1 |
424 |
jeremybenn |
// -*- C++ -*-
|
2 |
|
|
|
3 |
|
|
// Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
|
4 |
|
|
//
|
5 |
|
|
// This file is part of the GNU ISO C++ Library. This library is free
|
6 |
|
|
// software; you can redistribute it and/or modify it under the terms
|
7 |
|
|
// of the GNU General Public License as published by the Free Software
|
8 |
|
|
// Foundation; either version 3, or (at your option) any later
|
9 |
|
|
// version.
|
10 |
|
|
|
11 |
|
|
// This library is distributed in the hope that it will be useful, but
|
12 |
|
|
// WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
|
|
// General Public License for more details.
|
15 |
|
|
|
16 |
|
|
// Under Section 7 of GPL version 3, you are granted additional
|
17 |
|
|
// permissions described in the GCC Runtime Library Exception, version
|
18 |
|
|
// 3.1, as published by the Free Software Foundation.
|
19 |
|
|
|
20 |
|
|
// You should have received a copy of the GNU General Public License and
|
21 |
|
|
// a copy of the GCC Runtime Library Exception along with this program;
|
22 |
|
|
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
23 |
|
|
// <http://www.gnu.org/licenses/>.
|
24 |
|
|
|
25 |
|
|
/** @file parallel/find.h
|
26 |
|
|
* @brief Parallel implementation base for std::find(), std::equal()
|
27 |
|
|
* and related functions.
|
28 |
|
|
* This file is a GNU parallel extension to the Standard C++ Library.
|
29 |
|
|
*/
|
30 |
|
|
|
31 |
|
|
// Written by Felix Putze and Johannes Singler.
|
32 |
|
|
|
33 |
|
|
#ifndef _GLIBCXX_PARALLEL_FIND_H
|
34 |
|
|
#define _GLIBCXX_PARALLEL_FIND_H 1
|
35 |
|
|
|
36 |
|
|
#include <bits/stl_algobase.h>
|
37 |
|
|
|
38 |
|
|
#include <parallel/features.h>
|
39 |
|
|
#include <parallel/parallel.h>
|
40 |
|
|
#include <parallel/compatibility.h>
|
41 |
|
|
#include <parallel/equally_split.h>
|
42 |
|
|
|
43 |
|
|
namespace __gnu_parallel
|
44 |
|
|
{
|
45 |
|
|
/**
|
46 |
|
|
* @brief Parallel std::find, switch for different algorithms.
|
47 |
|
|
* @param __begin1 Begin iterator of first sequence.
|
48 |
|
|
* @param __end1 End iterator of first sequence.
|
49 |
|
|
* @param __begin2 Begin iterator of second sequence. Must have same
|
50 |
|
|
* length as first sequence.
|
51 |
|
|
* @param __pred Find predicate.
|
52 |
|
|
* @param __selector _Functionality (e. g. std::find_if(), std::equal(),...)
|
53 |
|
|
* @return Place of finding in both sequences.
|
54 |
|
|
*/
|
55 |
|
|
template<typename _RAIter1,
|
56 |
|
|
typename _RAIter2,
|
57 |
|
|
typename _Pred,
|
58 |
|
|
typename _Selector>
|
59 |
|
|
inline std::pair<_RAIter1, _RAIter2>
|
60 |
|
|
__find_template(_RAIter1 __begin1, _RAIter1 __end1,
|
61 |
|
|
_RAIter2 __begin2, _Pred __pred, _Selector __selector)
|
62 |
|
|
{
|
63 |
|
|
switch (_Settings::get().find_algorithm)
|
64 |
|
|
{
|
65 |
|
|
case GROWING_BLOCKS:
|
66 |
|
|
return __find_template(__begin1, __end1, __begin2, __pred,
|
67 |
|
|
__selector, growing_blocks_tag());
|
68 |
|
|
case CONSTANT_SIZE_BLOCKS:
|
69 |
|
|
return __find_template(__begin1, __end1, __begin2, __pred,
|
70 |
|
|
__selector, constant_size_blocks_tag());
|
71 |
|
|
case EQUAL_SPLIT:
|
72 |
|
|
return __find_template(__begin1, __end1, __begin2, __pred,
|
73 |
|
|
__selector, equal_split_tag());
|
74 |
|
|
default:
|
75 |
|
|
_GLIBCXX_PARALLEL_ASSERT(false);
|
76 |
|
|
return std::make_pair(__begin1, __begin2);
|
77 |
|
|
}
|
78 |
|
|
}
|
79 |
|
|
|
80 |
|
|
#if _GLIBCXX_FIND_EQUAL_SPLIT
|
81 |
|
|
|
82 |
|
|
/**
|
83 |
|
|
* @brief Parallel std::find, equal splitting variant.
