xref: /illumos-gate/usr/src/cmd/sendmail/libsm/rpool.c (revision 71269a2275bf5a143dad6461eee2710a344e7261)
1 /*
2  * Copyright (c) 2000-2004 Sendmail, Inc. and its suppliers.
3  *	All rights reserved.
4  *
5  * By using this file, you agree to the terms and conditions set
6  * forth in the LICENSE file which can be found at the top level of
7  * the sendmail distribution.
8  */
9 
10 #pragma ident	"%Z%%M%	%I%	%E% SMI"
11 
12 #include <sm/gen.h>
13 SM_RCSID("@(#)$Id: rpool.c,v 1.28 2004/08/03 20:44:04 ca Exp $")
14 
15 /*
16 **  resource pools
17 **  For documentation, see rpool.html
18 */
19 
20 #include <sm/exc.h>
21 #include <sm/heap.h>
22 #include <sm/rpool.h>
23 #include <sm/varargs.h>
24 #include <sm/conf.h>
25 #if _FFR_PERF_RPOOL
26 # include <syslog.h>
27 #endif /* _FFR_PERF_RPOOL */
28 
29 const char SmRpoolMagic[] = "sm_rpool";
30 
31 typedef union
32 {
33 	SM_POOLLINK_T	link;
34 	char		align[SM_ALIGN_SIZE];
35 } SM_POOLHDR_T;
36 
37 static char	*sm_rpool_allocblock_x __P((SM_RPOOL_T *, size_t));
38 static char	*sm_rpool_allocblock __P((SM_RPOOL_T *, size_t));
39 
40 /*
41 **  Tune this later
42 */
43 
44 #define POOLSIZE		4096
45 #define BIG_OBJECT_RATIO	10
46 
47 /*
48 **  SM_RPOOL_ALLOCBLOCK_X -- allocate a new block for an rpool.
49 **
50 **	Parameters:
51 **		rpool -- rpool to which the block should be added.
52 **		size -- size of block.
53 **
54 **	Returns:
55 **		Pointer to block.
56 **
57 **	Exceptions:
58 **		F:sm_heap -- out of memory
59 */
60 
61 static char *
62 sm_rpool_allocblock_x(rpool, size)
63 	SM_RPOOL_T *rpool;
64 	size_t size;
65 {
66 	SM_POOLLINK_T *p;
67 
68 	p = sm_malloc_x(sizeof(SM_POOLHDR_T) + size);
69 	p->sm_pnext = rpool->sm_pools;
70 	rpool->sm_pools = p;
71 	return (char*) p + sizeof(SM_POOLHDR_T);
72 }
73 
74 /*
75 **  SM_RPOOL_ALLOCBLOCK -- allocate a new block for an rpool.
76 **
77 **	Parameters:
78 **		rpool -- rpool to which the block should be added.
79 **		size -- size of block.
80 **
81 **	Returns:
82 **		Pointer to block, NULL on failure.
83 */
84 
85 static char *
86 sm_rpool_allocblock(rpool, size)
87 	SM_RPOOL_T *rpool;
88 	size_t size;
89 {
90 	SM_POOLLINK_T *p;
91 
92 	p = sm_malloc(sizeof(SM_POOLHDR_T) + size);
93 	if (p == NULL)
94 		return NULL;
95 	p->sm_pnext = rpool->sm_pools;
96 	rpool->sm_pools = p;
97 	return (char*) p + sizeof(SM_POOLHDR_T);
98 }
99 
100 /*
101 **  SM_RPOOL_MALLOC_TAGGED_X -- allocate memory from rpool
102 **
103 **	Parameters:
104 **		rpool -- rpool from which memory should be allocated;
105 **			can be NULL, use sm_malloc() then.
106 **		size -- size of block.
107 **		file -- filename.
108 **		line -- line number in file.
109 **		group -- heap group for debugging.
110 **
111 **	Returns:
112 **		Pointer to block.
