Commit | Line | Data |
---|---|---|
a0d0e21e | 1 | /* malloc.c |
8d063cd8 | 2 | * |
8d063cd8 LW |
3 | */ |
4 | ||
87c6202a | 5 | /* |
741df71a IZ |
6 | Here are some notes on configuring Perl's malloc. (For non-perl |
7 | usage see below.) | |
87c6202a IZ |
8 | |
9 | There are two macros which serve as bulk disablers of advanced | |
10 | features of this malloc: NO_FANCY_MALLOC, PLAIN_MALLOC (undef by | |
11 | default). Look in the list of default values below to understand | |
12 | their exact effect. Defining NO_FANCY_MALLOC returns malloc.c to the | |
13 | state of the malloc in Perl 5.004. Additionally defining PLAIN_MALLOC | |
14 | returns it to the state as of Perl 5.000. | |
15 | ||
16 | Note that some of the settings below may be ignored in the code based | |
17 | on values of other macros. The PERL_CORE symbol is only defined when | |
18 | perl itself is being compiled (so malloc can make some assumptions | |
19 | about perl's facilities being available to it). | |
20 | ||
21 | Each config option has a short description, followed by its name, | |
22 | default value, and a comment about the default (if applicable). Some | |
23 | options take a precise value, while the others are just boolean. | |
24 | The boolean ones are listed first. | |
25 | ||
26 | # Enable code for an emergency memory pool in $^M. See perlvar.pod | |
27 | # for a description of $^M. | |
28 | PERL_EMERGENCY_SBRK (!PLAIN_MALLOC && PERL_CORE) | |
29 | ||
30 | # Enable code for printing memory statistics. | |
31 | DEBUGGING_MSTATS (!PLAIN_MALLOC && PERL_CORE) | |
32 | ||
33 | # Move allocation info for small buckets into separate areas. | |
34 | # Memory optimization (especially for small allocations, of the | |
35 | # less than 64 bytes). Since perl usually makes a large number | |
36 | # of small allocations, this is usually a win. | |
37 | PACK_MALLOC (!PLAIN_MALLOC && !RCHECK) | |
38 | ||
39 | # Add one page to big powers of two when calculating bucket size. | |
40 | # This is targeted at big allocations, as are common in image | |
41 | # processing. | |
42 | TWO_POT_OPTIMIZE !PLAIN_MALLOC | |
43 | ||
44 | # Use intermediate bucket sizes between powers-of-two. This is | |
45 | # generally a memory optimization, and a (small) speed pessimization. | |
46 | BUCKETS_ROOT2 !NO_FANCY_MALLOC | |
47 | ||
48 | # Do not check small deallocations for bad free(). Memory | |
49 | # and speed optimization, error reporting pessimization. | |
50 | IGNORE_SMALL_BAD_FREE (!NO_FANCY_MALLOC && !RCHECK) | |
51 | ||
52 | # Use table lookup to decide in which bucket a given allocation will go. | |
53 | SMALL_BUCKET_VIA_TABLE !NO_FANCY_MALLOC | |
54 | ||
38ac2dc8 DD |
55 | # Use a perl-defined sbrk() instead of the (presumably broken or |
56 | # missing) system-supplied sbrk(). | |
57 | USE_PERL_SBRK undef | |
58 | ||
59 | # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally | |
60 | # only used with broken sbrk()s. | |
87c6202a IZ |
61 | PERL_SBRK_VIA_MALLOC undef |
62 | ||
38ac2dc8 DD |
63 | # Which allocator to use if PERL_SBRK_VIA_MALLOC |
64 | SYSTEM_ALLOC(a) malloc(a) | |
65 | ||
87c6202a IZ |
66 | # Disable memory overwrite checking with DEBUGGING. Memory and speed |
67 | # optimization, error reporting pessimization. | |
68 | NO_RCHECK undef | |
69 | ||
70 | # Enable memory overwrite checking with DEBUGGING. Memory and speed | |
71 | # pessimization, error reporting optimization | |
72 | RCHECK (DEBUGGING && !NO_RCHECK) | |
73 | ||
74 | # Failed allocations bigger than this size croak (if | |
75 | # PERL_EMERGENCY_SBRK is enabled) without touching $^M. See | |
76 | # perlvar.pod for a description of $^M. | |
77 | BIG_SIZE (1<<16) # 64K | |
78 | ||
79 | # Starting from this power of two, add an extra page to the | |
80 | # size of the bucket. This enables optimized allocations of sizes | |
81 | # close to powers of 2. Note that the value is indexed at 0. | |
82 | FIRST_BIG_POW2 15 # 32K, 16K is used too often | |
83 | ||
84 | # Estimate of minimal memory footprint. malloc uses this value to | |
85 | # request the most reasonable largest blocks of memory from the system. | |
86 | FIRST_SBRK (48*1024) | |
87 | ||
88 | # Round up sbrk()s to multiples of this. | |
89 | MIN_SBRK 2048 | |
90 | ||
91 | # Round up sbrk()s to multiples of this percent of footprint. | |
92 | MIN_SBRK_FRAC 3 | |
93 | ||
94 | # Add this much memory to big powers of two to get the bucket size. | |
95 | PERL_PAGESIZE 4096 | |
96 | ||
97 | # This many sbrk() discontinuities should be tolerated even | |
98 | # from the start without deciding that sbrk() is usually | |
99 | # discontinuous. | |
100 | SBRK_ALLOW_FAILURES 3 | |
101 | ||
102 | # This many continuous sbrk()s compensate for one discontinuous one. | |
103 | SBRK_FAILURE_PRICE 50 | |
104 | ||
28ac10b1 IZ |
105 | # Some configurations may ask for 12-byte-or-so allocations which |
106 | # require 8-byte alignment (?!). In such situation one needs to | |
107 | # define this to disable 12-byte bucket (will increase memory footprint) | |
108 | STRICT_ALIGNMENT undef | |
109 | ||
87c6202a IZ |
110 | This implementation assumes that calling PerlIO_printf() does not |
111 | result in any memory allocation calls (used during a panic). | |
112 | ||
113 | */ | |
114 | ||
741df71a IZ |
115 | /* |
116 | If used outside of Perl environment, it may be useful to redefine | |
117 | the following macros (listed below with defaults): | |
118 | ||
119 | # Type of address returned by allocation functions | |
120 | Malloc_t void * | |
121 | ||
122 | # Type of size argument for allocation functions | |
123 | MEM_SIZE unsigned long | |
124 | ||
125 | # Maximal value in LONG | |
126 | LONG_MAX 0x7FFFFFFF | |
127 | ||
128 | # Unsigned integer type big enough to keep a pointer | |
129 | UV unsigned long | |
130 | ||
131 | # Type of pointer with 1-byte granularity | |
132 | caddr_t char * | |
133 | ||
134 | # Type returned by free() | |
135 | Free_t void | |
136 | ||
137 | # Fatal error reporting function | |
138 | croak(format, arg) warn(idem) + exit(1) | |
139 | ||
140 | # Error reporting function | |
141 | warn(format, arg) fprintf(stderr, idem) | |
142 | ||
143 | # Locking/unlocking for MT operation | |
144 | MALLOC_LOCK MUTEX_LOCK(PL_malloc_mutex) | |
145 | MALLOC_UNLOCK MUTEX_UNLOCK(PL_malloc_mutex) | |
146 | ||
147 | # Locking/unlocking mutex for MT operation | |
148 | MUTEX_LOCK(l) void | |
149 | MUTEX_UNLOCK(l) void | |
150 | */ | |
151 | ||
e8bc2b5c GS |
152 | #ifndef NO_FANCY_MALLOC |
153 | # ifndef SMALL_BUCKET_VIA_TABLE | |
154 | # define SMALL_BUCKET_VIA_TABLE | |
155 | # endif | |
156 | # ifndef BUCKETS_ROOT2 | |
157 | # define BUCKETS_ROOT2 | |
158 | # endif | |
159 | # ifndef IGNORE_SMALL_BAD_FREE | |
160 | # define IGNORE_SMALL_BAD_FREE | |
161 | # endif | |
3562ef9b IZ |
162 | #endif |
163 | ||
e8bc2b5c GS |
164 | #ifndef PLAIN_MALLOC /* Bulk enable features */ |
165 | # ifndef PACK_MALLOC | |
166 | # define PACK_MALLOC | |
167 | # endif | |
168 | # ifndef TWO_POT_OPTIMIZE | |
169 | # define TWO_POT_OPTIMIZE | |
170 | # endif | |
d720c441 IZ |
171 | # if defined(PERL_CORE) && !defined(PERL_EMERGENCY_SBRK) |
172 | # define PERL_EMERGENCY_SBRK | |
e8bc2b5c GS |
173 | # endif |
174 | # if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS) | |
175 | # define DEBUGGING_MSTATS | |
176 | # endif | |
177 | #endif | |
178 | ||
179 | #define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */ | |
180 | #define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2) | |
181 | ||
182 | #if !(defined(I286) || defined(atarist)) | |
183 | /* take 2k unless the block is bigger than that */ | |
184 | # define LOG_OF_MIN_ARENA 11 | |
185 | #else | |
186 | /* take 16k unless the block is bigger than that | |
187 | (80286s like large segments!), probably good on the atari too */ | |
188 | # define LOG_OF_MIN_ARENA 14 | |
189 | #endif | |
190 | ||
8d063cd8 | 191 | #ifndef lint |
1944739a IZ |
192 | # if defined(DEBUGGING) && !defined(NO_RCHECK) |
193 | # define RCHECK | |
194 | # endif | |
e8bc2b5c GS |
195 | # if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE) |
196 | # undef IGNORE_SMALL_BAD_FREE | |
197 | # endif | |
8d063cd8 LW |
198 | /* |
199 | * malloc.c (Caltech) 2/21/82 | |
200 | * Chris Kingsley, kingsley@cit-20. | |
201 | * | |
202 | * This is a very fast storage allocator. It allocates blocks of a small | |
203 | * number of different sizes, and keeps free lists of each size. Blocks that | |
204 | * don't exactly fit are passed up to the next larger size. In this | |
205 | * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long. | |
cf5c4ad8 | 206 | * If PACK_MALLOC is defined, small blocks are 2^n bytes long. |
8d063cd8 | 207 | * This is designed for use in a program that uses vast quantities of memory, |
741df71a IZ |
208 | * but bombs when it runs out. |
209 | * | |
210 | * Modifications Copyright Ilya Zakharevich 1996-98. | |
211 | * | |
