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1 /* TODO: proper output */
2 
3 /*
4  *
5  *   Copyright (c) International Business Machines  Corp., 2001
6  *
7  *   This program is free software;  you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
15  *   the GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program;  if not, write to the Free Software
19  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /*
23  *  FILE        : pth_str01.c
24  *  DESCRIPTION : create a tree of threads
25  *  HISTORY:
26  *    04/09/2001 Paul Larson (plars@us.ibm.com)
27  *      -Ported
28  *
29  */
30 
31 #include <pthread.h>
32 #include <stdio.h>
33 #include <unistd.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <errno.h>
37 #include <stdint.h>
38 #include <sys/types.h>
39 #include "test.h"
40 #include "pth_str01.h"
41 
42 int depth = 3;
43 int breadth = 4;
44 int timeout = 30;		/* minutes */
45 int cdepth;			/* current depth */
46 int debug = 0;
47 
48 c_info *child_info;		/* pointer to info array */
49 int node_count;			/* number of nodes created so far */
50 pthread_mutex_t node_mutex;	/* mutex for the node_count */
51 pthread_cond_t node_condvar;	/* condition variable for node_count */
52 pthread_attr_t attr;		/* attributes for created threads */
53 
54 int num_nodes(int, int);
55 int synchronize_children(c_info *);
56 int doit(c_info *);
57 
58 char *TCID = "pth_str01";
59 int TST_TOTAL = 1;
60 
testexit(int value)61 void testexit(int value)
62 {
63 	if (value == 0)
64 		tst_resm(TPASS, "Test passed");
65 	else
66 		tst_resm(TFAIL, "Test failed");
67 
68 	exit(value);
69 }
70 
71 /*
72  * parse_args
73  *
74  * Parse command line arguments.  Any errors cause the program to exit
75  * at this point.
76  */
parse_args(int argc,char * argv[])77 static void parse_args(int argc, char *argv[])
78 {
79 	int opt, errflag = 0;
80 	int bflag = 0, dflag = 0, tflag = 0;
81 
82 	while ((opt = getopt(argc, argv, "b:d:t:Dh?")) != EOF) {
83 		switch (opt) {
84 		case 'b':
85 			if (bflag)
86 				errflag++;
87 			else {
88 				bflag++;
89 				breadth = atoi(optarg);
90 				if (breadth <= 0)
91 					errflag++;
92 			}
93 			break;
94 		case 'd':
95 			if (dflag)
96 				errflag++;
97 			else {
98 				dflag++;
99 				depth = atoi(optarg);
100 				if (depth <= 0)
101 					errflag++;
102 			}
103 			break;
104 		case 't':
105 			if (tflag)
106 				errflag++;
107 			else {
108 				tflag++;
109 				timeout = atoi(optarg);
110 				if (timeout <= 0)
111 					errflag++;
112 			}
113 			break;
114 		case 'D':
115 			debug = 1;
116 			break;
117 		case 'h':
118 		default:
119 			errflag++;
120 			break;
121 		}
122 	}
123 
124 	if (errflag) {
125 		fprintf(stderr,
126 			"usage: %s [-b <num>] [-d <num>] [-t <num>] [-D]",
127 			argv[0]);
128 		fprintf(stderr, " where:\n");
129 		fprintf(stderr, "\t-b <num>\tbreadth of child nodes\n");
130 		fprintf(stderr, "\t-d <num>\tdepth of child nodes\n");
131 		fprintf(stderr,
132 			"\t-t <num>\ttimeout for child communication (in minutes)\n");
133 		fprintf(stderr, "\t-D\t\tdebug mode on\n");
134 		testexit(1);
135 	}
136 
137 }
138 
139 /*
140  * num_nodes
141  *
142  * Caculate the number of child nodes for a given breadth and depth tree.
143  */
num_nodes(int b,int d)144 int num_nodes(int b, int d)
145 {
146 	int n, sum = 1, partial_exp = 1;
147 
148 	/*
149 	 * The total number of children = sum ( b ** n )
150 	 *                                n=0->d
151 	 * Since b ** 0 == 1, and it's hard to compute that kind of value
152 	 * in this simplistic loop, we start sum at 1 (above) to compensate
153 	 * and do the computations from 1->d below.
