexcept + { return load(); } + + operator __int_type() const volatile noexcept + { return load(); } + + __int_type + operator=(__int_type __i) noexcept + { + store(__i); + return __i; + } + + __int_type + operator=(__int_type __i) volatile noexcept + { + store(__i); + return __i; + } + + __int_type + operator++(int) noexcept + { return fetch_add(1); } + + __int_type + operator++(int) volatile noexcept + { return fetch_add(1); } + + __int_type + operator--(int) noexcept + { return fetch_sub(1); } + + __int_type + operator--(int) volatile noexcept + { return fetch_sub(1); } + + __int_type + operator++() noexcept + { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); } + + __int_type + operator++() volatile noexcept + { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); } + + __int_type + operator--() noexcept + { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); } + + __int_type + operator--() volatile noexcept + { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); } + + __int_type + operator+=(__int_type __i) noexcept + { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator+=(__int_type __i) volatile noexcept + { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator-=(__int_type __i) noexcept + { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator-=(__int_type __i) volatile noexcept + { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator&=(__int_type __i) noexcept + { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator&=(__int_type __i) volatile noexcept + { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator|=(__int_type __i) noexcept + { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator|=(__int_type __i) volatile noexcept + { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator^=(__int_type __i) noexcept + { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); } + + __int_type + operator^=(__int_type __i) volatile noexcept + { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); } + + bool + is_lock_free() const noexcept + { return __atomic_is_lock_free (sizeof (_M_i), &_M_i); } + + bool + is_lock_free() const volatile noexcept + { return __atomic_is_lock_free (sizeof (_M_i), &_M_i); } + + void + store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept + { + __glibcxx_assert(__m != memory_order_acquire); + __glibcxx_assert(__m != memory_order_acq_rel); + __glibcxx_assert(__m != memory_order_consume); + + __atomic_store_n(&_M_i, __i, __m); + } + + void + store(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { + __glibcxx_assert(__m != memory_order_acquire); + __glibcxx_assert(__m != memory_order_acq_rel); + __glibcxx_assert(__m != memory_order_consume); + + __atomic_store_n(&_M_i, __i, __m); + } + + __int_type + load(memory_order __m = memory_order_seq_cst) const noexcept + { + __glibcxx_assert(__m != memory_order_release); + __glibcxx_assert(__m != memory_order_acq_rel); + + return __atomic_load_n(&_M_i, __m); + } + + __int_type + load(memory_order __m = memory_order_seq_cst) const volatile noexcept + { + __glibcxx_assert(__m != memory_order_release); + __glibcxx_assert(__m != memory_order_acq_rel); + + return __atomic_load_n(&_M_i, __m); + } + + __int_type + exchange(__int_type __i, + memory_order __m = memory_order_seq_cst) noexcept + { + return __atomic_exchange_n(&_M_i, __i, __m); + } + + + __int_type + exchange(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { + return __atomic_exchange_n(&_M_i, __i, __m); + } + + bool + compare_exchange_weak(__int_type& __i1, __int_type __i2, + memory_order __m1, memory_order __m2) noexcept + { + __glibcxx_assert(__m2 != memory_order_release); + __glibcxx_assert(__m2 != memory_order_acq_rel); + __glibcxx_assert(__m2 <= __m1); + + return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2); + } + + bool + compare_exchange_weak(__int_type& __i1, __int_type __i2, + memory_order __m1, + memory_order __m2) volatile noexcept + { + __glibcxx_assert(__m2 != memory_order_release); + __glibcxx_assert(__m2 != memory_order_acq_rel); + __glibcxx_assert(__m2 <= __m1); + + return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2); + } + + bool + compare_exchange_weak(__int_type& __i1, __int_type __i2, + memory_order __m = memory_order_seq_cst) noexcept + { + return compare_exchange_weak(__i1, __i2, __m, + __calculate_memory_order(__m)); + } + + bool + compare_exchange_weak(__int_type& __i1, __int_type __i2, + memory_order __m = memory_order_seq_cst) volatile noexcept + { + return compare_exchange_weak(__i1, __i2, __m, + __calculate_memory_order(__m)); + } + + bool + compare_exchange_strong(__int_type& __i1, __int_type __i2, + memory_order __m1, memory_order __m2) noexcept + { + __glibcxx_assert(__m2 != memory_order_release); + __glibcxx_assert(__m2 != memory_order_acq_rel); + __glibcxx_assert(__m2 <= __m1); + + return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2); + } + + bool + compare_exchange_strong(__int_type& __i1, __int_type __i2, + memory_order __m1, + memory_order __m2) volatile noexcept + { + __glibcxx_assert(__m2 != memory_order_release); + __glibcxx_assert(__m2 != memory_order_acq_rel); + __glibcxx_assert(__m2 <= __m1); + + return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2); + } + + bool + compare_exchange_strong(__int_type& __i1, __int_type __i2, + memory_order __m = memory_order_seq_cst) noexcept + { + return compare_exchange_strong(__i1, __i2, __m, + __calculate_memory_order(__m)); + } + + bool + compare_exchange_strong(__int_type& __i1, __int_type __i2, + memory_order __m = memory_order_seq_cst) volatile noexcept + { + return compare_exchange_strong(__i1, __i2, __m, + __calculate_memory_order(__m)); + } + + __int_type + fetch_add(__int_type __i, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_add(&_M_i, __i, __m); } + + __int_type + fetch_add(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_add(&_M_i, __i, __m); } + + __int_type + fetch_sub(__int_type __i, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_sub(&_M_i, __i, __m); } + + __int_type + fetch_sub(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_sub(&_M_i, __i, __m); } + + __int_type + fetch_and(__int_type __i, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_and(&_M_i, __i, __m); } + + __int_type + fetch_and(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_and(&_M_i, __i, __m); } + + __int_type + fetch_or(__int_type __i, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_or(&_M_i, __i, __m); } + + __int_type + fetch_or(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_or(&_M_i, __i, __m); } + + __int_type + fetch_xor(__int_type __i, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_xor(&_M_i, __i, __m); } + + __int_type + fetch_xor(__int_type __i, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_xor(&_M_i, __i, __m); } + }; + + + /// Partial specialization for pointer types. + template + struct __atomic_base<_PTp*> + { + private: + typedef _PTp* __pointer_type; + + __pointer_type _M_p; + + public: + __atomic_base() noexcept = default; + ~__atomic_base() noexcept = default; + __atomic_base(const __atomic_base&) = delete; + __atomic_base& operator=(const __atomic_base&) = delete; + __atomic_base& operator=(const __atomic_base&) volatile = delete; + + // Requires __pointer_type convertible to _M_p. + constexpr __atomic_base(__pointer_type __p) noexcept : _M_p (__p) { } + + operator __pointer_type() const noexcept + { return load(); } + + operator __pointer_type() const volatile noexcept + { return load(); } + + __pointer_type + operator=(__pointer_type __p) noexcept + { + store(__p); + return __p; + } + + __pointer_type + operator=(__pointer_type __p) volatile noexcept + { + store(__p); + return __p; + } + + __pointer_type + operator++(int) noexcept + { return fetch_add(1); } + + __pointer_type + operator++(int) volatile noexcept + { return fetch_add(1); } + + __pointer_type + operator--(int) noexcept + { return fetch_sub(1); } + + __pointer_type + operator--(int) volatile noexcept + { return fetch_sub(1); } + + __pointer_type + operator++() noexcept + { return __atomic_add_fetch(&_M_p, 1, memory_order_seq_cst); } + + __pointer_type + operator++() volatile noexcept + { return __atomic_add_fetch(&_M_p, 1, memory_order_seq_cst); } + + __pointer_type + operator--() noexcept + { return __atomic_sub_fetch(&_M_p, 1, memory_order_seq_cst); } + + __pointer_type + operator--() volatile noexcept + { return __atomic_sub_fetch(&_M_p, 1, memory_order_seq_cst); } + + __pointer_type + operator+=(ptrdiff_t __d) noexcept + { return __atomic_add_fetch(&_M_p, __d, memory_order_seq_cst); } + + __pointer_type + operator+=(ptrdiff_t __d) volatile noexcept + { return __atomic_add_fetch(&_M_p, __d, memory_order_seq_cst); } + + __pointer_type + operator-=(ptrdiff_t __d) noexcept + { return __atomic_sub_fetch(&_M_p, __d, memory_order_seq_cst); } + + __pointer_type + operator-=(ptrdiff_t __d) volatile noexcept + { return __atomic_sub_fetch(&_M_p, __d, memory_order_seq_cst); } + + bool + is_lock_free() const noexcept + { return __atomic_is_lock_free (sizeof (_M_p), &_M_p); } + + bool + is_lock_free() const volatile noexcept + { return __atomic_is_lock_free (sizeof (_M_p), &_M_p); } + + void + store(__pointer_type __p, + memory_order __m = memory_order_seq_cst) noexcept + { + __glibcxx_assert(__m != memory_order_acquire); + __glibcxx_assert(__m != memory_order_acq_rel); + __glibcxx_assert(__m != memory_order_consume); + + __atomic_store_n(&_M_p, __p, __m); + } + + void + store(__pointer_type __p, + memory_order __m = memory_order_seq_cst) volatile noexcept + { + __glibcxx_assert(__m != memory_order_acquire); + __glibcxx_assert(__m != memory_order_acq_rel); + __glibcxx_assert(__m != memory_order_consume); + + __atomic_store_n(&_M_p, __p, __m); + } + + __pointer_type + load(memory_order __m = memory_order_seq_cst) const noexcept + { + __glibcxx_assert(__m != memory_order_release); + __glibcxx_assert(__m != memory_order_acq_rel); + + return __atomic_load_n(&_M_p, __m); + } + + __pointer_type + load(memory_order __m = memory_order_seq_cst) const volatile noexcept + { + __glibcxx_assert(__m != memory_order_release); + __glibcxx_assert(__m != memory_order_acq_rel); + + return __atomic_load_n(&_M_p, __m); + } + + __pointer_type + exchange(__pointer_type __p, + memory_order __m = memory_order_seq_cst) noexcept + { + return __atomic_exchange_n(&_M_p, __p, __m); + } + + + __pointer_type + exchange(__pointer_type __p, + memory_order __m = memory_order_seq_cst) volatile noexcept + { + return __atomic_exchange_n(&_M_p, __p, __m); + } + + bool + compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2, + memory_order __m1, + memory_order __m2) noexcept + { + __glibcxx_assert(__m2 != memory_order_release); + __glibcxx_assert(__m2 != memory_order_acq_rel); + __glibcxx_assert(__m2 <= __m1); + + return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, __m1, __m2); + } + + bool + compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2, + memory_order __m1, + memory_order __m2) volatile noexcept + { + __glibcxx_assert(__m2 != memory_order_release); + __glibcxx_assert(__m2 != memory_order_acq_rel); + __glibcxx_assert(__m2 <= __m1); + + return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, __m1, __m2); + } + + __pointer_type + fetch_add(ptrdiff_t __d, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_add(&_M_p, __d, __m); } + + __pointer_type + fetch_add(ptrdiff_t __d, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_add(&_M_p, __d, __m); } + + __pointer_type + fetch_sub(ptrdiff_t __d, + memory_order __m = memory_order_seq_cst) noexcept + { return __atomic_fetch_sub(&_M_p, __d, __m); } + + __pointer_type + fetch_sub(ptrdiff_t __d, + memory_order __m = memory_order_seq_cst) volatile noexcept + { return __atomic_fetch_sub(&_M_p, __d, __m); } + }; + // @} group atomics _GLIBCXX_END_NAMESPACE_VERSION -- cgit v1.2.1 From 8808bf16125e1bea5cd2e969d19a53b9618593f1 Mon Sep 17 00:00:00 2001 From: amacleod Date: Mon, 7 Nov 2011 20:06:39 +0000 Subject: 2011-11-07 Andrew MacLeod libstdc++-v3 * include/bits/atomic_base.h (atomic_thread_fence): Call builtin. (atomic_signal_fence): Call builtin. (atomic_flag::test_and_set): Call __atomic_exchange when it is lockfree, otherwise fall back to call __sync_lock_test_and_set. (atomic_flag::clear): Call __atomic_store when it is lockfree, otherwise fall back to call __sync_lock_release. gcc * doc/extend.texi: Docuemnt behaviour change for __atomic_exchange and __atomic_store. * optabs.c (expand_atomic_exchange): Expand to __sync_lock_test_and_set only when originated from that builtin. (expand_atomic_store): Expand to __sync_lock_release when originated from that builtin. * builtins.c (expand_builtin_sync_lock_test_and_set): Add flag that expand_atomic_exchange call originated from here. (expand_builtin_sync_lock_release): Add flag that expand_atomic_store call originated from here. (expand_builtin_atomic_exchange): Add origination flag. (expand_builtin_atomic_store): Add origination flag. * expr.h (expand_atomic_exchange, expand_atomic_store): Add boolean parameters to indicate implementation fall back options. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181111 138bc75d-0d04-0410-961f-82ee72b054a4 --- libstdc++-v3/include/bits/atomic_base.h | 60 +++++++++++++++++++++++++++++---- 1 file changed, 54 insertions(+), 6 deletions(-) (limited to 'libstdc++-v3/include/bits/atomic_base.h') diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h index 2e4a6a1894a..e297eb0e6ad 100644 --- a/libstdc++-v3/include/bits/atomic_base.h +++ b/libstdc++-v3/include/bits/atomic_base.h @@ -69,10 +69,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } void - atomic_thread_fence(memory_order) noexcept; + atomic_thread_fence(memory_order __m) noexcept + { + __atomic_thread_fence (__m); + } void - atomic_signal_fence(memory_order) noexcept; + atomic_signal_fence(memory_order __m) noexcept + { + __atomic_signal_fence (__m); + } /// kill_dependency template @@ -261,13 +267,35 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION bool test_and_set(memory_order __m = memory_order_seq_cst) noexcept { - return __atomic_exchange_n(&_M_i, 1, __m); + /* The standard *requires* this to be lock free. If exchange is not + always lock free, the resort to the old test_and_set. */ + if (__atomic_always_lock_free (sizeof (_M_i), 0)) + return __atomic_exchange_n(&_M_i, 1, __m); + else + { + /* Sync test and set is only guaranteed to be acquire. */ + if (__m == memory_order_seq_cst || __m == memory_order_release + || __m == memory_order_acq_rel) + atomic_thread_fence (__m); + return __sync_lock_test_and_set (&_M_i, 1); + } } bool test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept { - return __atomic_exchange_n(&_M_i, 1, __m); + /* The standard *requires* this to be lock free. If exchange is not + always lock free, the resort to the old test_and_set. */ + if (__atomic_always_lock_free (sizeof (_M_i), 0)) + return __atomic_exchange_n(&_M_i, 1, __m); + else + { + /* Sync test and set is only guaranteed to be acquire. */ + if (__m == memory_order_seq_cst || __m == memory_order_release + || __m == memory_order_acq_rel) + atomic_thread_fence (__m); + return __sync_lock_test_and_set (&_M_i, 1); + } } void @@ -277,7 +305,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __glibcxx_assert(__m != memory_order_acquire); __glibcxx_assert(__m != memory_order_acq_rel); - __atomic_store_n(&_M_i, 0, __m); + /* The standard *requires* this to be lock free. If store is not always + lock free, the resort to the old style __sync_lock_release. */ + if (__atomic_always_lock_free (sizeof (_M_i), 0)) + __atomic_store_n(&_M_i, 0, __m); + else + { + __sync_lock_release (&_M_i, 0); + /* __sync_lock_release is only guaranteed to be a release barrier. */ + if (__m == memory_order_seq_cst) + atomic_thread_fence (__m); + } } void @@ -287,7 +325,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __glibcxx_assert(__m != memory_order_acquire); __glibcxx_assert(__m != memory_order_acq_rel); - __atomic_store_n(&_M_i, 0, __m); + /* The standard *requires* this to be lock free. If store is not always + lock free, the resort to the old style __sync_lock_release. */ + if (__atomic_always_lock_free (sizeof (_M_i), 0)) + __atomic_store_n(&_M_i, 0, __m); + else + { + __sync_lock_release (&_M_i, 0); + /* __sync_lock_release is only guaranteed to be a release barrier. */ + if (__m == memory_order_seq_cst) + atomic_thread_fence (__m); + } } }; -- cgit v1.2.1 From e41ed5326fe37cae0d30182535b0e2e867f0fd1d Mon Sep 17 00:00:00 2001 From: amacleod Date: Mon, 7 Nov 2011 21:32:52 +0000 Subject: 2011-11-07 Andrew MacLeod * include/bits/atomic_base.h (atomic_thread_fence): Revert. (atomic_signal_fence): Revert. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181119 138bc75d-0d04-0410-961f-82ee72b054a4 --- libstdc++-v3/include/bits/atomic_base.h | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'libstdc++-v3/include/bits/atomic_base.h') diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h index e297eb0e6ad..5327c1bfa21 100644 --- a/libstdc++-v3/include/bits/atomic_base.h +++ b/libstdc++-v3/include/bits/atomic_base.h @@ -69,16 +69,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } void - atomic_thread_fence(memory_order __m) noexcept - { - __atomic_thread_fence (__m); - } + atomic_thread_fence(memory_order __m) noexcept; void - atomic_signal_fence(memory_order __m) noexcept - { - __atomic_signal_fence (__m); - } + atomic_signal_fence(memory_order __m) noexcept; /// kill_dependency template -- cgit v1.2.1