Line data Source code
1 : /*
2 : * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
3 : * opyright (c) 1999-2000 by Hewlett-Packard Company. All rights reserved.
4 : *
5 : * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
6 : * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
7 : *
8 : * Permission is hereby granted to use or copy this program
9 : * for any purpose, provided the above notices are retained on all copies.
10 : * Permission to modify the code and to distribute modified code is granted,
11 : * provided the above notices are retained, and a notice that the code was
12 : * modified is included with the above copyright notice.
13 : *
14 : */
15 :
16 : #include "private/gc_pmark.h"
17 :
18 : /*
19 : * Some simple primitives for allocation with explicit type information.
20 : * Simple objects are allocated such that they contain a GC_descr at the
21 : * end (in the last allocated word). This descriptor may be a procedure
22 : * which then examines an extended descriptor passed as its environment.
23 : *
24 : * Arrays are treated as simple objects if they have sufficiently simple
25 : * structure. Otherwise they are allocated from an array kind that supplies
26 : * a special mark procedure. These arrays contain a pointer to a
27 : * complex_descriptor as their last word.
28 : * This is done because the environment field is too small, and the collector
29 : * must trace the complex_descriptor.
30 : *
31 : * Note that descriptors inside objects may appear cleared, if we encounter a
32 : * false reference to an object on a free list. In the GC_descr case, this
33 : * is OK, since a 0 descriptor corresponds to examining no fields.
34 : * In the complex_descriptor case, we explicitly check for that case.
35 : *
36 : * MAJOR PARTS OF THIS CODE HAVE NOT BEEN TESTED AT ALL and are not testable,
37 : * since they are not accessible through the current interface.
38 : */
39 :
40 : #include "gc_typed.h"
41 :
42 : #define TYPD_EXTRA_BYTES (sizeof(word) - EXTRA_BYTES)
43 :
44 : STATIC GC_bool GC_explicit_typing_initialized = FALSE;
45 :
46 : STATIC int GC_explicit_kind = 0;
47 : /* Object kind for objects with indirect */
48 : /* (possibly extended) descriptors. */
49 :
50 : STATIC int GC_array_kind = 0;
51 : /* Object kind for objects with complex */
52 : /* descriptors and GC_array_mark_proc. */
53 :
54 : /* Extended descriptors. GC_typed_mark_proc understands these. */
55 : /* These are used for simple objects that are larger than what */
56 : /* can be described by a BITMAP_BITS sized bitmap. */
57 : typedef struct {
58 : word ed_bitmap; /* lsb corresponds to first word. */
59 : GC_bool ed_continued; /* next entry is continuation. */
60 : } ext_descr;
61 :
62 : /* Array descriptors. GC_array_mark_proc understands these. */
63 : /* We may eventually need to add provisions for headers and */
64 : /* trailers. Hence we provide for tree structured descriptors, */
65 : /* though we don't really use them currently. */
66 : typedef union ComplexDescriptor {
67 : struct LeafDescriptor { /* Describes simple array */
68 : word ld_tag;
69 : # define LEAF_TAG 1
70 : size_t ld_size; /* bytes per element */
71 : /* multiple of ALIGNMENT */
72 : size_t ld_nelements; /* Number of elements. */
73 : GC_descr ld_descriptor; /* A simple length, bitmap, */
74 : /* or procedure descriptor. */
75 : } ld;
76 : struct ComplexArrayDescriptor {
77 : word ad_tag;
78 : # define ARRAY_TAG 2
79 : size_t ad_nelements;
80 : union ComplexDescriptor * ad_element_descr;
81 : } ad;
82 : struct SequenceDescriptor {
83 : word sd_tag;
84 : # define SEQUENCE_TAG 3
85 : union ComplexDescriptor * sd_first;
86 : union ComplexDescriptor * sd_second;
87 : } sd;
88 : } complex_descriptor;
89 : #define TAG ld.ld_tag
90 :
91 : STATIC ext_descr * GC_ext_descriptors = NULL;
92 : /* Points to array of extended */
