xref: /freebsd/usr.bin/sort/radixsort.c (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2012 Oleg Moskalenko <mom040267@gmail.com>
5  * Copyright (C) 2012 Gabor Kovesdan <gabor@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <errno.h>
34 #include <err.h>
35 #include <langinfo.h>
36 #include <math.h>
37 #if defined(SORT_THREADS)
38 #include <pthread.h>
39 #include <semaphore.h>
40 #endif
41 #include <stdlib.h>
42 #include <string.h>
43 #include <wchar.h>
44 #include <wctype.h>
45 #include <unistd.h>
46 
47 #include "coll.h"
48 #include "radixsort.h"
49 
50 #define DEFAULT_SORT_FUNC_RADIXSORT mergesort
51 
52 #define TINY_NODE(sl) ((sl)->tosort_num < 65)
53 #define SMALL_NODE(sl) ((sl)->tosort_num < 5)
54 
55 /* are we sorting in reverse order ? */
56 static bool reverse_sort;
57 
58 /* sort sub-levels array size */
59 static const size_t slsz = 256 * sizeof(struct sort_level*);
60 
61 /* one sort level structure */
62 struct sort_level
63 {
64 	struct sort_level	**sublevels;
65 	struct sort_list_item	**leaves;
66 	struct sort_list_item	**sorted;
67 	struct sort_list_item	**tosort;
68 	size_t			  leaves_num;
69 	size_t			  leaves_sz;
70 	size_t			  level;
71 	size_t			  real_sln;
72 	size_t			  start_position;
73 	size_t			  sln;
74 	size_t			  tosort_num;
75 	size_t			  tosort_sz;
76 };
77 
78 /* stack of sort levels ready to be sorted */
79 struct level_stack {
80 	struct level_stack	 *next;
81 	struct sort_level	 *sl;
82 };
83 
84 static struct level_stack *g_ls;
85 
86 #if defined(SORT_THREADS)
87 /* stack guarding mutex */
88 static pthread_cond_t g_ls_cond;
89 static pthread_mutex_t g_ls_mutex;
90 
91 /* counter: how many items are left */
92 static size_t sort_left;
93 /* guarding mutex */
94 
95 /* semaphore to count threads */
96 static sem_t mtsem;
97 
98 /*
99  * Decrement items counter
100  */
101 static inline void
102 sort_left_dec(size_t n)
103 {
104 	pthread_mutex_lock(&g_ls_mutex);
105 	sort_left -= n;
106 	if (sort_left == 0 && nthreads > 1)
107 		pthread_cond_broadcast(&g_ls_cond);
108 	pthread_mutex_unlock(&g_ls_mutex);
109 }
110 
111 /*
112  * Do we have something to sort ?
113  *
114  * This routine does not need to be locked.
115  */
116 static inline bool
117 have_sort_left(void)
118 {
119 	bool ret;
120 
121 	ret = (sort_left > 0);
122 
123 	return (ret);
124 }
125 
126 #else
127 
128 #define sort_left_dec(n)
129 
130 #endif /* SORT_THREADS */
131 
132 static void
133 _push_ls(struct level_stack *ls)
134 {
135 
136 	ls->next = g_ls;
137 	g_ls = ls;
138 }
139 
140 /*
141  * Push sort level to the stack
142  */
143 static inline void
144 push_ls(struct sort_level *sl)
145 {
146 	struct level_stack *new_ls;
147 
148 	new_ls = sort_malloc(sizeof(struct level_stack));
149 	new_ls->sl = sl;
150 
151 #if defined(SORT_THREADS)
152 	if (nthreads > 1) {
153 		pthread_mutex_lock(&g_ls_mutex);
154 		_push_ls(new_ls);
155 		pthread_cond_signal(&g_ls_cond);
156 		pthread_mutex_unlock(&g_ls_mutex);
157 	} else
158 #endif
159 		_push_ls(new_ls);
160 }
161 
162 /*
163  * Pop sort level from the stack (single-threaded style)
164  */
165 static inline struct sort_level*
166 pop_ls_st(void)
167 {
168 	struct sort_level *sl;
169 
170 	if (g_ls) {
171 		struct level_stack *saved_ls;
172 
173 		sl = g_ls->sl;
174 		saved_ls = g_ls;
175 		g_ls = g_ls->next;
176 		sort_free(saved_ls);
177 	} else
178 		sl = NULL;
179 
180 	return (sl);
181 }
182 
183 #if defined(SORT_THREADS)
184 
185 /*
186  * Pop sort level from the stack (multi-threaded style)
187  */
188 static inline struct sort_level*
189 pop_ls_mt(void)
190 {
191 	struct level_stack *saved_ls;
192 	struct sort_level *sl;
193 
194 	pthread_mutex_lock(&g_ls_mutex);