212 | * Still very quick, but much more thrifty. (Std config is 10% slower | |
213 | * than it was, and takes 67% of old heap size for typical usage.) | |
214 | * | |
215 | * Allocations of small blocks are now table-driven to many different | |
216 | * buckets. Sizes of really big buckets are increased to accomodata | |
217 | * common size=power-of-2 blocks. Running-out-of-memory is made into | |
218 | * an exception. Deeply configurable and thread-safe. | |
219 | * | |
8d063cd8 LW |
220 | */ |
221 | ||
d720c441 IZ |
222 | #ifdef PERL_CORE |
223 | # include "EXTERN.h" | |
224 | # include "perl.h" | |
225 | #else | |
226 | # ifdef PERL_FOR_X2P | |
227 | # include "../EXTERN.h" | |
228 | # include "../perl.h" | |
229 | # else | |
230 | # include <stdlib.h> | |
231 | # include <stdio.h> | |
232 | # include <memory.h> | |
233 | # define _(arg) arg | |
234 | # ifndef Malloc_t | |
235 | # define Malloc_t void * | |
236 | # endif | |
237 | # ifndef MEM_SIZE | |
238 | # define MEM_SIZE unsigned long | |
239 | # endif | |
240 | # ifndef LONG_MAX | |
241 | # define LONG_MAX 0x7FFFFFFF | |
242 | # endif | |
243 | # ifndef UV | |
244 | # define UV unsigned long | |
245 | # endif | |
246 | # ifndef caddr_t | |
247 | # define caddr_t char * | |
248 | # endif | |
249 | # ifndef Free_t | |
250 | # define Free_t void | |
251 | # endif | |
252 | # define Copy(s,d,n,t) (void)memcpy((char*)(d),(char*)(s), (n) * sizeof(t)) | |
253 | # define PerlEnv_getenv getenv | |
254 | # define PerlIO_printf fprintf | |
255 | # define PerlIO_stderr() stderr | |
256 | # endif | |
e8bc2b5c | 257 | # ifndef croak /* make depend */ |
741df71a | 258 | # define croak(mess, arg) (warn((mess), (arg)), exit(1)) |
d720c441 IZ |
259 | # endif |
260 | # ifndef warn | |
741df71a | 261 | # define warn(mess, arg) fprintf(stderr, (mess), (arg)) |
e8bc2b5c GS |
262 | # endif |
263 | # ifdef DEBUG_m | |
264 | # undef DEBUG_m | |
265 | # endif | |
266 | # define DEBUG_m(a) | |
267 | # ifdef DEBUGGING | |
268 | # undef DEBUGGING | |
269 | # endif | |
270 | #endif | |
271 | ||
272 | #ifndef MUTEX_LOCK | |
273 | # define MUTEX_LOCK(l) | |
274 | #endif | |
275 | ||
276 | #ifndef MUTEX_UNLOCK | |
277 | # define MUTEX_UNLOCK(l) | |
278 | #endif | |
279 | ||
741df71a IZ |
280 | #ifndef MALLOC_LOCK |
281 | # define MALLOC_LOCK MUTEX_LOCK(PL_malloc_mutex) | |
282 | #endif | |
283 | ||
284 | #ifndef MALLOC_UNLOCK | |
285 | # define MALLOC_UNLOCK MUTEX_UNLOCK(PL_malloc_mutex) | |
286 | #endif | |
287 | ||
760ac839 | 288 | #ifdef DEBUGGING |
e8bc2b5c | 289 | # undef DEBUG_m |
4a33f861 | 290 | # define DEBUG_m(a) if (PL_debug & 128) a |
760ac839 LW |
291 | #endif |
292 | ||
e9397286 GS |
293 | /* |
294 | * Layout of memory: | |
295 | * ~~~~~~~~~~~~~~~~ | |
296 | * The memory is broken into "blocks" which occupy multiples of 2K (and | |
297 | * generally speaking, have size "close" to a power of 2). The addresses | |
298 | * of such *unused* blocks are kept in nextf[i] with big enough i. (nextf | |
299 | * is an array of linked lists.) (Addresses of used blocks are not known.) | |
300 | * | |
301 | * Moreover, since the algorithm may try to "bite" smaller blocks of out | |
302 | * of unused bigger ones, there are also regions of "irregular" size, | |
303 | * managed separately, by a linked list chunk_chain. | |
304 | * | |
305 | * The third type of storage is the sbrk()ed-but-not-yet-used space, its | |
306 | * end and size are kept in last_sbrk_top and sbrked_remains. | |
307 | * | |
308 | * Growing blocks "in place": | |
309 | * ~~~~~~~~~~~~~~~~~~~~~~~~~ | |
310 | * The address of the block with the greatest address is kept in last_op | |
311 | * (if not known, last_op is 0). If it is known that the memory above | |
312 | * last_op is not continuous, or contains a chunk from chunk_chain, | |
313 | * last_op is set to 0. | |
314 | * | |
315 | * The chunk with address last_op may be grown by expanding into | |
316 | * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous | |
317 | * memory. | |
318 | * | |
319 | * Management of last_op: | |
320 | * ~~~~~~~~~~~~~~~~~~~~~ | |
321 | * | |
322 | * free() never changes the boundaries of blocks, so is not relevant. | |
323 | * | |
324 | * The only way realloc() may change the boundaries of blocks is if it | |
325 | * grows a block "in place". However, in the case of success such a | |
326 | * chunk is automatically last_op, and it remains last_op. In the case | |
327 | * of failure getpages_adjacent() clears last_op. | |
328 | * | |
329 | * malloc() may change blocks by calling morecore() only. | |
330 | * | |
331 | * morecore() may create new blocks by: | |
332 | * a) biting pieces from chunk_chain (cannot create one above last_op); | |
333 | * b) biting a piece from an unused block (if block was last_op, this | |
334 | * may create a chunk from chain above last_op, thus last_op is | |
335 | * invalidated in such a case). | |
336 | * c) biting of sbrk()ed-but-not-yet-used space. This creates | |
337 | * a block which is last_op. | |
338 | * d) Allocating new pages by calling getpages(); | |
339 | * | |
340 | * getpages() creates a new block. It marks last_op at the bottom of | |
341 | * the chunk of memory it returns. | |
342 | * | |
343 | * Active pages footprint: | |
344 | * ~~~~~~~~~~~~~~~~~~~~~~ | |
345 | * Note that we do not need to traverse the lists in nextf[i], just take | |
346 | * the first element of this list. However, we *need* to traverse the | |
347 | * list in chunk_chain, but most the time it should be a very short one, | |
348 | * so we do not step on a lot of pages we are not going to use. | |
349 | * | |
350 | * Flaws: | |
351 | * ~~~~~ | |
352 | * get_from_bigger_buckets(): forget to increment price => Quite | |
353 | * aggressive. | |
354 | */ | |
355 | ||
135863df AB |
356 | /* I don't much care whether these are defined in sys/types.h--LAW */ |
357 | ||
358 | #define u_char unsigned char | |
359 | #define u_int unsigned int | |
e8bc2b5c GS |
360 | |
361 | #ifdef HAS_QUAD | |
362 | # define u_bigint UV /* Needs to eat *void. */ | |
363 | #else /* needed? */ | |
364 | # define u_bigint unsigned long /* Needs to eat *void. */ | |
365 | #endif | |
366 | ||
135863df | 367 | #define u_short unsigned short |
8d063cd8 | 368 | |
cf5c4ad8 | 369 | /* 286 and atarist like big chunks, which gives too much overhead. */ |
370 | #if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC) | |
e8bc2b5c | 371 | # undef PACK_MALLOC |
cf5c4ad8 | 372 | #endif |
373 | ||
8d063cd8 | 374 | /* |
cf5c4ad8 | 375 | * The description below is applicable if PACK_MALLOC is not defined. |
376 | * | |
8d063cd8 LW |
377 | * The overhead on a block is at least 4 bytes. When free, this space |
378 | * contains a pointer to the next free block, and the bottom two bits must | |
379 | * be zero. When in use, the first byte is set to MAGIC, and the second | |
380 | * byte is the size index. The remaining bytes are for alignment. | |
381 | * If range checking is enabled and the size of the block fits | |
382 | * in two bytes, then the top two bytes hold the size of the requested block | |
383 | * plus the range checking words, and the header word MINUS ONE. | |
384 | */ | |
385 | union overhead { | |
386 | union overhead *ov_next; /* when free */ | |
85e6fe83 | 387 | #if MEM_ALIGNBYTES > 4 |
c623bd54 | 388 | double strut; /* alignment problems */ |
a687059c | 389 | #endif |
8d063cd8 LW |
390 | struct { |
391 | u_char ovu_magic; /* magic number */ | |
392 | u_char ovu_index; /* bucket # */ | |
393 | #ifdef RCHECK | |
394 | u_short ovu_size; /* actual block size */ | |
395 | u_int ovu_rmagic; /* range magic number */ | |
396 | #endif | |
397 | } ovu; | |
398 | #define ov_magic ovu.ovu_magic | |
399 | #define ov_index ovu.ovu_index | |
400 | #define ov_size ovu.ovu_size | |
401 | #define ov_rmagic ovu.ovu_rmagic | |
402 | }; | |
403 | ||
760ac839 | 404 | #ifdef DEBUGGING |
d720c441 | 405 | static void botch _((char *diag, char *s)); |
a0d0e21e LW |
406 | #endif |
407 | static void morecore _((int bucket)); | |
408 | static int findbucket _((union overhead *freep, int srchlen)); | |
28ac10b1 | 409 | static void add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip); |
a0d0e21e | 410 | |
8d063cd8 LW |
411 | #define MAGIC 0xff /* magic # on accounting info */ |
412 | #define RMAGIC 0x55555555 /* magic # on range info */ | |
e8bc2b5c GS |
413 | #define RMAGIC_C 0x55 /* magic # on range info */ |
414 | ||
8d063cd8 | 415 | #ifdef RCHECK |
c2a5c2d2 IZ |
416 | # define RSLOP sizeof (u_int) |
417 | # ifdef TWO_POT_OPTIMIZE | |
e8bc2b5c | 418 | # define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) |
c2a5c2d2 | 419 | # else |
e8bc2b5c | 420 | # define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2) |
c2a5c2d2 | 421 | # endif |
8d063cd8 | 422 | #else |
c2a5c2d2 | 423 | # define RSLOP 0 |
8d063cd8 LW |
424 | #endif |
425 | ||
e8bc2b5c GS |
426 | #if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2) |
427 | # undef BUCKETS_ROOT2 | |