113 **
114 **	Exceptions:
115 **		F:sm_heap -- out of memory
116 **
117 **	Notice: XXX
118 **		if size == 0 and the rpool is new (no memory
119 **		allocated yet) NULL is returned!
120 **		We could solve this by
121 **		- wasting 1 byte (size < avail)
122 **		- checking for rpool->sm_poolptr != NULL
123 **		- not asking for 0 sized buffer
124 */
125 
126 void *
127 #if SM_HEAP_CHECK
128 sm_rpool_malloc_tagged_x(rpool, size, file, line, group)
129 	SM_RPOOL_T *rpool;
130 	size_t size;
131 	char *file;
132 	int line;
133 	int group;
134 #else /* SM_HEAP_CHECK */
135 sm_rpool_malloc_x(rpool, size)
136 	SM_RPOOL_T *rpool;
137 	size_t size;
138 #endif /* SM_HEAP_CHECK */
139 {
140 	char *ptr;
141 
142 	if (rpool == NULL)
143 		return sm_malloc_tagged_x(size, file, line, group);
144 
145 	/* Ensure that size is properly aligned. */
146 	if (size & SM_ALIGN_BITS)
147 		size = (size & ~SM_ALIGN_BITS) + SM_ALIGN_SIZE;
148 
149 	/* The common case.  This is optimized for speed. */
150 	if (size <= rpool->sm_poolavail)
151 	{
152 		ptr = rpool->sm_poolptr;
153 		rpool->sm_poolptr += size;
154 		rpool->sm_poolavail -= size;
155 		return ptr;
156 	}
157 
158 	/*
159 	**  The slow case: we need to call malloc.
160 	**  The SM_REQUIRE assertion is deferred until now, for speed.
161 	**  That's okay: we set rpool->sm_poolavail to 0 when we free an rpool,
162 	**  so the common case code won't be triggered on a dangling pointer.
163 	*/
164 
165 	SM_REQUIRE(rpool->sm_magic == SmRpoolMagic);
166 
167 	/*
168 	**  If size > sm_poolsize, then malloc a new block especially for
169 	**  this request.  Future requests will be allocated from the
170 	**  current pool.
171 	**
172 	**  What if the current pool is mostly unallocated, and the current
173 	**  request is larger than the available space, but < sm_poolsize?
174 	**  If we discard the current pool, and start allocating from a new
175 	**  pool, then we will be wasting a lot of space.  For this reason,
176 	**  we malloc a block just for the current request if size >
177 	**  sm_bigobjectsize, where sm_bigobjectsize <= sm_poolsize.
178 	**  Thus, the most space that we will waste at the end of a pool
179 	**  is sm_bigobjectsize - 1.
180 	*/
181 
182 	if (size > rpool->sm_bigobjectsize)
183 	{
184 #if _FFR_PERF_RPOOL
185 		++rpool->sm_nbigblocks;
186 #endif /* _FFR_PERF_RPOOL */
187 		return sm_rpool_allocblock_x(rpool, size);
188 	}
189 	SM_ASSERT(rpool->sm_bigobjectsize <= rpool->sm_poolsize);
190 	ptr = sm_rpool_allocblock_x(rpool, rpool->sm_poolsize);
191 	rpool->sm_poolptr = ptr + size;
192 	rpool->sm_poolavail = rpool->sm_poolsize - size;
193 #if _FFR_PERF_RPOOL
194 	++rpool->sm_npools;
195 #endif /* _FFR_PERF_RPOOL */
196 	return ptr;
197 }
198 
199 /*
200 **  SM_RPOOL_MALLOC_TAGGED -- allocate memory from rpool
201 **
202 **	Parameters:
203 **		rpool -- rpool from which memory should be allocated;
204 **			can be NULL, use sm_malloc() then.
205 **		size -- size of block.
206 **		file -- filename.
207 **		line -- line number in file.
208 **		group -- heap group for debugging.
