contrib/sendmail-8.13.7/libsm/rpool.c

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