X-Git-Url: http://wagnertech.de/git?a=blobdiff_plain;f=i686-linux-gnu-4.7%2Fusr%2Finclude%2Fc%2B%2B%2F4.7%2Fparallel%2Fsearch.h;fp=i686-linux-gnu-4.7%2Fusr%2Finclude%2Fc%2B%2B%2F4.7%2Fparallel%2Fsearch.h;h=b58ee9b8aee7eff339a54e94e30ed80ede61120b;hb=94df942c2c7bd3457276fe5b7367623cbb8c1302;hp=0000000000000000000000000000000000000000;hpb=4dd7d9155a920895ff7b1cb6b9c9c676aa62000a;p=cross.git diff --git a/i686-linux-gnu-4.7/usr/include/c++/4.7/parallel/search.h b/i686-linux-gnu-4.7/usr/include/c++/4.7/parallel/search.h new file mode 100644 index 0000000..b58ee9b --- /dev/null +++ b/i686-linux-gnu-4.7/usr/include/c++/4.7/parallel/search.h @@ -0,0 +1,172 @@ +// -*- C++ -*- + +// 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 3, or (at your option) any later +// version. + +// This library is distributed in the hope that it will be useful, but +// WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// General Public License for more details. + +// 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 +// . + +/** @file parallel/search.h + * @brief Parallel implementation base for std::search() and + * std::search_n(). + * This file is a GNU parallel extension to the Standard C++ Library. + */ + +// Written by Felix Putze. + +#ifndef _GLIBCXX_PARALLEL_SEARCH_H +#define _GLIBCXX_PARALLEL_SEARCH_H 1 + +#include + +#include +#include + +namespace __gnu_parallel +{ + /** + * @brief Precalculate __advances for Knuth-Morris-Pratt algorithm. + * @param __elements Begin iterator of sequence to search for. + * @param __length Length of sequence to search for. + * @param __off Returned __offsets. + */ + template + void + __calc_borders(_RAIter __elements, _DifferenceTp __length, + _DifferenceTp* __off) + { + typedef _DifferenceTp _DifferenceType; + + __off[0] = -1; + if (__length > 1) + __off[1] = 0; + _DifferenceType __k = 0; + for (_DifferenceType __j = 2; __j <= __length; __j++) + { + while ((__k >= 0) && !(__elements[__k] == __elements[__j-1])) + __k = __off[__k]; + __off[__j] = ++__k; + } + } + + // Generic parallel find algorithm (requires random access iterator). + + /** @brief Parallel std::search. + * @param __begin1 Begin iterator of first sequence. + * @param __end1 End iterator of first sequence. + * @param __begin2 Begin iterator of second sequence. + * @param __end2 End iterator of second sequence. + * @param __pred Find predicate. + * @return Place of finding in first sequences. */ + template + __RAIter1 + __search_template(__RAIter1 __begin1, __RAIter1 __end1, + __RAIter2 __begin2, __RAIter2 __end2, + _Pred __pred) + { + typedef std::iterator_traits<__RAIter1> _TraitsType; + typedef typename _TraitsType::difference_type _DifferenceType; + + _GLIBCXX_CALL((__end1 - __begin1) + (__end2 - __begin2)); + + _DifferenceType __pattern_length = __end2 - __begin2; + + // Pattern too short. + if(__pattern_length <= 0) + return __end1; + + // Last point to start search. + _DifferenceType __input_length = (__end1 - __begin1) - __pattern_length; + + // Where is first occurrence of pattern? defaults to end. + _DifferenceType __result = (__end1 - __begin1); + _DifferenceType *__splitters; + + // Pattern too long. + if (__input_length < 0) + return __end1; + + omp_lock_t __result_lock; + omp_init_lock(&__result_lock); + + _ThreadIndex __num_threads = std::max<_DifferenceType> + (1, std::min<_DifferenceType>(__input_length, + __get_max_threads())); + + _DifferenceType __advances[__pattern_length]; + __calc_borders(__begin2, __pattern_length, __advances); + +# pragma omp parallel num_threads(__num_threads) + { +# pragma omp single + { + __num_threads = omp_get_num_threads(); + __splitters = new _DifferenceType[__num_threads + 1]; + __equally_split(__input_length, __num_threads, __splitters); + } + + _ThreadIndex __iam = omp_get_thread_num(); + + _DifferenceType __start = __splitters[__iam], + __stop = __splitters[__iam + 1]; + + _DifferenceType __pos_in_pattern = 0; + bool __found_pattern = false; + + while (__start <= __stop && !__found_pattern) + { + // Get new value of result. +#pragma omp flush(__result) + // No chance for this thread to find first occurrence. + if (__result < __start) + break; + while (__pred(__begin1[__start + __pos_in_pattern], + __begin2[__pos_in_pattern])) + { + ++__pos_in_pattern; + if (__pos_in_pattern == __pattern_length) + { + // Found new candidate for result. + omp_set_lock(&__result_lock); + __result = std::min(__result, __start); + omp_unset_lock(&__result_lock); + + __found_pattern = true; + break; + } + } + // Make safe jump. + __start += (__pos_in_pattern - __advances[__pos_in_pattern]); + __pos_in_pattern = (__advances[__pos_in_pattern] < 0 + ? 0 : __advances[__pos_in_pattern]); + } + } //parallel + + omp_destroy_lock(&__result_lock); + + delete[] __splitters; + + // Return iterator on found element. + return (__begin1 + __result); + } +} // end namespace + +#endif /* _GLIBCXX_PARALLEL_SEARCH_H */