|
84 |
|
|
* @param __begin1 Begin iterator of first sequence.
|
85 |
|
|
* @param __end1 End iterator of first sequence.
|
86 |
|
|
* @param __begin2 Begin iterator of second sequence. Second __sequence
|
87 |
|
|
* must have same length as first sequence.
|
88 |
|
|
* @param __pred Find predicate.
|
89 |
|
|
* @param __selector _Functionality (e. g. std::find_if(), std::equal(),...)
|
90 |
|
|
* @return Place of finding in both sequences.
|
91 |
|
|
*/
|
92 |
|
|
template<typename _RAIter1,
|
93 |
|
|
typename _RAIter2,
|
94 |
|
|
typename _Pred,
|
95 |
|
|
typename _Selector>
|
96 |
|
|
std::pair<_RAIter1, _RAIter2>
|
97 |
|
|
__find_template(_RAIter1 __begin1, _RAIter1 __end1,
|
98 |
|
|
_RAIter2 __begin2, _Pred __pred,
|
99 |
|
|
_Selector __selector, equal_split_tag)
|
100 |
|
|
{
|
101 |
|
|
_GLIBCXX_CALL(__end1 - __begin1)
|
102 |
|
|
|
103 |
|
|
typedef std::iterator_traits<_RAIter1> _TraitsType;
|
104 |
|
|
typedef typename _TraitsType::difference_type _DifferenceType;
|
105 |
|
|
typedef typename _TraitsType::value_type _ValueType;
|
106 |
|
|
|
107 |
|
|
_DifferenceType __length = __end1 - __begin1;
|
108 |
|
|
_DifferenceType __result = __length;
|
109 |
|
|
_DifferenceType* __borders;
|
110 |
|
|
|
111 |
|
|
omp_lock_t __result_lock;
|
112 |
|
|
omp_init_lock(&__result_lock);
|
113 |
|
|
|
114 |
|
|
_ThreadIndex __num_threads = __get_max_threads();
|
115 |
|
|
# pragma omp parallel num_threads(__num_threads)
|
116 |
|
|
{
|
117 |
|
|
# pragma omp single
|
118 |
|
|
{
|
119 |
|
|
__num_threads = omp_get_num_threads();
|
120 |
|
|
__borders = new _DifferenceType[__num_threads + 1];
|
121 |
|
|
equally_split(__length, __num_threads, __borders);
|
122 |
|
|
} //single
|
123 |
|
|
|
124 |
|
|
_ThreadIndex __iam = omp_get_thread_num();
|
125 |
|
|
_DifferenceType __start = __borders[__iam],
|
126 |
|
|
__stop = __borders[__iam + 1];
|
127 |
|
|
|
128 |
|
|
_RAIter1 __i1 = __begin1 + __start;
|
129 |
|
|
_RAIter2 __i2 = __begin2 + __start;
|
130 |
|
|
for (_DifferenceType __pos = __start; __pos < __stop; ++__pos)
|
131 |
|
|
{
|
132 |
|
|
# pragma omp flush(__result)
|
133 |
|
|
// Result has been set to something lower.