209 **
210 **	Returns:
211 **		Pointer to block, NULL on failure.
212 **
213 **	Notice: XXX
214 **		if size == 0 and the rpool is new (no memory
215 **		allocated yet) NULL is returned!
216 **		We could solve this by
217 **		- wasting 1 byte (size < avail)
218 **		- checking for rpool->sm_poolptr != NULL
219 **		- not asking for 0 sized buffer
220 */
221 
222 void *
223 #if SM_HEAP_CHECK
224 sm_rpool_malloc_tagged(rpool, size, file, line, group)
225 	SM_RPOOL_T *rpool;
226 	size_t size;
227 	char *file;
228 	int line;
229 	int group;
230 #else /* SM_HEAP_CHECK */
231 sm_rpool_malloc(rpool, size)
232 	SM_RPOOL_T *rpool;
233 	size_t size;
234 #endif /* SM_HEAP_CHECK */
235 {
236 	char *ptr;
237 
238 	if (rpool == NULL)
239 		return sm_malloc_tagged(size, file, line, group);
240 
241 	/* Ensure that size is properly aligned. */
242 	if (size & SM_ALIGN_BITS)
243 		size = (size & ~SM_ALIGN_BITS) + SM_ALIGN_SIZE;
244 
245 	/* The common case.  This is optimized for speed. */
246 	if (size <= rpool->sm_poolavail)
247 	{
248 		ptr = rpool->sm_poolptr;
249 		rpool->sm_poolptr += size;
250 		rpool->sm_poolavail -= size;
251 		return ptr;
252 	}
253 
254 	/*
255 	**  The slow case: we need to call malloc.
256 	**  The SM_REQUIRE assertion is deferred until now, for speed.
257 	**  That's okay: we set rpool->sm_poolavail to 0 when we free an rpool,
258 	**  so the common case code won't be triggered on a dangling pointer.
259 	*/
260 
261 	SM_REQUIRE(rpool->sm_magic == SmRpoolMagic);
262 
263 	/*
264 	**  If size > sm_poolsize, then malloc a new block especially for
265 	**  this request.  Future requests will be allocated from the
266 	**  current pool.
267 	**
268 	**  What if the current pool is mostly unallocated, and the current
269 	**  request is larger than the available space, but < sm_poolsize?
270 	**  If we discard the current pool, and start allocating from a new
271 	**  pool, then we will be wasting a lot of space.  For this reason,
272 	**  we malloc a block just for the current request if size >
273 	**  sm_bigobjectsize, where sm_bigobjectsize <= sm_poolsize.
274 	**  Thus, the most space that we will waste at the end of a pool
275 	**  is sm_bigobjectsize - 1.
276 	*/
277 
278 	if (size > rpool->sm_bigobjectsize)
279 	{
280 #if _FFR_PERF_RPOOL
281 		++rpool->sm_nbigblocks;
282 #endif /* _FFR_PERF_RPOOL */
283 		return sm_rpool_allocblock(rpool, size);
284 	}
285 	SM_ASSERT(rpool->sm_bigobjectsize <= rpool->sm_poolsize);
286 	ptr = sm_rpool_allocblock(rpool, rpool->sm_poolsize);
287 	if (ptr == NULL)
288 		return NULL;
289 	rpool->sm_poolptr = ptr + size;
290 	rpool->sm_poolavail = rpool->sm_poolsize - size;
291 #if _FFR_PERF_RPOOL
292 	++rpool->sm_npools;
293 #endif /* _FFR_PERF_RPOOL */
294 	return ptr;
295 }
296 
297 /*
298 **  SM_RPOOL_NEW_X -- create a new rpool.
299 **
300 **	Parameters:
301 **		parent -- pointer to parent rpool, can be NULL.
302 **
303 **	Returns:
304 **		Pointer to new rpool.
