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 | ||
9ee81ef6 | 66 | # Minimal alignment (in bytes, should be a power of 2) of SYSTEM_ALLOC |
5bbd1ef5 IZ |
67 | SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES |
68 | ||
87c6202a IZ |
69 | # Disable memory overwrite checking with DEBUGGING. Memory and speed |
70 | # optimization, error reporting pessimization. | |
71 | NO_RCHECK undef | |
72 | ||
73 | # Enable memory overwrite checking with DEBUGGING. Memory and speed | |
74 | # pessimization, error reporting optimization | |
75 | RCHECK (DEBUGGING && !NO_RCHECK) | |
76 | ||
77 | # Failed allocations bigger than this size croak (if | |
78 | # PERL_EMERGENCY_SBRK is enabled) without touching $^M. See | |
79 | # perlvar.pod for a description of $^M. | |
80 | BIG_SIZE (1<<16) # 64K | |
81 | ||
82 | # Starting from this power of two, add an extra page to the | |
83 | # size of the bucket. This enables optimized allocations of sizes | |
84 | # close to powers of 2. Note that the value is indexed at 0. | |
85 | FIRST_BIG_POW2 15 # 32K, 16K is used too often | |
86 | ||
87 | # Estimate of minimal memory footprint. malloc uses this value to | |
88 | # request the most reasonable largest blocks of memory from the system. | |
89 | FIRST_SBRK (48*1024) | |
90 | ||
91 | # Round up sbrk()s to multiples of this. | |
92 | MIN_SBRK 2048 | |
93 | ||
94 | # Round up sbrk()s to multiples of this percent of footprint. | |
95 | MIN_SBRK_FRAC 3 | |
96 | ||
97 | # Add this much memory to big powers of two to get the bucket size. | |
98 | PERL_PAGESIZE 4096 | |
99 | ||
100 | # This many sbrk() discontinuities should be tolerated even | |
101 | # from the start without deciding that sbrk() is usually | |
102 | # discontinuous. | |
103 | SBRK_ALLOW_FAILURES 3 | |
104 | ||
105 | # This many continuous sbrk()s compensate for one discontinuous one. | |
106 | SBRK_FAILURE_PRICE 50 | |
107 | ||
28ac10b1 IZ |
108 | # Some configurations may ask for 12-byte-or-so allocations which |
109 | # require 8-byte alignment (?!). In such situation one needs to | |
110 | # define this to disable 12-byte bucket (will increase memory footprint) | |
111 | STRICT_ALIGNMENT undef | |
112 | ||
87c6202a IZ |
113 | This implementation assumes that calling PerlIO_printf() does not |
114 | result in any memory allocation calls (used during a panic). | |
115 | ||
116 | */ | |
117 | ||
741df71a IZ |
118 | /* |
119 | If used outside of Perl environment, it may be useful to redefine | |
120 | the following macros (listed below with defaults): | |
121 | ||
122 | # Type of address returned by allocation functions | |
123 | Malloc_t void * | |
124 | ||
125 | # Type of size argument for allocation functions | |
126 | MEM_SIZE unsigned long | |
127 | ||
128 | # Maximal value in LONG | |
129 | LONG_MAX 0x7FFFFFFF | |
130 | ||
131 | # Unsigned integer type big enough to keep a pointer | |
132 | UV unsigned long | |
133 | ||
134 | # Type of pointer with 1-byte granularity | |
135 | caddr_t char * | |
136 | ||
137 | # Type returned by free() | |
138 | Free_t void | |
139 | ||
5bbd1ef5 IZ |
140 | # Very fatal condition reporting function (cannot call any ) |
141 | fatalcroak(arg) write(2,arg,strlen(arg)) + exit(2) | |
142 | ||
741df71a IZ |
143 | # Fatal error reporting function |
144 | croak(format, arg) warn(idem) + exit(1) | |
145 | ||
146 | # Error reporting function | |
147 | warn(format, arg) fprintf(stderr, idem) | |
148 | ||
149 | # Locking/unlocking for MT operation | |
cea2e8a9 GS |
150 | MALLOC_LOCK MUTEX_LOCK_NOCONTEXT(&PL_malloc_mutex) |
151 | MALLOC_UNLOCK MUTEX_UNLOCK_NOCONTEXT(&PL_malloc_mutex) | |
741df71a IZ |
152 | |
153 | # Locking/unlocking mutex for MT operation | |
154 | MUTEX_LOCK(l) void | |
155 | MUTEX_UNLOCK(l) void | |
156 | */ | |
157 | ||
e8bc2b5c GS |
158 | #ifndef NO_FANCY_MALLOC |
159 | # ifndef SMALL_BUCKET_VIA_TABLE | |
160 | # define SMALL_BUCKET_VIA_TABLE | |
161 | # endif | |
162 | # ifndef BUCKETS_ROOT2 | |
163 | # define BUCKETS_ROOT2 | |
164 | # endif | |
165 | # ifndef IGNORE_SMALL_BAD_FREE | |
166 | # define IGNORE_SMALL_BAD_FREE | |
167 | # endif | |
3562ef9b IZ |
168 | #endif |
169 | ||
e8bc2b5c GS |
170 | #ifndef PLAIN_MALLOC /* Bulk enable features */ |
171 | # ifndef PACK_MALLOC | |
172 | # define PACK_MALLOC | |
173 | # endif | |
174 | # ifndef TWO_POT_OPTIMIZE | |
175 | # define TWO_POT_OPTIMIZE | |
176 | # endif | |
d720c441 IZ |
177 | # if defined(PERL_CORE) && !defined(PERL_EMERGENCY_SBRK) |
178 | # define PERL_EMERGENCY_SBRK | |
e8bc2b5c GS |
179 | # endif |
180 | # if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS) | |
181 | # define DEBUGGING_MSTATS | |
182 | # endif | |
183 | #endif | |
184 | ||
185 | #define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */ | |
186 | #define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2) | |
187 | ||
61ae2fbf | 188 | #if !(defined(I286) || defined(atarist) || defined(__MINT__)) |
e8bc2b5c GS |
189 | /* take 2k unless the block is bigger than that */ |
190 | # define LOG_OF_MIN_ARENA 11 | |
191 | #else | |
192 | /* take 16k unless the block is bigger than that | |
193 | (80286s like large segments!), probably good on the atari too */ | |
194 | # define LOG_OF_MIN_ARENA 14 | |
195 | #endif | |
196 | ||
8d063cd8 | 197 | #ifndef lint |
1944739a IZ |
198 | # if defined(DEBUGGING) && !defined(NO_RCHECK) |
199 | # define RCHECK | |
200 | # endif | |
e8bc2b5c GS |
201 | # if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE) |
202 | # undef IGNORE_SMALL_BAD_FREE | |
203 | # endif | |
8d063cd8 LW |
204 | /* |
205 | * malloc.c (Caltech) 2/21/82 | |
206 | * Chris Kingsley, kingsley@cit-20. | |
207 | * | |
208 | * This is a very fast storage allocator. It allocates blocks of a small | |
209 | * number of different sizes, and keeps free lists of each size. Blocks that | |
210 | * don't exactly fit are passed up to the next larger size. In this | |
211 | * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long. | |
cf5c4ad8 | 212 | * If PACK_MALLOC is defined, small blocks are 2^n bytes long. |
8d063cd8 | 213 | * This is designed for use in a program that uses vast quantities of memory, |
741df71a IZ |
214 | * but bombs when it runs out. |
215 | * | |
4eb8286e | 216 | * Modifications Copyright Ilya Zakharevich 1996-99. |
741df71a IZ |
217 | * |
218 | * Still very quick, but much more thrifty. (Std config is 10% slower | |
219 | * than it was, and takes 67% of old heap size for typical usage.) | |
220 | * | |
221 | * Allocations of small blocks are now table-driven to many different | |
222 | * buckets. Sizes of really big buckets are increased to accomodata | |
223 | * common size=power-of-2 blocks. Running-out-of-memory is made into | |
224 | * an exception. Deeply configurable and thread-safe. | |
225 | * | |
8d063cd8 LW |
226 | */ |
227 | ||
d720c441 IZ |
228 | #ifdef PERL_CORE |
229 | # include "EXTERN.h" | |
864dbfa3 | 230 | #define PERL_IN_MALLOC_C |
d720c441 | 231 | # include "perl.h" |
cea2e8a9 GS |
232 | # if defined(PERL_IMPLICIT_CONTEXT) |
233 | # define croak Perl_croak_nocontext | |
234 | # define warn Perl_warn_nocontext | |
235 | # endif | |
d720c441 IZ |
236 | #else |
237 | # ifdef PERL_FOR_X2P | |
238 | # include "../EXTERN.h" | |
239 | # include "../perl.h" | |
240 | # else | |
241 | # include <stdlib.h> | |
242 | # include <stdio.h> | |
243 | # include <memory.h> | |
244 | # define _(arg) arg | |
245 | # ifndef Malloc_t | |
246 | # define Malloc_t void * | |
247 | # endif | |
248 | # ifndef MEM_SIZE | |
249 | # define MEM_SIZE unsigned long | |
250 | # endif | |
251 | # ifndef LONG_MAX | |
252 | # define LONG_MAX 0x7FFFFFFF | |
253 | # endif | |
254 | # ifndef UV | |
255 | # define UV unsigned long | |
256 | # endif | |
257 | # ifndef caddr_t | |
258 | # define caddr_t char * | |
259 | # endif | |
260 | # ifndef Free_t | |
261 | # define Free_t void | |
262 | # endif | |
263 | # define Copy(s,d,n,t) (void)memcpy((char*)(d),(char*)(s), (n) * sizeof(t)) | |
264 | # define PerlEnv_getenv getenv | |
265 | # define PerlIO_printf fprintf | |
266 | # define PerlIO_stderr() stderr | |
267 | # endif | |
e8bc2b5c | 268 | # ifndef croak /* make depend */ |
741df71a | 269 | # define croak(mess, arg) (warn((mess), (arg)), exit(1)) |
d720c441 IZ |
270 | # endif |
271 | # ifndef warn | |
741df71a | 272 | # define warn(mess, arg) fprintf(stderr, (mess), (arg)) |
e8bc2b5c GS |
273 | # endif |
274 | # ifdef DEBUG_m | |
275 | # undef DEBUG_m | |
276 | # endif | |
277 | # define DEBUG_m(a) | |
278 | # ifdef DEBUGGING | |
279 | # undef DEBUGGING | |
280 | # endif | |
cea2e8a9 GS |
281 | # ifndef pTHX |
282 | # define pTHX void | |
283 | # define pTHX_ | |
284 | # define dTHX extern int Perl___notused | |
285 | # define WITH_THX(s) s | |
286 | # endif | |
c5be433b GS |
287 | # ifndef PERL_GET_INTERP |
288 | # define PERL_GET_INTERP PL_curinterp | |
289 | # endif | |
