xref: /titanic_41/usr/src/lib/libresolv2/common/isc/memcluster.c (revision 4bb7efa72ed531c10f097919636e67724ec4c25a)
1 /*
2  * Copyright 1998-2002 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1997,1999 by Internet Software Consortium.
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
14  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
16  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
17  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
18  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
19  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
20  * SOFTWARE.
21  */
22 
23 #pragma ident	"%Z%%M%	%I%	%E% SMI"
24 
25 /* When this symbol is defined allocations via memget are made slightly
26    bigger and some debugging info stuck before and after the region given
27    back to the caller. */
28 /* #define DEBUGGING_MEMCLUSTER */
29 #define MEMCLUSTER_ATEND
30 
31 
32 #if !defined(LINT) && !defined(CODECENTER)
33 static const char rcsid[] = "$Id: memcluster.c,v 8.23 2001/06/18 14:44:05 marka Exp $";
34 #endif /* not lint */
35 
36 #include "port_before.h"
37 
38 #include <sys/types.h>
39 #include <sys/uio.h>
40 #include <sys/param.h>
41 #include <sys/stat.h>
42 
43 #include <netinet/in.h>
44 #include <arpa/inet.h>
45 #include <arpa/nameser.h>
46 
47 #include <errno.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <time.h>
52 
53 #include <isc/memcluster.h>
54 #include <isc/assertions.h>
55 
56 #include "port_after.h"
57 
58 #ifdef MEMCLUSTER_RECORD
59 #ifndef DEBUGGING_MEMCLUSTER
60 #define DEBUGGING_MEMCLUSTER
61 #endif
62 #endif
63 
64 #define DEF_MAX_SIZE		1100
65 #define DEF_MEM_TARGET		4096
66 
67 typedef u_int32_t fence_t;
68 
69 typedef struct {
70 	void *			next;
71 #if defined(DEBUGGING_MEMCLUSTER)
72 #if defined(MEMCLUSTER_RECORD)
73 	const char *		file;
74 	int			line;
75 #endif
76 	size_t			size;
77 	fence_t			fencepost;
78 #endif
79 } memcluster_element;
80 
81 #define SMALL_SIZE_LIMIT sizeof(memcluster_element)
82 #define P_SIZE sizeof(void *)
83 #define FRONT_FENCEPOST 0xfebafeba
84 #define BACK_FENCEPOST 0xabefabef
85 #define FENCEPOST_SIZE 4
86 
87 #ifndef MEMCLUSTER_LITTLE_MALLOC
88 #define MEMCLUSTER_BIG_MALLOC 1
89 #define NUM_BASIC_BLOCKS 64
90 #endif
91 
92 struct stats {
93 	u_long			gets;
94 	u_long			totalgets;
95 	u_long			blocks;
96 	u_long			freefrags;
97 };
98 
99 /* Private data. */
100 
101 #ifdef	SUNW_MT_RESOLVER
102 #include <thread.h>
103 #include <synch.h>
104 static mutex_t			memlock = DEFAULTMUTEX;
105 #define	SUNW_MEMLOCK		(void)mutex_lock(&memlock)
106 #define	SUNW_MEMUNLOCK		(void)mutex_unlock(&memlock)
107 #define	SUNW_MEMLOCKBLOCK_BEGIN	{
108 #define	SUNW_MEMLOCKBLOCK_END	}
109 #else
110 #define	SUNW_MEMLOCK
111 #define	SUNW_MEMUNLOCK
112 #define	SUNW_MEMLOCKBLOCK_BEGIN
113 #define	SUNW_MEMLOCKBLOCK_END
114 #endif	/* SUNW_MT_RESOLVER */
115 
116 static size_t			max_size;
117 static size_t			mem_target;
118 static size_t			mem_target_half;
119 static size_t			mem_target_fudge;
120 static memcluster_element **	freelists;
121 #ifdef MEMCLUSTER_RECORD
122 static memcluster_element **	activelists;
123 #endif
124 #ifdef MEMCLUSTER_BIG_MALLOC
125 static memcluster_element *	basic_blocks;
126 #endif