428 | #endif | |
429 | ||
430 | #ifdef BUCKETS_ROOT2 | |
431 | # define BUCKET_TABLE_SHIFT 2 | |
432 | # define BUCKET_POW2_SHIFT 1 | |
433 | # define BUCKETS_PER_POW2 2 | |
434 | #else | |
435 | # define BUCKET_TABLE_SHIFT MIN_BUC_POW2 | |
436 | # define BUCKET_POW2_SHIFT 0 | |
437 | # define BUCKETS_PER_POW2 1 | |
438 | #endif | |
439 | ||
274c7500 IZ |
440 | #if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT)) |
441 | /* Figure out the alignment of void*. */ | |
442 | struct aligner { | |
443 | char c; | |
444 | void *p; | |
445 | }; | |
446 | # define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p))) | |
447 | #else | |
448 | # define ALIGN_SMALL MEM_ALIGNBYTES | |
449 | #endif | |
450 | ||
451 | #define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no)) | |
452 | ||
e8bc2b5c GS |
453 | #ifdef BUCKETS_ROOT2 |
454 | # define MAX_BUCKET_BY_TABLE 13 | |
455 | static u_short buck_size[MAX_BUCKET_BY_TABLE + 1] = | |
456 | { | |
457 | 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80, | |
458 | }; | |
459 | # define BUCKET_SIZE(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT))) | |
460 | # define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \ | |
461 | ? buck_size[i] \ | |
462 | : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \ | |
463 | - MEM_OVERHEAD(i) \ | |
464 | + POW2_OPTIMIZE_SURPLUS(i))) | |
465 | #else | |
466 | # define BUCKET_SIZE(i) (1 << ((i) >> BUCKET_POW2_SHIFT)) | |
467 | # define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i) + POW2_OPTIMIZE_SURPLUS(i)) | |
468 | #endif | |
469 | ||
470 | ||
cf5c4ad8 | 471 | #ifdef PACK_MALLOC |
e8bc2b5c GS |
472 | /* In this case it is assumed that if we do sbrk() in 2K units, we |
473 | * will get 2K aligned arenas (at least after some initial | |
474 | * alignment). The bucket number of the given subblock is on the start | |
475 | * of 2K arena which contains the subblock. Several following bytes | |
476 | * contain the magic numbers for the subblocks in the block. | |
cf5c4ad8 | 477 | * |
478 | * Sizes of chunks are powers of 2 for chunks in buckets <= | |
479 | * MAX_PACKED, after this they are (2^n - sizeof(union overhead)) (to | |
480 | * get alignment right). | |
481 | * | |
e8bc2b5c GS |
482 | * Consider an arena for 2^n with n>MAX_PACKED. We suppose that |
483 | * starts of all the chunks in a 2K arena are in different | |
484 | * 2^n-byte-long chunks. If the top of the last chunk is aligned on a | |
485 | * boundary of 2K block, this means that sizeof(union | |
486 | * overhead)*"number of chunks" < 2^n, or sizeof(union overhead)*2K < | |
487 | * 4^n, or n > 6 + log2(sizeof()/2)/2, since a chunk of size 2^n - | |
488 | * overhead is used. Since this rules out n = 7 for 8 byte alignment, | |
489 | * we specialcase allocation of the first of 16 128-byte-long chunks. | |
cf5c4ad8 | 490 | * |
491 | * Note that with the above assumption we automatically have enough | |
492 | * place for MAGIC at the start of 2K block. Note also that we | |
e8bc2b5c GS |
493 | * overlay union overhead over the chunk, thus the start of small chunks |
494 | * is immediately overwritten after freeing. */ | |
495 | # define MAX_PACKED_POW2 6 | |
496 | # define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT) | |
497 | # define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD) | |
498 | # define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1) | |
499 | # define TWOK_MASKED(x) ((u_bigint)(x) & ~TWOK_MASK) | |
500 | # define TWOK_SHIFT(x) ((u_bigint)(x) & TWOK_MASK) | |
cf5c4ad8 | 501 | # define OV_INDEXp(block) ((u_char*)(TWOK_MASKED(block))) |
502 | # define OV_INDEX(block) (*OV_INDEXp(block)) | |
503 | # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \ | |
e8bc2b5c GS |
504 | (TWOK_SHIFT(block)>> \ |
505 | (bucket>>BUCKET_POW2_SHIFT)) + \ | |
506 | (bucket >= MIN_NEEDS_SHIFT ? 1 : 0))) | |
507 | /* A bucket can have a shift smaller than it size, we need to | |
508 | shift its magic number so it will not overwrite index: */ | |
509 | # ifdef BUCKETS_ROOT2 | |
510 | # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */ | |
511 | # else | |
512 | # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */ | |
513 | # endif | |
cf5c4ad8 | 514 | # define CHUNK_SHIFT 0 |
515 | ||
e8bc2b5c GS |
516 | /* Number of active buckets of given ordinal. */ |
517 | #ifdef IGNORE_SMALL_BAD_FREE | |
518 | #define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */ | |
519 | # define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \ | |
520 | ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE(bucket) \ | |
521 | : n_blks[bucket] ) | |
522 | #else | |
523 | # define N_BLKS(bucket) n_blks[bucket] | |
524 | #endif | |
525 | ||
526 | static u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] = | |
527 | { | |
528 | # if BUCKETS_PER_POW2==1 | |
529 | 0, 0, | |
530 | (MIN_BUC_POW2==2 ? 384 : 0), | |
531 | 224, 120, 62, 31, 16, 8, 4, 2 | |
532 | # else | |
533 | 0, 0, 0, 0, | |
534 | (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */ | |
535 | 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2 | |
536 | # endif | |
537 | }; | |
538 | ||
539 | /* Shift of the first bucket with the given ordinal inside 2K chunk. */ | |
540 | #ifdef IGNORE_SMALL_BAD_FREE | |
541 | # define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \ | |
542 | ? ((1<<LOG_OF_MIN_ARENA) \ | |
543 | - BUCKET_SIZE(bucket) * N_BLKS(bucket)) \ | |
544 | : blk_shift[bucket]) | |
545 | #else | |
546 | # define BLK_SHIFT(bucket) blk_shift[bucket] | |
547 | #endif | |
548 | ||
549 | static u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] = | |
550 | { | |
551 | # if BUCKETS_PER_POW2==1 | |
552 | 0, 0, | |
553 | (MIN_BUC_POW2==2 ? 512 : 0), | |
554 | 256, 128, 64, 64, /* 8 to 64 */ | |
555 | 16*sizeof(union overhead), | |
556 | 8*sizeof(union overhead), | |
557 | 4*sizeof(union overhead), | |
558 | 2*sizeof(union overhead), | |
559 | # else | |
560 | 0, 0, 0, 0, | |
561 | (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0), | |
562 | 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */ | |
563 | 16*sizeof(union overhead), 16*sizeof(union overhead), | |
564 | 8*sizeof(union overhead), 8*sizeof(union overhead), | |
565 | 4*sizeof(union overhead), 4*sizeof(union overhead), | |
566 | 2*sizeof(union overhead), 2*sizeof(union overhead), | |
567 | # endif | |
568 | }; | |
cf5c4ad8 | 569 | |
cf5c4ad8 | 570 | #else /* !PACK_MALLOC */ |
571 | ||
572 | # define OV_MAGIC(block,bucket) (block)->ov_magic | |
573 | # define OV_INDEX(block) (block)->ov_index | |
574 | # define CHUNK_SHIFT 1 | |
e8bc2b5c | 575 | # define MAX_PACKED -1 |
cf5c4ad8 | 576 | #endif /* !PACK_MALLOC */ |
577 | ||
e8bc2b5c GS |
578 | #define M_OVERHEAD (sizeof(union overhead) + RSLOP) |
579 | ||
580 | #ifdef PACK_MALLOC | |
581 | # define MEM_OVERHEAD(bucket) \ | |
582 | (bucket <= MAX_PACKED ? 0 : M_OVERHEAD) | |
583 | # ifdef SMALL_BUCKET_VIA_TABLE | |
584 | # define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2) | |
585 | # define START_SHIFT MAX_PACKED_POW2 | |
586 | # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */ | |
587 | # define SIZE_TABLE_MAX 80 | |
588 | # else | |
589 | # define SIZE_TABLE_MAX 64 | |
590 | # endif | |
591 | static char bucket_of[] = | |
592 | { | |
593 | # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */ | |
594 | /* 0 to 15 in 4-byte increments. */ | |
595 | (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */ | |
596 | 6, /* 8 */ | |
274c7500 | 597 | IF_ALIGN_8(8,7), 8, /* 16/12, 16 */ |
e8bc2b5c GS |
598 | 9, 9, 10, 10, /* 24, 32 */ |
599 | 11, 11, 11, 11, /* 48 */ | |
600 | 12, 12, 12, 12, /* 64 */ | |
601 | 13, 13, 13, 13, /* 80 */ | |
602 | 13, 13, 13, 13 /* 80 */ | |
603 | # else /* !BUCKETS_ROOT2 */ | |
604 | /* 0 to 15 in 4-byte increments. */ | |
605 | (sizeof(void*) > 4 ? 3 : 2), | |
606 | 3, | |
607 | 4, 4, | |
608 | 5, 5, 5, 5, | |
609 | 6, 6, 6, 6, | |
610 | 6, 6, 6, 6 | |
611 | # endif /* !BUCKETS_ROOT2 */ | |
612 | }; | |
613 | # else /* !SMALL_BUCKET_VIA_TABLE */ | |
614 | # define START_SHIFTS_BUCKET MIN_BUCKET | |
615 | # define START_SHIFT (MIN_BUC_POW2 - 1) | |
616 | # endif /* !SMALL_BUCKET_VIA_TABLE */ | |
617 | #else /* !PACK_MALLOC */ | |
618 | # define MEM_OVERHEAD(bucket) M_OVERHEAD | |
619 | # ifdef SMALL_BUCKET_VIA_TABLE | |
620 | # undef SMALL_BUCKET_VIA_TABLE | |
621 | # endif | |
622 | # define START_SHIFTS_BUCKET MIN_BUCKET | |
623 | # define START_SHIFT (MIN_BUC_POW2 - 1) | |
624 | #endif /* !PACK_MALLOC */ | |
cf5c4ad8 | 625 | |
8d063cd8 | 626 | /* |
55497cff | 627 | * Big allocations are often of the size 2^n bytes. To make them a |
628 | * little bit better, make blocks of size 2^n+pagesize for big n. | |
629 | */ | |
630 | ||
631 | #ifdef TWO_POT_OPTIMIZE | |
632 | ||
5f05dabc | 633 | # ifndef PERL_PAGESIZE |
634 | # define PERL_PAGESIZE 4096 | |
635 | # endif | |
e8bc2b5c GS |
636 | # ifndef FIRST_BIG_POW2 |