e8bc2b5c GS |
290 | #endif |
291 | ||
292 | #ifndef MUTEX_LOCK | |
293 | # define MUTEX_LOCK(l) | |
294 | #endif | |
295 | ||
296 | #ifndef MUTEX_UNLOCK | |
297 | # define MUTEX_UNLOCK(l) | |
298 | #endif | |
299 | ||
741df71a | 300 | #ifndef MALLOC_LOCK |
cea2e8a9 | 301 | # define MALLOC_LOCK MUTEX_LOCK_NOCONTEXT(&PL_malloc_mutex) |
741df71a IZ |
302 | #endif |
303 | ||
304 | #ifndef MALLOC_UNLOCK | |
cea2e8a9 | 305 | # define MALLOC_UNLOCK MUTEX_UNLOCK_NOCONTEXT(&PL_malloc_mutex) |
741df71a IZ |
306 | #endif |
307 | ||
5bbd1ef5 IZ |
308 | # ifndef fatalcroak /* make depend */ |
309 | # define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2)) | |
310 | # endif | |
311 | ||
760ac839 | 312 | #ifdef DEBUGGING |
e8bc2b5c | 313 | # undef DEBUG_m |
0b250b9e GS |
314 | # define DEBUG_m(a) \ |
315 | STMT_START { \ | |
316 | if (PERL_GET_INTERP) { dTHX; if (PL_debug & 128) { a; } } \ | |
317 | } STMT_END | |
760ac839 LW |
318 | #endif |
319 | ||
e9397286 GS |
320 | /* |
321 | * Layout of memory: | |
322 | * ~~~~~~~~~~~~~~~~ | |
323 | * The memory is broken into "blocks" which occupy multiples of 2K (and | |
324 | * generally speaking, have size "close" to a power of 2). The addresses | |
325 | * of such *unused* blocks are kept in nextf[i] with big enough i. (nextf | |
326 | * is an array of linked lists.) (Addresses of used blocks are not known.) | |
327 | * | |
328 | * Moreover, since the algorithm may try to "bite" smaller blocks of out | |
329 | * of unused bigger ones, there are also regions of "irregular" size, | |
330 | * managed separately, by a linked list chunk_chain. | |
331 | * | |
332 | * The third type of storage is the sbrk()ed-but-not-yet-used space, its | |
333 | * end and size are kept in last_sbrk_top and sbrked_remains. | |
334 | * | |
335 | * Growing blocks "in place": | |
336 | * ~~~~~~~~~~~~~~~~~~~~~~~~~ | |
337 | * The address of the block with the greatest address is kept in last_op | |
338 | * (if not known, last_op is 0). If it is known that the memory above | |
339 | * last_op is not continuous, or contains a chunk from chunk_chain, | |
340 | * last_op is set to 0. | |
341 | * | |
342 | * The chunk with address last_op may be grown by expanding into | |
343 | * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous | |
344 | * memory. | |
345 | * | |
346 | * Management of last_op: | |
347 | * ~~~~~~~~~~~~~~~~~~~~~ | |
348 | * | |
349 | * free() never changes the boundaries of blocks, so is not relevant. | |
350 | * | |
351 | * The only way realloc() may change the boundaries of blocks is if it | |
352 | * grows a block "in place". However, in the case of success such a | |
353 | * chunk is automatically last_op, and it remains last_op. In the case | |
354 | * of failure getpages_adjacent() clears last_op. | |
355 | * | |
356 | * malloc() may change blocks by calling morecore() only. | |
357 | * | |
358 | * morecore() may create new blocks by: | |
359 | * a) biting pieces from chunk_chain (cannot create one above last_op); | |
360 | * b) biting a piece from an unused block (if block was last_op, this | |
361 | * may create a chunk from chain above last_op, thus last_op is | |
362 | * invalidated in such a case). | |
363 | * c) biting of sbrk()ed-but-not-yet-used space. This creates | |
364 | * a block which is last_op. | |
365 | * d) Allocating new pages by calling getpages(); | |
366 | * | |
367 | * getpages() creates a new block. It marks last_op at the bottom of | |
368 | * the chunk of memory it returns. | |
369 | * | |
370 | * Active pages footprint: | |
371 | * ~~~~~~~~~~~~~~~~~~~~~~ | |
372 | * Note that we do not need to traverse the lists in nextf[i], just take | |
373 | * the first element of this list. However, we *need* to traverse the | |
374 | * list in chunk_chain, but most the time it should be a very short one, | |
375 | * so we do not step on a lot of pages we are not going to use. | |
376 | * | |
377 | * Flaws: | |
378 | * ~~~~~ | |
379 | * get_from_bigger_buckets(): forget to increment price => Quite | |
380 | * aggressive. | |
381 | */ | |
382 | ||
135863df AB |
383 | /* I don't much care whether these are defined in sys/types.h--LAW */ |
384 | ||
385 | #define u_char unsigned char | |
386 | #define u_int unsigned int | |
e8bc2b5c GS |
387 | |
388 | #ifdef HAS_QUAD | |
389 | # define u_bigint UV /* Needs to eat *void. */ | |
390 | #else /* needed? */ | |
391 | # define u_bigint unsigned long /* Needs to eat *void. */ | |
392 | #endif | |
393 | ||
135863df | 394 | #define u_short unsigned short |
8d063cd8 | 395 | |
cf5c4ad8 | 396 | /* 286 and atarist like big chunks, which gives too much overhead. */ |
61ae2fbf | 397 | #if (defined(RCHECK) || defined(I286) || defined(atarist) || defined(__MINT__)) && defined(PACK_MALLOC) |
e8bc2b5c | 398 | # undef PACK_MALLOC |
cf5c4ad8 | 399 | #endif |
400 | ||
8d063cd8 | 401 | /* |
cf5c4ad8 | 402 | * The description below is applicable if PACK_MALLOC is not defined. |
403 | * | |
8d063cd8 LW |
404 | * The overhead on a block is at least 4 bytes. When free, this space |
405 | * contains a pointer to the next free block, and the bottom two bits must | |
406 | * be zero. When in use, the first byte is set to MAGIC, and the second | |
407 | * byte is the size index. The remaining bytes are for alignment. | |
408 | * If range checking is enabled and the size of the block fits | |
409 | * in two bytes, then the top two bytes hold the size of the requested block | |
410 | * plus the range checking words, and the header word MINUS ONE. | |
411 | */ | |
412 | union overhead { | |
413 | union overhead *ov_next; /* when free */ | |
85e6fe83 | 414 | #if MEM_ALIGNBYTES > 4 |
c623bd54 | 415 | double strut; /* alignment problems */ |
a687059c | 416 | #endif |
8d063cd8 LW |
417 | struct { |
418 | u_char ovu_magic; /* magic number */ | |
419 | u_char ovu_index; /* bucket # */ | |
420 | #ifdef RCHECK | |
421 | u_short ovu_size; /* actual block size */ | |
422 | u_int ovu_rmagic; /* range magic number */ | |
423 | #endif | |
424 | } ovu; | |
425 | #define ov_magic ovu.ovu_magic | |
426 | #define ov_index ovu.ovu_index | |
427 | #define ov_size ovu.ovu_size | |
428 | #define ov_rmagic ovu.ovu_rmagic | |
429 | }; | |
430 | ||
431 | #define MAGIC 0xff /* magic # on accounting info */ | |
432 | #define RMAGIC 0x55555555 /* magic # on range info */ | |
e8bc2b5c GS |
433 | #define RMAGIC_C 0x55 /* magic # on range info */ |
434 | ||
8d063cd8 | 435 | #ifdef RCHECK |
c2a5c2d2 IZ |
436 | # define RSLOP sizeof (u_int) |
437 | # ifdef TWO_POT_OPTIMIZE | |
e8bc2b5c | 438 | # define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) |
c2a5c2d2 | 439 | # else |
e8bc2b5c | 440 | # define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2) |
c2a5c2d2 | 441 | # endif |
8d063cd8 | 442 | #else |
c2a5c2d2 | 443 | # define RSLOP 0 |
8d063cd8 LW |
444 | #endif |
445 | ||
e8bc2b5c GS |
446 | #if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2) |
447 | # undef BUCKETS_ROOT2 | |
448 | #endif | |
449 | ||
450 | #ifdef BUCKETS_ROOT2 | |
451 | # define BUCKET_TABLE_SHIFT 2 | |
452 | # define BUCKET_POW2_SHIFT 1 | |
453 | # define BUCKETS_PER_POW2 2 | |
454 | #else | |
455 | # define BUCKET_TABLE_SHIFT MIN_BUC_POW2 | |
456 | # define BUCKET_POW2_SHIFT 0 | |
457 | # define BUCKETS_PER_POW2 1 | |
458 | #endif | |
459 | ||
274c7500 IZ |
460 | #if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT)) |
461 | /* Figure out the alignment of void*. */ | |
462 | struct aligner { | |
463 | char c; | |
464 | void *p; | |
465 | }; | |
466 | # define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p))) | |
467 | #else | |
468 | # define ALIGN_SMALL MEM_ALIGNBYTES | |
469 | #endif | |
470 | ||
471 | #define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no)) | |
472 | ||
e8bc2b5c GS |
473 | #ifdef BUCKETS_ROOT2 |
474 | # define MAX_BUCKET_BY_TABLE 13 | |
475 | static u_short buck_size[MAX_BUCKET_BY_TABLE + 1] = | |
476 | { | |
477 | 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80, | |
478 | }; | |
479 | # define BUCKET_SIZE(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT))) | |
480 | # define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \ | |
481 | ? buck_size[i] \ | |
482 | : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \ | |
483 | - MEM_OVERHEAD(i) \ | |
484 | + POW2_OPTIMIZE_SURPLUS(i))) | |
485 | #else | |
486 | # define BUCKET_SIZE(i) (1 << ((i) >> BUCKET_POW2_SHIFT)) | |
487 | # define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i) + POW2_OPTIMIZE_SURPLUS(i)) | |
488 | #endif | |
489 | ||
490 | ||
cf5c4ad8 | 491 | #ifdef PACK_MALLOC |
e8bc2b5c GS |
492 | /* In this case it is assumed that if we do sbrk() in 2K units, we |
493 | * will get 2K aligned arenas (at least after some initial | |
494 | * alignment). The bucket number of the given subblock is on the start | |
495 | * of 2K arena which contains the subblock. Several following bytes | |