127 static struct stats *		stats;
128 
129 /* Forward. */
130 
131 static size_t			quantize(size_t);
132 #if defined(DEBUGGING_MEMCLUSTER)
133 static void			check(unsigned char *, int, size_t);
134 #endif
135 
136 /* Public. */
137 
138 int
139 meminit(size_t init_max_size, size_t target_size) {
140 
141 #if defined(DEBUGGING_MEMCLUSTER)
142 	INSIST(sizeof(fence_t) == FENCEPOST_SIZE);
143 #endif
144 	if (freelists != NULL) {
145 		errno = EEXIST;
146 		return (-1);
147 	}
148 	if (init_max_size == 0)
149 		max_size = DEF_MAX_SIZE;
150 	else
151 		max_size = init_max_size;
152 	if (target_size == 0)
153 		mem_target = DEF_MEM_TARGET;
154 	else
155 		mem_target = target_size;
156 	mem_target_half = mem_target / 2;
157 	mem_target_fudge = mem_target + mem_target / 4;
158 	freelists = malloc(max_size * sizeof (memcluster_element *));
159 	stats = malloc((max_size+1) * sizeof (struct stats));
160 	if (freelists == NULL || stats == NULL) {
161 		errno = ENOMEM;
162 		return (-1);
163 	}
164 	memset(freelists, 0,
165 	       max_size * sizeof (memcluster_element *));
166 	memset(stats, 0, (max_size + 1) * sizeof (struct stats));
167 #ifdef MEMCLUSTER_RECORD
168 	activelists = malloc((max_size + 1) * sizeof (memcluster_element *));
169 	if (activelists == NULL) {
170 		errno = ENOMEM;
171 		return (-1);
172 	}
173 	memset(activelists, 0,
174 	       (max_size + 1) * sizeof (memcluster_element *));
175 #endif
176 #ifdef MEMCLUSTER_BIG_MALLOC
177 	basic_blocks = NULL;
178 #endif
179 	return (0);
180 }
181 
182 void *
183 __memget(size_t size) {
184 	return (__memget_record(size, NULL, 0));
185 }
186 
187 void *
188 __memget_record(size_t size, const char *file, int line) {
189 	size_t new_size = quantize(size);
190 #if defined(DEBUGGING_MEMCLUSTER)
191 	memcluster_element *e;
192 	char *p;
193 	fence_t fp = BACK_FENCEPOST;
194 #endif
195 	void *ret;
196 
197 	SUNW_MEMLOCK;
198 
199 #if !defined(MEMCLUSTER_RECORD)
200 	UNUSED(file);
201 	UNUSED(line);
202 #endif
203 	if (freelists == NULL)
204 		if (meminit(0, 0) == -1)
205 SUNW_MEMLOCKBLOCK_BEGIN
206 			SUNW_MEMUNLOCK;
207 			return (NULL);
208 SUNW_MEMLOCKBLOCK_END
209 	if (size == 0) {
210 		SUNW_MEMUNLOCK;
211 		errno = EINVAL;
212 		return (NULL);
213 	}
214 	if (size >= max_size || new_size >= max_size) {
215 		/* memget() was called on something beyond our upper limit. */
216 		stats[max_size].gets++;
217 		stats[max_size].totalgets++;
218 #if defined(DEBUGGING_MEMCLUSTER)
219 		e = malloc(new_size);
220 		if (e == NULL) {
221 			SUNW_MEMUNLOCK;
222 			errno = ENOMEM;
223 			return (NULL);
224 		}
225 		e->next = NULL;
226 		e->size = size;
227 #ifdef MEMCLUSTER_RECORD
228 		e->file = file;
229 		e->line = line;
230 		e->next = activelists[max_size];
231 		activelists[max_size] = e;
232 #endif
233 		SUNW_MEMUNLOCK;
234 		e->fencepost = FRONT_FENCEPOST;
235 		p = (char *)e + sizeof *e + size;
236 		memcpy(p, &fp, sizeof fp);
237 		return ((char *)e + sizeof *e);
238 #else
239 		SUNW_MEMUNLOCK;
240 		return (malloc(size));
241 #endif
242 	}
243 
244 	/*
245 	 * If there are no blocks in the free list for this size, get a chunk
246 	 * of memory and then break it up into "new_size"-sized blocks, adding
247 	 * them to the free list.
