mem.c 11.6 KB
Newer Older
Bob Halley's avatar
base  
Bob Halley committed
1
/*
Bob Halley's avatar
Bob Halley committed
2 3
 * Copyright (C) 1997, 1998  Internet Software Consortium.
 * 
Bob Halley's avatar
base  
Bob Halley committed
4 5 6
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
Bob Halley's avatar
Bob Halley committed
7
 * 
Bob Halley's avatar
base  
Bob Halley committed
8 9 10 11 12 13 14 15 16 17
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

Bob Halley's avatar
Bob Halley committed
18
#include <config.h>
Bob Halley's avatar
base  
Bob Halley committed
19 20 21

#include <stdio.h>
#include <stdlib.h>
Bob Halley's avatar
Bob Halley committed
22
#include <stddef.h>
Bob Halley's avatar
base  
Bob Halley committed
23 24 25
#include <string.h>

#include <isc/assertions.h>
26
#include <isc/error.h>
Bob Halley's avatar
Bob Halley committed
27
#include <isc/mem.h>
28
#ifndef ISC_SINGLETHREADED
Bob Halley's avatar
update  
Bob Halley committed
29 30 31
#include <isc/mutex.h>
#endif

Bob Halley's avatar
base  
Bob Halley committed
32 33 34 35 36 37
/*
 * Types.
 */

typedef struct {
	void *			next;
Bob Halley's avatar
Bob Halley committed
38
} element;
Bob Halley's avatar
base  
Bob Halley committed
39 40 41 42 43 44 45 46 47

typedef struct {
	size_t			size;
	/*
	 * This structure must be ALIGNMENT_SIZE bytes.
	 */
} *size_info;

struct stats {
Bob Halley's avatar
Bob Halley committed
48 49 50 51
	unsigned long		gets;
	unsigned long		totalgets;
	unsigned long		blocks;
	unsigned long		freefrags;
Bob Halley's avatar
base  
Bob Halley committed
52 53
};

Bob Halley's avatar
Bob Halley committed
54
struct isc_memctx {
Bob Halley's avatar
base  
Bob Halley committed
55 56
	size_t			max_size;
	size_t			mem_target;
Bob Halley's avatar
Bob Halley committed
57 58
	element **		freelists;
	element *		basic_blocks;
59 60 61
	unsigned char **	basic_table;
	unsigned int		basic_table_count;
	unsigned int		basic_table_size;
Bob Halley's avatar
Bob Halley committed
62 63
	unsigned char *		lowest;
	unsigned char *		highest;
Bob Halley's avatar
base  
Bob Halley committed
64
	struct stats *		stats;
Bob Halley's avatar
Bob Halley committed
65
	isc_mutex_t		mutex;
Bob Halley's avatar
base  
Bob Halley committed
66 67 68 69 70 71 72 73 74 75 76 77
};

/* Forward. */

static size_t			quantize(size_t);

/* Macros. */

#define DEF_MAX_SIZE		1100
#define DEF_MEM_TARGET		4096
#define ALIGNMENT_SIZE		sizeof (void *)
#define NUM_BASIC_BLOCKS	64			/* must be > 1 */
78
#define TABLE_INCREMENT		1024
Bob Halley's avatar
base  
Bob Halley committed
79

80
#ifndef ISC_SINGLETHREADED
Bob Halley's avatar
Bob Halley committed
81 82 83 84
#define LOCK_CONTEXT(ctx) \
	INSIST(isc_mutex_lock(&(ctx)->mutex) == ISC_R_SUCCESS)
#define UNLOCK_CONTEXT(ctx) \
	INSIST(isc_mutex_unlock(&(ctx)->mutex) == ISC_R_SUCCESS)
Bob Halley's avatar
update  
Bob Halley committed
85 86 87 88
#else
#define LOCK_CONTEXT(ctx)
#define UNLOCK_CONTEXT(ctx)
#endif
Bob Halley's avatar
base  
Bob Halley committed
89 90 91

/* Private Inline-able. */

Bob Halley's avatar
update  
Bob Halley committed
92
static inline size_t 
Bob Halley's avatar
base  
Bob Halley committed
93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113
quantize(size_t size) {
	int remainder;

	/*
	 * If there is no remainder for the integer division of 
	 *
	 *	(rightsize/ALIGNMENT_SIZE)
	 *
	 * then we already have a good size; if not, then we need
	 * to round up the result in order to get a size big
	 * enough to satisfy the request and be aligned on ALIGNMENT_SIZE
	 * byte boundaries.
	 */
	remainder = size % ALIGNMENT_SIZE;
	if (remainder != 0)
        	size += ALIGNMENT_SIZE - remainder;
	return (size);
}