496 | * contain the magic numbers for the subblocks in the block. | |
cf5c4ad8 | 497 | * |
498 | * Sizes of chunks are powers of 2 for chunks in buckets <= | |
499 | * MAX_PACKED, after this they are (2^n - sizeof(union overhead)) (to | |
500 | * get alignment right). | |
501 | * | |
e8bc2b5c GS |
502 | * Consider an arena for 2^n with n>MAX_PACKED. We suppose that |
503 | * starts of all the chunks in a 2K arena are in different | |
504 | * 2^n-byte-long chunks. If the top of the last chunk is aligned on a | |
505 | * boundary of 2K block, this means that sizeof(union | |
506 | * overhead)*"number of chunks" < 2^n, or sizeof(union overhead)*2K < | |
507 | * 4^n, or n > 6 + log2(sizeof()/2)/2, since a chunk of size 2^n - | |
508 | * overhead is used. Since this rules out n = 7 for 8 byte alignment, | |
509 | * we specialcase allocation of the first of 16 128-byte-long chunks. | |
cf5c4ad8 | 510 | * |
511 | * Note that with the above assumption we automatically have enough | |
512 | * place for MAGIC at the start of 2K block. Note also that we | |
e8bc2b5c GS |
513 | * overlay union overhead over the chunk, thus the start of small chunks |
514 | * is immediately overwritten after freeing. */ | |
515 | # define MAX_PACKED_POW2 6 | |
516 | # define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT) | |
517 | # define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD) | |
518 | # define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1) | |
519 | # define TWOK_MASKED(x) ((u_bigint)(x) & ~TWOK_MASK) | |
520 | # define TWOK_SHIFT(x) ((u_bigint)(x) & TWOK_MASK) | |
cf5c4ad8 | 521 | # define OV_INDEXp(block) ((u_char*)(TWOK_MASKED(block))) |
522 | # define OV_INDEX(block) (*OV_INDEXp(block)) | |
523 | # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \ | |
e8bc2b5c GS |
524 | (TWOK_SHIFT(block)>> \ |
525 | (bucket>>BUCKET_POW2_SHIFT)) + \ | |
526 | (bucket >= MIN_NEEDS_SHIFT ? 1 : 0))) | |
527 | /* A bucket can have a shift smaller than it size, we need to | |
528 | shift its magic number so it will not overwrite index: */ | |
529 | # ifdef BUCKETS_ROOT2 | |
530 | # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */ | |
531 | # else | |
532 | # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */ | |
533 | # endif | |
cf5c4ad8 | 534 | # define CHUNK_SHIFT 0 |
535 | ||
e8bc2b5c GS |
536 | /* Number of active buckets of given ordinal. */ |
537 | #ifdef IGNORE_SMALL_BAD_FREE | |
538 | #define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */ | |
539 | # define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \ | |
540 | ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE(bucket) \ | |
541 | : n_blks[bucket] ) | |
542 | #else | |
543 | # define N_BLKS(bucket) n_blks[bucket] | |
544 | #endif | |
545 | ||
546 | static u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] = | |
547 | { | |
548 | # if BUCKETS_PER_POW2==1 | |
549 | 0, 0, | |
550 | (MIN_BUC_POW2==2 ? 384 : 0), | |
551 | 224, 120, 62, 31, 16, 8, 4, 2 | |
552 | # else | |
553 | 0, 0, 0, 0, | |
554 | (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */ | |
555 | 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2 | |
556 | # endif | |
557 | }; | |
558 | ||
559 | /* Shift of the first bucket with the given ordinal inside 2K chunk. */ | |
560 | #ifdef IGNORE_SMALL_BAD_FREE | |
561 | # define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \ | |
562 | ? ((1<<LOG_OF_MIN_ARENA) \ | |
563 | - BUCKET_SIZE(bucket) * N_BLKS(bucket)) \ | |
564 | : blk_shift[bucket]) | |
565 | #else | |
566 | # define BLK_SHIFT(bucket) blk_shift[bucket] | |
567 | #endif | |
568 | ||
569 | static u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] = | |
570 | { | |
571 | # if BUCKETS_PER_POW2==1 | |
572 | 0, 0, | |
573 | (MIN_BUC_POW2==2 ? 512 : 0), | |
574 | 256, 128, 64, 64, /* 8 to 64 */ | |
575 | 16*sizeof(union overhead), | |
576 | 8*sizeof(union overhead), | |
577 | 4*sizeof(union overhead), | |
578 | 2*sizeof(union overhead), | |
579 | # else | |
580 | 0, 0, 0, 0, | |
581 | (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0), | |
582 | 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */ | |
583 | 16*sizeof(union overhead), 16*sizeof(union overhead), | |
584 | 8*sizeof(union overhead), 8*sizeof(union overhead), | |
585 | 4*sizeof(union overhead), 4*sizeof(union overhead), | |
586 | 2*sizeof(union overhead), 2*sizeof(union overhead), | |
587 | # endif | |
588 | }; | |
cf5c4ad8 | 589 | |
5bbd1ef5 IZ |
590 | # define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */ |
591 | # define WANTED_ALIGNMENT 0x800 /* 2k boundaries */ | |
592 | ||
cf5c4ad8 | 593 | #else /* !PACK_MALLOC */ |
594 | ||
595 | # define OV_MAGIC(block,bucket) (block)->ov_magic | |
596 | # define OV_INDEX(block) (block)->ov_index | |
597 | # define CHUNK_SHIFT 1 | |
e8bc2b5c | 598 | # define MAX_PACKED -1 |
5bbd1ef5 IZ |
599 | # define NEEDED_ALIGNMENT MEM_ALIGNBYTES |
600 | # define WANTED_ALIGNMENT 0x400 /* 1k boundaries */ | |
601 | ||
cf5c4ad8 | 602 | #endif /* !PACK_MALLOC */ |
603 | ||
e8bc2b5c GS |
604 | #define M_OVERHEAD (sizeof(union overhead) + RSLOP) |
605 | ||
606 | #ifdef PACK_MALLOC | |
607 | # define MEM_OVERHEAD(bucket) \ | |
608 | (bucket <= MAX_PACKED ? 0 : M_OVERHEAD) | |
609 | # ifdef SMALL_BUCKET_VIA_TABLE | |
610 | # define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2) | |
611 | # define START_SHIFT MAX_PACKED_POW2 | |
612 | # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */ | |
613 | # define SIZE_TABLE_MAX 80 | |
614 | # else | |
615 | # define SIZE_TABLE_MAX 64 | |
616 | # endif | |
617 | static char bucket_of[] = | |
618 | { | |
619 | # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */ | |
620 | /* 0 to 15 in 4-byte increments. */ | |
621 | (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */ | |
622 | 6, /* 8 */ | |
274c7500 | 623 | IF_ALIGN_8(8,7), 8, /* 16/12, 16 */ |
e8bc2b5c GS |
624 | 9, 9, 10, 10, /* 24, 32 */ |
625 | 11, 11, 11, 11, /* 48 */ | |
626 | 12, 12, 12, 12, /* 64 */ | |
627 | 13, 13, 13, 13, /* 80 */ | |
628 | 13, 13, 13, 13 /* 80 */ | |
629 | # else /* !BUCKETS_ROOT2 */ | |
630 | /* 0 to 15 in 4-byte increments. */ | |
631 | (sizeof(void*) > 4 ? 3 : 2), | |
632 | 3, | |
633 | 4, 4, | |
634 | 5, 5, 5, 5, | |
635 | 6, 6, 6, 6, | |
636 | 6, 6, 6, 6 | |
637 | # endif /* !BUCKETS_ROOT2 */ | |
638 | }; | |
639 | # else /* !SMALL_BUCKET_VIA_TABLE */ | |
640 | # define START_SHIFTS_BUCKET MIN_BUCKET | |
641 | # define START_SHIFT (MIN_BUC_POW2 - 1) | |
642 | # endif /* !SMALL_BUCKET_VIA_TABLE */ | |
643 | #else /* !PACK_MALLOC */ | |
644 | # define MEM_OVERHEAD(bucket) M_OVERHEAD | |
645 | # ifdef SMALL_BUCKET_VIA_TABLE | |
646 | # undef SMALL_BUCKET_VIA_TABLE | |
647 | # endif | |
648 | # define START_SHIFTS_BUCKET MIN_BUCKET | |
649 | # define START_SHIFT (MIN_BUC_POW2 - 1) | |
650 | #endif /* !PACK_MALLOC */ | |
cf5c4ad8 | 651 | |
8d063cd8 | 652 | /* |
55497cff | 653 | * Big allocations are often of the size 2^n bytes. To make them a |
654 | * little bit better, make blocks of size 2^n+pagesize for big n. | |
655 | */ | |
656 | ||
657 | #ifdef TWO_POT_OPTIMIZE | |
658 | ||
5f05dabc | 659 | # ifndef PERL_PAGESIZE |
660 | # define PERL_PAGESIZE 4096 | |
661 | # endif | |
e8bc2b5c GS |
662 | # ifndef FIRST_BIG_POW2 |
663 | # define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */ | |
5f05dabc | 664 | # endif |
e8bc2b5c | 665 | # define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2) |
55497cff | 666 | /* If this value or more, check against bigger blocks. */ |
667 | # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD) | |
668 | /* If less than this value, goes into 2^n-overhead-block. */ | |
669 | # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD) | |
670 | ||
e8bc2b5c GS |
671 | # define POW2_OPTIMIZE_ADJUST(nbytes) \ |
672 | ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0) | |
673 | # define POW2_OPTIMIZE_SURPLUS(bucket) \ | |
674 | ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0) | |
675 | ||
676 | #else /* !TWO_POT_OPTIMIZE */ | |
677 | # define POW2_OPTIMIZE_ADJUST(nbytes) | |
678 | # define POW2_OPTIMIZE_SURPLUS(bucket) 0 | |
679 | #endif /* !TWO_POT_OPTIMIZE */ | |
680 | ||
681 | #if defined(HAS_64K_LIMIT) && defined(PERL_CORE) | |
682 | # define BARK_64K_LIMIT(what,nbytes,size) \ | |
683 | if (nbytes > 0xffff) { \ | |
684 | PerlIO_printf(PerlIO_stderr(), \ | |
685 | "%s too large: %lx\n", what, size); \ | |
686 | my_exit(1); \ | |
687 | } | |
688 | #else /* !HAS_64K_LIMIT || !PERL_CORE */ | |
689 | # define BARK_64K_LIMIT(what,nbytes,size) | |
690 | #endif /* !HAS_64K_LIMIT || !PERL_CORE */ | |
55497cff | 691 | |
e8bc2b5c GS |
692 | #ifndef MIN_SBRK |
693 | # define MIN_SBRK 2048 | |
694 | #endif | |
695 | ||
696 | #ifndef FIRST_SBRK | |
d720c441 | 697 | # define FIRST_SBRK (48*1024) |
e8bc2b5c GS |
698 | #endif |
699 | ||