154 	 */
155 	for (n = 1; n <= d; n++) {
156 		partial_exp *= b;
157 		sum += partial_exp;
158 	}
159 
160 	return (sum);
161 }
162 
163 /*
164  * synchronize_children
165  *
166  * Register the child with the parent and then wait for all of the children
167  * at the same level to register also.  Return when everything is synched up.
168  */
synchronize_children(c_info * parent)169 int synchronize_children(c_info * parent)
170 {
171 	int my_index, rc;
172 	c_info *info_p;
173 	struct timespec timer;
174 
175 	if (debug) {
176 		printf("trying to lock node_mutex\n");
177 		fflush(stdout);
178 	}
179 
180 	/*
181 	 * Lock the node_count mutex to we can safely increment it.  We
182 	 * will unlock it when we broadcast that all of our siblings have
183 	 * been created or when we block waiting for that broadcast.
184 	 */
185 	pthread_mutex_lock(&node_mutex);
186 	my_index = node_count++;
187 
188 	tst_resm(TINFO, "thread %d started", my_index);
189 
190 	/*
191 	 * Get a pointer into the array of thread structures which will
192 	 * be "me".
193 	 */
194 	info_p = &child_info[my_index];
195 	info_p->index = my_index;
196 
197 	if (debug) {
198 		printf("thread %d info_p=%p\n", my_index, info_p);
199 		fflush(stdout);
200 	}
201 
202 	/*
203 	 * Register with parent bumping the parent's child_count variable.
204 	 * Make sure we have exclusive access to that variable before we
205 	 * do the increment.
206 	 */
207 	if (debug) {
208 		printf("thread %d locking child_mutex %p\n", my_index,
209 		       &parent->child_mutex);
210 		fflush(stdout);
211 	}
212 	pthread_mutex_lock(&parent->child_mutex);
213 	if (debug) {
214 		printf("thread %d bumping child_count (currently %d)\n",
215 		       my_index, parent->child_count);
216 		fflush(stdout);
217 	}
218 	parent->child_ptrs[parent->child_count++] = info_p;
219 	if (debug) {
220 		printf("thread %d unlocking child_mutex %p\n", my_index,
221 		       &parent->child_mutex);
222 		fflush(stdout);
223 	}
224 	pthread_mutex_unlock(&parent->child_mutex);
225 
226 	if (debug) {
227 		printf("thread %d node_count = %d\n", my_index, node_count);
228 		printf("expecting %d nodes\n", num_nodes(breadth, cdepth));
229 		fflush(stdout);
230 	}
231 
232 	/*
233 	 * Have all the nodes at our level in the tree been created yet?
234 	 * If so, then send out a broadcast to wake everyone else up (to let
235 	 * them know they can now create their children (if they are not
236 	 * leaf nodes)).  Otherwise, go to sleep waiting for the broadcast.
237 	 */
238 	if (node_count == num_nodes(breadth, cdepth)) {
239 
240 		/*
241 		 * Increase the current depth variable, as the tree is now
242 		 * fully one level taller.
243 		 */
244 		if (debug) {
245 			printf("thread %d doing cdepth++ (%d)\n", my_index,
246 			       cdepth);
247 			fflush(stdout);
248 		}
249 		cdepth++;
250 
251 		if (debug) {
252 			printf("thread %d sending child_mutex broadcast\n",
253 			       my_index);
254 			fflush(stdout);
255 		}
256 		/*
257 		 * Since all of our siblings have been created, this level of
258 		 * the tree is now allowed to continue its work, so wake up the
259 		 * rest of the siblings.
260 		 */
261 		pthread_cond_broadcast(&node_condvar);
262 
263 	} else {
264 
265 		/*
266 		 * In this case, not all of our siblings at this level of the
267 		 * tree have been created, so go to sleep and wait for the
268 		 * broadcast on node_condvar.
269 		 */
270 		if (debug) {
271 			printf("thread %d waiting for siblings to register\n",
272 			       my_index);
273 			fflush(stdout);
274 		}
275 		time(&timer.tv_sec);
276 		timer.tv_sec += (unsigned long)timeout *60;
277 		timer.tv_nsec = (unsigned long)0;
278 		if ((rc = pthread_cond_timedwait(&node_condvar, &node_mutex,
279 						 &timer))) {
280 			tst_resm(TINFO,
281 				 "pthread_cond_timedwait (sync) %d: %s\n",
282 				 my_index, strerror(rc));
283 			testexit(2);
284 		}
285 
286 		if (debug) {
287 			printf("thread %d is now unblocked\n", my_index);
288 			fflush(stdout);
289 		}
290 
291 	}
292 
293 	/*
294 	 * Unlock the node_mutex lock, as this thread is finished
295 	 * initializing.