93 : /* descriptors. */
94 :
95 : STATIC size_t GC_ed_size = 0; /* Current size of above arrays. */
96 : #define ED_INITIAL_SIZE 100
97 :
98 : STATIC size_t GC_avail_descr = 0; /* Next available slot. */
99 :
100 : STATIC int GC_typed_mark_proc_index = 0; /* Indices of my mark */
101 : STATIC int GC_array_mark_proc_index = 0; /* procedures. */
102 :
103 0 : STATIC void GC_push_typed_structures_proc(void)
104 : {
105 0 : GC_push_all((ptr_t)&GC_ext_descriptors,
106 : (ptr_t)&GC_ext_descriptors + sizeof(word));
107 0 : }
108 :
109 : /* Add a multiword bitmap to GC_ext_descriptors arrays. Return */
110 : /* starting index. */
111 : /* Returns -1 on failure. */
112 : /* Caller does not hold allocation lock. */
113 0 : STATIC signed_word GC_add_ext_descriptor(GC_bitmap bm, word nbits)
114 : {
115 0 : size_t nwords = divWORDSZ(nbits + WORDSZ-1);
116 : signed_word result;
117 : size_t i;
118 : word last_part;
119 : size_t extra_bits;
120 : DCL_LOCK_STATE;
121 :
122 0 : LOCK();
123 0 : while (GC_avail_descr + nwords >= GC_ed_size) {
124 : ext_descr * new;
125 : size_t new_size;
126 0 : word ed_size = GC_ed_size;
127 :
128 0 : if (ed_size == 0) {
129 0 : GC_push_typed_structures = GC_push_typed_structures_proc;
130 0 : UNLOCK();
131 0 : new_size = ED_INITIAL_SIZE;
132 : } else {
133 0 : UNLOCK();
134 0 : new_size = 2 * ed_size;
135 0 : if (new_size > MAX_ENV) return(-1);
136 : }
137 0 : new = (ext_descr *) GC_malloc_atomic(new_size * sizeof(ext_descr));
138 0 : if (new == 0) return(-1);
139 0 : LOCK();
140 0 : if (ed_size == GC_ed_size) {
141 0 : if (GC_avail_descr != 0) {
142 0 : BCOPY(GC_ext_descriptors, new,
143 : GC_avail_descr * sizeof(ext_descr));
144 : }
145 0 : GC_ed_size = new_size;
146 0 : GC_ext_descriptors = new;
147 : } /* else another thread already resized it in the meantime */
148 : }
149 0 : result = GC_avail_descr;
150 0 : for (i = 0; i < nwords-1; i++) {
151 0 : GC_ext_descriptors[result + i].ed_bitmap = bm[i];
152 0 : GC_ext_descriptors[result + i].ed_continued = TRUE;
153 : }
154 0 : last_part = bm[i];
155 : /* Clear irrelevant bits. */
156 0 : extra_bits = nwords * WORDSZ - nbits;
157 0 : last_part <<= extra_bits;
158 0 : last_part >>= extra_bits;
159 0 : GC_ext_descriptors[result + i].ed_bitmap = last_part;
160 0 : GC_ext_descriptors[result + i].ed_continued = FALSE;
161 0 : GC_avail_descr += nwords;
162 0 : UNLOCK();
163 0 : return(result);
164 : }
165 :
166 : /* Table of bitmap descriptors for n word long all pointer objects. */
167 : STATIC GC_descr GC_bm_table[WORDSZ/2];
168 :
169 : /* Return a descriptor for the concatenation of 2 nwords long objects, */
170 : /* each of which is described by descriptor. */
171 : /* The result is known to be short enough to fit into a bitmap */
172 : /* descriptor. */
173 : /* Descriptor is a GC_DS_LENGTH or GC_DS_BITMAP descriptor. */
174 0 : STATIC GC_descr GC_double_descr(GC_descr descriptor, word nwords)
175 : {
176 0 : if ((descriptor & GC_DS_TAGS) == GC_DS_LENGTH) {
177 0 : descriptor = GC_bm_table[BYTES_TO_WORDS((word)descriptor)];
178 : };
179 0 : descriptor |= (descriptor & ~GC_DS_TAGS) >> nwords;
180 0 : return(descriptor);
181 : }
182 :
183 : STATIC complex_descriptor *
184 : GC_make_sequence_descriptor(complex_descriptor *first,
185 : complex_descriptor *second);
186 :
187 : /* Build a descriptor for an array with nelements elements, */
188 : /* each of which can be described by a simple descriptor. */
189 : /* We try to optimize some common cases. */
190 : /* If the result is COMPLEX, then a complex_descr* is returned */
191 : /* in *complex_d. */
192 : /* If the result is LEAF, then we built a LeafDescriptor in */
193 : /* the structure pointed to by leaf. */
194 : /* The tag in the leaf structure is not set. */
195 : /* If the result is SIMPLE, then a GC_descr */
196 : /* is returned in *simple_d. */
