libcxx/include/__cxx03/__pstl/backends/std_thread.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___PSTL_BACKENDS_STD_THREAD_H
  10 #define _LIBCPP___PSTL_BACKENDS_STD_THREAD_H
  11
  12 #include <__cxx03/__config>
  13 #include <__cxx03/__pstl/backend_fwd.h>
  14 #include <__cxx03/__pstl/cpu_algos/any_of.h>
  15 #include <__cxx03/__pstl/cpu_algos/cpu_traits.h>
  16 #include <__cxx03/__pstl/cpu_algos/fill.h>
  17 #include <__cxx03/__pstl/cpu_algos/find_if.h>
  18 #include <__cxx03/__pstl/cpu_algos/for_each.h>
  19 #include <__cxx03/__pstl/cpu_algos/merge.h>
  20 #include <__cxx03/__pstl/cpu_algos/stable_sort.h>
  21 #include <__cxx03/__pstl/cpu_algos/transform.h>
  22 #include <__cxx03/__pstl/cpu_algos/transform_reduce.h>
  23 #include <__cxx03/__utility/empty.h>
  24 #include <__cxx03/__utility/move.h>
  25 #include <__cxx03/cstddef>
  26 #include <__cxx03/optional>
  27
  28 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  29 #  pragma GCC system_header
  30 #endif
  31
  32 _LIBCPP_PUSH_MACROS
  33 #include <__cxx03/__undef_macros>
  34
  35 _LIBCPP_BEGIN_NAMESPACE_STD
  36 namespace __pstl {
  37
  38 //
  39 // This partial backend implementation is for testing purposes only and not meant for production use. This will be
  40 // replaced by a proper implementation once the PSTL implementation is somewhat stable.
  41 //
  42 // This is intended to be used on top of the "default backend".
  43 //
  44
  45 template <>
  46 struct __cpu_traits<__std_thread_backend_tag> {
  47   template <class _RandomAccessIterator, class _Fp>
  48   _LIBCPP_HIDE_FROM_ABI static optional<__empty>
  49   __for_each(_RandomAccessIterator __first, _RandomAccessIterator __last, _Fp __f) {
  50     __f(__first, __last);
  51     return __empty{};
  52   }
  53
  54   template <class _Index, class _UnaryOp, class _Tp, class _BinaryOp, class _Reduce>
  55   _LIBCPP_HIDE_FROM_ABI static optional<_Tp>
  56   __transform_reduce(_Index __first, _Index __last, _UnaryOp, _Tp __init, _BinaryOp, _Reduce __reduce) {
  57     return __reduce(std::move(__first), std::move(__last), std::move(__init));
  58   }
  59
  60   template <class _RandomAccessIterator, class _Compare, class _LeafSort>
  61   _LIBCPP_HIDE_FROM_ABI static optional<__empty>
  62   __stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp, _LeafSort __leaf_sort) {
  63     __leaf_sort(__first, __last, __comp);
  64     return __empty{};
  65   }
  66
  67   _LIBCPP_HIDE_FROM_ABI static void __cancel_execution() {}
  68
  69   template <class _RandomAccessIterator1,
  70             class _RandomAccessIterator2,
  71             class _RandomAccessIterator3,
  72             class _Compare,
  73             class _LeafMerge>
  74   _LIBCPP_HIDE_FROM_ABI static optional<__empty>
  75   __merge(_RandomAccessIterator1 __first1,
  76           _RandomAccessIterator1 __last1,
  77           _RandomAccessIterator2 __first2,
  78           _RandomAccessIterator2 __last2,
  79           _RandomAccessIterator3 __outit,
  80           _Compare __comp,
  81           _LeafMerge __leaf_merge) {
  82     __leaf_merge(__first1, __last1, __first2, __last2, __outit, __comp);
  83     return __empty{};
  84   }
  85
  86   static constexpr size_t __lane_size = 64;
  87 };
  88
  89 // Mandatory implementations of the computational basis
  90 template <class _ExecutionPolicy>
  91 struct __find_if<__std_thread_backend_tag, _ExecutionPolicy>
  92     : __cpu_parallel_find_if<__std_thread_backend_tag, _ExecutionPolicy> {};
  93
  94 template <class _ExecutionPolicy>
  95 struct __for_each<__std_thread_backend_tag, _ExecutionPolicy>
  96     : __cpu_parallel_for_each<__std_thread_backend_tag, _ExecutionPolicy> {};
  97
  98 template <class _ExecutionPolicy>
  99 struct __merge<__std_thread_backend_tag, _ExecutionPolicy>
 100     : __cpu_parallel_merge<__std_thread_backend_tag, _ExecutionPolicy> {};
 101
 102 template <class _ExecutionPolicy>
 103 struct __stable_sort<__std_thread_backend_tag, _ExecutionPolicy>
 104     : __cpu_parallel_stable_sort<__std_thread_backend_tag, _ExecutionPolicy> {};
 105
 106 template <class _ExecutionPolicy>
 107 struct __transform<__std_thread_backend_tag, _ExecutionPolicy>
 108     : __cpu_parallel_transform<__std_thread_backend_tag, _ExecutionPolicy> {};
 109
 110 template <class _ExecutionPolicy>
 111 struct __transform_binary<__std_thread_backend_tag, _ExecutionPolicy>
 112     : __cpu_parallel_transform_binary<__std_thread_backend_tag, _ExecutionPolicy> {};
 113
 114 template <class _ExecutionPolicy>
 115 struct __transform_reduce<__std_thread_backend_tag, _ExecutionPolicy>
 116     : __cpu_parallel_transform_reduce<__std_thread_backend_tag, _ExecutionPolicy> {};
 117
 118 template <class _ExecutionPolicy>
 119 struct __transform_reduce_binary<__std_thread_backend_tag, _ExecutionPolicy>
 120     : __cpu_parallel_transform_reduce_binary<__std_thread_backend_tag, _ExecutionPolicy> {};
 121
 122 // Not mandatory, but better optimized
 123 template <class _ExecutionPolicy>
 124 struct __any_of<__std_thread_backend_tag, _ExecutionPolicy>
 125     : __cpu_parallel_any_of<__std_thread_backend_tag, _ExecutionPolicy> {};
 126
 127 template <class _ExecutionPolicy>
 128 struct __fill<__std_thread_backend_tag, _ExecutionPolicy>
 129     : __cpu_parallel_fill<__std_thread_backend_tag, _ExecutionPolicy> {};
 130
 131 } // namespace __pstl
 132 _LIBCPP_END_NAMESPACE_STD
 133
 134 _LIBCPP_POP_MACROS
 135
 136 #endif // _LIBCPP___PSTL_BACKENDS_STD_THREAD_H