|
134 |
|
|
if (__result < __pos)
|
135 |
|
|
break;
|
136 |
|
|
|
137 |
|
|
if (__selector(__i1, __i2, __pred))
|
138 |
|
|
{
|
139 |
|
|
omp_set_lock(&__result_lock);
|
140 |
|
|
if (__pos < __result)
|
141 |
|
|
__result = __pos;
|
142 |
|
|
omp_unset_lock(&__result_lock);
|
143 |
|
|
break;
|
144 |
|
|
}
|
145 |
|
|
++__i1;
|
146 |
|
|
++__i2;
|
147 |
|
|
}
|
148 |
|
|
} //parallel
|
149 |
|
|
|
150 |
|
|
omp_destroy_lock(&__result_lock);
|
151 |
|
|
delete[] __borders;
|
152 |
|
|
|
153 |
|
|
return std::pair<_RAIter1, _RAIter2>(__begin1 + __result,
|
154 |
|
|
__begin2 + __result);
|
155 |
|
|
}
|
156 |
|
|
|
157 |
|
|
#endif
|
158 |
|
|
|
159 |
|
|
#if _GLIBCXX_FIND_GROWING_BLOCKS
|
160 |
|
|
|
161 |
|
|
/**
|
162 |
|
|
* @brief Parallel std::find, growing block size variant.
|
163 |
|
|
* @param __begin1 Begin iterator of first sequence.
|
164 |
|
|
* @param __end1 End iterator of first sequence.
|
165 |
|
|
* @param __begin2 Begin iterator of second sequence. Second __sequence
|
166 |
|
|
* must have same length as first sequence.
|
167 |
|
|
* @param __pred Find predicate.
|
168 |
|
|
* @param __selector _Functionality (e. g. std::find_if(), std::equal(),...)
|
169 |
|
|
* @return Place of finding in both sequences.
|
170 |
|
|
* @see __gnu_parallel::_Settings::find_sequential_search_size
|
171 |
|
|
* @see __gnu_parallel::_Settings::find_initial_block_size
|
172 |
|
|
* @see __gnu_parallel::_Settings::find_maximum_block_size
|
173 |
|
|
* @see __gnu_parallel::_Settings::find_increasing_factor
|
174 |
|
|
*
|
175 |
|
|
* There are two main differences between the growing blocks and
|
176 |
|
|
* the constant-size blocks variants.
|
177 |
|
|
* 1. For GB, the block size grows; for CSB, the block size is fixed.
|
178 |
|
|
* 2. For GB, the blocks are allocated dynamically;
|
179 |
|
|
* for CSB, the blocks are allocated in a predetermined manner,
|
180 |
|
|
* namely spacial round-robin.
|
181 |
|
|
*/
|
182 |
|
|
template<typename _RAIter1,
|
183 |
|
|
typename _RAIter2,
|
184 |
|
|
typename _Pred,
|
185 |
|
|
typename _Selector>
|
186 |
|
|
std::pair<_RAIter1, _RAIter2>
|
187 |
|
|
__find_template(_RAIter1 __begin1, _RAIter1 __end1,
|
188 |
|
|
_RAIter2 __begin2, _Pred __pred, _Selector __selector,
|
189 |
|
|
growing_blocks_tag)
|
190 |
|
|
{
|
191 |
|
|
_GLIBCXX_CALL(__end1 - __begin1)
|
192 |
|
|
|
193 |
|
|
typedef std::iterator_traits<_RAIter1> _TraitsType;
|
194 |
|
|
typedef typename _TraitsType::difference_type _DifferenceType;
|
195 |
|
|
typedef typename _TraitsType::value_type _ValueType;
|
196 |
|
|
|
197 |
|
|
const _Settings& __s = _Settings::get();
|
198 |
|
|
|
199 |
|
|
_DifferenceType __length = __end1 - __begin1;
|
200 |
|
|
|
201 |
|
|
_DifferenceType
|
202 |
|
|
__sequential_search_size = std::min<_DifferenceType>
|
203 |
|
|
(__length, __s.find_sequential_search_size);
|
204 |
|
|
|
205 |
|
|
// Try it sequentially first.
