// -*- C++ -*-
-// Copyright (C) 2007, 2008 Free Software Foundation, Inc.
+// Copyright (C) 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
-// Foundation; either version 2, or (at your option) any later
+// Foundation; either version 3, or (at your option) any later
// version.
// This library is distributed in the hope that it will be useful, but
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
-// You should have received a copy of the GNU General Public License
-// along with this library; see the file COPYING. If not, write to
-// the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
-// MA 02111-1307, USA.
-
-// As a special exception, you may use this file as part of a free
-// software library without restriction. Specifically, if other files
-// instantiate templates or use macros or inline functions from this
-// file, or you compile this file and link it with other files to
-// produce an executable, this file does not by itself cause the
-// resulting executable to be covered by the GNU General Public
-// License. This exception does not however invalidate any other
-// reasons why the executable file might be covered by the GNU General
-// Public License.
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
/** @file parallel/par_loop.h
* @brief Parallelization of embarrassingly parallel execution by
#include <omp.h>
#include <parallel/settings.h>
#include <parallel/base.h>
+#include <parallel/equally_split.h>
namespace __gnu_parallel
{
-
-/** @brief Embarrassingly parallel algorithm for random access
- * iterators, using hand-crafted parallelization by equal splitting
- * the work.
- *
- * @param begin Begin iterator of element sequence.
- * @param end End iterator of element sequence.
- * @param o User-supplied functor (comparator, predicate, adding
- * functor, ...)
- * @param f Functor to "process" an element with op (depends on
- * desired functionality, e. g. for std::for_each(), ...).
- * @param r Functor to "add" a single result to the already
- * processed elements (depends on functionality).
- * @param base Base value for reduction.
- * @param output Pointer to position where final result is written to
- * @param bound Maximum number of elements processed (e. g. for
- * std::count_n()).
- * @return User-supplied functor (that may contain a part of the result).
- */
-template<typename RandomAccessIterator,
- typename Op,
- typename Fu,
- typename Red,
- typename Result>
- Op
- for_each_template_random_access_ed(RandomAccessIterator begin,
- RandomAccessIterator end,
- Op o, Fu& f, Red r, Result base,
- Result& output,
- typename std::iterator_traits
- <RandomAccessIterator>::
- difference_type bound)
- {
- typedef std::iterator_traits<RandomAccessIterator> traits_type;
- typedef typename traits_type::difference_type difference_type;
-
- const difference_type length = end - begin;
- Result *thread_results;
-
- thread_index_t num_threads =
- __gnu_parallel::min<difference_type>(get_max_threads(), length);
-
-# pragma omp parallel num_threads(num_threads)
+ /** @brief Embarrassingly parallel algorithm for random access
+ * iterators, using hand-crafted parallelization by equal splitting
+ * the work.
+ *
+ * @param __begin Begin iterator of element sequence.
+ * @param __end End iterator of element sequence.
+ * @param __o User-supplied functor (comparator, predicate, adding
+ * functor, ...)
+ * @param __f Functor to "process" an element with __op (depends on
+ * desired functionality, e. g. for std::for_each(), ...).
+ * @param __r Functor to "add" a single __result to the already
+ * processed elements (depends on functionality).
+ * @param __base Base value for reduction.
+ * @param __output Pointer to position where final result is written to
+ * @param __bound Maximum number of elements processed (e. g. for
+ * std::count_n()).
+ * @return User-supplied functor (that may contain a part of the result).
+ */
+ template<typename _RAIter,
+ typename _Op,
+ typename _Fu,
+ typename _Red,
+ typename _Result>
+ _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)
+ {
+ typedef std::iterator_traits<_RAIter> _TraitsType;
+ typedef typename _TraitsType::difference_type _DifferenceType;
+ const _DifferenceType __length = __end - __begin;
+ _Result *__thread_results;
+ bool* __constructed;
+
+ _ThreadIndex __num_threads = __gnu_parallel::min<_DifferenceType>
+ (__get_max_threads(), __length);
+
+# pragma omp parallel num_threads(__num_threads)
{
# pragma omp single
- {
- num_threads = omp_get_num_threads();
- thread_results = new Result[num_threads];
- }
-
- thread_index_t iam = omp_get_thread_num();
-
- // Neutral element.
- Result reduct = Result();
-
- difference_type
- start = equally_split_point(length, num_threads, iam),
- stop = equally_split_point(length, num_threads, iam + 1);
-
- if (start < stop)
- {
- reduct = f(o, begin + start);
- ++start;
- }
-
- for (; start < stop; ++start)
- reduct = r(reduct, f(o, begin + start));
-
- thread_results[iam] = reduct;
+ {
+ __num_threads = omp_get_num_threads();
+ __thread_results = static_cast<_Result*>
+ (::operator new(__num_threads * sizeof(_Result)));
+ __constructed = new bool[__num_threads];
+ }
+
+ _ThreadIndex __iam = omp_get_thread_num();
+
+ // Neutral element.
+ _Result* __reduct = static_cast<_Result*>
+ (::operator new(sizeof(_Result)));
+
+ _DifferenceType
+ __start = __equally_split_point(__length, __num_threads, __iam),
+ __stop = __equally_split_point(__length, __num_threads, __iam + 1);
+
+ if (__start < __stop)
+ {
+ new(__reduct) _Result(__f(__o, __begin + __start));
+ ++__start;
+ __constructed[__iam] = true;
+ }
+ else
+ __constructed[__iam] = false;
+
+ for (; __start < __stop; ++__start)
+ *__reduct = __r(*__reduct, __f(__o, __begin + __start));
+
+ __thread_results[__iam] = *__reduct;
} //parallel
- for (thread_index_t i = 0; i < num_threads; ++i)
- output = r(output, thread_results[i]);
+ for (_ThreadIndex __i = 0; __i < __num_threads; ++__i)
+ if (__constructed[__i])
+ __output = __r(__output, __thread_results[__i]);
+
+ // Points to last element processed (needed as return value for
+ // some algorithms like transform).
+ __f._M_finish_iterator = __begin + __length;
- // Points to last element processed (needed as return value for
- // some algorithms like transform).
- f.finish_iterator = begin + length;
+ delete[] __thread_results;
+ delete[] __constructed;
- return o;
- }
+ return __o;
+ }
} // end namespace
-#endif
+#endif /* _GLIBCXX_PARALLEL_PAR_LOOP_H */
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