248 	 */
249 	if (freelists[new_size] == NULL) {
250 		int i, frags;
251 		size_t total_size;
252 		void *new;
253 		char *curr, *next;
254 
255 #ifdef MEMCLUSTER_BIG_MALLOC
256 		if (basic_blocks == NULL) {
257 			new = malloc(NUM_BASIC_BLOCKS * mem_target);
258 			if (new == NULL) {
259 				SUNW_MEMUNLOCK;
260 				errno = ENOMEM;
261 				return (NULL);
262 			}
263 			curr = new;
264 			next = curr + mem_target;
265 			for (i = 0; i < (NUM_BASIC_BLOCKS - 1); i++) {
266 				((memcluster_element *)curr)->next = next;
267 				curr = next;
268 				next += mem_target;
269 			}
270 			/*
271 			 * curr is now pointing at the last block in the
272 			 * array.
273 			 */
274 			((memcluster_element *)curr)->next = NULL;
275 			basic_blocks = new;
276 		}
277 		total_size = mem_target;
278 		new = basic_blocks;
279 		basic_blocks = basic_blocks->next;
280 #else
281 		if (new_size > mem_target_half)
282 			total_size = mem_target_fudge;
283 		else
284 			total_size = mem_target;
285 		new = malloc(total_size);
286 		if (new == NULL) {
287 			SUNW_MEMUNLOCK;
288 			errno = ENOMEM;
289 			return (NULL);
290 		}
291 #endif
292 		frags = total_size / new_size;
293 		stats[new_size].blocks++;
294 		stats[new_size].freefrags += frags;
295 		/* Set up a linked-list of blocks of size "new_size". */
296 		curr = new;
297 		next = curr + new_size;
298 		for (i = 0; i < (frags - 1); i++) {
299 #if defined (DEBUGGING_MEMCLUSTER)
300 			memset(curr, 0xa5, new_size);
301 #endif
302 			((memcluster_element *)curr)->next = next;
303 			curr = next;
304 			next += new_size;
305 		}
306 		/* curr is now pointing at the last block in the array. */
307 #if defined (DEBUGGING_MEMCLUSTER)
308 		memset(curr, 0xa5, new_size);
309 #endif
310 		((memcluster_element *)curr)->next = freelists[new_size];
311 		freelists[new_size] = new;
312 	}
313 
314 	/* The free list uses the "rounded-up" size "new_size". */
315 #if defined (DEBUGGING_MEMCLUSTER)
316 	e = freelists[new_size];
317 	ret = (char *)e + sizeof *e;
318 	/*
319 	 * Check to see if this buffer has been written to while on free list.
320 	 */
321 	check(ret, 0xa5, new_size - sizeof *e);
322 	/*
323 	 * Mark memory we are returning.
324 	 */
325 	memset(ret, 0xe5, size);
326 #else
327 	ret = freelists[new_size];
328 #endif
329 	freelists[new_size] = freelists[new_size]->next;
330 #if defined(DEBUGGING_MEMCLUSTER)
331 	e->next = NULL;
332 	e->size = size;
333 	e->fencepost = FRONT_FENCEPOST;
334 #ifdef MEMCLUSTER_RECORD
335 	e->file = file;
336 	e->line = line;
337 	e->next = activelists[size];
338 	activelists[size] = e;
339 #endif
340 	p = (char *)e + sizeof *e + size;
341 	memcpy(p, &fp, sizeof fp);
342 #endif
343 
344 	/*
345 	 * The stats[] uses the _actual_ "size" requested by the
346 	 * caller, with the caveat (in the code above) that "size" >= the
347 	 * max. size (max_size) ends up getting recorded as a call to
348 	 * max_size.
