# 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       _ThreadIndex _M_num_threads;
    00050
    00051     public:
    00052       /** @brief Default constructor. Use default number of threads. */
    00053       parallel_tag()
    00054       { _M_num_threads = 0; }
    00055
    00056       /** @brief Default constructor. Recommend number of threads to use.
    00057        *  @param __num_threads Desired number of threads. */
    00058       parallel_tag(_ThreadIndex __num_threads)
    00059       { _M_num_threads = __num_threads; }
    00060
    00061       /** @brief Find out desired number of threads.
    00062        *  @return Desired number of threads. */
    00063       _ThreadIndex __get_num_threads()
    00064       {
    00065         if(_M_num_threads == 0)
    00066           return omp_get_max_threads();
    00067         else
    00068           return _M_num_threads;
    00069       }
    00070
    00071       /** @brief Set the desired number of threads.
    00072        *  @param __num_threads Desired number of threads. */
    00073       void set_num_threads(_ThreadIndex __num_threads)
    00074       { _M_num_threads = __num_threads; }
    00075   };
    00076
    00077   /** @brief Recommends parallel execution using the
    00078       default parallel algorithm. */
    00079   struct default_parallel_tag : public parallel_tag
    00080   {
    00081     default_parallel_tag() { }
    00082     default_parallel_tag(_ThreadIndex __num_threads)
    00083     : parallel_tag(__num_threads) { }
    00084   };
    00085
    00086   /** @brief Recommends parallel execution using dynamic
    00087       load-balancing at compile time. */
    00088   struct balanced_tag : public parallel_tag { };
    00089
    00090   /** @brief Recommends parallel execution using static
    00091       load-balancing at compile time. */
    00092   struct unbalanced_tag : public parallel_tag { };
    00093
    00094   /** @brief Recommends parallel execution using OpenMP dynamic
    00095       load-balancing at compile time. */
    00096   struct omp_loop_tag : public parallel_tag { };
    00097
    00098   /** @brief Recommends parallel execution using OpenMP static
    00099       load-balancing at compile time. */
    00100   struct omp_loop_static_tag : public parallel_tag { };
    00101
    00102
    00103   /** @brief Base class for for std::find() variants. */
    00104   struct find_tag { };
    00105
    00106
    00107   /** @brief Forces parallel merging
    00108    *  with exact splitting, at compile time. */
    00109   struct exact_tag : public parallel_tag
    00110   {
    00111     exact_tag() { }
    00112     exact_tag(_ThreadIndex __num_threads)
    00113     : parallel_tag(__num_threads) { }
    00114   };
    00115
    00116   /** @brief Forces parallel merging
    00117    *  with exact splitting, at compile time. */
    00118   struct sampling_tag : public parallel_tag
    00119   {
    00120     sampling_tag() { }
    00121     sampling_tag(_ThreadIndex __num_threads)
    00122     : parallel_tag(__num_threads) { }
    00123   };
    00124
    00125
    00126   /** @brief Forces parallel sorting using multiway mergesort
    00127    *  at compile time. */
    00128   struct multiway_mergesort_tag : public parallel_tag
    00129   {
    00130     multiway_mergesort_tag() { }
    00131     multiway_mergesort_tag(_ThreadIndex __num_threads)
    00132     : parallel_tag(__num_threads) { }
    00133   };
    00134
    00135   /** @brief Forces parallel sorting using multiway mergesort
    00136    *  with exact splitting at compile time. */
    00137   struct multiway_mergesort_exact_tag : public parallel_tag
    00138   {
    00139     multiway_mergesort_exact_tag() { }
    00140     multiway_mergesort_exact_tag(_ThreadIndex __num_threads)
    00141     : parallel_tag(__num_threads) { }
    00142   };
    00143
    00144   /** @brief Forces parallel sorting using multiway mergesort
    00145    *  with splitting by sampling at compile time. */
    00146   struct multiway_mergesort_sampling_tag : public parallel_tag
    00147   {
    00148     multiway_mergesort_sampling_tag() { }
    00149     multiway_mergesort_sampling_tag(_ThreadIndex __num_threads)
    00150     : parallel_tag(__num_threads) { }
    00151   };
    00152
    00153   /** @brief Forces parallel sorting using unbalanced quicksort
    00154    *  at compile time. */
    00155   struct quicksort_tag : public parallel_tag
    00156   {
    00157     quicksort_tag() { }
    00158     quicksort_tag(_ThreadIndex __num_threads)
    00159     : parallel_tag(__num_threads) { }
    00160   };
    00161
    00162   /** @brief Forces parallel sorting using balanced quicksort
    00163    *  at compile time. */
    00164   struct balanced_quicksort_tag : public parallel_tag
    00165   {
    00166     balanced_quicksort_tag() { }
    00167     balanced_quicksort_tag(_ThreadIndex __num_threads)
    00168     : parallel_tag(__num_threads) { }
    00169   };
    00170
    00171
    00172   /** @brief Selects the growing block size variant for std::find().
    00173       @see _GLIBCXX_FIND_GROWING_BLOCKS */
    00174   struct growing_blocks_tag : public find_tag { };
    00175
    00176   /** @brief Selects the constant block size variant for std::find().
    00177       @see _GLIBCXX_FIND_CONSTANT_SIZE_BLOCKS */
    00178   struct constant_size_blocks_tag : public find_tag { };
    00179
    00180   /** @brief Selects the equal splitting variant for std::find().
    00181       @see _GLIBCXX_FIND_EQUAL_SPLIT */
    00182   struct equal_split_tag : public find_tag { };
    00183 }
    00184
    00185 #endif /* _GLIBCXX_PARALLEL_TAGS_H */