700 | /* Minimal sbrk in percents of what is already alloced. */ | |
701 | #ifndef MIN_SBRK_FRAC | |
702 | # define MIN_SBRK_FRAC 3 | |
703 | #endif | |
704 | ||
705 | #ifndef SBRK_ALLOW_FAILURES | |
706 | # define SBRK_ALLOW_FAILURES 3 | |
707 | #endif | |
55497cff | 708 | |
e8bc2b5c GS |
709 | #ifndef SBRK_FAILURE_PRICE |
710 | # define SBRK_FAILURE_PRICE 50 | |
55497cff | 711 | #endif |
712 | ||
e8bc2b5c GS |
713 | #if defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE) |
714 | ||
715 | # ifndef BIG_SIZE | |
716 | # define BIG_SIZE (1<<16) /* 64K */ | |
717 | # endif | |
718 | ||
3541dd58 | 719 | #ifdef I_MACH_CTHREADS |
772fe5b3 HM |
720 | # undef MUTEX_LOCK |
721 | # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END | |
722 | # undef MUTEX_UNLOCK | |
723 | # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END | |
3541dd58 HM |
724 | #endif |
725 | ||
55497cff | 726 | static char *emergency_buffer; |
727 | static MEM_SIZE emergency_buffer_size; | |
728 | ||
cea2e8a9 GS |
729 | static int findbucket (union overhead *freep, int srchlen); |
730 | static void morecore (register int bucket); | |
731 | # if defined(DEBUGGING) | |
732 | static void botch (char *diag, char *s); | |
733 | # endif | |
734 | static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip); | |
735 | static Malloc_t emergency_sbrk (MEM_SIZE size); | |
736 | static void* get_from_chain (MEM_SIZE size); | |
737 | static void* get_from_bigger_buckets(int bucket, MEM_SIZE size); | |
738 | static union overhead *getpages (int needed, int *nblksp, int bucket); | |
739 | static int getpages_adjacent(int require); | |
740 | ||
741 | static Malloc_t | |
742 | emergency_sbrk(MEM_SIZE size) | |
55497cff | 743 | { |
28ac10b1 IZ |
744 | MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA; |
745 | ||
55497cff | 746 | if (size >= BIG_SIZE) { |
747 | /* Give the possibility to recover: */ | |
741df71a | 748 | MALLOC_UNLOCK; |
1b979e0a | 749 | croak("Out of memory during \"large\" request for %i bytes", size); |
55497cff | 750 | } |
751 | ||
28ac10b1 IZ |
752 | if (emergency_buffer_size >= rsize) { |
753 | char *old = emergency_buffer; | |
754 | ||
755 | emergency_buffer_size -= rsize; | |
756 | emergency_buffer += rsize; | |
757 | return old; | |
758 | } else { | |
cea2e8a9 | 759 | dTHX; |
55497cff | 760 | /* First offense, give a possibility to recover by dieing. */ |
761 | /* No malloc involved here: */ | |
4a33f861 | 762 | GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0); |
55497cff | 763 | SV *sv; |
764 | char *pv; | |
28ac10b1 | 765 | int have = 0; |
2d8e6c8d | 766 | STRLEN n_a; |
55497cff | 767 | |
28ac10b1 IZ |
768 | if (emergency_buffer_size) { |
769 | add_to_chain(emergency_buffer, emergency_buffer_size, 0); | |
770 | emergency_buffer_size = 0; | |
771 | emergency_buffer = Nullch; | |
772 | have = 1; | |
773 | } | |
4a33f861 | 774 | if (!gvp) gvp = (GV**)hv_fetch(PL_defstash, "\015", 1, 0); |
55497cff | 775 | if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv) |
28ac10b1 IZ |
776 | || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD)) { |
777 | if (have) | |
778 | goto do_croak; | |
55497cff | 779 | return (char *)-1; /* Now die die die... */ |
28ac10b1 | 780 | } |
55497cff | 781 | /* Got it, now detach SvPV: */ |
2d8e6c8d | 782 | pv = SvPV(sv, n_a); |
55497cff | 783 | /* Check alignment: */ |
5bbd1ef5 | 784 | if (((UV)(pv - sizeof(union overhead))) & (NEEDED_ALIGNMENT - 1)) { |
55497cff | 785 | PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n"); |
bbce6d69 | 786 | return (char *)-1; /* die die die */ |
55497cff | 787 | } |
788 | ||
28ac10b1 IZ |
789 | emergency_buffer = pv - sizeof(union overhead); |
790 | emergency_buffer_size = malloced_size(pv) + M_OVERHEAD; | |
55497cff | 791 | SvPOK_off(sv); |
28ac10b1 IZ |
792 | SvPVX(sv) = Nullch; |
793 | SvCUR(sv) = SvLEN(sv) = 0; | |
55497cff | 794 | } |
28ac10b1 | 795 | do_croak: |
741df71a | 796 | MALLOC_UNLOCK; |
28ac10b1 | 797 | croak("Out of memory during request for %i bytes", size); |
55497cff | 798 | } |
799 | ||
e8bc2b5c | 800 | #else /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */ |
55497cff | 801 | # define emergency_sbrk(size) -1 |
e8bc2b5c | 802 | #endif /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */ |
55497cff | 803 | |
804 | /* | |
e8bc2b5c | 805 | * nextf[i] is the pointer to the next free block of size 2^i. The |
8d063cd8 LW |
806 | * smallest allocatable block is 8 bytes. The overhead information |
807 | * precedes the data area returned to the user. | |
808 | */ | |
e8bc2b5c | 809 | #define NBUCKETS (32*BUCKETS_PER_POW2 + 1) |
8d063cd8 | 810 | static union overhead *nextf[NBUCKETS]; |
cf5c4ad8 | 811 | |
812 | #ifdef USE_PERL_SBRK | |
813 | #define sbrk(a) Perl_sbrk(a) | |
20ce7b12 | 814 | Malloc_t Perl_sbrk (int size); |
8ac85365 NIS |
815 | #else |
816 | #ifdef DONT_DECLARE_STD | |
817 | #ifdef I_UNISTD | |
818 | #include <unistd.h> | |
819 | #endif | |
cf5c4ad8 | 820 | #else |
52082926 | 821 | extern Malloc_t sbrk(int); |
8ac85365 | 822 | #endif |
cf5c4ad8 | 823 | #endif |
8d063cd8 | 824 | |
c07a80fd | 825 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
826 | /* |
827 | * nmalloc[i] is the difference between the number of mallocs and frees | |
828 | * for a given block size. | |
829 | */ | |
830 | static u_int nmalloc[NBUCKETS]; | |
5f05dabc | 831 | static u_int sbrk_slack; |
832 | static u_int start_slack; | |
8d063cd8 LW |
833 | #endif |
834 | ||
e8bc2b5c GS |
835 | static u_int goodsbrk; |
836 | ||
760ac839 | 837 | #ifdef DEBUGGING |
3541dd58 HM |
838 | #undef ASSERT |
839 | #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p)); else | |
cea2e8a9 GS |
840 | static void |
841 | botch(char *diag, char *s) | |
8d063cd8 | 842 | { |
d720c441 | 843 | PerlIO_printf(PerlIO_stderr(), "assertion botched (%s?): %s\n", diag, s); |
3028581b | 844 | PerlProc_abort(); |
8d063cd8 LW |
845 | } |
846 | #else | |
3541dd58 | 847 | #define ASSERT(p, diag) |
8d063cd8 LW |
848 | #endif |
849 | ||
2304df62 | 850 | Malloc_t |
86058a2d | 851 | Perl_malloc(register size_t nbytes) |
8d063cd8 LW |
852 | { |
853 | register union overhead *p; | |
e8bc2b5c | 854 | register int bucket; |
ee0007ab | 855 | register MEM_SIZE shiftr; |
8d063cd8 | 856 | |
c2a5c2d2 | 857 | #if defined(DEBUGGING) || defined(RCHECK) |
ee0007ab | 858 | MEM_SIZE size = nbytes; |
45d8adaa LW |
859 | #endif |
860 | ||
e8bc2b5c | 861 | BARK_64K_LIMIT("Allocation",nbytes,nbytes); |
45d8adaa LW |
862 | #ifdef DEBUGGING |
863 | if ((long)nbytes < 0) | |
cea2e8a9 | 864 | croak("%s", "panic: malloc"); |
45d8adaa | 865 | #endif |
45d8adaa | 866 | |
741df71a | 867 | MALLOC_LOCK; |
8d063cd8 LW |
868 | /* |
869 | * Convert amount of memory requested into | |
870 | * closest block size stored in hash buckets | |
871 | * which satisfies request. Account for | |
872 | * space used per block for accounting. | |
873 | */ | |
cf5c4ad8 | 874 | #ifdef PACK_MALLOC |
e8bc2b5c GS |
875 | # ifdef SMALL_BUCKET_VIA_TABLE |
876 | if (nbytes == 0) | |
877 | bucket = MIN_BUCKET; | |
878 | else if (nbytes <= SIZE_TABLE_MAX) { | |
879 | bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT]; | |
880 | } else | |
881 | # else | |
043bf814 RB |
882 | if (nbytes == 0) |
883 | nbytes = 1; | |
e8bc2b5c GS |
884 | if (nbytes <= MAX_POW2_ALGO) goto do_shifts; |
885 | else | |
886 | # endif | |
55497cff | 887 | #endif |
e8bc2b5c GS |
888 | { |
889 | POW2_OPTIMIZE_ADJUST(nbytes); | |
890 | nbytes += M_OVERHEAD; | |
891 | nbytes = (nbytes + 3) &~ 3; | |
892 | do_shifts: | |
893 | shiftr = (nbytes - 1) >> START_SHIFT; | |
894 | bucket = START_SHIFTS_BUCKET; | |
895 | /* apart from this loop, this is O(1) */ | |
896 | while (shiftr >>= 1) | |
897 | bucket += BUCKETS_PER_POW2; | |
cf5c4ad8 | 898 | } |
8d063cd8 LW |
899 | /* |
900 | * If nothing in hash bucket right now, | |
901 | * request more memory from the system. | |
902 | */ | |
903 | if (nextf[bucket] == NULL) | |
904 | morecore(bucket); | |
e8bc2b5c | 905 | if ((p = nextf[bucket]) == NULL) { |
741df71a | 906 | MALLOC_UNLOCK; |
55497cff | 907 | #ifdef PERL_CORE |
0b250b9e GS |
908 | { |
909 | dTHX; | |
910 | if (!PL_nomemok) { | |
911 | PerlIO_puts(PerlIO_stderr(),"Out of memory!\n"); | |
912 | my_exit(1); | |
913 | } | |
ee0007ab | 914 | } |
45d8adaa | 915 | #else |
8d063cd8 | 916 | return (NULL); |
45d8adaa LW |
917 | #endif |
918 | } | |
919 | ||
e8bc2b5c GS |
920 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
921 | "0x%lx: (%05lu) malloc %ld bytes\n", | |
4a33f861 | 922 | (unsigned long)(p+1), (unsigned long)(PL_an++), |
e8bc2b5c | 923 | (long)size)); |
45d8adaa | 924 | |
8d063cd8 | 925 | /* remove from linked list */ |
802004fa DD |
926 | #if defined(RCHECK) |
927 | if (((UV)p) & (MEM_ALIGNBYTES - 1)) | |
760ac839 | 928 | PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n", |
a0d0e21e | 929 | (unsigned long)*((int*)p),(unsigned long)p); |
bf38876a LW |