195 
196 	for (;;) {
197 		if (g_ls) {
198 			sl = g_ls->sl;
199 			saved_ls = g_ls;
200 			g_ls = g_ls->next;
201 			break;
202 		}
203 		sl = NULL;
204 		saved_ls = NULL;
205 
206 		if (have_sort_left() == 0)
207 			break;
208 		pthread_cond_wait(&g_ls_cond, &g_ls_mutex);
209 	}
210 
211 	pthread_mutex_unlock(&g_ls_mutex);
212 
213 	sort_free(saved_ls);
214 
215 	return (sl);
216 }
217 
218 #endif /* defined(SORT_THREADS) */
219 
220 static void
221 add_to_sublevel(struct sort_level *sl, struct sort_list_item *item, size_t indx)
222 {
223 	struct sort_level *ssl;
224 
225 	ssl = sl->sublevels[indx];
226 
227 	if (ssl == NULL) {
228 		ssl = sort_malloc(sizeof(struct sort_level));
229 		memset(ssl, 0, sizeof(struct sort_level));
230 
231 		ssl->level = sl->level + 1;
232 		sl->sublevels[indx] = ssl;
233 
234 		++(sl->real_sln);
235 	}
236 
237 	if (++(ssl->tosort_num) > ssl->tosort_sz) {
238 		ssl->tosort_sz = ssl->tosort_num + 128;
239 		ssl->tosort = sort_realloc(ssl->tosort,
240 		    sizeof(struct sort_list_item*) * (ssl->tosort_sz));
241 	}
242 
243 	ssl->tosort[ssl->tosort_num - 1] = item;
244 }
245 
246 static inline void
247 add_leaf(struct sort_level *sl, struct sort_list_item *item)
248 {
249 
250 	if (++(sl->leaves_num) > sl->leaves_sz) {
251 		sl->leaves_sz = sl->leaves_num + 128;
252 		sl->leaves = sort_realloc(sl->leaves,
253 		    (sizeof(struct sort_list_item*) * (sl->leaves_sz)));
254 	}
255 	sl->leaves[sl->leaves_num - 1] = item;
256 }
257 
258 static inline int
259 get_wc_index(struct sort_list_item *sli, size_t level)
260 {
261 	const size_t wcfact = (MB_CUR_MAX == 1) ? 1 : sizeof(wchar_t);
262 	const struct key_value *kv;
263 	const struct bwstring *bws;
264 
265 	kv = get_key_from_keys_array(&sli->ka, 0);
266 	bws = kv->k;
267 
268 	if ((BWSLEN(bws) * wcfact > level)) {
269 		wchar_t res;
270 
271 		/*
272 		 * Sort wchar strings a byte at a time, rather than a single
273 		 * byte from each wchar.
274 		 */
275 		res = (wchar_t)BWS_GET(bws, level / wcfact);
276 		/* Sort most-significant byte first. */
277 		if (level % wcfact < wcfact - 1)
278 			res = (res >> (8 * (wcfact - 1 - (level % wcfact))));
279 
280 		return (res & 0xff);
281 	}
282 
283 	return (-1);
284 }
285 
286 static void
287 place_item(struct sort_level *sl, size_t item)
288 {
289 	struct sort_list_item *sli;
290 	int c;
291 
292 	sli = sl->tosort[item];
293 	c = get_wc_index(sli, sl->level);
294 
295 	if (c == -1)
296 		add_leaf(sl, sli);
297 	else
298 		add_to_sublevel(sl, sli, c);
299 }
300 
301 static void
302 free_sort_level(struct sort_level *sl)
303 {
304 
305 	if (sl) {
306 		if (sl->leaves)
307 			sort_free(sl->leaves);
308 
309 		if (sl->level > 0)
310 			sort_free(sl->tosort);
311 
312 		if (sl->sublevels) {
313 			struct sort_level *slc;
314 			size_t sln;
315 
316 			sln = sl->sln;
317 
318 			for (size_t i = 0; i < sln; ++i) {
319 				slc = sl->sublevels[i];
320 				if (slc)
321 					free_sort_level(slc);
322 			}
323 
324 			sort_free(sl->sublevels);
325 		}
326 
327 		sort_free(sl);
328 	}
329 }
330 
331 static void
332 run_sort_level_next(struct sort_level *sl)
333 {
334 	const size_t wcfact = (MB_CUR_MAX == 1) ? 1 : sizeof(wchar_t);
335 	struct sort_level *slc;
336 	size_t i, sln, tosort_num;
337 
338 	if (sl->sublevels) {
339 		sort_free(sl->sublevels);
340 		sl->sublevels = NULL;
341 	}
342 
343 	switch (sl->tosort_num) {
344 	case 0:
345 		goto end;
346 	case (1):
347 		sl->sorted[sl->start_position] = sl->tosort[0];
348 		sort_left_dec(1);
349 		goto end;
350 	case (2):
351 		/*
352 		 * Radixsort only processes a single byte at a time.  In wchar
353 		 * mode, this can be a subset of the length of a character.