/* Public. */

Bob Halley's avatar
Bob Halley committed
114 115 116 117 118 119 120
isc_result_t
isc_memctx_create(size_t init_max_size, size_t target_size,
		  isc_memctx_t *ctxp)
{
	isc_memctx_t ctx;

	REQUIRE(ctxp != NULL && *ctxp == NULL);
Bob Halley's avatar
base  
Bob Halley committed
121 122 123 124 125 126 127 128 129 130

	ctx = malloc(sizeof *ctx);
	if (init_max_size == 0)
		ctx->max_size = DEF_MAX_SIZE;
	else
		ctx->max_size = init_max_size;
	if (target_size == 0)
		ctx->mem_target = DEF_MEM_TARGET;
	else
		ctx->mem_target = target_size;
Bob Halley's avatar
Bob Halley committed
131
	ctx->freelists = malloc(ctx->max_size * sizeof (element *));
Bob Halley's avatar
base  
Bob Halley committed
132 133
	if (ctx->freelists == NULL) {
		free(ctx);
Bob Halley's avatar
Bob Halley committed
134
		return (ISC_R_NOMEMORY);
Bob Halley's avatar
base  
Bob Halley committed
135 136
	}
	memset(ctx->freelists, 0,
Bob Halley's avatar
Bob Halley committed
137
	       ctx->max_size * sizeof (element *));
Bob Halley's avatar
base  
Bob Halley committed
138 139 140 141
	ctx->stats = malloc((ctx->max_size+1) * sizeof (struct stats));
	if (ctx->stats == NULL) {
		free(ctx->freelists);
		free(ctx);
Bob Halley's avatar
Bob Halley committed
142
		return (ISC_R_NOMEMORY);
Bob Halley's avatar
base  
Bob Halley committed
143 144 145
	}
	memset(ctx->stats, 0, (ctx->max_size + 1) * sizeof (struct stats));
	ctx->basic_blocks = NULL;
146 147 148
	ctx->basic_table = NULL;
	ctx->basic_table_count = 0;
	ctx->basic_table_size = 0;
Bob Halley's avatar
base  
Bob Halley committed
149 150
	ctx->lowest = NULL;
	ctx->highest = NULL;
Bob Halley's avatar
Bob Halley committed
151
	if (isc_mutex_init(&ctx->mutex) != ISC_R_SUCCESS) {
Bob Halley's avatar
update  
Bob Halley committed
152 153 154
		free(ctx->stats);
		free(ctx->freelists);
		free(ctx);
Bob Halley's avatar
Bob Halley committed
155
		UNEXPECTED_ERROR(__FILE__, __LINE__,
Bob Halley's avatar
Bob Halley committed
156
				 "isc_mutex_init() failed");
Bob Halley's avatar
Bob Halley committed
157
		return (ISC_R_UNEXPECTED);
Bob Halley's avatar
update  
Bob Halley committed
158
	}
Bob Halley's avatar
base  
Bob Halley committed
159
	*ctxp = ctx;
Bob Halley's avatar
Bob Halley committed
160
	return (ISC_R_SUCCESS);
Bob Halley's avatar
base  
Bob Halley committed
161 162 163
}

void
Bob Halley's avatar
Bob Halley committed
164
isc_memctx_destroy(isc_memctx_t *ctxp) {
165
	unsigned int i;
Bob Halley's avatar
Bob Halley committed
166
	isc_memctx_t ctx;
167

Bob Halley's avatar
base  
Bob Halley committed
168
	REQUIRE(ctxp != NULL);
Bob Halley's avatar
Bob Halley committed
169

170 171 172 173 174 175 176 177 178 179
	ctx = *ctxp;

	for (i = 0; i <= ctx->max_size; i++)
		INSIST(ctx->stats[i].gets == 0);

	for (i = 0; i < ctx->basic_table_count; i++)
		free(ctx->basic_table[i]);
	free(ctx->freelists);
	free(ctx->stats);
	free(ctx->basic_table);
Bob Halley's avatar
Bob Halley committed
180
	(void)isc_mutex_destroy(&ctx->mutex);
181
	free(ctx);
Bob Halley's avatar
base  
Bob Halley committed
182 183 184 185