930 | #endif |
931 | nextf[bucket] = p->ov_next; | |
e8bc2b5c GS |
932 | #ifdef IGNORE_SMALL_BAD_FREE |
933 | if (bucket >= FIRST_BUCKET_WITH_CHECK) | |
934 | #endif | |
935 | OV_MAGIC(p, bucket) = MAGIC; | |
cf5c4ad8 | 936 | #ifndef PACK_MALLOC |
937 | OV_INDEX(p) = bucket; | |
938 | #endif | |
8d063cd8 LW |
939 | #ifdef RCHECK |
940 | /* | |
941 | * Record allocated size of block and | |
942 | * bound space with magic numbers. | |
943 | */ | |
8d063cd8 | 944 | p->ov_rmagic = RMAGIC; |
e8bc2b5c GS |
945 | if (bucket <= MAX_SHORT_BUCKET) { |
946 | int i; | |
947 | ||
948 | nbytes = size + M_OVERHEAD; | |
949 | p->ov_size = nbytes - 1; | |
950 | if ((i = nbytes & 3)) { | |
951 | i = 4 - i; | |
952 | while (i--) | |
953 | *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C; | |
954 | } | |
955 | nbytes = (nbytes + 3) &~ 3; | |
956 | *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC; | |
957 | } | |
8d063cd8 | 958 | #endif |
741df71a | 959 | MALLOC_UNLOCK; |
cf5c4ad8 | 960 | return ((Malloc_t)(p + CHUNK_SHIFT)); |
8d063cd8 LW |
961 | } |
962 | ||
e8bc2b5c GS |
963 | static char *last_sbrk_top; |
964 | static char *last_op; /* This arena can be easily extended. */ | |
965 | static int sbrked_remains; | |
966 | static int sbrk_good = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE; | |
967 | ||
968 | #ifdef DEBUGGING_MSTATS | |
969 | static int sbrks; | |
970 | #endif | |
971 | ||
972 | struct chunk_chain_s { | |
973 | struct chunk_chain_s *next; | |
974 | MEM_SIZE size; | |
975 | }; | |
976 | static struct chunk_chain_s *chunk_chain; | |
977 | static int n_chunks; | |
978 | static char max_bucket; | |
979 | ||
980 | /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */ | |
cea2e8a9 GS |
981 | static void * |
982 | get_from_chain(MEM_SIZE size) | |
e8bc2b5c GS |
983 | { |
984 | struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain; | |
985 | struct chunk_chain_s **oldgoodp = NULL; | |
986 | long min_remain = LONG_MAX; | |
987 | ||
988 | while (elt) { | |
989 | if (elt->size >= size) { | |
990 | long remains = elt->size - size; | |
991 | if (remains >= 0 && remains < min_remain) { | |
992 | oldgoodp = oldp; | |
993 | min_remain = remains; | |
994 | } | |
995 | if (remains == 0) { | |
996 | break; | |
997 | } | |
998 | } | |
999 | oldp = &( elt->next ); | |
1000 | elt = elt->next; | |
1001 | } | |
1002 | if (!oldgoodp) return NULL; | |
1003 | if (min_remain) { | |
1004 | void *ret = *oldgoodp; | |
1005 | struct chunk_chain_s *next = (*oldgoodp)->next; | |
1006 | ||
1007 | *oldgoodp = (struct chunk_chain_s *)((char*)ret + size); | |
1008 | (*oldgoodp)->size = min_remain; | |
1009 | (*oldgoodp)->next = next; | |
1010 | return ret; | |
1011 | } else { | |
1012 | void *ret = *oldgoodp; | |
1013 | *oldgoodp = (*oldgoodp)->next; | |
1014 | n_chunks--; | |
1015 | return ret; | |
1016 | } | |
1017 | } | |
1018 | ||
cea2e8a9 GS |
1019 | static void |
1020 | add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip) | |
e8bc2b5c GS |
1021 | { |
1022 | struct chunk_chain_s *next = chunk_chain; | |
1023 | char *cp = (char*)p; | |
1024 | ||
1025 | cp += chip; | |
1026 | chunk_chain = (struct chunk_chain_s *)cp; | |
1027 | chunk_chain->size = size - chip; | |
1028 | chunk_chain->next = next; | |
1029 | n_chunks++; | |
1030 | } | |
1031 | ||
cea2e8a9 GS |
1032 | static void * |
1033 | get_from_bigger_buckets(int bucket, MEM_SIZE size) | |
e8bc2b5c GS |
1034 | { |
1035 | int price = 1; | |
1036 | static int bucketprice[NBUCKETS]; | |
1037 | while (bucket <= max_bucket) { | |
1038 | /* We postpone stealing from bigger buckets until we want it | |
1039 | often enough. */ | |
1040 | if (nextf[bucket] && bucketprice[bucket]++ >= price) { | |
1041 | /* Steal it! */ | |
1042 | void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT); | |
1043 | bucketprice[bucket] = 0; | |
1044 | if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) { | |
1045 | last_op = NULL; /* Disable optimization */ | |
1046 | } | |
1047 | nextf[bucket] = nextf[bucket]->ov_next; | |
1048 | #ifdef DEBUGGING_MSTATS | |
1049 | nmalloc[bucket]--; | |
1050 | start_slack -= M_OVERHEAD; | |
1051 | #endif | |
1052 | add_to_chain(ret, (BUCKET_SIZE(bucket) + | |
1053 | POW2_OPTIMIZE_SURPLUS(bucket)), | |
1054 | size); | |
1055 | return ret; | |
1056 | } | |
1057 | bucket++; | |
1058 | } | |
1059 | return NULL; | |
1060 | } | |
1061 | ||
cea2e8a9 GS |
1062 | static union overhead * |
1063 | getpages(int needed, int *nblksp, int bucket) | |
fa423c5b IZ |
1064 | { |
1065 | /* Need to do (possibly expensive) system call. Try to | |
1066 | optimize it for rare calling. */ | |
1067 | MEM_SIZE require = needed - sbrked_remains; | |
1068 | char *cp; | |
1069 | union overhead *ovp; | |
1070 | int slack = 0; | |
1071 | ||
1072 | if (sbrk_good > 0) { | |
1073 | if (!last_sbrk_top && require < FIRST_SBRK) | |
1074 | require = FIRST_SBRK; | |
1075 | else if (require < MIN_SBRK) require = MIN_SBRK; | |
1076 | ||
1077 | if (require < goodsbrk * MIN_SBRK_FRAC / 100) | |
1078 | require = goodsbrk * MIN_SBRK_FRAC / 100; | |
1079 | require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK; | |
1080 | } else { | |
1081 | require = needed; | |
1082 | last_sbrk_top = 0; | |
1083 | sbrked_remains = 0; | |
1084 | } | |
1085 | ||
1086 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1087 | "sbrk(%ld) for %ld-byte-long arena\n", | |
1088 | (long)require, (long) needed)); | |
1089 | cp = (char *)sbrk(require); | |
1090 | #ifdef DEBUGGING_MSTATS | |
1091 | sbrks++; | |
1092 | #endif | |
1093 | if (cp == last_sbrk_top) { | |
1094 | /* Common case, anything is fine. */ | |
1095 | sbrk_good++; | |
1096 | ovp = (union overhead *) (cp - sbrked_remains); | |
e9397286 | 1097 | last_op = cp - sbrked_remains; |
fa423c5b IZ |
1098 | sbrked_remains = require - (needed - sbrked_remains); |
1099 | } else if (cp == (char *)-1) { /* no more room! */ | |
1100 | ovp = (union overhead *)emergency_sbrk(needed); | |
1101 | if (ovp == (union overhead *)-1) | |
1102 | return 0; | |
e9397286 GS |
1103 | if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */ |
1104 | last_op = 0; | |
1105 | } | |
fa423c5b IZ |
1106 | return ovp; |
1107 | } else { /* Non-continuous or first sbrk(). */ | |
1108 | long add = sbrked_remains; | |
1109 | char *newcp; | |
1110 | ||
1111 | if (sbrked_remains) { /* Put rest into chain, we | |
1112 | cannot use it right now. */ | |
1113 | add_to_chain((void*)(last_sbrk_top - sbrked_remains), | |
1114 | sbrked_remains, 0); | |
1115 | } | |
1116 | ||
1117 | /* Second, check alignment. */ | |
1118 | slack = 0; | |
1119 | ||
61ae2fbf | 1120 | #if !defined(atarist) && !defined(__MINT__) /* on the atari we dont have to worry about this */ |
fa423c5b | 1121 | # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */ |
5bbd1ef5 IZ |
1122 | /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may |
1123 | improve performance of memory access. */ | |
1124 | if ((UV)cp & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */ | |
1125 | slack = WANTED_ALIGNMENT - ((UV)cp & (WANTED_ALIGNMENT - 1)); | |
fa423c5b IZ |
1126 | add += slack; |
1127 | } | |
1128 | # endif | |
61ae2fbf | 1129 | #endif /* !atarist && !MINT */ |
fa423c5b IZ |
1130 | |
1131 | if (add) { | |
1132 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1133 | "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", | |
1134 | (long)add, (long) slack, | |
1135 | (long) sbrked_remains)); | |
1136 | newcp = (char *)sbrk(add); | |
1137 | #if defined(DEBUGGING_MSTATS) | |
1138 | sbrks++; | |
1139 | sbrk_slack += add; | |
1140 | #endif | |
1141 | if (newcp != cp + require) { | |
1142 | /* Too bad: even rounding sbrk() is not continuous.*/ | |
1143 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1144 | "failed to fix bad sbrk()\n")); | |
1145 | #ifdef PACK_MALLOC | |
1146 | if (slack) { | |
741df71a | 1147 | MALLOC_UNLOCK; |
5bbd1ef5 | 1148 | fatalcroak("panic: Off-page sbrk\n"); |
fa423c5b IZ |
1149 | } |
1150 | #endif | |
1151 | if (sbrked_remains) { | |
1152 | /* Try again. */ | |
1153 | #if defined(DEBUGGING_MSTATS) | |
1154 | sbrk_slack += require; | |
1155 | #endif | |
1156 | require = needed; | |
1157 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1158 | "straight sbrk(%ld)\n", | |
1159 | (long)require)); | |
1160 | cp = (char *)sbrk(require); | |
1161 | #ifdef DEBUGGING_MSTATS | |
1162 | sbrks++; | |
1163 | #endif | |
1164 | if (cp == (char *)-1) | |
1165 | return 0; | |
1166 | } | |
1167 | sbrk_good = -1; /* Disable optimization! | |
1168 | Continue with not-aligned... */ | |
1169 | } else { | |
1170 | cp += slack; | |
1171 | require += sbrked_remains; | |
1172 | } | |
1173 | } | |
1174 | ||
1175 | if (last_sbrk_top) { | |
1176 | sbrk_good -= SBRK_FAILURE_PRICE; | |
1177 | } | |
1178 | ||
1179 | ovp = (union overhead *) cp; | |
1180 | /* | |
1181 | * Round up to minimum allocation size boundary | |