637 | # define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */ | |
5f05dabc | 638 | # endif |
e8bc2b5c | 639 | # define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2) |
55497cff | 640 | /* If this value or more, check against bigger blocks. */ |
641 | # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD) | |
642 | /* If less than this value, goes into 2^n-overhead-block. */ | |
643 | # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD) | |
644 | ||
e8bc2b5c GS |
645 | # define POW2_OPTIMIZE_ADJUST(nbytes) \ |
646 | ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0) | |
647 | # define POW2_OPTIMIZE_SURPLUS(bucket) \ | |
648 | ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0) | |
649 | ||
650 | #else /* !TWO_POT_OPTIMIZE */ | |
651 | # define POW2_OPTIMIZE_ADJUST(nbytes) | |
652 | # define POW2_OPTIMIZE_SURPLUS(bucket) 0 | |
653 | #endif /* !TWO_POT_OPTIMIZE */ | |
654 | ||
655 | #if defined(HAS_64K_LIMIT) && defined(PERL_CORE) | |
656 | # define BARK_64K_LIMIT(what,nbytes,size) \ | |
657 | if (nbytes > 0xffff) { \ | |
658 | PerlIO_printf(PerlIO_stderr(), \ | |
659 | "%s too large: %lx\n", what, size); \ | |
660 | my_exit(1); \ | |
661 | } | |
662 | #else /* !HAS_64K_LIMIT || !PERL_CORE */ | |
663 | # define BARK_64K_LIMIT(what,nbytes,size) | |
664 | #endif /* !HAS_64K_LIMIT || !PERL_CORE */ | |
55497cff | 665 | |
e8bc2b5c GS |
666 | #ifndef MIN_SBRK |
667 | # define MIN_SBRK 2048 | |
668 | #endif | |
669 | ||
670 | #ifndef FIRST_SBRK | |
d720c441 | 671 | # define FIRST_SBRK (48*1024) |
e8bc2b5c GS |
672 | #endif |
673 | ||
674 | /* Minimal sbrk in percents of what is already alloced. */ | |
675 | #ifndef MIN_SBRK_FRAC | |
676 | # define MIN_SBRK_FRAC 3 | |
677 | #endif | |
678 | ||
679 | #ifndef SBRK_ALLOW_FAILURES | |
680 | # define SBRK_ALLOW_FAILURES 3 | |
681 | #endif | |
55497cff | 682 | |
e8bc2b5c GS |
683 | #ifndef SBRK_FAILURE_PRICE |
684 | # define SBRK_FAILURE_PRICE 50 | |
55497cff | 685 | #endif |
686 | ||
e8bc2b5c GS |
687 | #if defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE) |
688 | ||
689 | # ifndef BIG_SIZE | |
690 | # define BIG_SIZE (1<<16) /* 64K */ | |
691 | # endif | |
692 | ||
3541dd58 | 693 | #ifdef I_MACH_CTHREADS |
772fe5b3 HM |
694 | # undef MUTEX_LOCK |
695 | # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END | |
696 | # undef MUTEX_UNLOCK | |
697 | # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END | |
3541dd58 HM |
698 | #endif |
699 | ||
55497cff | 700 | static char *emergency_buffer; |
701 | static MEM_SIZE emergency_buffer_size; | |
df0003d4 | 702 | static Malloc_t emergency_sbrk(MEM_SIZE size); |
55497cff | 703 | |
52082926 | 704 | static Malloc_t |
df0003d4 | 705 | emergency_sbrk(MEM_SIZE size) |
55497cff | 706 | { |
28ac10b1 IZ |
707 | MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA; |
708 | ||
55497cff | 709 | if (size >= BIG_SIZE) { |
710 | /* Give the possibility to recover: */ | |
741df71a | 711 | MALLOC_UNLOCK; |
1b979e0a | 712 | croak("Out of memory during \"large\" request for %i bytes", size); |
55497cff | 713 | } |
714 | ||
28ac10b1 IZ |
715 | if (emergency_buffer_size >= rsize) { |
716 | char *old = emergency_buffer; | |
717 | ||
718 | emergency_buffer_size -= rsize; | |
719 | emergency_buffer += rsize; | |
720 | return old; | |
721 | } else { | |
18f739ee | 722 | dTHR; |
55497cff | 723 | /* First offense, give a possibility to recover by dieing. */ |
724 | /* No malloc involved here: */ | |
4a33f861 | 725 | GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0); |
55497cff | 726 | SV *sv; |
727 | char *pv; | |
28ac10b1 | 728 | int have = 0; |
55497cff | 729 | |
28ac10b1 IZ |
730 | if (emergency_buffer_size) { |
731 | add_to_chain(emergency_buffer, emergency_buffer_size, 0); | |
732 | emergency_buffer_size = 0; | |
733 | emergency_buffer = Nullch; | |
734 | have = 1; | |
735 | } | |
4a33f861 | 736 | if (!gvp) gvp = (GV**)hv_fetch(PL_defstash, "\015", 1, 0); |
55497cff | 737 | if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv) |
28ac10b1 IZ |
738 | || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD)) { |
739 | if (have) | |
740 | goto do_croak; | |
55497cff | 741 | return (char *)-1; /* Now die die die... */ |
28ac10b1 | 742 | } |
55497cff | 743 | /* Got it, now detach SvPV: */ |
6b88bc9c | 744 | pv = SvPV(sv, PL_na); |
55497cff | 745 | /* Check alignment: */ |
28ac10b1 | 746 | if (((UV)(pv - sizeof(union overhead))) & ((1<<LOG_OF_MIN_ARENA) - 1)) { |
55497cff | 747 | PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n"); |
bbce6d69 | 748 | return (char *)-1; /* die die die */ |
55497cff | 749 | } |
750 | ||
28ac10b1 IZ |
751 | emergency_buffer = pv - sizeof(union overhead); |
752 | emergency_buffer_size = malloced_size(pv) + M_OVERHEAD; | |
55497cff | 753 | SvPOK_off(sv); |
28ac10b1 IZ |
754 | SvPVX(sv) = Nullch; |
755 | SvCUR(sv) = SvLEN(sv) = 0; | |
55497cff | 756 | } |
28ac10b1 | 757 | do_croak: |
741df71a | 758 | MALLOC_UNLOCK; |
28ac10b1 | 759 | croak("Out of memory during request for %i bytes", size); |
55497cff | 760 | } |
761 | ||
e8bc2b5c | 762 | #else /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */ |
55497cff | 763 | # define emergency_sbrk(size) -1 |
e8bc2b5c | 764 | #endif /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */ |
55497cff | 765 | |
766 | /* | |
e8bc2b5c | 767 | * nextf[i] is the pointer to the next free block of size 2^i. The |
8d063cd8 LW |
768 | * smallest allocatable block is 8 bytes. The overhead information |
769 | * precedes the data area returned to the user. | |
770 | */ | |
e8bc2b5c | 771 | #define NBUCKETS (32*BUCKETS_PER_POW2 + 1) |
8d063cd8 | 772 | static union overhead *nextf[NBUCKETS]; |
cf5c4ad8 | 773 | |
774 | #ifdef USE_PERL_SBRK | |
775 | #define sbrk(a) Perl_sbrk(a) | |
52082926 | 776 | Malloc_t Perl_sbrk _((int size)); |
8ac85365 NIS |
777 | #else |
778 | #ifdef DONT_DECLARE_STD | |
779 | #ifdef I_UNISTD | |
780 | #include <unistd.h> | |
781 | #endif | |
cf5c4ad8 | 782 | #else |
52082926 | 783 | extern Malloc_t sbrk(int); |
8ac85365 | 784 | #endif |
cf5c4ad8 | 785 | #endif |
8d063cd8 | 786 | |
c07a80fd | 787 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
788 | /* |
789 | * nmalloc[i] is the difference between the number of mallocs and frees | |
790 | * for a given block size. | |
791 | */ | |
792 | static u_int nmalloc[NBUCKETS]; | |
5f05dabc | 793 | static u_int sbrk_slack; |
794 | static u_int start_slack; | |
8d063cd8 LW |
795 | #endif |
796 | ||
e8bc2b5c GS |
797 | static u_int goodsbrk; |
798 | ||
760ac839 | 799 | #ifdef DEBUGGING |
3541dd58 HM |
800 | #undef ASSERT |
801 | #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p)); else | |
ee0007ab | 802 | static void |
d720c441 | 803 | botch(char *diag, char *s) |
8d063cd8 | 804 | { |
d720c441 | 805 | PerlIO_printf(PerlIO_stderr(), "assertion botched (%s?): %s\n", diag, s); |
3028581b | 806 | PerlProc_abort(); |
8d063cd8 LW |
807 | } |
808 | #else | |
3541dd58 | 809 | #define ASSERT(p, diag) |
8d063cd8 LW |
810 | #endif |
811 | ||
2304df62 | 812 | Malloc_t |
8ac85365 | 813 | malloc(register size_t nbytes) |
8d063cd8 LW |
814 | { |
815 | register union overhead *p; | |
e8bc2b5c | 816 | register int bucket; |
ee0007ab | 817 | register MEM_SIZE shiftr; |
8d063cd8 | 818 | |
c2a5c2d2 | 819 | #if defined(DEBUGGING) || defined(RCHECK) |
ee0007ab | 820 | MEM_SIZE size = nbytes; |
45d8adaa LW |
821 | #endif |
822 | ||
e8bc2b5c | 823 | BARK_64K_LIMIT("Allocation",nbytes,nbytes); |
45d8adaa LW |
824 | #ifdef DEBUGGING |
825 | if ((long)nbytes < 0) | |
d720c441 | 826 | croak("%s", "panic: malloc"); |
45d8adaa | 827 | #endif |
45d8adaa | 828 | |
741df71a | 829 | MALLOC_LOCK; |
8d063cd8 LW |
830 | /* |
831 | * Convert amount of memory requested into | |
832 | * closest block size stored in hash buckets | |
833 | * which satisfies request. Account for | |
834 | * space used per block for accounting. | |
835 | */ | |
cf5c4ad8 | 836 | #ifdef PACK_MALLOC |
e8bc2b5c GS |
837 | # ifdef SMALL_BUCKET_VIA_TABLE |
838 | if (nbytes == 0) | |
839 | bucket = MIN_BUCKET; | |
840 | else if (nbytes <= SIZE_TABLE_MAX) { | |
841 | bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT]; | |
842 | } else | |
843 | # else | |
043bf814 RB |
844 | if (nbytes == 0) |
845 | nbytes = 1; | |
e8bc2b5c GS |
846 | if (nbytes <= MAX_POW2_ALGO) goto do_shifts; |
847 | else | |
848 | # endif | |
55497cff | 849 | #endif |
e8bc2b5c GS |
850 | { |
851 | POW2_OPTIMIZE_ADJUST(nbytes); | |
852 | nbytes += M_OVERHEAD; | |
853 | nbytes = (nbytes + 3) &~ 3; | |
854 | do_shifts: | |
855 | shiftr = (nbytes - 1) >> START_SHIFT; | |
856 | bucket = START_SHIFTS_BUCKET; | |
857 | /* apart from this loop, this is O(1) */ | |
858 | while (shiftr >>= 1) | |
859 | bucket += BUCKETS_PER_POW2; | |
cf5c4ad8 | 860 | } |
8d063cd8 LW |
861 | /* |
862 | * If nothing in hash bucket right now, | |
863 | * request more memory from the system. | |
864 | */ | |
865 | if (nextf[bucket] == NULL) | |