197 : /* If the result is NO_MEM, then */
198 : /* we failed to allocate the descriptor. */
199 : /* The implementation knows that GC_DS_LENGTH is 0. */
200 : /* *leaf, *complex_d, and *simple_d may be used as temporaries */
201 : /* during the construction. */
202 : #define COMPLEX 2
203 : #define LEAF 1
204 : #define SIMPLE 0
205 : #define NO_MEM (-1)
206 0 : STATIC int GC_make_array_descriptor(size_t nelements, size_t size,
207 : GC_descr descriptor, GC_descr *simple_d,
208 : complex_descriptor **complex_d,
209 : struct LeafDescriptor * leaf)
210 : {
211 : # define OPT_THRESHOLD 50
212 : /* For larger arrays, we try to combine descriptors of adjacent */
213 : /* descriptors to speed up marking, and to reduce the amount */
214 : /* of space needed on the mark stack. */
215 0 : if ((descriptor & GC_DS_TAGS) == GC_DS_LENGTH) {
216 0 : if (descriptor == (GC_descr)size) {
217 0 : *simple_d = nelements * descriptor;
218 0 : return(SIMPLE);
219 0 : } else if ((word)descriptor == 0) {
220 0 : *simple_d = (GC_descr)0;
221 0 : return(SIMPLE);
222 : }
223 : }
224 0 : if (nelements <= OPT_THRESHOLD) {
225 0 : if (nelements <= 1) {
226 0 : if (nelements == 1) {
227 0 : *simple_d = descriptor;
228 0 : return(SIMPLE);
229 : } else {
230 0 : *simple_d = (GC_descr)0;
231 0 : return(SIMPLE);
232 : }
233 : }
234 0 : } else if (size <= BITMAP_BITS/2
235 0 : && (descriptor & GC_DS_TAGS) != GC_DS_PROC
236 0 : && (size & (sizeof(word)-1)) == 0) {
237 : int result =
238 0 : GC_make_array_descriptor(nelements/2, 2*size,
239 : GC_double_descr(descriptor,
240 : BYTES_TO_WORDS(size)),
241 0 : simple_d, complex_d, leaf);
242 0 : if ((nelements & 1) == 0) {
243 0 : return(result);
244 : } else {
245 : struct LeafDescriptor * one_element =
246 0 : (struct LeafDescriptor *)
247 0 : GC_malloc_atomic(sizeof(struct LeafDescriptor));
248 :
249 0 : if (result == NO_MEM || one_element == 0) return(NO_MEM);
250 0 : one_element -> ld_tag = LEAF_TAG;
251 0 : one_element -> ld_size = size;
252 0 : one_element -> ld_nelements = 1;
253 0 : one_element -> ld_descriptor = descriptor;
254 0 : switch(result) {
255 : case SIMPLE:
256 : {
257 : struct LeafDescriptor * beginning =
258 0 : (struct LeafDescriptor *)
259 0 : GC_malloc_atomic(sizeof(struct LeafDescriptor));
260 0 : if (beginning == 0) return(NO_MEM);
261 0 : beginning -> ld_tag = LEAF_TAG;
262 0 : beginning -> ld_size = size;
263 0 : beginning -> ld_nelements = 1;
264 0 : beginning -> ld_descriptor = *simple_d;
265 0 : *complex_d = GC_make_sequence_descriptor(
266 : (complex_descriptor *)beginning,
267 : (complex_descriptor *)one_element);
268 0 : break;
269 : }
270 : case LEAF:
271 : {
272 : struct LeafDescriptor * beginning =
273 0 : (struct LeafDescriptor *)
274 0 : GC_malloc_atomic(sizeof(struct LeafDescriptor));
275 0 : if (beginning == 0) return(NO_MEM);
276 0 : beginning -> ld_tag = LEAF_TAG;
277 0 : beginning -> ld_size = leaf -> ld_size;
278 0 : beginning -> ld_nelements = leaf -> ld_nelements;
279 0 : beginning -> ld_descriptor = leaf -> ld_descriptor;
280 0 : *complex_d = GC_make_sequence_descriptor(
281 : (complex_descriptor *)beginning,
282 : (complex_descriptor *)one_element);
283 0 : break;
284 : }
285 : case COMPLEX:
286 0 : *complex_d = GC_make_sequence_descriptor(
287 : *complex_d,
288 : (complex_descriptor *)one_element);
289 : break;
290 : }
291 0 : return(COMPLEX);
292 : }
293 : }
294 :
295 0 : leaf -> ld_size = size;
296 0 : leaf -> ld_nelements = nelements;
297 0 : leaf -> ld_descriptor = descriptor;
298 0 : return(LEAF);
299 : }
300 :
301 : STATIC complex_descriptor *
302 0 : GC_make_sequence_descriptor(complex_descriptor *first,
303 : complex_descriptor *second)
304 : {
305 : struct SequenceDescriptor * result =
306 0 : (struct SequenceDescriptor *)
307 0 : GC_malloc(sizeof(struct SequenceDescriptor));