1182 | * and deduct from block count to reflect. | |
1183 | */ | |
1184 | ||
5bbd1ef5 IZ |
1185 | # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES |
1186 | if ((UV)ovp & (NEEDED_ALIGNMENT - 1)) | |
1187 | fatalcroak("Misalignment of sbrk()\n"); | |
1188 | else | |
1189 | # endif | |
fa423c5b | 1190 | #ifndef I286 /* Again, this should always be ok on an 80286 */ |
5bbd1ef5 | 1191 | if ((UV)ovp & (MEM_ALIGNBYTES - 1)) { |
fa423c5b IZ |
1192 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1193 | "fixing sbrk(): %d bytes off machine alignement\n", | |
5bbd1ef5 IZ |
1194 | (int)((UV)ovp & (MEM_ALIGNBYTES - 1)))); |
1195 | ovp = (union overhead *)(((UV)ovp + MEM_ALIGNBYTES) & | |
1196 | (MEM_ALIGNBYTES - 1)); | |
fa423c5b IZ |
1197 | (*nblksp)--; |
1198 | # if defined(DEBUGGING_MSTATS) | |
1199 | /* This is only approx. if TWO_POT_OPTIMIZE: */ | |
5bbd1ef5 | 1200 | sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT)); |
fa423c5b IZ |
1201 | # endif |
1202 | } | |
1203 | #endif | |
5bbd1ef5 | 1204 | ; /* Finish `else' */ |
fa423c5b | 1205 | sbrked_remains = require - needed; |
e9397286 | 1206 | last_op = cp; |
fa423c5b IZ |
1207 | } |
1208 | last_sbrk_top = cp + require; | |
fa423c5b IZ |
1209 | #ifdef DEBUGGING_MSTATS |
1210 | goodsbrk += require; | |
1211 | #endif | |
1212 | return ovp; | |
1213 | } | |
1214 | ||
cea2e8a9 GS |
1215 | static int |
1216 | getpages_adjacent(int require) | |
fa423c5b IZ |
1217 | { |
1218 | if (require <= sbrked_remains) { | |
1219 | sbrked_remains -= require; | |
1220 | } else { | |
1221 | char *cp; | |
1222 | ||
1223 | require -= sbrked_remains; | |
1224 | /* We do not try to optimize sbrks here, we go for place. */ | |
1225 | cp = (char*) sbrk(require); | |
1226 | #ifdef DEBUGGING_MSTATS | |
1227 | sbrks++; | |
1228 | goodsbrk += require; | |
1229 | #endif | |
1230 | if (cp == last_sbrk_top) { | |
1231 | sbrked_remains = 0; | |
1232 | last_sbrk_top = cp + require; | |
1233 | } else { | |
28ac10b1 IZ |
1234 | if (cp == (char*)-1) { /* Out of memory */ |
1235 | #ifdef DEBUGGING_MSTATS | |
1236 | goodsbrk -= require; | |
1237 | #endif | |
1238 | return 0; | |
1239 | } | |
fa423c5b IZ |
1240 | /* Report the failure: */ |
1241 | if (sbrked_remains) | |
1242 | add_to_chain((void*)(last_sbrk_top - sbrked_remains), | |
1243 | sbrked_remains, 0); | |
1244 | add_to_chain((void*)cp, require, 0); | |
1245 | sbrk_good -= SBRK_FAILURE_PRICE; | |
1246 | sbrked_remains = 0; | |
1247 | last_sbrk_top = 0; | |
1248 | last_op = 0; | |
1249 | return 0; | |
1250 | } | |
1251 | } | |
1252 | ||
1253 | return 1; | |
1254 | } | |
1255 | ||
8d063cd8 LW |
1256 | /* |
1257 | * Allocate more memory to the indicated bucket. | |
1258 | */ | |
cea2e8a9 GS |
1259 | static void |
1260 | morecore(register int bucket) | |
8d063cd8 | 1261 | { |
72aaf631 | 1262 | register union overhead *ovp; |
8d063cd8 | 1263 | register int rnu; /* 2^rnu bytes will be requested */ |
fa423c5b | 1264 | int nblks; /* become nblks blocks of the desired size */ |
bbce6d69 | 1265 | register MEM_SIZE siz, needed; |
8d063cd8 LW |
1266 | |
1267 | if (nextf[bucket]) | |
1268 | return; | |
e8bc2b5c | 1269 | if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) { |
741df71a | 1270 | MALLOC_UNLOCK; |
d720c441 | 1271 | croak("%s", "Out of memory during ridiculously large request"); |
55497cff | 1272 | } |
d720c441 | 1273 | if (bucket > max_bucket) |
e8bc2b5c | 1274 | max_bucket = bucket; |
d720c441 | 1275 | |
e8bc2b5c GS |
1276 | rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT)) |
1277 | ? LOG_OF_MIN_ARENA | |
1278 | : (bucket >> BUCKET_POW2_SHIFT) ); | |
1279 | /* This may be overwritten later: */ | |
1280 | nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */ | |
1281 | needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket); | |
1282 | if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */ | |
1283 | ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT; | |
1284 | nextf[rnu << BUCKET_POW2_SHIFT] | |
1285 | = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next; | |
1286 | #ifdef DEBUGGING_MSTATS | |
1287 | nmalloc[rnu << BUCKET_POW2_SHIFT]--; | |
1288 | start_slack -= M_OVERHEAD; | |
1289 | #endif | |
1290 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1291 | "stealing %ld bytes from %ld arena\n", | |
1292 | (long) needed, (long) rnu << BUCKET_POW2_SHIFT)); | |
1293 | } else if (chunk_chain | |
1294 | && (ovp = (union overhead*) get_from_chain(needed))) { | |
1295 | DEBUG_m(PerlIO_printf(Perl_debug_log, | |
1296 | "stealing %ld bytes from chain\n", | |
1297 | (long) needed)); | |
d720c441 IZ |
1298 | } else if ( (ovp = (union overhead*) |
1299 | get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1, | |
1300 | needed)) ) { | |
e8bc2b5c GS |
1301 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1302 | "stealing %ld bytes from bigger buckets\n", | |
1303 | (long) needed)); | |
1304 | } else if (needed <= sbrked_remains) { | |
1305 | ovp = (union overhead *)(last_sbrk_top - sbrked_remains); | |
1306 | sbrked_remains -= needed; | |
1307 | last_op = (char*)ovp; | |
fa423c5b IZ |
1308 | } else |
1309 | ovp = getpages(needed, &nblks, bucket); | |
e8bc2b5c | 1310 | |
fa423c5b IZ |
1311 | if (!ovp) |
1312 | return; | |
e8bc2b5c | 1313 | |
8d063cd8 LW |
1314 | /* |
1315 | * Add new memory allocated to that on | |
1316 | * free list for this hash bucket. | |
1317 | */ | |
e8bc2b5c | 1318 | siz = BUCKET_SIZE(bucket); |
cf5c4ad8 | 1319 | #ifdef PACK_MALLOC |
72aaf631 | 1320 | *(u_char*)ovp = bucket; /* Fill index. */ |
e8bc2b5c GS |
1321 | if (bucket <= MAX_PACKED) { |
1322 | ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket)); | |
1323 | nblks = N_BLKS(bucket); | |
cf5c4ad8 | 1324 | # ifdef DEBUGGING_MSTATS |
e8bc2b5c | 1325 | start_slack += BLK_SHIFT(bucket); |
cf5c4ad8 | 1326 | # endif |
e8bc2b5c GS |
1327 | } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) { |
1328 | ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket)); | |
cf5c4ad8 | 1329 | siz -= sizeof(union overhead); |
72aaf631 | 1330 | } else ovp++; /* One chunk per block. */ |
e8bc2b5c | 1331 | #endif /* PACK_MALLOC */ |
72aaf631 | 1332 | nextf[bucket] = ovp; |
5f05dabc | 1333 | #ifdef DEBUGGING_MSTATS |
1334 | nmalloc[bucket] += nblks; | |
e8bc2b5c GS |
1335 | if (bucket > MAX_PACKED) { |
1336 | start_slack += M_OVERHEAD * nblks; | |
1337 | } | |
5f05dabc | 1338 | #endif |
8d063cd8 | 1339 | while (--nblks > 0) { |
72aaf631 MB |
1340 | ovp->ov_next = (union overhead *)((caddr_t)ovp + siz); |
1341 | ovp = (union overhead *)((caddr_t)ovp + siz); | |
8d063cd8 | 1342 | } |
8595d6f1 | 1343 | /* Not all sbrks return zeroed memory.*/ |
72aaf631 | 1344 | ovp->ov_next = (union overhead *)NULL; |
cf5c4ad8 | 1345 | #ifdef PACK_MALLOC |
e8bc2b5c GS |
1346 | if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */ |
1347 | union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next; | |
1348 | nextf[7*BUCKETS_PER_POW2] = | |
1349 | (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2] | |
1350 | - sizeof(union overhead)); | |
1351 | nextf[7*BUCKETS_PER_POW2]->ov_next = n_op; | |
cf5c4ad8 | 1352 | } |
1353 | #endif /* !PACK_MALLOC */ | |
8d063cd8 LW |
1354 | } |
1355 | ||
94b6baf5 | 1356 | Free_t |
86058a2d | 1357 | Perl_mfree(void *mp) |
cea2e8a9 | 1358 | { |
ee0007ab | 1359 | register MEM_SIZE size; |
72aaf631 | 1360 | register union overhead *ovp; |
352d5a3a | 1361 | char *cp = (char*)mp; |
cf5c4ad8 | 1362 | #ifdef PACK_MALLOC |
1363 | u_char bucket; | |
1364 | #endif | |
8d063cd8 | 1365 | |
e8bc2b5c GS |
1366 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1367 | "0x%lx: (%05lu) free\n", | |
4a33f861 | 1368 | (unsigned long)cp, (unsigned long)(PL_an++))); |
45d8adaa | 1369 | |
cf5c4ad8 | 1370 | if (cp == NULL) |
1371 | return; | |
72aaf631 | 1372 | ovp = (union overhead *)((caddr_t)cp |
e8bc2b5c | 1373 | - sizeof (union overhead) * CHUNK_SHIFT); |
cf5c4ad8 | 1374 | #ifdef PACK_MALLOC |
72aaf631 | 1375 | bucket = OV_INDEX(ovp); |
cf5c4ad8 | 1376 | #endif |
e8bc2b5c GS |
1377 | #ifdef IGNORE_SMALL_BAD_FREE |
1378 | if ((bucket >= FIRST_BUCKET_WITH_CHECK) | |
1379 | && (OV_MAGIC(ovp, bucket) != MAGIC)) | |
1380 | #else | |
1381 | if (OV_MAGIC(ovp, bucket) != MAGIC) | |
1382 | #endif | |
1383 | { | |
68dc0745 | 1384 | static int bad_free_warn = -1; |
cf5c4ad8 | 1385 | if (bad_free_warn == -1) { |
5fd9e9a4 | 1386 | char *pbf = PerlEnv_getenv("PERL_BADFREE"); |
cf5c4ad8 | 1387 | bad_free_warn = (pbf) ? atoi(pbf) : 1; |
1388 | } | |
1389 | if (!bad_free_warn) | |
1390 | return; | |
8990e307 | 1391 | #ifdef RCHECK |
a687059c | 1392 | warn("%s free() ignored", |
72aaf631 | 1393 | ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad"); |
8990e307 | 1394 | #else |
d720c441 | 1395 | warn("%s", "Bad free() ignored"); |
8990e307 | 1396 | #endif |
8d063cd8 | 1397 | return; /* sanity */ |
e8bc2b5c | 1398 | } |
741df71a | 1399 | MALLOC_LOCK; |
