boost/atomic/detail/ops_windows.hpp

   1 /*
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * Copyright (c) 2009 Helge Bahmann
   7  * Copyright (c) 2012 Tim Blechmann
   8  * Copyright (c) 2014 Andrey Semashev
   9  */
  10 /*!
  11  * \file   atomic/detail/ops_windows.hpp
  12  *
  13  * This header contains implementation of the \c operations template.
  14  *
  15  * This implementation is the most basic version for Windows. It should
  16  * work for any non-MSVC-like compilers as long as there are Interlocked WinAPI
  17  * functions available. This version is also used for WinCE.
  18  *
  19  * Notably, this implementation is not as efficient as other
  20  * versions based on compiler intrinsics.
  21  */
  22
  23 #ifndef BOOST_ATOMIC_DETAIL_OPS_WINDOWS_HPP_INCLUDED_
  24 #define BOOST_ATOMIC_DETAIL_OPS_WINDOWS_HPP_INCLUDED_
  25
  26 #include <boost/memory_order.hpp>
  27 #include <boost/type_traits/make_signed.hpp>
  28 #include <boost/atomic/detail/config.hpp>
  29 #include <boost/atomic/detail/interlocked.hpp>
  30 #include <boost/atomic/detail/storage_type.hpp>
  31 #include <boost/atomic/detail/operations_fwd.hpp>
  32 #include <boost/atomic/capabilities.hpp>
  33 #include <boost/atomic/detail/ops_msvc_common.hpp>
  34 #include <boost/atomic/detail/ops_extending_cas_based.hpp>
  35
  36 #ifdef BOOST_HAS_PRAGMA_ONCE
  37 #pragma once
  38 #endif
  39
  40 namespace boost {
  41 namespace atomics {
  42 namespace detail {
  43
  44 struct windows_operations_base
  45 {
  46     static BOOST_FORCEINLINE void hardware_full_fence() BOOST_NOEXCEPT
  47     {
  48         long tmp;
  49         BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&tmp, 0);
  50     }
  51
  52     static BOOST_FORCEINLINE void fence_before(memory_order) BOOST_NOEXCEPT
  53     {
  54         BOOST_ATOMIC_DETAIL_COMPILER_BARRIER();
  55     }
  56
  57     static BOOST_FORCEINLINE void fence_after(memory_order) BOOST_NOEXCEPT
  58     {
  59         BOOST_ATOMIC_DETAIL_COMPILER_BARRIER();
  60     }
  61 };
  62
  63 template< typename T, typename Derived >
  64 struct windows_operations :
  65     public windows_operations_base
  66 {
  67     typedef T storage_type;
  68
  69     static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  70     {
  71         Derived::exchange(storage, v, order);
  72     }
  73
  74     static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order order) BOOST_NOEXCEPT
  75     {
  76         return Derived::fetch_add(const_cast< storage_type volatile& >(storage), (storage_type)0, order);
  77     }
  78
  79     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  80     {
  81         typedef typename make_signed< storage_type >::type signed_storage_type;
  82         return Derived::fetch_add(storage, static_cast< storage_type >(-static_cast< signed_storage_type >(v)), order);
  83     }
  84
  85     static BOOST_FORCEINLINE bool compare_exchange_weak(
  86         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
  87     {
  88         return Derived::compare_exchange_strong(storage, expected, desired, success_order, failure_order);
  89     }
  90
  91     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
  92     {
  93         return !!Derived::exchange(storage, (storage_type)1, order);
  94     }
  95
  96     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
  97     {
  98         store(storage, (storage_type)0, order);
  99     }
 100
 101     static BOOST_FORCEINLINE bool is_lock_free(storage_type const volatile&) BOOST_NOEXCEPT
 102     {
 103         return true;
 104     }
 105 };
 106
 107 template< bool Signed >
 108 struct operations< 4u, Signed > :
 109     public windows_operations< typename make_storage_type< 4u, Signed >::type, operations< 4u, Signed > >
 110 {
 111     typedef windows_operations< typename make_storage_type< 4u, Signed >::type, operations< 4u, Signed > > base_type;
 112     typedef typename base_type::storage_type storage_type;
 113
 114     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
 115     {
 116         base_type::fence_before(order);
 117         v = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD(&storage, v));
 118         base_type::fence_after(order);
 119         return v;
 120     }
 121
 122     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
 123     {
 124         base_type::fence_before(order);
 125         v = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&storage, v));
 126         base_type::fence_after(order);
 127         return v;
 128     }
 129
 130     static BOOST_FORCEINLINE bool compare_exchange_strong(
 131         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
 132     {
 133         storage_type previous = expected;
 134         base_type::fence_before(success_order);
 135         storage_type old_val = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&storage, desired, previous));
 136         expected = old_val;
 137         // The success and failure fences are the same anyway
 138         base_type::fence_after(success_order);
 139         return (previous == old_val);
 140     }
 141
 142     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
 143     {
 144 #if defined(BOOST_ATOMIC_INTERLOCKED_AND)
 145         base_type::fence_before(order);
 146         v = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_AND(&storage, v));
 147         base_type::fence_after(order);
 148         return v;
 149 #else
 150         storage_type res = storage;
 151         while (!compare_exchange_strong(storage, res, res & v, order, memory_order_relaxed)) {}
 152         return res;
 153 #endif
 154     }
 155
 156     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
 157     {
 158 #if defined(BOOST_ATOMIC_INTERLOCKED_OR)
 159         base_type::fence_before(order);
 160         v = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_OR(&storage, v));
 161         base_type::fence_after(order);
 162         return v;
 163 #else
 164         storage_type res = storage;
 165         while (!compare_exchange_strong(storage, res, res | v, order, memory_order_relaxed)) {}
 166         return res;
 167 #endif
 168     }
 169
 170     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
 171     {
 172 #if defined(BOOST_ATOMIC_INTERLOCKED_XOR)
 173         base_type::fence_before(order);
 174         v = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_XOR(&storage, v));
 175         base_type::fence_after(order);
 176         return v;
 177 #else
 178         storage_type res = storage;
 179         while (!compare_exchange_strong(storage, res, res ^ v, order, memory_order_relaxed)) {}
 180         return res;
 181 #endif
 182     }
 183 };
 184
 185 template< bool Signed >
 186 struct operations< 1u, Signed > :
 187     public extending_cas_based_operations< operations< 4u, Signed >, 1u, Signed >
 188 {
 189 };
 190
 191 template< bool Signed >
 192 struct operations< 2u, Signed > :
 193     public extending_cas_based_operations< operations< 4u, Signed >, 2u, Signed >
 194 {
 195 };
 196
 197 BOOST_FORCEINLINE void thread_fence(memory_order order) BOOST_NOEXCEPT
 198 {
 199     BOOST_ATOMIC_DETAIL_COMPILER_BARRIER();
 200     if (order == memory_order_seq_cst)
 201         windows_operations_base::hardware_full_fence();
 202     BOOST_ATOMIC_DETAIL_COMPILER_BARRIER();
 203 }
 204
 205 BOOST_FORCEINLINE void signal_fence(memory_order order) BOOST_NOEXCEPT
 206 {
 207     if (order != memory_order_relaxed)
 208         BOOST_ATOMIC_DETAIL_COMPILER_BARRIER();
 209 }
 210
 211 } // namespace detail
 212 } // namespace atomics
 213 } // namespace boost
 214
 215 #endif // BOOST_ATOMIC_DETAIL_OPS_WINDOWS_HPP_INCLUDED_