866 | morecore(bucket); | |
e8bc2b5c | 867 | if ((p = nextf[bucket]) == NULL) { |
741df71a | 868 | MALLOC_UNLOCK; |
55497cff | 869 | #ifdef PERL_CORE |
4a33f861 | 870 | if (!PL_nomemok) { |
760ac839 | 871 | PerlIO_puts(PerlIO_stderr(),"Out of memory!\n"); |
79072805 | 872 | my_exit(1); |
ee0007ab | 873 | } |
45d8adaa | 874 | #else |
8d063cd8 | 875 | return (NULL); |
45d8adaa LW |
876 | #endif |
877 | } | |
878 | ||
e8bc2b5c GS |
879 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
880 | "0x%lx: (%05lu) malloc %ld bytes\n", | |
4a33f861 | 881 | (unsigned long)(p+1), (unsigned long)(PL_an++), |
e8bc2b5c | 882 | (long)size)); |
45d8adaa | 883 | |
8d063cd8 | 884 | /* remove from linked list */ |
802004fa DD |
885 | #if defined(RCHECK) |
886 | if (((UV)p) & (MEM_ALIGNBYTES - 1)) | |
760ac839 | 887 | PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n", |
a0d0e21e | 888 | (unsigned long)*((int*)p),(unsigned long)p); |
bf38876a LW |
889 | #endif |
890 | nextf[bucket] = p->ov_next; | |
e8bc2b5c GS |
891 | #ifdef IGNORE_SMALL_BAD_FREE |
892 | if (bucket >= FIRST_BUCKET_WITH_CHECK) | |
893 | #endif | |
894 | OV_MAGIC(p, bucket) = MAGIC; | |
cf5c4ad8 | 895 | #ifndef PACK_MALLOC |
896 | OV_INDEX(p) = bucket; | |
897 | #endif | |
8d063cd8 LW |
898 | #ifdef RCHECK |
899 | /* | |
900 | * Record allocated size of block and | |
901 | * bound space with magic numbers. | |
902 | */ | |
8d063cd8 | 903 | p->ov_rmagic = RMAGIC; |
e8bc2b5c GS |
904 | if (bucket <= MAX_SHORT_BUCKET) { |
905 | int i; | |
906 | ||
907 | nbytes = size + M_OVERHEAD; | |
908 | p->ov_size = nbytes - 1; | |
909 | if ((i = nbytes & 3)) { | |
910 | i = 4 - i; | |
911 | while (i--) | |
912 | *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C; | |
913 | } | |
914 | nbytes = (nbytes + 3) &~ 3; | |
915 | *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC; | |
916 | } | |
8d063cd8 | 917 | #endif |
741df71a | 918 | MALLOC_UNLOCK; |
cf5c4ad8 | 919 | return ((Malloc_t)(p + CHUNK_SHIFT)); |
8d063cd8 LW |
920 | } |
921 | ||
e8bc2b5c GS |
922 | static char *last_sbrk_top; |
923 | static char *last_op; /* This arena can be easily extended. */ | |
924 | static int sbrked_remains; | |
925 | static int sbrk_good = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE; | |
926 | ||
927 | #ifdef DEBUGGING_MSTATS | |
928 | static int sbrks; | |
929 | #endif | |
930 | ||
931 | struct chunk_chain_s { | |
932 | struct chunk_chain_s *next; | |
933 | MEM_SIZE size; | |
934 | }; | |
935 | static struct chunk_chain_s *chunk_chain; | |
936 | static int n_chunks; | |
937 | static char max_bucket; | |
938 | ||
939 | /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */ | |
940 | static void * | |
941 | get_from_chain(MEM_SIZE size) | |
942 | { | |
943 | struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain; | |
944 | struct chunk_chain_s **oldgoodp = NULL; | |
945 | long min_remain = LONG_MAX; | |
946 | ||
947 | while (elt) { | |
948 | if (elt->size >= size) { | |
949 | long remains = elt->size - size; | |
950 | if (remains >= 0 && remains < min_remain) { | |
951 | oldgoodp = oldp; | |
952 | min_remain = remains; | |
953 | } | |
954 | if (remains == 0) { | |
955 | break; | |
956 | } | |
957 | } | |
958 | oldp = &( elt->next ); | |
959 | elt = elt->next; | |
960 | } | |
961 | if (!oldgoodp) return NULL; | |
962 | if (min_remain) { | |
963 | void *ret = *oldgoodp; | |
964 | struct chunk_chain_s *next = (*oldgoodp)->next; | |
965 | ||
966 | *oldgoodp = (struct chunk_chain_s *)((char*)ret + size); | |
967 | (*oldgoodp)->size = min_remain; | |
968 | (*oldgoodp)->next = next; | |
969 | return ret; | |
970 | } else { | |
971 | void *ret = *oldgoodp; | |
972 | *oldgoodp = (*oldgoodp)->next; | |
973 | n_chunks--; | |
974 | return ret; | |
975 | } | |
976 | } | |
977 | ||
978 | static void | |
979 | add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip) | |
980 | { | |
981 | struct chunk_chain_s *next = chunk_chain; | |
982 | char *cp = (char*)p; | |
983 | ||
984 | cp += chip; | |
985 | chunk_chain = (struct chunk_chain_s *)cp; | |
986 | chunk_chain->size = size - chip; | |
987 | chunk_chain->next = next; | |
988 | n_chunks++; | |
989 | } | |
990 | ||
991 | static void * | |
992 | get_from_bigger_buckets(int bucket, MEM_SIZE size) | |
993 | { | |
994 | int price = 1; | |
995 | static int bucketprice[NBUCKETS]; | |
996 | while (bucket <= max_bucket) { | |
997 | /* We postpone stealing from bigger buckets until we want it | |
998 | often enough. */ | |
999 | if (nextf[bucket] && bucketprice[bucket]++ >= price) { | |
1000 | /* Steal it! */ | |
1001 | void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT); | |
1002 | bucketprice[bucket] = 0; | |
1003 | if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) { | |
1004 | last_op = NULL; /* Disable optimization */ | |
1005 | } | |
1006 | nextf[bucket] = nextf[bucket]->ov_next; | |
1007 | #ifdef DEBUGGING_MSTATS | |
1008 | nmalloc[bucket]--; | |
1009 | start_slack -= M_OVERHEAD; | |
1010 | #endif | |
1011 | add_to_chain(ret, (BUCKET_SIZE(bucket) + | |
1012 | POW2_OPTIMIZE_SURPLUS(bucket)), | |
1013 | size); | |
1014 | return ret; | |
1015 | } | |
1016 | bucket++; | |
1017 | } | |
1018 | return NULL; | |
1019 | } | |
1020 | ||
fa423c5b IZ |
1021 | static union overhead * |
1022 | getpages(int needed, int *nblksp, int bucket) | |
1023 | { | |
1024 | /* Need to do (possibly expensive) system call. Try to | |
1025 | optimize it for rare calling. */ | |
1026 | MEM_SIZE require = needed - sbrked_remains; | |
1027 | char *cp; | |
1028 | union overhead *ovp; | |
1029 | int slack = 0; | |
1030 | ||
1031 | if (sbrk_good > 0) { | |
1032 | if (!last_sbrk_top && require < FIRST_SBRK) | |
1033 | require = FIRST_SBRK; | |
1034 | else if (require < MIN_SBRK) require = MIN_SBRK; | |
1035 | ||
1036 | if (require < goodsbrk * MIN_SBRK_FRAC / 100) | |
1037 | require = goodsbrk * MIN_SBRK_FRAC / 100; | |
1038 | require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK; | |
1039 | } else { | |
1040 | require = needed; | |
1041 | last_sbrk_top = 0; | |
1042 | sbrked_remains = 0; | |
1043 | } | |
1044 | ||
1045 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1046 | "sbrk(%ld) for %ld-byte-long arena\n", | |
1047 | (long)require, (long) needed)); | |
1048 | cp = (char *)sbrk(require); | |
1049 | #ifdef DEBUGGING_MSTATS | |
1050 | sbrks++; | |
1051 | #endif | |
1052 | if (cp == last_sbrk_top) { | |
1053 | /* Common case, anything is fine. */ | |
1054 | sbrk_good++; | |
1055 | ovp = (union overhead *) (cp - sbrked_remains); | |
e9397286 | 1056 | last_op = cp - sbrked_remains; |
fa423c5b IZ |
1057 | sbrked_remains = require - (needed - sbrked_remains); |
1058 | } else if (cp == (char *)-1) { /* no more room! */ | |
1059 | ovp = (union overhead *)emergency_sbrk(needed); | |
1060 | if (ovp == (union overhead *)-1) | |
1061 | return 0; | |
e9397286 GS |
1062 | if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */ |
1063 | last_op = 0; | |
1064 | } | |
fa423c5b IZ |
1065 | return ovp; |
1066 | } else { /* Non-continuous or first sbrk(). */ | |
1067 | long add = sbrked_remains; | |
1068 | char *newcp; | |
1069 | ||
1070 | if (sbrked_remains) { /* Put rest into chain, we | |
1071 | cannot use it right now. */ | |
1072 | add_to_chain((void*)(last_sbrk_top - sbrked_remains), | |
1073 | sbrked_remains, 0); | |
1074 | } | |
1075 | ||
1076 | /* Second, check alignment. */ | |
1077 | slack = 0; | |
1078 | ||
1079 | #ifndef atarist /* on the atari we dont have to worry about this */ | |
1080 | # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */ | |
1081 | ||
1082 | /* CHUNK_SHIFT is 1 for PACK_MALLOC, 0 otherwise. */ | |
1083 | if ((UV)cp & (0x7FF >> CHUNK_SHIFT)) { /* Not aligned. */ | |
1084 | slack = (0x800 >> CHUNK_SHIFT) | |
1085 | - ((UV)cp & (0x7FF >> CHUNK_SHIFT)); | |
1086 | add += slack; | |
1087 | } | |
1088 | # endif | |
1089 | #endif /* atarist */ | |
1090 | ||
1091 | if (add) { | |
1092 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1093 | "sbrk(%ld) to fix non-continuous/off-page sbrk:\n\t%ld for alignement,\t%ld were assumed to come from the tail of the previous sbrk\n", | |
1094 | (long)add, (long) slack, | |
1095 | (long) sbrked_remains)); | |
1096 | newcp = (char *)sbrk(add); | |
1097 | #if defined(DEBUGGING_MSTATS) | |
1098 | sbrks++; | |
1099 | sbrk_slack += add; | |
1100 | #endif | |
1101 | if (newcp != cp + require) { | |
1102 | /* Too bad: even rounding sbrk() is not continuous.*/ | |
1103 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1104 | "failed to fix bad sbrk()\n")); | |
1105 | #ifdef PACK_MALLOC | |
1106 | if (slack) { | |
741df71a | 1107 | MALLOC_UNLOCK; |
fa423c5b IZ |
1108 | croak("%s", "panic: Off-page sbrk"); |
1109 | } | |
1110 | #endif | |
1111 | if (sbrked_remains) { | |
1112 | /* Try again. */ | |
1113 | #if defined(DEBUGGING_MSTATS) | |
1114 | sbrk_slack += require; | |
1115 | #endif | |
1116 | require = needed; | |