8d063cd8 | 1400 | #ifdef RCHECK |
3541dd58 | 1401 | ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite"); |
e8bc2b5c GS |
1402 | if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) { |
1403 | int i; | |
1404 | MEM_SIZE nbytes = ovp->ov_size + 1; | |
1405 | ||
1406 | if ((i = nbytes & 3)) { | |
1407 | i = 4 - i; | |
1408 | while (i--) { | |
3541dd58 | 1409 | ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i)) |
d720c441 | 1410 | == RMAGIC_C, "chunk's tail overwrite"); |
e8bc2b5c GS |
1411 | } |
1412 | } | |
1413 | nbytes = (nbytes + 3) &~ 3; | |
3541dd58 | 1414 | ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite"); |
e8bc2b5c | 1415 | } |
72aaf631 | 1416 | ovp->ov_rmagic = RMAGIC - 1; |
8d063cd8 | 1417 | #endif |
3541dd58 | 1418 | ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite"); |
72aaf631 MB |
1419 | size = OV_INDEX(ovp); |
1420 | ovp->ov_next = nextf[size]; | |
1421 | nextf[size] = ovp; | |
741df71a | 1422 | MALLOC_UNLOCK; |
8d063cd8 LW |
1423 | } |
1424 | ||
1425 | /* | |
1426 | * When a program attempts "storage compaction" as mentioned in the | |
1427 | * old malloc man page, it realloc's an already freed block. Usually | |
1428 | * this is the last block it freed; occasionally it might be farther | |
1429 | * back. We have to search all the free lists for the block in order | |
1430 | * to determine its bucket: 1st we make one pass thru the lists | |
1431 | * checking only the first block in each; if that fails we search | |
378cc40b | 1432 | * ``reall_srchlen'' blocks in each list for a match (the variable |
8d063cd8 LW |
1433 | * is extern so the caller can modify it). If that fails we just copy |
1434 | * however many bytes was given to realloc() and hope it's not huge. | |
1435 | */ | |
22c35a8c | 1436 | #define reall_srchlen 4 /* 4 should be plenty, -1 =>'s whole list */ |
8d063cd8 | 1437 | |
2304df62 | 1438 | Malloc_t |
86058a2d | 1439 | Perl_realloc(void *mp, size_t nbytes) |
cea2e8a9 | 1440 | { |
ee0007ab | 1441 | register MEM_SIZE onb; |
72aaf631 | 1442 | union overhead *ovp; |
d720c441 IZ |
1443 | char *res; |
1444 | int prev_bucket; | |
e8bc2b5c GS |
1445 | register int bucket; |
1446 | int was_alloced = 0, incr; | |
352d5a3a | 1447 | char *cp = (char*)mp; |
8d063cd8 | 1448 | |
e8bc2b5c | 1449 | #if defined(DEBUGGING) || !defined(PERL_CORE) |
ee0007ab | 1450 | MEM_SIZE size = nbytes; |
45d8adaa | 1451 | |
45d8adaa | 1452 | if ((long)nbytes < 0) |
cea2e8a9 | 1453 | croak("%s", "panic: realloc"); |
45d8adaa | 1454 | #endif |
e8bc2b5c GS |
1455 | |
1456 | BARK_64K_LIMIT("Reallocation",nbytes,size); | |
1457 | if (!cp) | |
86058a2d | 1458 | return Perl_malloc(nbytes); |
45d8adaa | 1459 | |
741df71a | 1460 | MALLOC_LOCK; |
72aaf631 | 1461 | ovp = (union overhead *)((caddr_t)cp |
e8bc2b5c GS |
1462 | - sizeof (union overhead) * CHUNK_SHIFT); |
1463 | bucket = OV_INDEX(ovp); | |
1464 | #ifdef IGNORE_SMALL_BAD_FREE | |
1465 | if ((bucket < FIRST_BUCKET_WITH_CHECK) | |
1466 | || (OV_MAGIC(ovp, bucket) == MAGIC)) | |
1467 | #else | |
1468 | if (OV_MAGIC(ovp, bucket) == MAGIC) | |
1469 | #endif | |
1470 | { | |
55497cff | 1471 | was_alloced = 1; |
8d063cd8 LW |
1472 | } else { |
1473 | /* | |
1474 | * Already free, doing "compaction". | |
1475 | * | |
1476 | * Search for the old block of memory on the | |
1477 | * free list. First, check the most common | |
1478 | * case (last element free'd), then (this failing) | |
378cc40b | 1479 | * the last ``reall_srchlen'' items free'd. |
8d063cd8 LW |
1480 | * If all lookups fail, then assume the size of |
1481 | * the memory block being realloc'd is the | |
1482 | * smallest possible. | |
1483 | */ | |
e8bc2b5c GS |
1484 | if ((bucket = findbucket(ovp, 1)) < 0 && |
1485 | (bucket = findbucket(ovp, reall_srchlen)) < 0) | |
1486 | bucket = 0; | |
8d063cd8 | 1487 | } |
e8bc2b5c | 1488 | onb = BUCKET_SIZE_REAL(bucket); |
55497cff | 1489 | /* |
1490 | * avoid the copy if same size block. | |
e8bc2b5c GS |
1491 | * We are not agressive with boundary cases. Note that it might |
1492 | * (for a small number of cases) give false negative if | |
55497cff | 1493 | * both new size and old one are in the bucket for |
e8bc2b5c GS |
1494 | * FIRST_BIG_POW2, but the new one is near the lower end. |
1495 | * | |
1496 | * We do not try to go to 1.5 times smaller bucket so far. | |
55497cff | 1497 | */ |
e8bc2b5c GS |
1498 | if (nbytes > onb) incr = 1; |
1499 | else { | |
1500 | #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING | |
1501 | if ( /* This is a little bit pessimal if PACK_MALLOC: */ | |
1502 | nbytes > ( (onb >> 1) - M_OVERHEAD ) | |
1503 | # ifdef TWO_POT_OPTIMIZE | |
1504 | || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND ) | |
1505 | # endif | |
1506 | ) | |
1507 | #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */ | |
1508 | prev_bucket = ( (bucket > MAX_PACKED + 1) | |
1509 | ? bucket - BUCKETS_PER_POW2 | |
1510 | : bucket - 1); | |
1511 | if (nbytes > BUCKET_SIZE_REAL(prev_bucket)) | |
1512 | #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */ | |
1513 | incr = 0; | |
1514 | else incr = -1; | |
1515 | } | |
1516 | if (!was_alloced | |
2ce36478 | 1517 | #ifdef STRESS_REALLOC |
e8bc2b5c | 1518 | || 1 /* always do it the hard way */ |
2ce36478 | 1519 | #endif |
e8bc2b5c GS |
1520 | ) goto hard_way; |
1521 | else if (incr == 0) { | |
852c2e52 | 1522 | inplace_label: |
a687059c LW |
1523 | #ifdef RCHECK |
1524 | /* | |
1525 | * Record new allocated size of block and | |
1526 | * bound space with magic numbers. | |
1527 | */ | |
72aaf631 | 1528 | if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) { |
e8bc2b5c GS |
1529 | int i, nb = ovp->ov_size + 1; |
1530 | ||
1531 | if ((i = nb & 3)) { | |
1532 | i = 4 - i; | |
1533 | while (i--) { | |
3541dd58 | 1534 | ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite"); |
e8bc2b5c GS |
1535 | } |
1536 | } | |
1537 | nb = (nb + 3) &~ 3; | |
3541dd58 | 1538 | ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite"); |
a687059c LW |
1539 | /* |
1540 | * Convert amount of memory requested into | |
1541 | * closest block size stored in hash buckets | |
1542 | * which satisfies request. Account for | |
1543 | * space used per block for accounting. | |
1544 | */ | |
cf5c4ad8 | 1545 | nbytes += M_OVERHEAD; |
72aaf631 | 1546 | ovp->ov_size = nbytes - 1; |
e8bc2b5c GS |
1547 | if ((i = nbytes & 3)) { |
1548 | i = 4 - i; | |
1549 | while (i--) | |
1550 | *((char *)((caddr_t)ovp + nbytes - RSLOP + i)) | |
1551 | = RMAGIC_C; | |
1552 | } | |
1553 | nbytes = (nbytes + 3) &~ 3; | |
72aaf631 | 1554 | *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC; |
a687059c LW |
1555 | } |
1556 | #endif | |
45d8adaa | 1557 | res = cp; |
741df71a | 1558 | MALLOC_UNLOCK; |
42ac124e IZ |
1559 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1560 | "0x%lx: (%05lu) realloc %ld bytes inplace\n", | |
1561 | (unsigned long)res,(unsigned long)(PL_an++), | |
1562 | (long)size)); | |
e8bc2b5c GS |
1563 | } else if (incr == 1 && (cp - M_OVERHEAD == last_op) |
1564 | && (onb > (1 << LOG_OF_MIN_ARENA))) { | |
1565 | MEM_SIZE require, newarena = nbytes, pow; | |
1566 | int shiftr; | |
1567 | ||
1568 | POW2_OPTIMIZE_ADJUST(newarena); | |
1569 | newarena = newarena + M_OVERHEAD; | |
1570 | /* newarena = (newarena + 3) &~ 3; */ | |
1571 | shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA; | |
1572 | pow = LOG_OF_MIN_ARENA + 1; | |
1573 | /* apart from this loop, this is O(1) */ | |
1574 | while (shiftr >>= 1) | |
1575 | pow++; | |
1576 | newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2); | |
1577 | require = newarena - onb - M_OVERHEAD; | |
1578 | ||
fa423c5b | 1579 | if (getpages_adjacent(require)) { |
e8bc2b5c | 1580 | #ifdef DEBUGGING_MSTATS |
fa423c5b IZ |
1581 | nmalloc[bucket]--; |
1582 | nmalloc[pow * BUCKETS_PER_POW2]++; | |
e8bc2b5c | 1583 | #endif |
fa423c5b IZ |
1584 | *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */ |
1585 | goto inplace_label; | |
1586 | } else | |
1587 | goto hard_way; | |
e8bc2b5c GS |
1588 | } else { |
1589 | hard_way: | |
741df71a | 1590 | MALLOC_UNLOCK; |
42ac124e IZ |
1591 | DEBUG_m(PerlIO_printf(Perl_debug_log, |
1592 | "0x%lx: (%05lu) realloc %ld bytes the hard way\n", | |
1593 | (unsigned long)cp,(unsigned long)(PL_an++), | |
1594 | (long)size)); | |
86058a2d | 1595 | if ((res = (char*)Perl_malloc(nbytes)) == NULL) |
e8bc2b5c GS |
1596 | return (NULL); |
1597 | if (cp != res) /* common optimization */ | |
1598 | Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char); | |
1599 | if (was_alloced) | |
86058a2d | 1600 | Perl_mfree(cp); |
45d8adaa | 1601 | } |
2304df62 | 1602 | return ((Malloc_t)res); |
8d063cd8 LW |
1603 | } |
1604 | ||
1605 | /* | |
1606 | * Search ``srchlen'' elements of each free list for a block whose | |
1607 | * header starts at ``freep''. If srchlen is -1 search the whole list. | |
