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00039 #ifndef _GLIBCXX_PARALLEL_SEARCH_H
00040 #define _GLIBCXX_PARALLEL_SEARCH_H 1
00041
00042 #include <bits/stl_algobase.h>
00043
00044 #include <parallel/parallel.h>
00045 #include <parallel/equally_split.h>
00046
00047
00048 namespace __gnu_parallel
00049 {
00050
00051
00052
00053
00054
00055
00056 template<typename RandomAccessIterator, typename _DifferenceTp>
00057 void
00058 calc_borders(RandomAccessIterator elements, _DifferenceTp length,
00059 _DifferenceTp* off)
00060 {
00061 typedef _DifferenceTp difference_type;
00062
00063 off[0] = -1;
00064 if (length > 1)
00065 off[1] = 0;
00066 difference_type k = 0;
00067 for (difference_type j = 2; j <= length; j++)
00068 {
00069 while ((k >= 0) && !(elements[k] == elements[j-1]))
00070 k = off[k];
00071 off[j] = ++k;
00072 }
00073 }
00074
00075
00076
00077
00078
00079
00080
00081
00082
00083
00084 template<typename _RandomAccessIterator1,
00085 typename _RandomAccessIterator2,
00086 typename Pred>
00087 _RandomAccessIterator1
00088 search_template(_RandomAccessIterator1 begin1, _RandomAccessIterator1 end1,
00089 _RandomAccessIterator2 begin2, _RandomAccessIterator2 end2,
00090 Pred pred)
00091 {
00092 typedef std::iterator_traits<_RandomAccessIterator1> traits_type;
00093 typedef typename traits_type::difference_type difference_type;
00094
00095 _GLIBCXX_CALL((end1 - begin1) + (end2 - begin2));
00096
00097 difference_type pattern_length = end2 - begin2;
00098
00099
00100 if(pattern_length <= 0)
00101 return end1;
00102
00103
00104 difference_type input_length = (end1 - begin1) - pattern_length;
00105
00106
00107 difference_type result = (end1 - begin1);
00108 difference_type *splitters;
00109
00110
00111 if (input_length < 0)
00112 return end1;
00113
00114 omp_lock_t result_lock;
00115 omp_init_lock(&result_lock);
00116
00117 thread_index_t num_threads =
00118 std::max<difference_type>(1,
00119 std::min<difference_type>(input_length, get_max_threads()));
00120
00121 difference_type advances[pattern_length];
00122 calc_borders(begin2, pattern_length, advances);
00123
00124 # pragma omp parallel num_threads(num_threads)
00125 {
00126 # pragma omp single
00127 {
00128 num_threads = omp_get_num_threads();
00129 splitters = new difference_type[num_threads + 1];
00130 equally_split(input_length, num_threads, splitters);
00131 }
00132
00133 thread_index_t iam = omp_get_thread_num();
00134
00135 difference_type start = splitters[iam], stop = splitters[iam + 1];
00136
00137 difference_type pos_in_pattern = 0;
00138 bool found_pattern = false;
00139
00140 while (start <= stop && !found_pattern)
00141 {
00142
00143 #pragma omp flush(result)
00144
00145 if (result < start)
00146 break;
00147 while (pred(begin1[start + pos_in_pattern],
00148 begin2[pos_in_pattern]))
00149 {
00150 ++pos_in_pattern;
00151 if (pos_in_pattern == pattern_length)
00152 {
00153
00154 omp_set_lock(&result_lock);
00155 result = std::min(result, start);
00156 omp_unset_lock(&result_lock);
00157
00158 found_pattern = true;
00159 break;
00160 }
00161 }
00162
00163 start += (pos_in_pattern - advances[pos_in_pattern]);
00164 pos_in_pattern =
00165 (advances[pos_in_pattern] < 0) ? 0 : advances[pos_in_pattern];
00166 }
00167 }
00168
00169 omp_destroy_lock(&result_lock);
00170
00171 delete[] splitters;
00172
00173
00174 return (begin1 + result);
00175 }
00176 }
00177
00178 #endif