libstdc++
for_each.h
Go to the documentation of this file.
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)
73  (__begin, __end, __user_op, __functionality, __reduction,
74  __reduction_start, __output, __bound);
75  else if (__parallelism_tag == parallel_omp_loop)
77  (__begin, __end, __user_op, __functionality, __reduction,
78  __reduction_start, __output, __bound);
79  else if (__parallelism_tag == parallel_omp_loop_static)
81  (__begin, __end, __user_op, __functionality, __reduction,
82  __reduction_start, __output, __bound);
83  else //e. g. parallel_balanced
85  (__begin, __end, __user_op, __functionality, __reduction,
86  __reduction_start, __output, __bound);
87  }
88 }
89 
90 #endif /* _GLIBCXX_PARALLEL_FOR_EACH_H */
_Op __for_each_template_random_access_omp_loop(_RAIter __begin, _RAIter __end, _Op __o, _Fu &__f, _Red __r, _Result __base, _Result &__output, typename std::iterator_traits< _RAIter >::difference_type __bound)
Embarrassingly parallel algorithm for random access iterators, using an OpenMP for loop.
Definition: omp_loop.h:67
Runtime settings and tuning parameters, heuristics to decide whether to use parallelized algorithms....
_UserOp __for_each_template_random_access(_IIter __begin, _IIter __end, _UserOp __user_op, _Functionality &__functionality, _Red __reduction, _Result __reduction_start, _Result &__output, typename std::iterator_traits< _IIter >::difference_type __bound, _Parallelism __parallelism_tag)
Chose the desired algorithm by evaluating __parallelism_tag.
Definition: for_each.h:61
Parallel with OpenMP dynamic load-balancing.
Definition: types.h:56
Parallelization of embarrassingly parallel execution by means of an OpenMP for loop....
_Op __for_each_template_random_access_workstealing(_RAIter __begin, _RAIter __end, _Op __op, _Fu &__f, _Red __r, _Result __base, _Result &__output, typename std::iterator_traits< _RAIter >::difference_type __bound)
Work stealing algorithm for random access iterators.
Definition: workstealing.h:99
GNU parallel code for public use.
Parallelization of embarrassingly parallel execution by means of equal splitting. This file is a GNU ...
Parallel with OpenMP static load-balancing.
Definition: types.h:59
Parallel unbalanced (equal-sized chunks).
Definition: types.h:50
_Op __for_each_template_random_access_ed(_RAIter __begin, _RAIter __end, _Op __o, _Fu &__f, _Red __r, _Result __base, _Result &__output, typename std::iterator_traits< _RAIter >::difference_type __bound)
Embarrassingly parallel algorithm for random access iterators, using hand-crafted parallelization by ...
Definition: par_loop.h:67
_Parallelism
Run-time equivalents for the compile-time tags.
Definition: types.h:44
Parallelization of embarrassingly parallel execution by means of work-stealing.