|
206 |
|
|
std::pair<_RAIter1, _RAIter2>
|
207 |
|
|
__find_seq_result = __selector._M_sequential_algorithm
|
208 |
|
|
(__begin1, __begin1 + __sequential_search_size,
|
209 |
|
|
__begin2, __pred);
|
210 |
|
|
|
211 |
|
|
if (__find_seq_result.first != (__begin1 + __sequential_search_size))
|
212 |
|
|
return __find_seq_result;
|
213 |
|
|
|
214 |
|
|
// Index of beginning of next free block (after sequential find).
|
215 |
|
|
_DifferenceType __next_block_start = __sequential_search_size;
|
216 |
|
|
_DifferenceType __result = __length;
|
217 |
|
|
|
218 |
|
|
omp_lock_t __result_lock;
|
219 |
|
|
omp_init_lock(&__result_lock);
|
220 |
|
|
|
221 |
|
|
_ThreadIndex __num_threads = __get_max_threads();
|
222 |
|
|
# pragma omp parallel shared(__result) num_threads(__num_threads)
|
223 |
|
|
{
|
224 |
|
|
# pragma omp single
|
225 |
|
|
__num_threads = omp_get_num_threads();
|
226 |
|
|
|
227 |
|
|
// Not within first __k elements -> start parallel.
|
228 |
|
|
_ThreadIndex __iam = omp_get_thread_num();
|
229 |
|
|
|
230 |
|
|
_DifferenceType __block_size = __s.find_initial_block_size;
|
231 |
|
|
_DifferenceType __start = __fetch_and_add<_DifferenceType>
|
232 |
|
|
(&__next_block_start, __block_size);
|
233 |
|
|
|
234 |
|
|
// Get new block, update pointer to next block.
|
235 |
|
|
_DifferenceType __stop =
|
236 |
|
|
std::min<_DifferenceType>(__length, __start + __block_size);
|
237 |
|
|
|
238 |
|
|
std::pair<_RAIter1, _RAIter2> __local_result;
|
239 |
|
|
|
240 |
|
|
while (__start < __length)
|
241 |
|
|
{
|
242 |
|
|
# pragma omp flush(__result)
|
243 |
|
|
// Get new value of result.
|
244 |
|
|
if (__result < __start)
|
245 |
|
|
{
|
246 |
|
|
// No chance to find first element.
|
247 |
|
|
break;
|
248 |
|
|
}
|
249 |
|
|
|
250 |
|
|
__local_result = __selector._M_sequential_algorithm
|
251 |
|
|
(__begin1 + __start, __begin1 + __stop,
|
252 |
|
|
__begin2 + __start, __pred);
|
253 |
|
|
|
254 |
|
|
if (__local_result.first != (__begin1 + __stop))
|
255 |
|
|
{
|
256 |
|
|
omp_set_lock(&__result_lock);
|
257 |
|
|
if ((__local_result.first - __begin1) < __result)
|
258 |
|
|
{
|
259 |
|
|
__result = __local_result.first - __begin1;
|
260 |
|
|
|
261 |
|
|
// Result cannot be in future blocks, stop algorithm.
|
262 |
|
|
__fetch_and_add<_DifferenceType>(&__next_block_start,
|
263 |
|
|
__length);
|
264 |
|
|
}
|
265 |
|
|
omp_unset_lock(&__result_lock);
|
266 |
|
|
}
|
267 |
|
|
|
268 |
|
|
__block_size = std::min<_DifferenceType>
|
269 |
|
|
(__block_size * __s.find_increasing_factor,
|
270 |
|
|
__s.find_maximum_block_size);
|
271 |
|
|
|
272 |
|
|
// Get new block, update pointer to next block.