1117 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1118 | "straight sbrk(%ld)\n", | |
1119 | (long)require)); | |
1120 | cp = (char *)sbrk(require); | |
1121 | #ifdef DEBUGGING_MSTATS | |
1122 | sbrks++; | |
1123 | #endif | |
1124 | if (cp == (char *)-1) | |
1125 | return 0; | |
1126 | } | |
1127 | sbrk_good = -1; /* Disable optimization! | |
1128 | Continue with not-aligned... */ | |
1129 | } else { | |
1130 | cp += slack; | |
1131 | require += sbrked_remains; | |
1132 | } | |
1133 | } | |
1134 | ||
1135 | if (last_sbrk_top) { | |
1136 | sbrk_good -= SBRK_FAILURE_PRICE; | |
1137 | } | |
1138 | ||
1139 | ovp = (union overhead *) cp; | |
1140 | /* | |
1141 | * Round up to minimum allocation size boundary | |
1142 | * and deduct from block count to reflect. | |
1143 | */ | |
1144 | ||
1145 | #ifndef I286 /* Again, this should always be ok on an 80286 */ | |
1146 | if ((UV)ovp & 7) { | |
1147 | ovp = (union overhead *)(((UV)ovp + 8) & ~7); | |
1148 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1149 | "fixing sbrk(): %d bytes off machine alignement\n", | |
1150 | (int)((UV)ovp & 7))); | |
1151 | (*nblksp)--; | |
1152 | # if defined(DEBUGGING_MSTATS) | |
1153 | /* This is only approx. if TWO_POT_OPTIMIZE: */ | |
1154 | sbrk_slack += (1 << bucket); | |
1155 | # endif | |
1156 | } | |
1157 | #endif | |
1158 | sbrked_remains = require - needed; | |
e9397286 | 1159 | last_op = cp; |
fa423c5b IZ |
1160 | } |
1161 | last_sbrk_top = cp + require; | |
fa423c5b IZ |
1162 | #ifdef DEBUGGING_MSTATS |
1163 | goodsbrk += require; | |
1164 | #endif | |
1165 | return ovp; | |
1166 | } | |
1167 | ||
1168 | static int | |
1169 | getpages_adjacent(int require) | |
1170 | { | |
1171 | if (require <= sbrked_remains) { | |
1172 | sbrked_remains -= require; | |
1173 | } else { | |
1174 | char *cp; | |
1175 | ||
1176 | require -= sbrked_remains; | |
1177 | /* We do not try to optimize sbrks here, we go for place. */ | |
1178 | cp = (char*) sbrk(require); | |
1179 | #ifdef DEBUGGING_MSTATS | |
1180 | sbrks++; | |
1181 | goodsbrk += require; | |
1182 | #endif | |
1183 | if (cp == last_sbrk_top) { | |
1184 | sbrked_remains = 0; | |
1185 | last_sbrk_top = cp + require; | |
1186 | } else { | |
28ac10b1 IZ |
1187 | if (cp == (char*)-1) { /* Out of memory */ |
1188 | #ifdef DEBUGGING_MSTATS | |
1189 | goodsbrk -= require; | |
1190 | #endif | |
1191 | return 0; | |
1192 | } | |
fa423c5b IZ |
1193 | /* Report the failure: */ |
1194 | if (sbrked_remains) | |
1195 | add_to_chain((void*)(last_sbrk_top - sbrked_remains), | |
1196 | sbrked_remains, 0); | |
1197 | add_to_chain((void*)cp, require, 0); | |
1198 | sbrk_good -= SBRK_FAILURE_PRICE; | |
1199 | sbrked_remains = 0; | |
1200 | last_sbrk_top = 0; | |
1201 | last_op = 0; | |
1202 | return 0; | |
1203 | } | |
1204 | } | |
1205 | ||
1206 | return 1; | |
1207 | } | |
1208 | ||
8d063cd8 LW |
1209 | /* |
1210 | * Allocate more memory to the indicated bucket. | |
1211 | */ | |
a0d0e21e | 1212 | static void |
8ac85365 | 1213 | morecore(register int bucket) |
8d063cd8 | 1214 | { |
72aaf631 | 1215 | register union overhead *ovp; |
8d063cd8 | 1216 | register int rnu; /* 2^rnu bytes will be requested */ |
fa423c5b | 1217 | int nblks; /* become nblks blocks of the desired size */ |
bbce6d69 | 1218 | register MEM_SIZE siz, needed; |
8d063cd8 LW |
1219 | |
1220 | if (nextf[bucket]) | |
1221 | return; | |
e8bc2b5c | 1222 | if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) { |
741df71a | 1223 | MALLOC_UNLOCK; |
d720c441 | 1224 | croak("%s", "Out of memory during ridiculously large request"); |
55497cff | 1225 | } |
d720c441 | 1226 | if (bucket > max_bucket) |
e8bc2b5c | 1227 | max_bucket = bucket; |
d720c441 | 1228 | |
e8bc2b5c GS |
1229 | rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT)) |
1230 | ? LOG_OF_MIN_ARENA | |
1231 | : (bucket >> BUCKET_POW2_SHIFT) ); | |
1232 | /* This may be overwritten later: */ | |
1233 | nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */ | |
1234 | needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket); | |
1235 | if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */ | |
1236 | ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT; | |
1237 | nextf[rnu << BUCKET_POW2_SHIFT] | |
1238 | = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next; | |
1239 | #ifdef DEBUGGING_MSTATS | |
1240 | nmalloc[rnu << BUCKET_POW2_SHIFT]--; | |
1241 | start_slack -= M_OVERHEAD; | |
1242 | #endif | |
1243 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1244 | "stealing %ld bytes from %ld arena\n", | |
1245 | (long) needed, (long) rnu << BUCKET_POW2_SHIFT)); | |
1246 | } else if (chunk_chain | |
1247 | && (ovp = (union overhead*) get_from_chain(needed))) { | |
1248 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1249 | "stealing %ld bytes from chain\n", | |
1250 | (long) needed)); | |
d720c441 IZ |
1251 | } else if ( (ovp = (union overhead*) |
1252 | get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1, | |
1253 | needed)) ) { | |
e8bc2b5c GS |
1254 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1255 | "stealing %ld bytes from bigger buckets\n", | |
1256 | (long) needed)); | |
1257 | } else if (needed <= sbrked_remains) { | |
1258 | ovp = (union overhead *)(last_sbrk_top - sbrked_remains); | |
1259 | sbrked_remains -= needed; | |
1260 | last_op = (char*)ovp; | |
fa423c5b IZ |
1261 | } else |
1262 | ovp = getpages(needed, &nblks, bucket); | |
e8bc2b5c | 1263 | |
fa423c5b IZ |
1264 | if (!ovp) |
1265 | return; | |
e8bc2b5c | 1266 | |
8d063cd8 LW |
1267 | /* |
1268 | * Add new memory allocated to that on | |
1269 | * free list for this hash bucket. | |
1270 | */ | |
e8bc2b5c | 1271 | siz = BUCKET_SIZE(bucket); |
cf5c4ad8 | 1272 | #ifdef PACK_MALLOC |
72aaf631 | 1273 | *(u_char*)ovp = bucket; /* Fill index. */ |
e8bc2b5c GS |
1274 | if (bucket <= MAX_PACKED) { |
1275 | ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket)); | |
1276 | nblks = N_BLKS(bucket); | |
cf5c4ad8 | 1277 | # ifdef DEBUGGING_MSTATS |
e8bc2b5c | 1278 | start_slack += BLK_SHIFT(bucket); |
cf5c4ad8 | 1279 | # endif |
e8bc2b5c GS |
1280 | } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) { |
1281 | ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket)); | |
cf5c4ad8 | 1282 | siz -= sizeof(union overhead); |
72aaf631 | 1283 | } else ovp++; /* One chunk per block. */ |
e8bc2b5c | 1284 | #endif /* PACK_MALLOC */ |
72aaf631 | 1285 | nextf[bucket] = ovp; |
5f05dabc | 1286 | #ifdef DEBUGGING_MSTATS |
1287 | nmalloc[bucket] += nblks; | |
e8bc2b5c GS |
1288 | if (bucket > MAX_PACKED) { |
1289 | start_slack += M_OVERHEAD * nblks; | |
1290 | } | |
5f05dabc | 1291 | #endif |
8d063cd8 | 1292 | while (--nblks > 0) { |
72aaf631 MB |
1293 | ovp->ov_next = (union overhead *)((caddr_t)ovp + siz); |
1294 | ovp = (union overhead *)((caddr_t)ovp + siz); | |
8d063cd8 | 1295 | } |
8595d6f1 | 1296 | /* Not all sbrks return zeroed memory.*/ |
72aaf631 | 1297 | ovp->ov_next = (union overhead *)NULL; |
cf5c4ad8 | 1298 | #ifdef PACK_MALLOC |
e8bc2b5c GS |
1299 | if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */ |
1300 | union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next; | |
1301 | nextf[7*BUCKETS_PER_POW2] = | |
1302 | (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2] | |
1303 | - sizeof(union overhead)); | |
1304 | nextf[7*BUCKETS_PER_POW2]->ov_next = n_op; | |
cf5c4ad8 | 1305 | } |
1306 | #endif /* !PACK_MALLOC */ | |
8d063cd8 LW |
1307 | } |
1308 | ||
94b6baf5 | 1309 | Free_t |
8ac85365 | 1310 | free(void *mp) |
8d063cd8 | 1311 | { |
ee0007ab | 1312 | register MEM_SIZE size; |
72aaf631 | 1313 | register union overhead *ovp; |
352d5a3a | 1314 | char *cp = (char*)mp; |
cf5c4ad8 | 1315 | #ifdef PACK_MALLOC |
1316 | u_char bucket; | |
1317 | #endif | |
8d063cd8 | 1318 | |
e8bc2b5c GS |
1319 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1320 | "0x%lx: (%05lu) free\n", | |
4a33f861 | 1321 | (unsigned long)cp, (unsigned long)(PL_an++))); |
45d8adaa | 1322 | |
cf5c4ad8 | 1323 | if (cp == NULL) |
1324 | return; | |
72aaf631 | 1325 | ovp = (union overhead *)((caddr_t)cp |
e8bc2b5c | 1326 | - sizeof (union overhead) * CHUNK_SHIFT); |
cf5c4ad8 | 1327 | #ifdef PACK_MALLOC |
72aaf631 | 1328 | bucket = OV_INDEX(ovp); |
cf5c4ad8 | 1329 | #endif |
e8bc2b5c GS |
1330 | #ifdef IGNORE_SMALL_BAD_FREE |
1331 | if ((bucket >= FIRST_BUCKET_WITH_CHECK) | |
1332 | && (OV_MAGIC(ovp, bucket) != MAGIC)) | |
1333 | #else | |
1334 | if (OV_MAGIC(ovp, bucket) != MAGIC) | |
1335 | #endif | |
1336 | { | |
68dc0745 | 1337 | static int bad_free_warn = -1; |
cf5c4ad8 | 1338 | if (bad_free_warn == -1) { |
5fd9e9a4 | 1339 | char *pbf = PerlEnv_getenv("PERL_BADFREE"); |
cf5c4ad8 | 1340 | bad_free_warn = (pbf) ? atoi(pbf) : 1; |
1341 | } | |
1342 | if (!bad_free_warn) | |
1343 | return; | |
8990e307 | 1344 | #ifdef RCHECK |
a687059c | 1345 | warn("%s free() ignored", |
72aaf631 | 1346 | ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad"); |
8990e307 | 1347 | #else |