354 		 * list_coll_offset() offset is in units of wchar, not bytes.
355 		 * So to calculate the offset, we must divide by
356 		 * sizeof(wchar_t) and round down to the index of the first
357 		 * character this level references.
358 		 */
359 		if (list_coll_offset(&(sl->tosort[0]), &(sl->tosort[1]),
360 		    sl->level / wcfact) > 0) {
361 			sl->sorted[sl->start_position++] = sl->tosort[1];
362 			sl->sorted[sl->start_position] = sl->tosort[0];
363 		} else {
364 			sl->sorted[sl->start_position++] = sl->tosort[0];
365 			sl->sorted[sl->start_position] = sl->tosort[1];
366 		}
367 		sort_left_dec(2);
368 
369 		goto end;
370 	default:
371 		if (TINY_NODE(sl) || (sl->level > 15)) {
372 			listcoll_t func;
373 
374 			/*
375 			 * Collate comparison offset is in units of
376 			 * character-width, so we must divide the level (bytes)
377 			 * by operating character width (wchar_t or char).  See
378 			 * longer comment above.
379 			 */
380 			func = get_list_call_func(sl->level / wcfact);
381 
382 			sl->leaves = sl->tosort;
383 			sl->leaves_num = sl->tosort_num;
384 			sl->leaves_sz = sl->leaves_num;
385 			sl->leaves = sort_realloc(sl->leaves,
386 			    (sizeof(struct sort_list_item *) *
387 			    (sl->leaves_sz)));
388 			sl->tosort = NULL;
389 			sl->tosort_num = 0;
390 			sl->tosort_sz = 0;
391 			sl->sln = 0;
392 			sl->real_sln = 0;
393 			if (sort_opts_vals.sflag) {
394 				if (mergesort(sl->leaves, sl->leaves_num,
395 				    sizeof(struct sort_list_item *),
396 				    (int(*)(const void *, const void *)) func) == -1)
397 					/* NOTREACHED */
398 					err(2, "Radix sort error 3");
399 			} else
400 				DEFAULT_SORT_FUNC_RADIXSORT(sl->leaves, sl->leaves_num,
401 				    sizeof(struct sort_list_item *),
402 				    (int(*)(const void *, const void *)) func);
403 
404 			memcpy(sl->sorted + sl->start_position,
405 			    sl->leaves, sl->leaves_num *
406 			    sizeof(struct sort_list_item*));
407 
408 			sort_left_dec(sl->leaves_num);
409 
410 			goto end;
411 		} else {
412 			sl->tosort_sz = sl->tosort_num;
413 			sl->tosort = sort_realloc(sl->tosort,
414 			    sizeof(struct sort_list_item*) * (sl->tosort_sz));
415 		}
416 	}
417 
418 	sl->sln = 256;
419 	sl->sublevels = sort_malloc(slsz);
420 	memset(sl->sublevels, 0, slsz);
421 
422 	sl->real_sln = 0;
423 
424 	tosort_num = sl->tosort_num;
425 	for (i = 0; i < tosort_num; ++i)
426 		place_item(sl, i);
427 
428 	sort_free(sl->tosort);
429 	sl->tosort = NULL;
430 	sl->tosort_num = 0;
431 	sl->tosort_sz = 0;
432 
433 	if (sl->leaves_num > 1) {
434 		if (keys_num > 1) {
435 			if (sort_opts_vals.sflag) {
436 				mergesort(sl->leaves, sl->leaves_num,
437 				    sizeof(struct sort_list_item *),
438 				    (int(*)(const void *, const void *)) list_coll);
439 			} else {
440 				DEFAULT_SORT_FUNC_RADIXSORT(sl->leaves, sl->leaves_num,
441 				    sizeof(struct sort_list_item *),
442 				    (int(*)(const void *, const void *)) list_coll);
443 			}
444 		} else if (!sort_opts_vals.sflag && sort_opts_vals.complex_sort) {
445 			DEFAULT_SORT_FUNC_RADIXSORT(sl->leaves, sl->leaves_num,
446 			    sizeof(struct sort_list_item *),
447 			    (int(*)(const void *, const void *)) list_coll_by_str_only);
448 		}
449 	}
450 
451 	sl->leaves_sz = sl->leaves_num;