305 */
306 
307 SM_RPOOL_T *
308 sm_rpool_new_x(parent)
309 	SM_RPOOL_T *parent;
310 {
311 	SM_RPOOL_T *rpool;
312 
313 	rpool = sm_malloc_x(sizeof(SM_RPOOL_T));
314 	if (parent == NULL)
315 		rpool->sm_parentlink = NULL;
316 	else
317 	{
318 		SM_TRY
319 			rpool->sm_parentlink = sm_rpool_attach_x(parent,
320 					(SM_RPOOL_RFREE_T) sm_rpool_free,
321 					(void *) rpool);
322 		SM_EXCEPT(exc, "*")
323 			sm_free(rpool);
324 			sm_exc_raise_x(exc);
325 		SM_END_TRY
326 	}
327 	rpool->sm_magic = SmRpoolMagic;
328 
329 	rpool->sm_poolsize = POOLSIZE - sizeof(SM_POOLHDR_T);
330 	rpool->sm_bigobjectsize = rpool->sm_poolsize / BIG_OBJECT_RATIO;
331 	rpool->sm_poolptr = NULL;
332 	rpool->sm_poolavail = 0;
333 	rpool->sm_pools = NULL;
334 
335 	rpool->sm_rptr = NULL;
336 	rpool->sm_ravail = 0;
337 	rpool->sm_rlists = NULL;
338 #if _FFR_PERF_RPOOL
339 	rpool->sm_nbigblocks = 0;
340 	rpool->sm_npools = 0;
341 #endif /* _FFR_PERF_RPOOL */
342 
343 	return rpool;
344 }
345 
346 /*
347 **  SM_RPOOL_SETSIZES -- set sizes for rpool.
348 **
349 **	Parameters:
350 **		poolsize -- size of a single rpool block.
351 **		bigobjectsize -- if this size is exceeded, an individual
352 **			block is allocated (must be less or equal poolsize).
353 **
354 **	Returns:
355 **		none.
356 */
357 
358 void
359 sm_rpool_setsizes(rpool, poolsize, bigobjectsize)
360 	SM_RPOOL_T *rpool;
361 	size_t poolsize;
362 	size_t bigobjectsize;
363 {
364 	SM_REQUIRE(poolsize >= bigobjectsize);
365 	if (poolsize == 0)
366 		poolsize = POOLSIZE - sizeof(SM_POOLHDR_T);
367 	if (bigobjectsize == 0)
368 		bigobjectsize = poolsize / BIG_OBJECT_RATIO;
369 	rpool->sm_poolsize = poolsize;
370 	rpool->sm_bigobjectsize = bigobjectsize;
371 }
372 
373 /*
374 **  SM_RPOOL_FREE -- free an rpool and release all of its resources.
375 **
376 **	Parameters:
377 **		rpool -- rpool to free.
378 **
379 **	Returns:
380 **		none.
381 */
382 
383 void
384 sm_rpool_free(rpool)
385 	SM_RPOOL_T *rpool;
386 {
387 	SM_RLIST_T *rl, *rnext;
388 	SM_RESOURCE_T *r, *rmax;
389 	SM_POOLLINK_T *pp, *pnext;
390 
391 	if (rpool == NULL)
392 		return;
393 
394 	/*
395 	**  It's important to free the resources before the memory pools,
396 	**  because the resource free functions might modify the contents
397 	**  of the memory pools.
398 	*/
399 
400 	rl = rpool->sm_rlists;
401 	if (rl != NULL)
402 	{
403 		rmax = rpool->sm_rptr;
404 		for (;;)
405 		{
406 			for (r = rl->sm_rvec; r < rmax; ++r)
407 			{
408 				if (r->sm_rfree != NULL)
409 					r->sm_rfree(r->sm_rcontext);
410 			}
411 			rnext = rl->sm_rnext;
412 			sm_free(rl);
413 			if (rnext == NULL)
414 				break;
415 			rl = rnext;
416 			rmax = &rl->sm_rvec[SM_RLIST_MAX];
417 		}
418 	}
419 
420 	/*
421 	**  Now free the memory pools.