349 	 */
350 	stats[size].gets++;
351 	stats[size].totalgets++;
352 	stats[new_size].freefrags--;
353 	SUNW_MEMUNLOCK;
354 #if defined(DEBUGGING_MEMCLUSTER)
355 	return ((char *)e + sizeof *e);
356 #else
357 	return (ret);
358 #endif
359 }
360 
361 /*
362  * This is a call from an external caller,
363  * so we want to count this as a user "put".
364  */
365 void
366 __memput(void *mem, size_t size) {
367 	__memput_record(mem, size, NULL, 0);
368 }
369 
370 void
371 __memput_record(void *mem, size_t size, const char *file, int line) {
372 	size_t new_size = quantize(size);
373 #if defined (DEBUGGING_MEMCLUSTER)
374 	memcluster_element *e;
375 	memcluster_element *el;
376 #ifdef MEMCLUSTER_RECORD
377 	memcluster_element *prev;
378 #endif
379 	fence_t fp;
380 	char *p;
381 #endif
382 
383 	SUNW_MEMLOCK;
384 
385 #if !defined (MEMCLUSTER_RECORD)
386 	UNUSED(file);
387 	UNUSED(line);
388 #endif
389 
390 	REQUIRE(freelists != NULL);
391 
392 	if (size == 0) {
393 		SUNW_MEMUNLOCK;
394 		errno = EINVAL;
395 		return;
396 	}
397 
398 #if defined (DEBUGGING_MEMCLUSTER)
399 	e = (memcluster_element *) ((char *)mem - sizeof *e);
400 	INSIST(e->fencepost == FRONT_FENCEPOST);
401 	INSIST(e->size == size);
402 	p = (char *)e + sizeof *e + size;
403 	memcpy(&fp, p, sizeof fp);
404 	INSIST(fp == BACK_FENCEPOST);
405 	INSIST(((int)mem % 4) == 0);
406 #ifdef MEMCLUSTER_RECORD
407 	prev = NULL;
408 	if (size == max_size || new_size >= max_size)
409 		el = activelists[max_size];
410 	else
411 		el = activelists[size];
412 	while (el != NULL && el != e) {
413 		prev = el;
414 		el = el->next;
415 	}
416 	INSIST(el != NULL);	/* double free */
417 	if (prev == NULL) {
418 		if (size == max_size || new_size >= max_size)
419 			activelists[max_size] = el->next;
420 		else
421 			activelists[size] = el->next;
422 	} else
423 		prev->next = el->next;
424 #endif
425 #endif
426 
427 	if (size == max_size || new_size >= max_size) {
428 		/* memput() called on something beyond our upper limit */
429 #if defined(DEBUGGING_MEMCLUSTER)
430 		free(e);
431 #else
432 		free(mem);
433 #endif
434 
435 		INSIST(stats[max_size].gets != 0);
436 		stats[max_size].gets--;
437 		SUNW_MEMUNLOCK;
438 		return;
439 	}
440 
441 	/* The free list uses the "rounded-up" size "new_size": */
442 #if defined(DEBUGGING_MEMCLUSTER)
443 	memset(mem, 0xa5, new_size - sizeof *e); /* catch write after free */
444 	e->size = 0;	/* catch double memput() */
445 #ifdef MEMCLUSTER_RECORD
446 	e->file = file;
447 	e->line = line;
448 #endif
449 #ifdef MEMCLUSTER_ATEND
450 	e->next = NULL;
451 	el = freelists[new_size];
452 	while (el != NULL && el->next != NULL)
453 		el = el->next;
454 	if (el)
455 		el->next = e;
456 	else
457 		freelists[new_size] = e;
458 #else
459 	e->next = freelists[new_size];
460 	freelists[new_size] = (void *)e;
461 #endif
462 #else
463 	((memcluster_element *)mem)->next = freelists[new_size];
464 	freelists[new_size] = (memcluster_element *)mem;
465 #endif
466 
467 	/*
468 	 * The stats[] uses the _actual_ "size" requested by the
469 	 * caller, with the caveat (in the code above) that "size" >= the
470 	 * max. size (max_size) ends up getting recorded as a call to
471 	 * max_size.