|
273 |
|
|
__start = __fetch_and_add<_DifferenceType>(&__next_block_start,
|
274 |
|
|
__block_size);
|
275 |
|
|
__stop = (__length < (__start + __block_size)
|
276 |
|
|
? __length : (__start + __block_size));
|
277 |
|
|
}
|
278 |
|
|
} //parallel
|
279 |
|
|
|
280 |
|
|
omp_destroy_lock(&__result_lock);
|
281 |
|
|
|
282 |
|
|
// Return iterator on found element.
|
283 |
|
|
return
|
284 |
|
|
std::pair<_RAIter1, _RAIter2>(__begin1 + __result,
|
285 |
|
|
__begin2 + __result);
|
286 |
|
|
}
|
287 |
|
|
|
288 |
|
|
#endif
|
289 |
|
|
|
290 |
|
|
#if _GLIBCXX_FIND_CONSTANT_SIZE_BLOCKS
|
291 |
|
|
|
292 |
|
|
/**
|
293 |
|
|
* @brief Parallel std::find, constant block size variant.
|
294 |
|
|
* @param __begin1 Begin iterator of first sequence.
|
295 |
|
|
* @param __end1 End iterator of first sequence.
|
296 |
|
|
* @param __begin2 Begin iterator of second sequence. Second __sequence
|
297 |
|
|
* must have same length as first sequence.
|
298 |
|
|
* @param __pred Find predicate.
|
299 |
|
|
* @param __selector _Functionality (e. g. std::find_if(), std::equal(),...)
|
300 |
|
|
* @return Place of finding in both sequences.
|
301 |
|
|
* @see __gnu_parallel::_Settings::find_sequential_search_size
|
302 |
|
|
* @see __gnu_parallel::_Settings::find_block_size
|
303 |
|
|
* There are two main differences between the growing blocks and the
|
304 |
|
|
* constant-size blocks variants.
|
305 |
|
|
* 1. For GB, the block size grows; for CSB, the block size is fixed.
|
306 |
|
|
* 2. For GB, the blocks are allocated dynamically; for CSB, the
|
307 |
|
|
* blocks are allocated in a predetermined manner, namely spacial
|
308 |
|
|
* round-robin.
|
309 |
|
|
*/
|
310 |
|
|
template<typename _RAIter1,
|
311 |
|
|
typename _RAIter2,
|
312 |
|
|
typename _Pred,
|
313 |
|
|
typename _Selector>
|
314 |
|
|
std::pair<_RAIter1, _RAIter2>
|
315 |
|
|
__find_template(_RAIter1 __begin1, _RAIter1 __end1,
|
316 |
|
|
_RAIter2 __begin2, _Pred __pred, _Selector __selector,
|
317 |
|
|
constant_size_blocks_tag)
|
318 |
|
|
{
|
319 |
|
|
_GLIBCXX_CALL(__end1 - __begin1)
|
320 |
|
|
typedef std::iterator_traits<_RAIter1> _TraitsType;
|
321 |
|
|
typedef typename _TraitsType::difference_type _DifferenceType;
|
322 |
|
|
typedef typename _TraitsType::value_type _ValueType;
|
323 |
|
|
|
324 |
|
|
const _Settings& __s = _Settings::get();
|
325 |
|
|
|
326 |
|
|
_DifferenceType __length = __end1 - __begin1;
|
327 |
|
|
|
328 |
|
|
_DifferenceType __sequential_search_size = std::min<_DifferenceType>
|
329 |
|
|
(__length, __s.find_sequential_search_size);
|
330 |
|
|
|
331 |
|
|
// Try it sequentially first.