422 	*/
423 
424 	for (pp = rpool->sm_pools; pp != NULL; pp = pnext)
425 	{
426 		pnext = pp->sm_pnext;
427 		sm_free(pp);
428 	}
429 
430 	/*
431 	**  Disconnect rpool from its parent.
432 	*/
433 
434 	if (rpool->sm_parentlink != NULL)
435 		*rpool->sm_parentlink = NULL;
436 
437 	/*
438 	**  Setting these fields to zero means that any future to attempt
439 	**  to use the rpool after it is freed will cause an assertion failure.
440 	*/
441 
442 	rpool->sm_magic = NULL;
443 	rpool->sm_poolavail = 0;
444 	rpool->sm_ravail = 0;
445 
446 #if _FFR_PERF_RPOOL
447 	if (rpool->sm_nbigblocks > 0 || rpool->sm_npools > 1)
448 		syslog(LOG_NOTICE,
449 			"perf: rpool=%lx, sm_nbigblocks=%d, sm_npools=%d",
450 			(long) rpool, rpool->sm_nbigblocks, rpool->sm_npools);
451 	rpool->sm_nbigblocks = 0;
452 	rpool->sm_npools = 0;
453 #endif /* _FFR_PERF_RPOOL */
454 	sm_free(rpool);
455 }
456 
457 /*
458 **  SM_RPOOL_ATTACH_X -- attach a resource to an rpool.
459 **
460 **	Parameters:
461 **		rpool -- rpool to which resource should be attached.
462 **		rfree -- function to call when rpool is freed.
463 **		rcontext -- argument for function to call when rpool is freed.
464 **
465 **	Returns:
466 **		Pointer to allocated function.
467 **
468 **	Exceptions:
469 **		F:sm_heap -- out of memory
470 */
471 
472 SM_RPOOL_ATTACH_T
473 sm_rpool_attach_x(rpool, rfree, rcontext)
474 	SM_RPOOL_T *rpool;
475 	SM_RPOOL_RFREE_T rfree;
476 	void *rcontext;
477 {
478 	SM_RLIST_T *rl;
479 	SM_RPOOL_ATTACH_T a;
480 
481 	SM_REQUIRE_ISA(rpool, SmRpoolMagic);
482 
483 	if (rpool->sm_ravail == 0)
484 	{
485 		rl = sm_malloc_x(sizeof(SM_RLIST_T));
486 		rl->sm_rnext = rpool->sm_rlists;
487 		rpool->sm_rlists = rl;
488 		rpool->sm_rptr = rl->sm_rvec;
489 		rpool->sm_ravail = SM_RLIST_MAX;
490 	}
491 
492 	a = &rpool->sm_rptr->sm_rfree;
493 	rpool->sm_rptr->sm_rfree = rfree;
494 	rpool->sm_rptr->sm_rcontext = rcontext;
495 	++rpool->sm_rptr;
496 	--rpool->sm_ravail;
497 	return a;
498 }
499 
500 #if DO_NOT_USE_STRCPY
501 /*
502 **  SM_RPOOL_STRDUP_X -- Create a copy of a C string
503 **
504 **	Parameters:
505 **		rpool -- rpool to use.
506 **		s -- the string to copy.
507 **
508 **	Returns:
509 **		pointer to newly allocated string.
510 */
511 
512 char *
513 sm_rpool_strdup_x(rpool, s)
514 	SM_RPOOL_T *rpool;
515 	const char *s;
516 {
517 	size_t l;
518 	char *n;
519 
520 	l = strlen(s);
521 	SM_ASSERT(l + 1 > l);
522 	n = sm_rpool_malloc_x(rpool, l + 1);
523 	sm_strlcpy(n, s, l + 1);
524 	return n;
525 }
526 #endif /* DO_NOT_USE_STRCPY */
527