1608 | * Return bucket number, or -1 if not found. | |
1609 | */ | |
ee0007ab | 1610 | static int |
8ac85365 | 1611 | findbucket(union overhead *freep, int srchlen) |
8d063cd8 LW |
1612 | { |
1613 | register union overhead *p; | |
1614 | register int i, j; | |
1615 | ||
1616 | for (i = 0; i < NBUCKETS; i++) { | |
1617 | j = 0; | |
1618 | for (p = nextf[i]; p && j != srchlen; p = p->ov_next) { | |
1619 | if (p == freep) | |
1620 | return (i); | |
1621 | j++; | |
1622 | } | |
1623 | } | |
1624 | return (-1); | |
1625 | } | |
1626 | ||
cf5c4ad8 | 1627 | Malloc_t |
86058a2d | 1628 | Perl_calloc(register size_t elements, register size_t size) |
cf5c4ad8 | 1629 | { |
1630 | long sz = elements * size; | |
86058a2d | 1631 | Malloc_t p = Perl_malloc(sz); |
cf5c4ad8 | 1632 | |
1633 | if (p) { | |
1634 | memset((void*)p, 0, sz); | |
1635 | } | |
1636 | return p; | |
1637 | } | |
1638 | ||
e8bc2b5c | 1639 | MEM_SIZE |
cea2e8a9 | 1640 | Perl_malloced_size(void *p) |
e8bc2b5c | 1641 | { |
8d6dde3e IZ |
1642 | union overhead *ovp = (union overhead *) |
1643 | ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT); | |
1644 | int bucket = OV_INDEX(ovp); | |
1645 | #ifdef RCHECK | |
1646 | /* The caller wants to have a complete control over the chunk, | |
1647 | disable the memory checking inside the chunk. */ | |
1648 | if (bucket <= MAX_SHORT_BUCKET) { | |
1649 | MEM_SIZE size = BUCKET_SIZE_REAL(bucket); | |
1650 | ovp->ov_size = size + M_OVERHEAD - 1; | |
1651 | *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC; | |
1652 | } | |
1653 | #endif | |
e8bc2b5c GS |
1654 | return BUCKET_SIZE_REAL(bucket); |
1655 | } | |
1656 | ||
e8bc2b5c GS |
1657 | # ifdef BUCKETS_ROOT2 |
1658 | # define MIN_EVEN_REPORT 6 | |
1659 | # else | |
1660 | # define MIN_EVEN_REPORT MIN_BUCKET | |
1661 | # endif | |
8d063cd8 LW |
1662 | /* |
1663 | * mstats - print out statistics about malloc | |
1664 | * | |
1665 | * Prints two lines of numbers, one showing the length of the free list | |
1666 | * for each size category, the second showing the number of mallocs - | |
1667 | * frees for each size category. | |
1668 | */ | |
ee0007ab | 1669 | void |
864dbfa3 | 1670 | Perl_dump_mstats(pTHX_ char *s) |
8d063cd8 | 1671 | { |
df31f264 | 1672 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
1673 | register int i, j; |
1674 | register union overhead *p; | |
e8bc2b5c | 1675 | int topbucket=0, topbucket_ev=0, topbucket_odd=0, totfree=0, total=0; |
c07a80fd | 1676 | u_int nfree[NBUCKETS]; |
e8bc2b5c GS |
1677 | int total_chain = 0; |
1678 | struct chunk_chain_s* nextchain = chunk_chain; | |
8d063cd8 | 1679 | |
e8bc2b5c | 1680 | for (i = MIN_BUCKET ; i < NBUCKETS; i++) { |
8d063cd8 LW |
1681 | for (j = 0, p = nextf[i]; p; p = p->ov_next, j++) |
1682 | ; | |
c07a80fd | 1683 | nfree[i] = j; |
e8bc2b5c GS |
1684 | totfree += nfree[i] * BUCKET_SIZE_REAL(i); |
1685 | total += nmalloc[i] * BUCKET_SIZE_REAL(i); | |
1686 | if (nmalloc[i]) { | |
1687 | i % 2 ? (topbucket_odd = i) : (topbucket_ev = i); | |
1688 | topbucket = i; | |
1689 | } | |
c07a80fd | 1690 | } |
1691 | if (s) | |
e8bc2b5c | 1692 | PerlIO_printf(PerlIO_stderr(), |
d720c441 | 1693 | "Memory allocation statistics %s (buckets %ld(%ld)..%ld(%ld)\n", |
e8bc2b5c | 1694 | s, |
d720c441 IZ |
1695 | (long)BUCKET_SIZE_REAL(MIN_BUCKET), |
1696 | (long)BUCKET_SIZE(MIN_BUCKET), | |
1697 | (long)BUCKET_SIZE_REAL(topbucket), (long)BUCKET_SIZE(topbucket)); | |
5f05dabc | 1698 | PerlIO_printf(PerlIO_stderr(), "%8d free:", totfree); |
e8bc2b5c GS |
1699 | for (i = MIN_EVEN_REPORT; i <= topbucket; i += BUCKETS_PER_POW2) { |
1700 | PerlIO_printf(PerlIO_stderr(), | |
1701 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1702 | ? " %5d" | |
1703 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1704 | nfree[i]); | |
1705 | } | |
1706 | #ifdef BUCKETS_ROOT2 | |
1707 | PerlIO_printf(PerlIO_stderr(), "\n\t "); | |
1708 | for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) { | |
1709 | PerlIO_printf(PerlIO_stderr(), | |
1710 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1711 | ? " %5d" | |
1712 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1713 | nfree[i]); | |
8d063cd8 | 1714 | } |
e8bc2b5c | 1715 | #endif |
5f05dabc | 1716 | PerlIO_printf(PerlIO_stderr(), "\n%8d used:", total - totfree); |
e8bc2b5c GS |
1717 | for (i = MIN_EVEN_REPORT; i <= topbucket; i += BUCKETS_PER_POW2) { |
1718 | PerlIO_printf(PerlIO_stderr(), | |
1719 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1720 | ? " %5d" | |
1721 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1722 | nmalloc[i] - nfree[i]); | |
c07a80fd | 1723 | } |
e8bc2b5c GS |
1724 | #ifdef BUCKETS_ROOT2 |
1725 | PerlIO_printf(PerlIO_stderr(), "\n\t "); | |
1726 | for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) { | |
1727 | PerlIO_printf(PerlIO_stderr(), | |
1728 | ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2) | |
1729 | ? " %5d" | |
1730 | : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")), | |
1731 | nmalloc[i] - nfree[i]); | |
1732 | } | |
1733 | #endif | |
1734 | while (nextchain) { | |
1735 | total_chain += nextchain->size; | |
1736 | nextchain = nextchain->next; | |
1737 | } | |
1738 | PerlIO_printf(PerlIO_stderr(), "\nTotal sbrk(): %d/%d:%d. Odd ends: pad+heads+chain+tail: %d+%d+%d+%d.\n", | |
1739 | goodsbrk + sbrk_slack, sbrks, sbrk_good, sbrk_slack, | |
1740 | start_slack, total_chain, sbrked_remains); | |
df31f264 | 1741 | #endif /* DEBUGGING_MSTATS */ |
c07a80fd | 1742 | } |
a687059c | 1743 | #endif /* lint */ |
cf5c4ad8 | 1744 | |
cf5c4ad8 | 1745 | #ifdef USE_PERL_SBRK |
1746 | ||
8f1f23e8 | 1747 | # if defined(__MACHTEN_PPC__) || defined(NeXT) || defined(__NeXT__) |
38ac2dc8 DD |
1748 | # define PERL_SBRK_VIA_MALLOC |
1749 | /* | |
1750 | * MachTen's malloc() returns a buffer aligned on a two-byte boundary. | |
1751 | * While this is adequate, it may slow down access to longer data | |
1752 | * types by forcing multiple memory accesses. It also causes | |
1753 | * complaints when RCHECK is in force. So we allocate six bytes | |
1754 | * more than we need to, and return an address rounded up to an | |
1755 | * eight-byte boundary. | |
1756 | * | |
1757 | * 980701 Dominic Dunlop <domo@computer.org> | |
1758 | */ | |
5bbd1ef5 | 1759 | # define SYSTEM_ALLOC_ALIGNMENT 2 |
38ac2dc8 DD |
1760 | # endif |
1761 | ||
760ac839 | 1762 | # ifdef PERL_SBRK_VIA_MALLOC |
cf5c4ad8 | 1763 | |
1764 | /* it may seem schizophrenic to use perl's malloc and let it call system */ | |
1765 | /* malloc, the reason for that is only the 3.2 version of the OS that had */ | |
1766 | /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */ | |
1767 | /* end to the cores */ | |
1768 | ||
38ac2dc8 DD |
1769 | # ifndef SYSTEM_ALLOC |
1770 | # define SYSTEM_ALLOC(a) malloc(a) | |
1771 | # endif | |
5bbd1ef5 IZ |
1772 | # ifndef SYSTEM_ALLOC_ALIGNMENT |
1773 | # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES | |
1774 | # endif | |
cf5c4ad8 | 1775 | |
760ac839 | 1776 | # endif /* PERL_SBRK_VIA_MALLOC */ |
cf5c4ad8 | 1777 | |
1778 | static IV Perl_sbrk_oldchunk; | |
1779 | static long Perl_sbrk_oldsize; | |
1780 | ||
760ac839 LW |
1781 | # define PERLSBRK_32_K (1<<15) |
1782 | # define PERLSBRK_64_K (1<<16) | |
cf5c4ad8 | 1783 | |
b63effbb | 1784 | Malloc_t |
df0003d4 | 1785 | Perl_sbrk(int size) |
cf5c4ad8 | 1786 | { |
1787 | IV got; | |
1788 | int small, reqsize; | |
1789 | ||
1790 | if (!size) return 0; | |
55497cff | 1791 | #ifdef PERL_CORE |
cf5c4ad8 | 1792 | reqsize = size; /* just for the DEBUG_m statement */ |
1793 | #endif | |
57569e04 HM |
1794 | #ifdef PACK_MALLOC |
1795 | size = (size + 0x7ff) & ~0x7ff; | |
1796 | #endif | |
cf5c4ad8 | 1797 | if (size <= Perl_sbrk_oldsize) { |
1798 | got = Perl_sbrk_oldchunk; | |
1799 | Perl_sbrk_oldchunk += size; | |
1800 | Perl_sbrk_oldsize -= size; | |
1801 | } else { | |
1802 | if (size >= PERLSBRK_32_K) { | |
1803 | small = 0; | |
1804 | } else { | |
cf5c4ad8 | 1805 | size = PERLSBRK_64_K; |
1806 | small = 1; | |
1807 | } | |
5bbd1ef5 IZ |
1808 | # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT |
1809 | size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT; | |
1810 | # endif | |
cf5c4ad8 | 1811 | got = (IV)SYSTEM_ALLOC(size); |
5bbd1ef5 | 1812 | # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT |
5a7d6335 | 1813 | got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1); |
5bbd1ef5 | 1814 | # endif |
cf5c4ad8 | 1815 | if (small) { |
1816 | /* Chunk is small, register the rest for future allocs. */ | |
1817 | Perl_sbrk_oldchunk = got + reqsize; | |
1818 | Perl_sbrk_oldsize = size - reqsize; | |
1819 | } | |
1820 | } | |
1821 | ||
fb73857a | 1822 | DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n", |
cf5c4ad8 | 1823 | size, reqsize, Perl_sbrk_oldsize, got)); |
cf5c4ad8 | 1824 | |
1825 | return (void *)got; | |
1826 | } | |
1827 | ||
1828 | #endif /* ! defined USE_PERL_SBRK */ |