d720c441 | 1348 | warn("%s", "Bad free() ignored"); |
8990e307 | 1349 | #endif |
8d063cd8 | 1350 | return; /* sanity */ |
e8bc2b5c | 1351 | } |
741df71a | 1352 | MALLOC_LOCK; |
8d063cd8 | 1353 | #ifdef RCHECK |
3541dd58 | 1354 | ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite"); |
e8bc2b5c GS |
1355 | if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) { |
1356 | int i; | |
1357 | MEM_SIZE nbytes = ovp->ov_size + 1; | |
1358 | ||
1359 | if ((i = nbytes & 3)) { | |
1360 | i = 4 - i; | |
1361 | while (i--) { | |
3541dd58 | 1362 | ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i)) |
d720c441 | 1363 | == RMAGIC_C, "chunk's tail overwrite"); |
e8bc2b5c GS |
1364 | } |
1365 | } | |
1366 | nbytes = (nbytes + 3) &~ 3; | |
3541dd58 | 1367 | ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite"); |
e8bc2b5c | 1368 | } |
72aaf631 | 1369 | ovp->ov_rmagic = RMAGIC - 1; |
8d063cd8 | 1370 | #endif |
3541dd58 | 1371 | ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite"); |
72aaf631 MB |
1372 | size = OV_INDEX(ovp); |
1373 | ovp->ov_next = nextf[size]; | |
1374 | nextf[size] = ovp; | |
741df71a | 1375 | MALLOC_UNLOCK; |
8d063cd8 LW |
1376 | } |
1377 | ||
1378 | /* | |
1379 | * When a program attempts "storage compaction" as mentioned in the | |
1380 | * old malloc man page, it realloc's an already freed block. Usually | |
1381 | * this is the last block it freed; occasionally it might be farther | |
1382 | * back. We have to search all the free lists for the block in order | |
1383 | * to determine its bucket: 1st we make one pass thru the lists | |
1384 | * checking only the first block in each; if that fails we search | |
378cc40b | 1385 | * ``reall_srchlen'' blocks in each list for a match (the variable |
8d063cd8 LW |
1386 | * is extern so the caller can modify it). If that fails we just copy |
1387 | * however many bytes was given to realloc() and hope it's not huge. | |
1388 | */ | |
22c35a8c | 1389 | #define reall_srchlen 4 /* 4 should be plenty, -1 =>'s whole list */ |
8d063cd8 | 1390 | |
2304df62 | 1391 | Malloc_t |
8ac85365 | 1392 | realloc(void *mp, size_t nbytes) |
8d063cd8 | 1393 | { |
ee0007ab | 1394 | register MEM_SIZE onb; |
72aaf631 | 1395 | union overhead *ovp; |
d720c441 IZ |
1396 | char *res; |
1397 | int prev_bucket; | |
e8bc2b5c GS |
1398 | register int bucket; |
1399 | int was_alloced = 0, incr; | |
352d5a3a | 1400 | char *cp = (char*)mp; |
8d063cd8 | 1401 | |
e8bc2b5c | 1402 | #if defined(DEBUGGING) || !defined(PERL_CORE) |
ee0007ab | 1403 | MEM_SIZE size = nbytes; |
45d8adaa | 1404 | |
45d8adaa | 1405 | if ((long)nbytes < 0) |
d720c441 | 1406 | croak("%s", "panic: realloc"); |
45d8adaa | 1407 | #endif |
e8bc2b5c GS |
1408 | |
1409 | BARK_64K_LIMIT("Reallocation",nbytes,size); | |
1410 | if (!cp) | |
1411 | return malloc(nbytes); | |
45d8adaa | 1412 | |
741df71a | 1413 | MALLOC_LOCK; |
72aaf631 | 1414 | ovp = (union overhead *)((caddr_t)cp |
e8bc2b5c GS |
1415 | - sizeof (union overhead) * CHUNK_SHIFT); |
1416 | bucket = OV_INDEX(ovp); | |
1417 | #ifdef IGNORE_SMALL_BAD_FREE | |
1418 | if ((bucket < FIRST_BUCKET_WITH_CHECK) | |
1419 | || (OV_MAGIC(ovp, bucket) == MAGIC)) | |
1420 | #else | |
1421 | if (OV_MAGIC(ovp, bucket) == MAGIC) | |
1422 | #endif | |
1423 | { | |
55497cff | 1424 | was_alloced = 1; |
8d063cd8 LW |
1425 | } else { |
1426 | /* | |
1427 | * Already free, doing "compaction". | |
1428 | * | |
1429 | * Search for the old block of memory on the | |
1430 | * free list. First, check the most common | |
1431 | * case (last element free'd), then (this failing) | |
378cc40b | 1432 | * the last ``reall_srchlen'' items free'd. |
8d063cd8 LW |
1433 | * If all lookups fail, then assume the size of |
1434 | * the memory block being realloc'd is the | |
1435 | * smallest possible. | |
1436 | */ | |
e8bc2b5c GS |
1437 | if ((bucket = findbucket(ovp, 1)) < 0 && |
1438 | (bucket = findbucket(ovp, reall_srchlen)) < 0) | |
1439 | bucket = 0; | |
8d063cd8 | 1440 | } |
e8bc2b5c | 1441 | onb = BUCKET_SIZE_REAL(bucket); |
55497cff | 1442 | /* |
1443 | * avoid the copy if same size block. | |
e8bc2b5c GS |
1444 | * We are not agressive with boundary cases. Note that it might |
1445 | * (for a small number of cases) give false negative if | |
55497cff | 1446 | * both new size and old one are in the bucket for |
e8bc2b5c GS |
1447 | * FIRST_BIG_POW2, but the new one is near the lower end. |
1448 | * | |
1449 | * We do not try to go to 1.5 times smaller bucket so far. | |
55497cff | 1450 | */ |
e8bc2b5c GS |
1451 | if (nbytes > onb) incr = 1; |
1452 | else { | |
1453 | #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING | |
1454 | if ( /* This is a little bit pessimal if PACK_MALLOC: */ | |
1455 | nbytes > ( (onb >> 1) - M_OVERHEAD ) | |
1456 | # ifdef TWO_POT_OPTIMIZE | |
1457 | || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND ) | |
1458 | # endif | |
1459 | ) | |
1460 | #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */ | |
1461 | prev_bucket = ( (bucket > MAX_PACKED + 1) | |
1462 | ? bucket - BUCKETS_PER_POW2 | |
1463 | : bucket - 1); | |
1464 | if (nbytes > BUCKET_SIZE_REAL(prev_bucket)) | |
1465 | #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */ | |
1466 | incr = 0; | |
1467 | else incr = -1; | |
1468 | } | |
1469 | if (!was_alloced | |
2ce36478 | 1470 | #ifdef STRESS_REALLOC |
e8bc2b5c | 1471 | || 1 /* always do it the hard way */ |
2ce36478 | 1472 | #endif |
e8bc2b5c GS |
1473 | ) goto hard_way; |
1474 | else if (incr == 0) { | |
852c2e52 | 1475 | inplace_label: |
a687059c LW |
1476 | #ifdef RCHECK |
1477 | /* | |
1478 | * Record new allocated size of block and | |
1479 | * bound space with magic numbers. | |
1480 | */ | |
72aaf631 | 1481 | if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) { |
e8bc2b5c GS |
1482 | int i, nb = ovp->ov_size + 1; |
1483 | ||
1484 | if ((i = nb & 3)) { | |
1485 | i = 4 - i; | |
1486 | while (i--) { | |
3541dd58 | 1487 | ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite"); |
e8bc2b5c GS |
1488 | } |
1489 | } | |
1490 | nb = (nb + 3) &~ 3; | |
3541dd58 | 1491 | ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite"); |
a687059c LW |
1492 | /* |
1493 | * Convert amount of memory requested into | |
1494 | * closest block size stored in hash buckets | |
1495 | * which satisfies request. Account for | |
1496 | * space used per block for accounting. | |
1497 | */ | |
cf5c4ad8 | 1498 | nbytes += M_OVERHEAD; |
72aaf631 | 1499 | ovp->ov_size = nbytes - 1; |
e8bc2b5c GS |
1500 | if ((i = nbytes & 3)) { |
1501 | i = 4 - i; | |
1502 | while (i--) | |
1503 | *((char *)((caddr_t)ovp + nbytes - RSLOP + i)) | |
1504 | = RMAGIC_C; | |
1505 | } | |
1506 | nbytes = (nbytes + 3) &~ 3; | |
72aaf631 | 1507 | *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC; |
a687059c LW |
1508 | } |
1509 | #endif | |
45d8adaa | 1510 | res = cp; |
741df71a | 1511 | MALLOC_UNLOCK; |
42ac124e IZ |
1512 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1513 | "0x%lx: (%05lu) realloc %ld bytes inplace\n", | |
1514 | (unsigned long)res,(unsigned long)(PL_an++), | |
1515 | (long)size)); | |
e8bc2b5c GS |
1516 | } else if (incr == 1 && (cp - M_OVERHEAD == last_op) |
1517 | && (onb > (1 << LOG_OF_MIN_ARENA))) { | |
1518 | MEM_SIZE require, newarena = nbytes, pow; | |
1519 | int shiftr; | |
1520 | ||
1521 | POW2_OPTIMIZE_ADJUST(newarena); | |
1522 | newarena = newarena + M_OVERHEAD; | |
1523 | /* newarena = (newarena + 3) &~ 3; */ | |
1524 | shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA; | |
1525 | pow = LOG_OF_MIN_ARENA + 1; | |
1526 | /* apart from this loop, this is O(1) */ | |
1527 | while (shiftr >>= 1) | |
1528 | pow++; | |
1529 | newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2); | |
1530 | require = newarena - onb - M_OVERHEAD; | |
1531 | ||
fa423c5b | 1532 | if (getpages_adjacent(require)) { |
e8bc2b5c | 1533 | #ifdef DEBUGGING_MSTATS |
fa423c5b IZ |
1534 | nmalloc[bucket]--; |
1535 | nmalloc[pow * BUCKETS_PER_POW2]++; | |
e8bc2b5c | 1536 | #endif |
fa423c5b IZ |
1537 | *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */ |
1538 | goto inplace_label; | |
1539 | } else | |
1540 | goto hard_way; | |
e8bc2b5c GS |
1541 | } else { |
1542 | hard_way: | |
741df71a | 1543 | MALLOC_UNLOCK; |
42ac124e IZ |
1544 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1545 | "0x%lx: (%05lu) realloc %ld bytes the hard way\n", | |
1546 | (unsigned long)cp,(unsigned long)(PL_an++), | |
1547 | (long)size)); | |
e8bc2b5c GS |
1548 | if ((res = (char*)malloc(nbytes)) == NULL) |
1549 | return (NULL); | |
1550 | if (cp != res) /* common optimization */ | |
1551 | Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char); | |
1552 | if (was_alloced) | |
1553 | free(cp); | |
45d8adaa | 1554 | } |
2304df62 | 1555 | return ((Malloc_t)res); |
8d063cd8 LW |
1556 | } |
1557 | ||
1558 | /* | |
1559 | * Search ``srchlen'' elements of each free list for a block whose | |