452 	sl->leaves = sort_realloc(sl->leaves, (sizeof(struct sort_list_item *) *
453 	    (sl->leaves_sz)));
454 
455 	if (!reverse_sort) {
456 		memcpy(sl->sorted + sl->start_position, sl->leaves,
457 		    sl->leaves_num * sizeof(struct sort_list_item*));
458 		sl->start_position += sl->leaves_num;
459 		sort_left_dec(sl->leaves_num);
460 
461 		sort_free(sl->leaves);
462 		sl->leaves = NULL;
463 		sl->leaves_num = 0;
464 		sl->leaves_sz = 0;
465 
466 		sln = sl->sln;
467 
468 		for (i = 0; i < sln; ++i) {
469 			slc = sl->sublevels[i];
470 
471 			if (slc) {
472 				slc->sorted = sl->sorted;
473 				slc->start_position = sl->start_position;
474 				sl->start_position += slc->tosort_num;
475 				if (SMALL_NODE(slc))
476 					run_sort_level_next(slc);
477 				else
478 					push_ls(slc);
479 				sl->sublevels[i] = NULL;
480 			}
481 		}
482 
483 	} else {
484 		size_t n;
485 
486 		sln = sl->sln;
487 
488 		for (i = 0; i < sln; ++i) {
489 			n = sln - i - 1;
490 			slc = sl->sublevels[n];
491 
492 			if (slc) {
493 				slc->sorted = sl->sorted;
494 				slc->start_position = sl->start_position;
495 				sl->start_position += slc->tosort_num;
496 				if (SMALL_NODE(slc))
497 					run_sort_level_next(slc);
498 				else
499 					push_ls(slc);
500 				sl->sublevels[n] = NULL;
501 			}
502 		}
503 
504 		memcpy(sl->sorted + sl->start_position, sl->leaves,
505 		    sl->leaves_num * sizeof(struct sort_list_item*));
506 		sort_left_dec(sl->leaves_num);
507 	}
508 
509 end:
510 	free_sort_level(sl);
511 }
512 
513 /*
514  * Single-threaded sort cycle
515  */
516 static void
517 run_sort_cycle_st(void)
518 {
519 	struct sort_level *slc;
520 
521 	for (;;) {
522 		slc = pop_ls_st();
523 		if (slc == NULL) {
524 			break;
525 		}
526 		run_sort_level_next(slc);
527 	}
528 }
529 
530 #if defined(SORT_THREADS)
531 
532 /*
533  * Multi-threaded sort cycle
534  */
535 static void
536 run_sort_cycle_mt(void)
537 {
538 	struct sort_level *slc;
539 
540 	for (;;) {
541 		slc = pop_ls_mt();
542 		if (slc == NULL)
543 			break;
544 		run_sort_level_next(slc);
545 	}
546 }
547 
548 /*
549  * Sort cycle thread (in multi-threaded mode)
550  */
551 static void*
552 sort_thread(void* arg)
553 {
554 	run_sort_cycle_mt();
555 	sem_post(&mtsem);
556 
557 	return (arg);
558 }
559 
560 #endif /* defined(SORT_THREADS) */
561 
562 static void
563 run_top_sort_level(struct sort_level *sl)
564 {
565 	struct sort_level *slc;
566 
567 	reverse_sort = sort_opts_vals.kflag ? keys[0].sm.rflag :
568 	    default_sort_mods->rflag;
569 
570 	sl->start_position = 0;
571 	sl->sln = 256;
572 	sl->sublevels = sort_malloc(slsz);
573 	memset(sl->sublevels, 0, slsz);
574 
575 	for (size_t i = 0; i < sl->tosort_num; ++i)
576 		place_item(sl, i);
577 
578 	if (sl->leaves_num > 1) {
579 		if (keys_num > 1) {
580 			if (sort_opts_vals.sflag) {
581 				mergesort(sl->leaves, sl->leaves_num,
582 				    sizeof(struct sort_list_item *),
583 				    (int(*)(const void *, const void *)) list_coll);
584 			} else {
585 				DEFAULT_SORT_FUNC_RADIXSORT(sl->leaves, sl->leaves_num,
586 				    sizeof(struct sort_list_item *),
587 				    (int(*)(const void *, const void *)) list_coll);
588 			}
589 		} else if (!sort_opts_vals.sflag && sort_opts_vals.complex_sort) {