296 	 */
297 	if (debug) {
298 		printf("thread %d unlocking node_mutex\n", my_index);
299 		fflush(stdout);
300 	}
301 	pthread_mutex_unlock(&node_mutex);
302 	if (debug) {
303 		printf("thread %d unlocked node_mutex\n", my_index);
304 		fflush(stdout);
305 	}
306 
307 	if (debug) {
308 		printf("synchronize_children returning %d\n", my_index);
309 		fflush(stdout);
310 	}
311 
312 	return (my_index);
313 
314 }
315 
316 /*
317  * doit
318  *
319  * Do it.
320  */
doit(c_info * parent)321 int doit(c_info * parent)
322 {
323 	int rc, child, my_index;
324 	void *status;
325 	c_info *info_p;
326 	struct timespec timer;
327 
328 	if (parent != NULL) {
329 		/*
330 		 * Synchronize with our siblings so that all the children at
331 		 * a given level have been created before we allow those children
332 		 * to spawn new ones (or do anything else for that matter).
333 		 */
334 		if (debug) {
335 			printf("non-root child calling synchronize_children\n");
336 			fflush(stdout);
337 		}
338 		my_index = synchronize_children(parent);
339 		if (debug) {
340 			printf("non-root child has been assigned index %d\n",
341 			       my_index);
342 			fflush(stdout);
343 		}
344 	} else {
345 		/*
346 		 * The first thread has no one with which to synchronize, so
347 		 * set some initial values for things.
348 		 */
349 		if (debug) {
350 			printf("root child\n");
351 			fflush(stdout);
352 		}
353 		cdepth = 1;
354 		my_index = 0;
355 		node_count = 1;
356 	}
357 
358 	/*
359 	 * Figure out our place in the pthread array.
360 	 */
361 	info_p = &child_info[my_index];
362 
363 	if (debug) {
364 		printf("thread %d getting to heart of doit.\n", my_index);
365 		printf("info_p=%p, cdepth=%d, depth=%d\n", info_p, cdepth,
366 		       depth);
367 		fflush(stdout);
368 	}
369 
370 	if (cdepth <= depth) {
371 
372 		/*
373 		 * Since the tree is not yet complete (it is not yet tall enough),
374 		 * we need to create another level of children.
375 		 */
376 
377 		tst_resm(TINFO, "thread %d creating kids, cdepth=%d", my_index,
378 			 cdepth);
379 
380 		/*
381 		 * Create breadth children.
382 		 */
383 		for (child = 0; child < breadth; child++) {
384 			if (debug) {
385 				printf("thread %d making child %d, ptr=%p\n",
386 				       my_index, child,
387 				       &(info_p->threads[child]));
388 				fflush(stdout);
389 			}
390 			if ((rc =
391 			     pthread_create(&(info_p->threads[child]), &attr,
392 					    (void *)doit, (void *)info_p))) {
393 				tst_resm(TINFO, "pthread_create (doit): %s",
394 					 strerror(rc));
395 				testexit(3);
396 			} else {
397 				if (debug) {
398 					printf
399 					    ("pthread_create made thread %p\n",
400 					     &(info_p->threads[child]));
401 					fflush(stdout);
402 				}
403 			}
404 		}
405 
406 		if (debug) {
407 			printf("thread %d waits on kids, cdepth=%d\n", my_index,
408 			       cdepth);
409 			fflush(stdout);
410 		}
411 
412 		/*
413 		 * Wait for our children to finish before we exit ourselves.
414 		 */
415 		for (child = 0; child < breadth; child++) {
416 			if (debug) {
417 				printf("attempting join on thread %p\n",
418 				       &(info_p->threads[child]));
419 				fflush(stdout);
420 			}
421 			if ((rc =
422 			     pthread_join((info_p->threads[child]), &status))) {
423 				if (debug) {
424 					printf
425 					    ("join failed on thread %d, status addr=%p: %s\n",
426 					     my_index, status, strerror(rc));
427 					fflush(stdout);
428 				}
429 				testexit(4);
430 			} else {
431 				if (debug) {
432 					printf("thread %d joined child %d ok\n",
433 					       my_index, child);
434 					fflush(stdout);
435 				}
436 			}
437 		}
438 
439 	} else {
440 
441 		/*
442 		 * This is the leaf node case.  These children don't create
443 		 * any kids; they just talk amongst themselves.
