contrib/gcc-8.0/libstdc++-v3/include/parallel/for_each.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2007-2018 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file parallel/for_each.h
  26  *  @brief Main interface for embarrassingly parallel functions.
  27  *
  28  *  The explicit implementation are in other header files, like
  29  *  workstealing.h, par_loop.h, omp_loop.h, and omp_loop_static.h.
  30  *  This file is a GNU parallel extension to the Standard C++ Library.
  31  */
  32
  33 // Written by Felix Putze.
  34
  35 #ifndef _GLIBCXX_PARALLEL_FOR_EACH_H
  36 #define _GLIBCXX_PARALLEL_FOR_EACH_H 1
  37
  38 #include <parallel/settings.h>
  39 #include <parallel/par_loop.h>
  40 #include <parallel/omp_loop.h>
  41 #include <parallel/workstealing.h>
  42
  43 namespace __gnu_parallel
  44 {
  45   /** @brief Chose the desired algorithm by evaluating @c __parallelism_tag.
  46    *  @param __begin Begin iterator of input sequence.
  47    *  @param __end End iterator of input sequence.
  48    *  @param __user_op A user-specified functor (comparator, predicate,
  49    *  associative operator,...)
  50    *  @param __functionality functor to @a process an element with
  51    *  __user_op (depends on desired functionality, e. g. accumulate,
  52    *  for_each,...
  53    *  @param __reduction Reduction functor.
  54    *  @param __reduction_start Initial value for reduction.
  55    *  @param __output Output iterator.
  56    *  @param __bound Maximum number of elements processed.
  57    *  @param __parallelism_tag Parallelization method */
  58   template<typename _IIter, typename _UserOp,
  59            typename _Functionality, typename _Red, typename _Result>
  60     _UserOp
  61     __for_each_template_random_access(_IIter __begin, _IIter __end,
  62                                       _UserOp __user_op,
  63                                       _Functionality& __functionality,
  64                                       _Red __reduction,
  65                                       _Result __reduction_start,
  66                                       _Result& __output, typename
  67                                       std::iterator_traits<_IIter>::
  68                                       difference_type __bound,
  69                                       _Parallelism __parallelism_tag)
  70     {
  71       if (__parallelism_tag == parallel_unbalanced)
  72         return __for_each_template_random_access_ed
  73           (__begin, __end, __user_op, __functionality, __reduction,
  74            __reduction_start, __output, __bound);
  75       else if (__parallelism_tag == parallel_omp_loop)
  76         return __for_each_template_random_access_omp_loop
  77           (__begin, __end, __user_op, __functionality, __reduction,
  78            __reduction_start, __output, __bound);
  79       else if (__parallelism_tag == parallel_omp_loop_static)
  80         return __for_each_template_random_access_omp_loop
  81           (__begin, __end, __user_op, __functionality, __reduction,
  82            __reduction_start, __output, __bound);
  83       else      //e. g. parallel_balanced
  84         return __for_each_template_random_access_workstealing
  85           (__begin, __end, __user_op, __functionality, __reduction,
  86            __reduction_start, __output, __bound);
  87   }
  88 }
  89
  90 #endif /* _GLIBCXX_PARALLEL_FOR_EACH_H */