590 			DEFAULT_SORT_FUNC_RADIXSORT(sl->leaves, sl->leaves_num,
591 			    sizeof(struct sort_list_item *),
592 			    (int(*)(const void *, const void *)) list_coll_by_str_only);
593 		}
594 	}
595 
596 	if (!reverse_sort) {
597 		memcpy(sl->tosort + sl->start_position, sl->leaves,
598 		    sl->leaves_num * sizeof(struct sort_list_item*));
599 		sl->start_position += sl->leaves_num;
600 		sort_left_dec(sl->leaves_num);
601 
602 		for (size_t i = 0; i < sl->sln; ++i) {
603 			slc = sl->sublevels[i];
604 
605 			if (slc) {
606 				slc->sorted = sl->tosort;
607 				slc->start_position = sl->start_position;
608 				sl->start_position += slc->tosort_num;
609 				push_ls(slc);
610 				sl->sublevels[i] = NULL;
611 			}
612 		}
613 
614 	} else {
615 		size_t n;
616 
617 		for (size_t i = 0; i < sl->sln; ++i) {
618 
619 			n = sl->sln - i - 1;
620 			slc = sl->sublevels[n];
621 
622 			if (slc) {
623 				slc->sorted = sl->tosort;
624 				slc->start_position = sl->start_position;
625 				sl->start_position += slc->tosort_num;
626 				push_ls(slc);
627 				sl->sublevels[n] = NULL;
628 			}
629 		}
630 
631 		memcpy(sl->tosort + sl->start_position, sl->leaves,
632 		    sl->leaves_num * sizeof(struct sort_list_item*));
633 
634 		sort_left_dec(sl->leaves_num);
635 	}
636 
637 #if defined(SORT_THREADS)
638 	if (nthreads < 2) {
639 #endif
640 		run_sort_cycle_st();
641 #if defined(SORT_THREADS)
642 	} else {
643 		size_t i;
644 
645 		for(i = 0; i < nthreads; ++i) {
646 			pthread_attr_t attr;
647 			pthread_t pth;
648 
649 			pthread_attr_init(&attr);
650 			pthread_attr_setdetachstate(&attr, PTHREAD_DETACHED);
651 
652 			for (;;) {
653 				int res = pthread_create(&pth, &attr,
654 				    sort_thread, NULL);
655 				if (res >= 0)
656 					break;
657 				if (errno == EAGAIN) {
658 					pthread_yield();
659 					continue;
660 				}
661 				err(2, NULL);
662 			}
663 
664 			pthread_attr_destroy(&attr);
665 		}
666 
667 		for (i = 0; i < nthreads; ++i)
668 			sem_wait(&mtsem);
669 	}
670 #endif /* defined(SORT_THREADS) */
671 }
672 
673 static void
674 run_sort(struct sort_list_item **base, size_t nmemb)
675 {
676 	struct sort_level *sl;
677 
678 #if defined(SORT_THREADS)
679 	size_t nthreads_save = nthreads;
680 	if (nmemb < MT_SORT_THRESHOLD)
681 		nthreads = 1;
682 
683 	if (nthreads > 1) {
684 		pthread_mutexattr_t mattr;
685 
686 		pthread_mutexattr_init(&mattr);
687 		pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_ADAPTIVE_NP);
688 
689 		pthread_mutex_init(&g_ls_mutex, &mattr);
690 		pthread_cond_init(&g_ls_cond, NULL);
691 
692 		pthread_mutexattr_destroy(&mattr);
693 
694 		sem_init(&mtsem, 0, 0);
695 
696 	}
697 #endif
698 
699 	sl = sort_malloc(sizeof(struct sort_level));
700 	memset(sl, 0, sizeof(struct sort_level));
701 
702 	sl->tosort = base;
703 	sl->tosort_num = nmemb;
704 	sl->tosort_sz = nmemb;
705 
706 #if defined(SORT_THREADS)
707 	sort_left = nmemb;
708 #endif
709 
710 	run_top_sort_level(sl);
711 
712 	free_sort_level(sl);
713 
714 #if defined(SORT_THREADS)
715 	if (nthreads > 1) {
716 		sem_destroy(&mtsem);
717 		pthread_mutex_destroy(&g_ls_mutex);
718 	}
719 	nthreads = nthreads_save;
720 #endif
721 }
722 
723 void
724 rxsort(struct sort_list_item **base, size_t nmemb)
725 {
726 
727 	run_sort(base, nmemb);
728 }
729