444 		 */
445 		tst_resm(TINFO, "thread %d is a leaf node, depth=%d", my_index,
446 			 cdepth);
447 
448 		/*
449 		 * Talk to siblings (children of the same parent node).
450 		 */
451 		if (breadth > 1) {
452 
453 			for (child = 0; child < breadth; child++) {
454 				/*
455 				 * Don't talk to yourself.
456 				 */
457 				if (parent->child_ptrs[child] != info_p) {
458 					if (debug) {
459 						printf
460 						    ("thread %d locking talk_mutex\n",
461 						     my_index);
462 						fflush(stdout);
463 					}
464 					pthread_mutex_lock(&
465 							   (parent->
466 							    child_ptrs[child]->
467 							    talk_mutex));
468 					if (++parent->child_ptrs[child]->
469 					    talk_count == (breadth - 1)) {
470 						if (debug) {
471 							printf
472 							    ("thread %d talk siblings\n",
473 							     my_index);
474 							fflush(stdout);
475 						}
476 						if ((rc =
477 						     pthread_cond_broadcast
478 						     (&parent->
479 						      child_ptrs[child]->
480 						      talk_condvar))) {
481 							tst_resm(TINFO,
482 								 "pthread_cond_broadcast: %s\n",
483 								 strerror(rc));
484 							testexit(5);
485 						}
486 					}
487 					if (debug) {
488 						printf
489 						    ("thread %d unlocking talk_mutex\n",
490 						     my_index);
491 						fflush(stdout);
492 					}
493 					pthread_mutex_unlock(&
494 							     (parent->
495 							      child_ptrs
496 							      [child]->
497 							      talk_mutex));
498 				}
499 			}
500 
501 			/*
502 			 * Wait until the breadth - 1 siblings have contacted us.
503 			 */
504 			if (debug) {
505 				printf("thread %d waiting for talk siblings\n",
506 				       my_index);
507 				fflush(stdout);
508 			}
509 
510 			pthread_mutex_lock(&info_p->talk_mutex);
511 			if (info_p->talk_count < (breadth - 1)) {
512 				time(&timer.tv_sec);
513 				timer.tv_sec += (unsigned long)timeout *60;
514 				timer.tv_nsec = (unsigned long)0;
515 				if ((rc =
516 				     pthread_cond_timedwait(&info_p->
517 							    talk_condvar,
518 							    &info_p->talk_mutex,
519 							    &timer))) {
520 					tst_resm(TINFO,
521 						 "pthread_cond_timedwait (leaf) %d: %s\n",
522 						 my_index, strerror(rc));
523 					testexit(6);
524 				}
525 			}
526 			pthread_mutex_unlock(&info_p->talk_mutex);
527 
528 		}
529 
530 	}
531 
532 	/*
533 	 * Our work is done.  We're outta here.
534 	 */
535 	tst_resm(TINFO, "thread %d exiting, depth=%d, status=%d, addr=%p",
536 		 my_index, cdepth, info_p->status, info_p);
537 
538 	pthread_exit(0);
539 
540 }
541 
542 /*
543  * main
544  */
main(int argc,char * argv[])545 int main(int argc, char *argv[])
546 {
547 	int rc, ind, total;
548 	pthread_t root_thread;
549 
550 	parse_args(argc, argv);
551 
552 	/*
553 	 * Initialize node mutex.
554 	 */
555 	if ((rc = pthread_mutex_init(&node_mutex, NULL))) {
556 		tst_resm(TINFO, "pthread_mutex_init(node_mutex): %s",
557 			 strerror(rc));
558 		testexit(7);
559 	}
560 
561 	/*
562 	 * Initialize node condition variable.
563 	 */
564 	if ((rc = pthread_cond_init(&node_condvar, NULL))) {
565 		tst_resm(TINFO, "pthread_cond_init(node_condvar): %s",
566 			 strerror(rc));
567 		testexit(8);
568 	}
569 
570 	/*
571 	 * Allocate pthread info structure array.