|
332 |
|
|
std::pair<_RAIter1, _RAIter2>
|
333 |
|
|
__find_seq_result = __selector._M_sequential_algorithm
|
334 |
|
|
(__begin1, __begin1 + __sequential_search_size, __begin2, __pred);
|
335 |
|
|
|
336 |
|
|
if (__find_seq_result.first != (__begin1 + __sequential_search_size))
|
337 |
|
|
return __find_seq_result;
|
338 |
|
|
|
339 |
|
|
_DifferenceType __result = __length;
|
340 |
|
|
omp_lock_t __result_lock;
|
341 |
|
|
omp_init_lock(&__result_lock);
|
342 |
|
|
|
343 |
|
|
// Not within first __sequential_search_size elements -> start parallel.
|
344 |
|
|
|
345 |
|
|
_ThreadIndex __num_threads = __get_max_threads();
|
346 |
|
|
# pragma omp parallel shared(__result) num_threads(__num_threads)
|
347 |
|
|
{
|
348 |
|
|
# pragma omp single
|
349 |
|
|
__num_threads = omp_get_num_threads();
|
350 |
|
|
|
351 |
|
|
_ThreadIndex __iam = omp_get_thread_num();
|
352 |
|
|
_DifferenceType __block_size = __s.find_initial_block_size;
|
353 |
|
|
|
354 |
|
|
// First element of thread's current iteration.
|
355 |
|
|
_DifferenceType __iteration_start = __sequential_search_size;
|
356 |
|
|
|
357 |
|
|
// Where to work (initialization).
|
358 |
|
|
_DifferenceType __start = __iteration_start + __iam * __block_size;
|
359 |
|
|
_DifferenceType __stop = std::min<_DifferenceType>(__length,
|
360 |
|
|
__start
|
361 |
|
|
+ __block_size);
|
362 |
|
|
|
363 |
|
|
std::pair<_RAIter1, _RAIter2> __local_result;
|
364 |
|
|
|
365 |
|
|
while (__start < __length)
|
366 |
|
|
{
|
367 |
|
|
// Get new value of result.
|
368 |
|
|
# pragma omp flush(__result)
|
369 |
|
|
// No chance to find first element.
|
370 |
|
|
if (__result < __start)
|
371 |
|
|
break;
|
372 |
|
|
|
373 |
|
|
__local_result = __selector._M_sequential_algorithm
|
374 |
|
|
(__begin1 + __start, __begin1 + __stop,
|
375 |
|
|
__begin2 + __start, __pred);
|
376 |
|
|
|
377 |
|
|
if (__local_result.first != (__begin1 + __stop))
|
378 |
|
|
{
|
379 |
|
|
omp_set_lock(&__result_lock);
|
380 |
|
|
if ((__local_result.first - __begin1) < __result)
|
381 |
|
|
__result = __local_result.first - __begin1;
|
382 |
|
|
omp_unset_lock(&__result_lock);
|
383 |
|
|
// Will not find better value in its interval.
|
384 |
|
|
break;
|
385 |
|
|
}
|
386 |
|
|
|
387 |
|
|
__iteration_start += __num_threads * __block_size;
|
388 |
|
|
|
389 |
|
|
// Where to work.
|
390 |
|
|
__start = __iteration_start + __iam * __block_size;
|
391 |
|
|
__stop = std::min<_DifferenceType>(__length,
|
392 |
|
|
__start + __block_size);
|
393 |
|
|
}
|
394 |
|
|
} //parallel
|
395 |
|
|
|
396 |
|
|
omp_destroy_lock(&__result_lock);
|
397 |
|
|
|
398 |
|
|
// Return iterator on found element.
|
399 |
|
|
return std::pair<_RAIter1, _RAIter2>(__begin1 + __result,
|
400 |
|
|
__begin2 + __result);
|
401 |
|
|
}
|
402 |
|
|
#endif
|
403 |
|
|
} // end namespace
|
404 |
|
|
|
405 |
|
|
#endif /* _GLIBCXX_PARALLEL_FIND_H */
|