# tags.h

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    00001 // -*- C++ -*-
    00002
    00003 // Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
    00004 //
    00005 // This file is part of the GNU ISO C++ Library.  This library is free
    00006 // software; you can redistribute it and/or modify it under the terms
    00007 // of the GNU General Public License as published by the Free Software
    00008 // Foundation; either version 3, or (at your option) any later
    00009 // version.
    00010
    00011 // This library is distributed in the hope that it will be useful, but
    00012 // WITHOUT ANY WARRANTY; without even the implied warranty of
    00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00014 // General Public License for more details.
    00015
    00016 // Under Section 7 of GPL version 3, you are granted additional
    00017 // permissions described in the GCC Runtime Library Exception, version
    00018 // 3.1, as published by the Free Software Foundation.
    00019
    00020 // You should have received a copy of the GNU General Public License and
    00021 // a copy of the GCC Runtime Library Exception along with this program;
    00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    00023 // <http://www.gnu.org/licenses/>.
    00024
    00025 /**
    00026  * @file parallel/tags.h
    00027  * @brief Tags for compile-time selection.
    00028  *  This file is a GNU parallel extension to the Standard C++ Library.
    00029  */
    00030
    00031 // Written by Johannes Singler and Felix Putze.
    00032
    00033 #ifndef _GLIBCXX_PARALLEL_TAGS_H
    00034 #define _GLIBCXX_PARALLEL_TAGS_H 1
    00035
    00036 #include <omp.h>
    00037 #include <parallel/types.h>
    00038
    00039 namespace __gnu_parallel
    00040 {
    00041   /** @brief Forces sequential execution at compile time. */
    00042   struct sequential_tag { };
    00043
    00044   /** @brief Recommends parallel execution at compile time,
    00045    *  optionally using a user-specified number of threads. */
    00046   struct parallel_tag
    00047   {
    00048     private:
    00049       thread_index_t num_threads;
    00050
    00051     public:
    00052       /** @brief Default constructor. Use default number of threads. */
    00053       parallel_tag()
    00054       {
    00055         this->num_threads = 0;
    00056       }
    00057
    00058       /** @brief Default constructor. Recommend number of threads to use.
    00059        *  @param num_threads Desired number of threads. */
    00060       parallel_tag(thread_index_t num_threads)
    00061       {
    00062         this->num_threads = num_threads;
    00063       }
    00064
    00065       /** @brief Find out desired number of threads.
    00066        *  @return Desired number of threads. */
    00067       inline thread_index_t get_num_threads()
    00068       {
    00069         if(num_threads == 0)
    00070           return omp_get_max_threads();
    00071         else
    00072           return num_threads;
    00073       }
    00074
    00075       /** @brief Set the desired number of threads.
    00076        *  @param num_threads Desired number of threads. */
    00077       inline void set_num_threads(thread_index_t num_threads)
    00078       {
    00079         this->num_threads = num_threads;
    00080       }
    00081   };
    00082
    00083   /** @brief Recommends parallel execution using the
    00084       default parallel algorithm. */
    00085   struct default_parallel_tag : public parallel_tag
    00086   {
    00087       default_parallel_tag() { }
    00088       default_parallel_tag(thread_index_t num_threads)
    00089           : parallel_tag(num_threads) { }
    00090   };
    00091
    00092   /** @brief Recommends parallel execution using dynamic
    00093       load-balancing at compile time. */
    00094   struct balanced_tag : public parallel_tag { };
    00095
    00096   /** @brief Recommends parallel execution using static
    00097       load-balancing at compile time. */
    00098   struct unbalanced_tag : public parallel_tag { };
    00099
    00100   /** @brief Recommends parallel execution using OpenMP dynamic
    00101       load-balancing at compile time. */
    00102   struct omp_loop_tag : public parallel_tag { };
    00103
    00104   /** @brief Recommends parallel execution using OpenMP static
    00105       load-balancing at compile time. */
    00106   struct omp_loop_static_tag : public parallel_tag { };
    00107
    00108
    00109   /** @brief Base class for for std::find() variants. */
    00110   struct find_tag { };
    00111
    00112
    00113   /** @brief Forces parallel merging
    00114    *  with exact splitting, at compile time. */
    00115   struct exact_tag : public parallel_tag
    00116   {
    00117       exact_tag() { }
    00118       exact_tag(thread_index_t num_threads)
    00119           : parallel_tag(num_threads) { }
    00120   };
    00121
    00122   /** @brief Forces parallel merging
    00123    *  with exact splitting, at compile time. */
    00124   struct sampling_tag : public parallel_tag
    00125   {
    00126       sampling_tag() { }
    00127       sampling_tag(thread_index_t num_threads)
    00128           : parallel_tag(num_threads) { }
    00129   };
    00130
    00131
    00132   /** @brief Forces parallel sorting using multiway mergesort
    00133    *  at compile time. */
    00134   struct multiway_mergesort_tag : public parallel_tag
    00135   {
    00136       multiway_mergesort_tag() { }
    00137       multiway_mergesort_tag(thread_index_t num_threads)
    00138           : parallel_tag(num_threads) { }
    00139   };
    00140
    00141   /** @brief Forces parallel sorting using multiway mergesort
    00142    *  with exact splitting at compile time. */
    00143   struct multiway_mergesort_exact_tag : public parallel_tag
    00144   {
    00145       multiway_mergesort_exact_tag() { }
    00146       multiway_mergesort_exact_tag(thread_index_t num_threads)
    00147           : parallel_tag(num_threads) { }
    00148   };
    00149
    00150   /** @brief Forces parallel sorting using multiway mergesort
    00151    *  with splitting by sampling at compile time. */
    00152   struct multiway_mergesort_sampling_tag : public parallel_tag
    00153   {
    00154       multiway_mergesort_sampling_tag() { }
    00155       multiway_mergesort_sampling_tag(thread_index_t num_threads)
    00156           : parallel_tag(num_threads) { }
    00157   };
    00158
    00159   /** @brief Forces parallel sorting using unbalanced quicksort
    00160    *  at compile time. */
    00161   struct quicksort_tag : public parallel_tag
    00162   {
    00163       quicksort_tag() { }
    00164       quicksort_tag(thread_index_t num_threads)
    00165           : parallel_tag(num_threads) { }
    00166   };
    00167
    00168   /** @brief Forces parallel sorting using balanced quicksort
    00169    *  at compile time. */
    00170   struct balanced_quicksort_tag : public parallel_tag
    00171   {
    00172       balanced_quicksort_tag() { }
    00173       balanced_quicksort_tag(thread_index_t num_threads)
    00174           : parallel_tag(num_threads) { }
    00175   };
    00176
    00177
    00178   /** @brief Selects the growing block size variant for std::find().
    00179       @see _GLIBCXX_FIND_GROWING_BLOCKS */
    00180   struct growing_blocks_tag : public find_tag { };
    00181
    00182   /** @brief Selects the constant block size variant for std::find().
    00183       @see _GLIBCXX_FIND_CONSTANT_SIZE_BLOCKS */
    00184   struct constant_size_blocks_tag : public find_tag { };
    00185
    00186   /** @brief Selects the equal splitting variant for std::find().
    00187       @see _GLIBCXX_FIND_EQUAL_SPLIT */
    00188   struct equal_split_tag : public find_tag { };
    00189 }
    00190
    00191 #endif /* _GLIBCXX_PARALLEL_TAGS_H */