572 	 */
573 	total = num_nodes(breadth, depth);
574 	tst_resm(TINFO, "Allocating %d nodes.", total);
575 	if ((child_info = malloc(total * sizeof(c_info)))
576 	    == NULL) {
577 		perror("malloc child_info");
578 		testexit(10);
579 	}
580 	memset(child_info, 0x00, total * sizeof(c_info));
581 
582 	if (debug) {
583 		printf("Initializing array for %d children\n", total);
584 		fflush(stdout);
585 	}
586 
587 	/*
588 	 * Allocate array of pthreads descriptors and initialize variables.
589 	 */
590 	for (ind = 0; ind < total; ind++) {
591 
592 		if ((child_info[ind].threads = malloc(breadth * sizeof(pthread_t)))
593 		    == NULL) {
594 			perror("malloc threads");
595 			testexit(11);
596 		}
597 		memset(child_info[ind].threads, 0x00,
598 		       breadth * sizeof(pthread_t));
599 
600 		if ((child_info[ind].child_ptrs = malloc(breadth * sizeof(c_info *))) == NULL) {
601 			perror("malloc child_ptrs");
602 			testexit(12);
603 		}
604 		memset(child_info[ind].child_ptrs, 0x00,
605 		       breadth * sizeof(c_info *));
606 
607 		if ((rc = pthread_mutex_init(&child_info[ind].child_mutex,
608 					     NULL))) {
609 			tst_resm(TINFO, "pthread_mutex_init child_mutex: %s",
610 				 strerror(rc));
611 			testexit(13);
612 		}
613 
614 		if ((rc = pthread_mutex_init(&child_info[ind].talk_mutex,
615 					     NULL))) {
616 			tst_resm(TINFO, "pthread_mutex_init talk_mutex: %s",
617 				 strerror(rc));
618 			testexit(14);
619 		}
620 
621 		if ((rc = pthread_cond_init(&child_info[ind].child_condvar,
622 					    NULL))) {
623 			tst_resm(TINFO,
624 				 "pthread_cond_init child_condvar: %s\n",
625 				 strerror(rc));
626 			testexit(15);
627 		}
628 
629 		if ((rc = pthread_cond_init(&child_info[ind].talk_condvar,
630 					    NULL))) {
631 			tst_resm(TINFO, "pthread_cond_init talk_condvar: %s",
632 				 strerror(rc));
633 			testexit(16);
634 		}
635 
636 		if (debug) {
637 			printf("Successfully initialized child %d.\n", ind);
638 			fflush(stdout);
639 		}
640 
641 	}
642 
643 	tst_resm(TINFO,
644 		 "Creating root thread attributes via pthread_attr_init.");
645 
646 	if ((rc = pthread_attr_init(&attr))) {
647 		tst_resm(TINFO, "pthread_attr_init: %s", strerror(rc));
648 		testexit(17);
649 	}
650 
651 	/*
652 	 * Make sure that all the thread children we create have the
653 	 * PTHREAD_CREATE_JOINABLE attribute.  If they don't, then the
654 	 * pthread_join call will sometimes fail and cause mass confusion.
655 	 */
656 	if ((rc = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE))
657 	    ) {
658 		tst_resm(TINFO, "pthread_attr_setdetachstate: %s",
659 			 strerror(rc));
660 		testexit(18);
661 	}
662 
663 	tst_resm(TINFO, "Creating root thread via pthread_create.");
664 
665 	if ((rc = pthread_create(&root_thread, &attr, (void *)doit, NULL))) {
666 		tst_resm(TINFO, "pthread_create: %s", strerror(rc));
667 		testexit(19);
668 	}
669 
670 	if (debug) {
671 		printf("Doing pthread_join.\n");
672 		fflush(stdout);
673 	}
674 
675 	/*
676 	 * Wait for the root child to exit.
677 	 */
678 	if ((rc = pthread_join(root_thread, NULL))) {
679 		tst_resm(TINFO, "pthread_join: %s", strerror(rc));
680 		testexit(20);
681 	}
682 
683 	if (debug) {
684 		printf("About to pthread_exit.\n");
685 		fflush(stdout);
686 	}
687 
688 	testexit(0);
689 
690 	exit(0);
691 }
692