	*ctxp = NULL;
}

186
static void
Bob Halley's avatar
Bob Halley committed
187
more_basic_blocks(isc_memctx_t ctx) {
188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220
	void *new;
	unsigned char *curr, *next;
	unsigned char *first, *last;
	unsigned char **table;
	unsigned int table_size;
	int i;

	/* Require: we hold the context lock. */

	if (ctx->basic_table_count <= ctx->basic_table_size) {
		table_size = ctx->basic_table_size + TABLE_INCREMENT;
		table = malloc(table_size * sizeof (unsigned char *));
		if (table == NULL)
			return;
		memcpy(table, ctx->basic_table,
		       ctx->basic_table_size * sizeof (unsigned char *));
		free(ctx->basic_table);
		ctx->basic_table = table;
		ctx->basic_table_size = table_size;
	} else
		table = NULL;

	new = malloc(NUM_BASIC_BLOCKS * ctx->mem_target);
	if (new == NULL) {
		if (table != NULL)
			free(table);
		return;
	}
	ctx->basic_table[ctx->basic_table_count] = new;
	ctx->basic_table_count++;
	curr = new;
	next = curr + ctx->mem_target;
	for (i = 0; i < (NUM_BASIC_BLOCKS - 1); i++) {
Bob Halley's avatar
Bob Halley committed
221
		((element *)curr)->next = next;
222 223 224 225 226 227 228
		curr = next;
		next += ctx->mem_target;
	}
	/*
	 * curr is now pointing at the last block in the
	 * array.
	 */
Bob Halley's avatar
Bob Halley committed
229
	((element *)curr)->next = NULL;
230 231 232 233 234 235 236 237 238
	first = new;
	last = first + NUM_BASIC_BLOCKS * ctx->mem_target - 1;
	if (first < ctx->lowest || ctx->lowest == NULL)
		ctx->lowest = first;
	if (last > ctx->highest)
		ctx->highest = last;
	ctx->basic_blocks = new;
}

Bob Halley's avatar
base  
Bob Halley committed
239
void *
Bob Halley's avatar
Bob Halley committed
240
__isc_mem_get(isc_memctx_t ctx, size_t size) {
Bob Halley's avatar
base  
Bob Halley committed
241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266
	size_t new_size = quantize(size);
	void *ret;

	REQUIRE(size > 0);

	LOCK_CONTEXT(ctx);

	if (size >= ctx->max_size || new_size >= ctx->max_size) {
		/* memget() was called on something beyond our upper limit. */
		ret = malloc(size);
		if (ret != NULL) {
			ctx->stats[ctx->max_size].gets++;
			ctx->stats[ctx->max_size].totalgets++;
		}
		goto done;
	}

	/* 
	 * If there are no blocks in the free list for this size, get a chunk
	 * of memory and then break it up into "new_size"-sized blocks, adding
	 * them to the free list.
	 */
	if (ctx->freelists[new_size] == NULL) {
		int i, frags;
		size_t total_size;
		void *new;
Bob Halley's avatar
Bob Halley committed
267
		unsigned char *curr, *next;
Bob Halley's avatar
base  
Bob Halley committed
268 269

		if (ctx->basic_blocks == NULL) {
270 271
			more_basic_blocks(ctx);
			if (ctx->basic_blocks == NULL) {
Bob Halley's avatar
base  
Bob Halley committed
272 273 274 275 276 277 278 279 280 281 282 283 284 285
				ret = NULL;
				goto done;
			}
		}
		total_size = ctx->mem_target;
		new = ctx->basic_blocks;
		ctx->basic_blocks = ctx->basic_blocks->next;
		frags = total_size / new_size;
		ctx->stats[new_size].blocks++;
		ctx->stats[new_size].freefrags += frags;
		/* Set up a linked-list of blocks of size "new_size". */
		curr = new;
		next = curr + new_size;
		for (i = 0; i < (frags - 1); i++) {
Bob Halley's avatar
Bob Halley committed
286
			((element *)curr)->next = next;
Bob Halley's avatar
base  
Bob Halley committed
287 288 289 290
			curr = next;
			next += new_size;
		}
		/* curr is now pointing at the last block in the array. */
Bob Halley's avatar
Bob Halley committed
291
		((element *)curr)->next = NULL;
Bob Halley's avatar
base  
Bob Halley committed
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319
		ctx->freelists[new_size] = new;
	}

	/* The free list uses the "rounded-up" size "new_size": */
	ret = ctx->freelists[new_size];
	ctx->freelists[new_size] = ctx->freelists[new_size]->next;