472 	 */
473 	INSIST(stats[size].gets != 0);
474 	stats[size].gets--;
475 	stats[new_size].freefrags++;
476 	SUNW_MEMUNLOCK;
477 }
478 
479 void *
480 __memget_debug(size_t size, const char *file, int line) {
481 	void *ptr;
482 	ptr = __memget_record(size, file, line);
483 	fprintf(stderr, "%s:%d: memget(%lu) -> %p\n", file, line,
484 		(u_long)size, ptr);
485 	return (ptr);
486 }
487 
488 void
489 __memput_debug(void *ptr, size_t size, const char *file, int line) {
490 	fprintf(stderr, "%s:%d: memput(%p, %lu)\n", file, line, ptr,
491 		(u_long)size);
492 	__memput_record(ptr, size, file, line);
493 }
494 
495 /*
496  * Print the stats[] on the stream "out" with suitable formatting.
497  */
498 void
499 memstats(FILE *out) {
500 	size_t i;
501 #ifdef MEMCLUSTER_RECORD
502 	memcluster_element *e;
503 #endif
504 
505 	SUNW_MEMLOCK;
506 	if (freelists == NULL)
507 SUNW_MEMLOCKBLOCK_BEGIN
508 		SUNW_MEMUNLOCK;
509 		return;
510 SUNW_MEMLOCKBLOCK_END
511 	for (i = 1; i <= max_size; i++) {
512 		const struct stats *s = &stats[i];
513 
514 		if (s->totalgets == 0 && s->gets == 0)
515 			continue;
516 		fprintf(out, "%s%5d: %11lu gets, %11lu rem",
517 			(i == max_size) ? ">=" : "  ",
518 			i, s->totalgets, s->gets);
519 		if (s->blocks != 0)
520 			fprintf(out, " (%lu bl, %lu ff)",
521 				s->blocks, s->freefrags);
522 		fputc('\n', out);
523 	}
524 #ifdef MEMCLUSTER_RECORD
525 	fprintf(out, "Active Memory:\n");
526 	for (i = 1; i <= max_size; i++) {
527 		if ((e = activelists[i]) != NULL)
528 			while (e != NULL) {
529 				fprintf(out, "%s:%d %p:%d\n",
530 				        e->file != NULL ? e->file :
531 						"<UNKNOWN>", e->line,
532 					(char *)e + sizeof *e, e->size);
533 				e = e->next;
534 			}
535 	}
536 #endif
537 	SUNW_MEMUNLOCK;
538 }
539 
540 int
541 memactive(void) {
542 	size_t i;
543 
544 	if (stats == NULL)
545 		return (0);
546 	for (i = 1; i <= max_size; i++)
547 		if (stats[i].gets != 0)
548 			return (1);
549 	return (0);
550 }
551 
552 /* Private. */
553 
554 /*
555  * Round up size to a multiple of sizeof(void *).  This guarantees that a
556  * block is at least sizeof void *, and that we won't violate alignment
557  * restrictions, both of which are needed to make lists of blocks.
558  */
559 static size_t
560 quantize(size_t size) {
561 	int remainder;
562 	/*
563 	 * If there is no remainder for the integer division of
564 	 *
565 	 *	(rightsize/P_SIZE)
566 	 *
567 	 * then we already have a good size; if not, then we need
568 	 * to round up the result in order to get a size big
569 	 * enough to satisfy the request _and_ aligned on P_SIZE boundaries.
570 	 */
571 	remainder = size % P_SIZE;
572 	if (remainder != 0)
573 		size += P_SIZE - remainder;
574 #if defined(DEBUGGING_MEMCLUSTER)
575 	return (size + SMALL_SIZE_LIMIT + sizeof (int));
576 #else
577 	return (size);
578 #endif
579 }
580 
581 #if defined(DEBUGGING_MEMCLUSTER)
582 static void
583 check(unsigned char *a, int value, size_t len) {
584 	size_t i;
585 	for (i = 0; i < len; i++)
586 		INSIST(a[i] == value);
587 }
588 #endif
589