contrib/gcc-4.4/libstdc++-v3/include/parallel/tags.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2007, 2008, 2009 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 /**
  26  * @file parallel/tags.h
  27  * @brief Tags for compile-time selection.
  28  *  This file is a GNU parallel extension to the Standard C++ Library.
  29  */
  30
  31 // Written by Johannes Singler and Felix Putze.
  32
  33 #ifndef _GLIBCXX_PARALLEL_TAGS_H
  34 #define _GLIBCXX_PARALLEL_TAGS_H 1
  35
  36 #include <omp.h>
  37 #include <parallel/types.h>
  38
  39 namespace __gnu_parallel
  40 {
  41   /** @brief Forces sequential execution at compile time. */
  42   struct sequential_tag { };
  43
  44   /** @brief Recommends parallel execution at compile time,
  45    *  optionally using a user-specified number of threads. */
  46   struct parallel_tag
  47   {
  48     private:
  49       thread_index_t num_threads;
  50
  51     public:
  52       /** @brief Default constructor. Use default number of threads. */
  53       parallel_tag()
  54       {
  55         this->num_threads = 0;
  56       }
  57
  58       /** @brief Default constructor. Recommend number of threads to use.
  59        *  @param num_threads Desired number of threads. */
  60       parallel_tag(thread_index_t num_threads)
  61       {
  62         this->num_threads = num_threads;
  63       }
  64
  65       /** @brief Find out desired number of threads.
  66        *  @return Desired number of threads. */
  67       inline thread_index_t get_num_threads()
  68       {
  69         if(num_threads == 0)
  70           return omp_get_max_threads();
  71         else
  72           return num_threads;
  73       }
  74
  75       /** @brief Set the desired number of threads.
  76        *  @param num_threads Desired number of threads. */
  77       inline void set_num_threads(thread_index_t num_threads)
  78       {
  79         this->num_threads = num_threads;
  80       }
  81   };
  82
  83   /** @brief Recommends parallel execution using the
  84       default parallel algorithm. */
  85   struct default_parallel_tag : public parallel_tag
  86   {
  87       default_parallel_tag() { }
  88       default_parallel_tag(thread_index_t num_threads)
  89           : parallel_tag(num_threads) { }
  90   };
  91
  92   /** @brief Recommends parallel execution using dynamic
  93       load-balancing at compile time. */
  94   struct balanced_tag : public parallel_tag { };
  95
  96   /** @brief Recommends parallel execution using static
  97       load-balancing at compile time. */
  98   struct unbalanced_tag : public parallel_tag { };
  99
 100   /** @brief Recommends parallel execution using OpenMP dynamic
 101       load-balancing at compile time. */
 102   struct omp_loop_tag : public parallel_tag { };
 103
 104   /** @brief Recommends parallel execution using OpenMP static
 105       load-balancing at compile time. */
 106   struct omp_loop_static_tag : public parallel_tag { };
 107
 108
 109   /** @brief Base class for for std::find() variants. */
 110   struct find_tag { };
 111
 112
 113   /** @brief Forces parallel merging
 114    *  with exact splitting, at compile time. */
 115   struct exact_tag : public parallel_tag
 116   {
 117       exact_tag() { }
 118       exact_tag(thread_index_t num_threads)
 119           : parallel_tag(num_threads) { }
 120   };
 121
 122   /** @brief Forces parallel merging
 123    *  with exact splitting, at compile time. */
 124   struct sampling_tag : public parallel_tag
 125   {
 126       sampling_tag() { }
 127       sampling_tag(thread_index_t num_threads)
 128           : parallel_tag(num_threads) { }
 129   };
 130
 131
 132   /** @brief Forces parallel sorting using multiway mergesort
 133    *  at compile time. */
 134   struct multiway_mergesort_tag : public parallel_tag
 135   {
 136       multiway_mergesort_tag() { }
 137       multiway_mergesort_tag(thread_index_t num_threads)
 138           : parallel_tag(num_threads) { }
 139   };
 140
 141   /** @brief Forces parallel sorting using multiway mergesort
 142    *  with exact splitting at compile time. */
 143   struct multiway_mergesort_exact_tag : public parallel_tag
 144   {
 145       multiway_mergesort_exact_tag() { }
 146       multiway_mergesort_exact_tag(thread_index_t num_threads)
 147           : parallel_tag(num_threads) { }
 148   };
 149
 150   /** @brief Forces parallel sorting using multiway mergesort
 151    *  with splitting by sampling at compile time. */
 152   struct multiway_mergesort_sampling_tag : public parallel_tag
 153   {
 154       multiway_mergesort_sampling_tag() { }
 155       multiway_mergesort_sampling_tag(thread_index_t num_threads)
 156           : parallel_tag(num_threads) { }
 157   };
 158
 159   /** @brief Forces parallel sorting using unbalanced quicksort
 160    *  at compile time. */
 161   struct quicksort_tag : public parallel_tag
 162   {
 163       quicksort_tag() { }
 164       quicksort_tag(thread_index_t num_threads)
 165           : parallel_tag(num_threads) { }
 166   };
 167
 168   /** @brief Forces parallel sorting using balanced quicksort
 169    *  at compile time. */
 170   struct balanced_quicksort_tag : public parallel_tag
 171   {
 172       balanced_quicksort_tag() { }
 173       balanced_quicksort_tag(thread_index_t num_threads)
 174           : parallel_tag(num_threads) { }
 175   };
 176
 177
 178   /** @brief Selects the growing block size variant for std::find().
 179       @see _GLIBCXX_FIND_GROWING_BLOCKS */
 180   struct growing_blocks_tag : public find_tag { };
 181
 182   /** @brief Selects the constant block size variant for std::find().
 183       @see _GLIBCXX_FIND_CONSTANT_SIZE_BLOCKS */
 184   struct constant_size_blocks_tag : public find_tag { };
 185
 186   /** @brief Selects the equal splitting variant for std::find().
 187       @see _GLIBCXX_FIND_EQUAL_SPLIT */
 188   struct equal_split_tag : public find_tag { };
 189 }
 190
 191 #endif /* _GLIBCXX_PARALLEL_TAGS_H */