	/* 
	 * The stats[] uses the _actual_ "size" requested by the
	 * caller, with the caveat (in the code above) that "size" >= the
	 * max. size (max_size) ends up getting recorded as a call to
	 * max_size.
	 */
	ctx->stats[size].gets++;
	ctx->stats[size].totalgets++;
	ctx->stats[new_size].freefrags--;

 done:
	UNLOCK_CONTEXT(ctx);

	return (ret);
}

/* 
 * This is a call from an external caller, 
 * so we want to count this as a user "put". 
 */
void
Bob Halley's avatar
Bob Halley committed
320
__isc_mem_put(isc_memctx_t ctx, void *mem, size_t size) {
Bob Halley's avatar
base  
Bob Halley committed
321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
	size_t new_size = quantize(size);

	REQUIRE(size > 0);

	LOCK_CONTEXT(ctx);

	if (size == ctx->max_size || new_size >= ctx->max_size) {
		/* memput() called on something beyond our upper limit */
		free(mem);
		INSIST(ctx->stats[ctx->max_size].gets != 0);
		ctx->stats[ctx->max_size].gets--;
		goto done;
	}

	/* The free list uses the "rounded-up" size "new_size": */
Bob Halley's avatar
Bob Halley committed
336 337
	((element *)mem)->next = ctx->freelists[new_size];
	ctx->freelists[new_size] = (element *)mem;
Bob Halley's avatar
base  
Bob Halley committed
338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353

	/* 
	 * The stats[] uses the _actual_ "size" requested by the
	 * caller, with the caveat (in the code above) that "size" >= the
	 * max. size (max_size) ends up getting recorded as a call to
	 * max_size.
	 */
	INSIST(ctx->stats[size].gets != 0);
	ctx->stats[size].gets--;
	ctx->stats[new_size].freefrags++;

 done:
	UNLOCK_CONTEXT(ctx);
}

void *
Bob Halley's avatar
Bob Halley committed
354
__isc_mem_getdebug(isc_memctx_t ctx, size_t size, const char *file, int line) {
Bob Halley's avatar
base  
Bob Halley committed
355
	void *ptr;
Bob Halley's avatar
Bob Halley committed
356 357

	ptr = __isc_mem_get(ctx, size);
Bob Halley's avatar
base  
Bob Halley committed
358
	fprintf(stderr, "%s:%d: mem_get(%p, %lu) -> %p\n", file, line,
Bob Halley's avatar
Bob Halley committed
359
		ctx, (unsigned long)size, ptr);
Bob Halley's avatar
base  
Bob Halley committed
360 361 362 363
	return (ptr);
}

void
Bob Halley's avatar
Bob Halley committed
364 365
__isc_mem_putdebug(isc_memctx_t ctx, void *ptr, size_t size, const char *file,
		   int line)
Bob Halley's avatar
base  
Bob Halley committed
366 367
{
	fprintf(stderr, "%s:%d: mem_put(%p, %p, %lu)\n", file, line, 
Bob Halley's avatar
Bob Halley committed
368
		ctx, ptr, (unsigned long)size);
Bob Halley's avatar
Bob Halley committed
369
	__isc_mem_put(ctx, ptr, size);
Bob Halley's avatar
base  
Bob Halley committed
370 371 372 373 374 375
}

/*
 * Print the stats[] on the stream "out" with suitable formatting.
 */
void
Bob Halley's avatar
Bob Halley committed
376
isc_mem_stats(isc_memctx_t ctx, FILE *out) {
Bob Halley's avatar
base  
Bob Halley committed
377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399
	size_t i;

	LOCK_CONTEXT(ctx);

	if (ctx->freelists == NULL)
		return;
	for (i = 1; i <= ctx->max_size; i++) {
		const struct stats *s = &ctx->stats[i];

		if (s->totalgets == 0 && s->gets == 0)
			continue;
		fprintf(out, "%s%5d: %11lu gets, %11lu rem",
			(i == ctx->max_size) ? ">=" : "  ",
			i, s->totalgets, s->gets);
		if (s->blocks != 0)
			fprintf(out, " (%lu bl, %lu ff)",
				s->blocks, s->freefrags);
		fputc('\n', out);
	}

	UNLOCK_CONTEXT(ctx);
}

Bob Halley's avatar
Bob Halley committed
400 401
isc_boolean_t
isc_mem_valid(isc_memctx_t ctx, void *ptr) {
Bob Halley's avatar
Bob Halley committed
402
	unsigned char *cp = ptr;
Bob Halley's avatar
Bob Halley committed
403
	isc_boolean_t result = ISC_FALSE;
Bob Halley's avatar
base  
Bob Halley committed
404 405 406 407