1560 | * header starts at ``freep''. If srchlen is -1 search the whole list. | |
1561 | * Return bucket number, or -1 if not found. | |
1562 | */ | |
ee0007ab | 1563 | static int |
8ac85365 | 1564 | findbucket(union overhead *freep, int srchlen) |
8d063cd8 LW |
1565 | { |
1566 | register union overhead *p; | |
1567 | register int i, j; | |
1568 | ||
1569 | for (i = 0; i < NBUCKETS; i++) { | |
1570 | j = 0; | |
1571 | for (p = nextf[i]; p && j != srchlen; p = p->ov_next) { | |
1572 | if (p == freep) | |
1573 | return (i); | |
1574 | j++; | |
1575 | } | |
1576 | } | |
1577 | return (-1); | |
1578 | } | |
1579 | ||
cf5c4ad8 | 1580 | Malloc_t |
8ac85365 | 1581 | calloc(register size_t elements, register size_t size) |
cf5c4ad8 | 1582 | { |
1583 | long sz = elements * size; | |
1584 | Malloc_t p = malloc(sz); | |
1585 | ||
1586 | if (p) { | |
1587 | memset((void*)p, 0, sz); | |
1588 | } | |
1589 | return p; | |
1590 | } | |
1591 | ||
e8bc2b5c GS |
1592 | MEM_SIZE |
1593 | malloced_size(void *p) | |
1594 | { | |
8d6dde3e IZ |
1595 | union overhead *ovp = (union overhead *) |
1596 | ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT); | |
1597 | int bucket = OV_INDEX(ovp); | |
1598 | #ifdef RCHECK | |
1599 | /* The caller wants to have a complete control over the chunk, | |
1600 | disable the memory checking inside the chunk. */ | |
1601 | if (bucket <= MAX_SHORT_BUCKET) { | |
1602 | MEM_SIZE size = BUCKET_SIZE_REAL(bucket); | |
1603 | ovp->ov_size = size + M_OVERHEAD - 1; | |
1604 | *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC; | |
1605 | } | |
1606 | #endif | |
e8bc2b5c GS |
1607 | return BUCKET_SIZE_REAL(bucket); |
1608 | } | |
1609 | ||
c07a80fd | 1610 | #ifdef DEBUGGING_MSTATS |
e8bc2b5c GS |
1611 | |
1612 | # ifdef BUCKETS_ROOT2 | |
1613 | # define MIN_EVEN_REPORT 6 | |
1614 | # else | |
1615 | # define MIN_EVEN_REPORT MIN_BUCKET | |
1616 | # endif | |
8d063cd8 LW |
1617 | /* |
1618 | * mstats - print out statistics about malloc | |
1619 | * | |
1620 | * Prints two lines of numbers, one showing the length of the free list | |
1621 | * for each size category, the second showing the number of mallocs - | |
1622 | * frees for each size category. | |
1623 | */ | |
ee0007ab | 1624 | void |
8ac85365 | 1625 | dump_mstats(char *s) |
8d063cd8 LW |
1626 | { |
1627 | register int i, j; | |
1628 | register union overhead *p; | |
e8bc2b5c | 1629 | int topbucket=0, topbucket_ev=0, topbucket_odd=0, totfree=0, total=0; |
c07a80fd | 1630 | u_int nfree[NBUCKETS]; |
e8bc2b5c GS |
1631 | int total_chain = 0; |
1632 | struct chunk_chain_s* nextchain = chunk_chain; | |
8d063cd8 | 1633 | |
e8bc2b5c | 1634 | for (i = MIN_BUCKET ; i < NBUCKETS; i++) { |
8d063cd8 LW |
1635 | for (j = 0, p = nextf[i]; p; p = p->ov_next, j++) |
1636 | ; | |
c07a80fd | 1637 | nfree[i] = j; |
e8bc2b5c GS |
1638 | totfree += nfree[i] * BUCKET_SIZE_REAL(i); |
1639 | total += nmalloc[i] * BUCKET_SIZE_REAL(i); | |
1640 | if (nmalloc[i]) { | |
1641 | i % 2 ? (topbucket_odd = i) : (topbucket_ev = i); | |
1642 | topbucket = i; | |
1643 | } | |
c07a80fd | 1644 | } |
1645 | if (s) | |
e8bc2b5c | 1646 | PerlIO_printf(PerlIO_stderr(), |
d720c441 | 1647 | "Memory allocation statistics %s (buckets %ld(%ld)..%ld(%ld)\n", |
e8bc2b5c | 1648 | s, |
d720c441 IZ |
1649 | (long)BUCKET_SIZE_REAL(MIN_BUCKET), |
1650 | (long)BUCKET_SIZE(MIN_BUCKET), | |
1651 | (long)BUCKET_SIZE_REAL(topbucket), (long)BUCKET_SIZE(topbucket)); | |
5f05dabc | 1652 | PerlIO_printf(PerlIO_stderr(), "%8d free:", totfree); |
e8bc2b5c GS |
1653 | for (i = MIN_EVEN_REPORT; i <= topbucket; i += BUCKETS_PER_POW2) { |
1654 | PerlIO_printf(PerlIO_stderr(), | |
1655 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1656 | ? " %5d" | |
1657 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1658 | nfree[i]); | |
1659 | } | |
1660 | #ifdef BUCKETS_ROOT2 | |
1661 | PerlIO_printf(PerlIO_stderr(), "\n\t "); | |
1662 | for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) { | |
1663 | PerlIO_printf(PerlIO_stderr(), | |
1664 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1665 | ? " %5d" | |
1666 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1667 | nfree[i]); | |
8d063cd8 | 1668 | } |
e8bc2b5c | 1669 | #endif |
5f05dabc | 1670 | PerlIO_printf(PerlIO_stderr(), "\n%8d used:", total - totfree); |
e8bc2b5c GS |
1671 | for (i = MIN_EVEN_REPORT; i <= topbucket; i += BUCKETS_PER_POW2) { |
1672 | PerlIO_printf(PerlIO_stderr(), | |
1673 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1674 | ? " %5d" | |
1675 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1676 | nmalloc[i] - nfree[i]); | |
c07a80fd | 1677 | } |
e8bc2b5c GS |
1678 | #ifdef BUCKETS_ROOT2 |
1679 | PerlIO_printf(PerlIO_stderr(), "\n\t "); | |
1680 | for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) { | |
1681 | PerlIO_printf(PerlIO_stderr(), | |
1682 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1683 | ? " %5d" | |
1684 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1685 | nmalloc[i] - nfree[i]); | |
1686 | } | |
1687 | #endif | |
1688 | while (nextchain) { | |
1689 | total_chain += nextchain->size; | |
1690 | nextchain = nextchain->next; | |
1691 | } | |
1692 | PerlIO_printf(PerlIO_stderr(), "\nTotal sbrk(): %d/%d:%d. Odd ends: pad+heads+chain+tail: %d+%d+%d+%d.\n", | |
1693 | goodsbrk + sbrk_slack, sbrks, sbrk_good, sbrk_slack, | |
1694 | start_slack, total_chain, sbrked_remains); | |
c07a80fd | 1695 | } |
1696 | #else | |
1697 | void | |
8ac85365 | 1698 | dump_mstats(char *s) |
c07a80fd | 1699 | { |
8d063cd8 LW |
1700 | } |
1701 | #endif | |
a687059c | 1702 | #endif /* lint */ |
cf5c4ad8 | 1703 | |
1704 | ||
1705 | #ifdef USE_PERL_SBRK | |
1706 | ||
2c92fcc0 | 1707 | # if defined(__MACHTEN_PPC__) || defined(__NeXT__) |
38ac2dc8 DD |
1708 | # define PERL_SBRK_VIA_MALLOC |
1709 | /* | |
1710 | * MachTen's malloc() returns a buffer aligned on a two-byte boundary. | |
1711 | * While this is adequate, it may slow down access to longer data | |
1712 | * types by forcing multiple memory accesses. It also causes | |
1713 | * complaints when RCHECK is in force. So we allocate six bytes | |
1714 | * more than we need to, and return an address rounded up to an | |
1715 | * eight-byte boundary. | |
1716 | * | |
1717 | * 980701 Dominic Dunlop <domo@computer.org> | |
1718 | */ | |
1719 | # define SYSTEM_ALLOC(a) ((void *)(((unsigned)malloc((a)+6)+6)&~7)) | |
1720 | # endif | |
1721 | ||
760ac839 | 1722 | # ifdef PERL_SBRK_VIA_MALLOC |
72e5b9db | 1723 | # if defined(HIDEMYMALLOC) || defined(EMBEDMYMALLOC) |
38ac2dc8 DD |
1724 | # undef malloc /* Expose names that */ |
1725 | # undef calloc /* HIDEMYMALLOC hides */ | |
1726 | # undef realloc | |
1727 | # undef free | |
760ac839 | 1728 | # else |
72e5b9db | 1729 | # include "Error: -DPERL_SBRK_VIA_MALLOC needs -D(HIDE|EMBED)MYMALLOC" |
760ac839 | 1730 | # endif |
cf5c4ad8 | 1731 | |
1732 | /* it may seem schizophrenic to use perl's malloc and let it call system */ | |
1733 | /* malloc, the reason for that is only the 3.2 version of the OS that had */ | |
1734 | /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */ | |
1735 | /* end to the cores */ | |
1736 | ||
38ac2dc8 DD |
1737 | # ifndef SYSTEM_ALLOC |
1738 | # define SYSTEM_ALLOC(a) malloc(a) | |
1739 | # endif | |
cf5c4ad8 | 1740 | |
760ac839 | 1741 | # endif /* PERL_SBRK_VIA_MALLOC */ |
cf5c4ad8 | 1742 | |
1743 | static IV Perl_sbrk_oldchunk; | |
1744 | static long Perl_sbrk_oldsize; | |
1745 | ||
760ac839 LW |
1746 | # define PERLSBRK_32_K (1<<15) |
1747 | # define PERLSBRK_64_K (1<<16) | |
cf5c4ad8 | 1748 | |
b63effbb | 1749 | Malloc_t |
df0003d4 | 1750 | Perl_sbrk(int size) |
cf5c4ad8 | 1751 | { |
1752 | IV got; | |
1753 | int small, reqsize; | |
1754 | ||
1755 | if (!size) return 0; | |
55497cff | 1756 | #ifdef PERL_CORE |
cf5c4ad8 | 1757 | reqsize = size; /* just for the DEBUG_m statement */ |
1758 | #endif | |
57569e04 HM |
1759 | #ifdef PACK_MALLOC |
1760 | size = (size + 0x7ff) & ~0x7ff; | |
1761 | #endif | |
cf5c4ad8 | 1762 | if (size <= Perl_sbrk_oldsize) { |
1763 | got = Perl_sbrk_oldchunk; | |
1764 | Perl_sbrk_oldchunk += size; | |
1765 | Perl_sbrk_oldsize -= size; | |
1766 | } else { | |
1767 | if (size >= PERLSBRK_32_K) { | |
1768 | small = 0; | |
1769 | } else { | |
cf5c4ad8 | 1770 | size = PERLSBRK_64_K; |
1771 | small = 1; | |
1772 | } | |
1773 | got = (IV)SYSTEM_ALLOC(size); | |
57569e04 HM |
1774 | #ifdef PACK_MALLOC |
1775 | got = (got + 0x7ff) & ~0x7ff; | |
1776 | #endif | |
cf5c4ad8 | 1777 | if (small) { |
1778 | /* Chunk is small, register the rest for future allocs. */ | |
1779 | Perl_sbrk_oldchunk = got + reqsize; | |
1780 | Perl_sbrk_oldsize = size - reqsize; | |
1781 | } | |
1782 | } | |
1783 | ||
fb73857a | 1784 | DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n", |
cf5c4ad8 | 1785 | size, reqsize, Perl_sbrk_oldsize, got)); |
cf5c4ad8 | 1786 | |
1787 | return (void *)got; | |
1788 | } | |
1789 | ||
1790 | #endif /* ! defined USE_PERL_SBRK */ |