// -*- C++ -*- // Copyright (C) 2007-2018 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/unique_copy.h * @brief Parallel implementations of std::unique_copy(). * This file is a GNU parallel extension to the Standard C++ Library. */ // Written by Robert Geisberger and Robin Dapp. #ifndef _GLIBCXX_PARALLEL_UNIQUE_COPY_H #define _GLIBCXX_PARALLEL_UNIQUE_COPY_H 1 #include #include namespace __gnu_parallel { /** @brief Parallel std::unique_copy(), w/__o explicit equality predicate. * @param __first Begin iterator of input sequence. * @param __last End iterator of input sequence. * @param __result Begin iterator of result __sequence. * @param __binary_pred Equality predicate. * @return End iterator of result __sequence. */ template _OutputIterator __parallel_unique_copy(_IIter __first, _IIter __last, _OutputIterator __result, _BinaryPredicate __binary_pred) { _GLIBCXX_CALL(__last - __first) typedef std::iterator_traits<_IIter> _TraitsType; typedef typename _TraitsType::value_type _ValueType; typedef typename _TraitsType::difference_type _DifferenceType; _DifferenceType __size = __last - __first; if (__size == 0) return __result; // Let the first thread process two parts. _DifferenceType *__counter; _DifferenceType *__borders; _ThreadIndex __num_threads = __get_max_threads(); // First part contains at least one element. # pragma omp parallel num_threads(__num_threads) { # pragma omp single { __num_threads = omp_get_num_threads(); __borders = new _DifferenceType[__num_threads + 2]; __equally_split(__size, __num_threads + 1, __borders); __counter = new _DifferenceType[__num_threads + 1]; } _ThreadIndex __iam = omp_get_thread_num(); _DifferenceType __begin, __end; // Check for length without duplicates // Needed for position in output _DifferenceType __i = 0; _OutputIterator __out = __result; if (__iam == 0) { __begin = __borders[0] + 1; // == 1 __end = __borders[__iam + 1]; ++__i; *__out++ = *__first; for (_IIter __iter = __first + __begin; __iter < __first + __end; ++__iter) { if (!__binary_pred(*__iter, *(__iter - 1))) { ++__i; *__out++ = *__iter; } } } else { __begin = __borders[__iam]; //one part __end = __borders[__iam + 1]; for (_IIter __iter = __first + __begin; __iter < __first + __end; ++__iter) { if (!__binary_pred(*__iter, *(__iter - 1))) ++__i; } } __counter[__iam] = __i; // Last part still untouched. _DifferenceType __begin_output; # pragma omp barrier // Store result in output on calculated positions. __begin_output = 0; if (__iam == 0) { for (_ThreadIndex __t = 0; __t < __num_threads; ++__t) __begin_output += __counter[__t]; __i = 0; _OutputIterator __iter_out = __result + __begin_output; __begin = __borders[__num_threads]; __end = __size; for (_IIter __iter = __first + __begin; __iter < __first + __end; ++__iter) { if (__iter == __first || !__binary_pred(*__iter, *(__iter - 1))) { ++__i; *__iter_out++ = *__iter; } } __counter[__num_threads] = __i; } else { for (_ThreadIndex __t = 0; __t < __iam; __t++) __begin_output += __counter[__t]; _OutputIterator __iter_out = __result + __begin_output; for (_IIter __iter = __first + __begin; __iter < __first + __end; ++__iter) { if (!__binary_pred(*__iter, *(__iter - 1))) *__iter_out++ = *__iter; } } } _DifferenceType __end_output = 0; for (_ThreadIndex __t = 0; __t < __num_threads + 1; __t++) __end_output += __counter[__t]; delete[] __borders; return __result + __end_output; } /** @brief Parallel std::unique_copy(), without explicit equality predicate * @param __first Begin iterator of input sequence. * @param __last End iterator of input sequence. * @param __result Begin iterator of result __sequence. * @return End iterator of result __sequence. */ template inline _OutputIterator __parallel_unique_copy(_IIter __first, _IIter __last, _OutputIterator __result) { typedef typename std::iterator_traits<_IIter>::value_type _ValueType; return __parallel_unique_copy(__first, __last, __result, std::equal_to<_ValueType>()); } }//namespace __gnu_parallel #endif /* _GLIBCXX_PARALLEL_UNIQUE_COPY_H */