	LOCK_CONTEXT(ctx);

	if (ctx->lowest != NULL && cp >= ctx->lowest && cp <= ctx->highest)
Bob Halley's avatar
Bob Halley committed
408
		result = ISC_TRUE;
Bob Halley's avatar
base  
Bob Halley committed
409 410 411

	UNLOCK_CONTEXT(ctx);

Bob Halley's avatar
Bob Halley committed
412
	return (result);
Bob Halley's avatar
base  
Bob Halley committed
413 414 415 416 417 418 419
}

/*
 * Replacements for malloc() and free().
 */

void *
Bob Halley's avatar
Bob Halley committed
420
isc_mem_allocate(isc_memctx_t ctx, size_t size) {
Bob Halley's avatar
base  
Bob Halley committed
421 422 423
	size_info si;

	size += ALIGNMENT_SIZE;
Bob Halley's avatar
Bob Halley committed
424
	si = isc_mem_get(ctx, size);
Bob Halley's avatar
base  
Bob Halley committed
425 426 427 428 429 430 431
	if (si == NULL)
		return (NULL);
	si->size = size;
	return (&si[1]);
}

void
Bob Halley's avatar
Bob Halley committed
432
isc_mem_free(isc_memctx_t ctx, void *ptr) {
Bob Halley's avatar
base  
Bob Halley committed
433 434 435
	size_info si;

	si = &(((size_info)ptr)[-1]);
Bob Halley's avatar
Bob Halley committed
436
	isc_mem_put(ctx, si, si->size);
Bob Halley's avatar
base  
Bob Halley committed
437 438
}

Bob Halley's avatar
Bob Halley committed
439 440
#ifdef ISC_MEMCLUSTER_LEGACY

Bob Halley's avatar
base  
Bob Halley committed
441 442 443 444
/*
 * Public Legacy.
 */

Bob Halley's avatar
Bob Halley committed
445 446
static isc_memctx_t 		default_context = NULL;

Bob Halley's avatar
base  
Bob Halley committed
447 448 449 450 451
int
meminit(size_t init_max_size, size_t target_size) {
	/* need default_context lock here */
	if (default_context != NULL)
		return (-1);
Bob Halley's avatar
Bob Halley committed
452
	return (isc_mem_create(init_max_size, target_size, &default_context));
Bob Halley's avatar
base  
Bob Halley committed
453 454
}

Bob Halley's avatar
Bob Halley committed
455
isc_memctx_t
Bob Halley's avatar
base  
Bob Halley committed
456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482
mem_default_context(void) {
	/* need default_context lock here */
	if (default_context == NULL && meminit(0, 0) == -1)
		return (NULL);
	return (default_context);
}

void *
__memget(size_t size) {
	/* need default_context lock here */
	if (default_context == NULL && meminit(0, 0) == -1)
		return (NULL);
	return (__mem_get(default_context, size));
}

void
__memput(void *mem, size_t size) {
	/* need default_context lock here */
	REQUIRE(default_context != NULL);
	__mem_put(default_context, mem, size);
}

void *
__memget_debug(size_t size, const char *file, int line) {
	void *ptr;
	ptr = __memget(size);
	fprintf(stderr, "%s:%d: memget(%lu) -> %p\n", file, line,
Bob Halley's avatar
Bob Halley committed
483
		(unsigned long)size, ptr);
Bob Halley's avatar
base  
Bob Halley committed
484 485 486 487 488 489
	return (ptr);
}

void
__memput_debug(void *ptr, size_t size, const char *file, int line) {
	fprintf(stderr, "%s:%d: memput(%p, %lu)\n", file, line, 
Bob Halley's avatar
Bob Halley committed
490
		ptr, (unsigned long)size);
Bob Halley's avatar
base  
Bob Halley committed
491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506
	__memput(ptr, size);
}

int
memvalid(void *ptr) {
	/* need default_context lock here */
	REQUIRE(default_context != NULL);
	return (mem_valid(default_context, ptr));
}

void
memstats(FILE *out) {
	/* need default_context lock here */
	REQUIRE(default_context != NULL);
	mem_stats(default_context, out);
}
Bob Halley's avatar
Bob Halley committed
507 508

#endif /* ISC_MEMCLUSTER_LEGACY */