308 : /* Can't result in overly conservative marking, since tags are */
309 : /* very small integers. Probably faster than maintaining type */
310 : /* info. */
311 0 : if (result != 0) {
312 0 : result -> sd_tag = SEQUENCE_TAG;
313 0 : result -> sd_first = first;
314 0 : result -> sd_second = second;
315 : }
316 0 : return((complex_descriptor *)result);
317 : }
318 :
319 : #ifdef UNDEFINED
320 : complex_descriptor * GC_make_complex_array_descriptor(word nelements,
321 : complex_descriptor *descr)
322 : {
323 : struct ComplexArrayDescriptor * result =
324 : (struct ComplexArrayDescriptor *)
325 : GC_malloc(sizeof(struct ComplexArrayDescriptor));
326 :
327 : if (result != 0) {
328 : result -> ad_tag = ARRAY_TAG;
329 : result -> ad_nelements = nelements;
330 : result -> ad_element_descr = descr;
331 : }
332 : return((complex_descriptor *)result);
333 : }
334 : #endif
335 :
336 : STATIC ptr_t * GC_eobjfreelist = NULL;
337 :
338 : STATIC ptr_t * GC_arobjfreelist = NULL;
339 :
340 : STATIC mse * GC_typed_mark_proc(word * addr, mse * mark_stack_ptr,
341 : mse * mark_stack_limit, word env);
342 :
343 : STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
344 : mse * mark_stack_limit, word env);
345 :
346 : /* Caller does not hold allocation lock. */
347 0 : STATIC void GC_init_explicit_typing(void)
348 : {
349 : register unsigned i;
350 : DCL_LOCK_STATE;
351 :
352 : GC_STATIC_ASSERT(sizeof(struct LeafDescriptor) % sizeof(word) == 0);
353 0 : LOCK();
354 0 : if (GC_explicit_typing_initialized) {
355 0 : UNLOCK();
356 0 : return;
357 : }
358 0 : GC_explicit_typing_initialized = TRUE;
359 : /* Set up object kind with simple indirect descriptor. */
360 0 : GC_eobjfreelist = (ptr_t *)GC_new_free_list_inner();
361 0 : GC_explicit_kind = GC_new_kind_inner(
362 : (void **)GC_eobjfreelist,
363 : (((word)WORDS_TO_BYTES(-1)) | GC_DS_PER_OBJECT),
364 : TRUE, TRUE);
365 : /* Descriptors are in the last word of the object. */
366 0 : GC_typed_mark_proc_index = GC_new_proc_inner(GC_typed_mark_proc);
367 : /* Set up object kind with array descriptor. */
368 0 : GC_arobjfreelist = (ptr_t *)GC_new_free_list_inner();
369 0 : GC_array_mark_proc_index = GC_new_proc_inner(GC_array_mark_proc);
370 0 : GC_array_kind = GC_new_kind_inner(
371 : (void **)GC_arobjfreelist,
372 0 : GC_MAKE_PROC(GC_array_mark_proc_index, 0),
373 : FALSE, TRUE);
374 0 : for (i = 0; i < WORDSZ/2; i++) {
375 0 : GC_descr d = (((word)(-1)) >> (WORDSZ - i)) << (WORDSZ - i);
376 0 : d |= GC_DS_BITMAP;
377 0 : GC_bm_table[i] = d;
378 : }
379 0 : UNLOCK();
380 : }
381 :
382 0 : STATIC mse * GC_typed_mark_proc(word * addr, mse * mark_stack_ptr,
383 : mse * mark_stack_limit, word env)
384 : {
385 0 : word bm = GC_ext_descriptors[env].ed_bitmap;
386 0 : word * current_p = addr;
387 : word current;
388 0 : ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
389 0 : ptr_t least_ha = GC_least_plausible_heap_addr;
390 : DECLARE_HDR_CACHE;
391 :
392 0 : INIT_HDR_CACHE;
393 0 : for (; bm != 0; bm >>= 1, current_p++) {
394 0 : if (bm & 1) {
395 0 : current = *current_p;
396 : FIXUP_POINTER(current);
397 0 : if ((ptr_t)current >= least_ha && (ptr_t)current <= greatest_ha) {
398 0 : PUSH_CONTENTS((ptr_t)current, mark_stack_ptr,
399 : mark_stack_limit, (ptr_t)current_p, exit1);
400 : }
401 : }
402 : }
403 0 : if (GC_ext_descriptors[env].ed_continued) {
404 : /* Push an entry with the rest of the descriptor back onto the */
405 : /* stack. Thus we never do too much work at once. Note that */
406 : /* we also can't overflow the mark stack unless we actually */
407 : /* mark something. */
408 0 : mark_stack_ptr++;
409 0 : if (mark_stack_ptr >= mark_stack_limit) {
410 0 : mark_stack_ptr = GC_signal_mark_stack_overflow(mark_stack_ptr);
411 : }
412 0 : mark_stack_ptr -> mse_start = (ptr_t)(addr + WORDSZ);
413 0 : mark_stack_ptr -> mse_descr =
414 0 : GC_MAKE_PROC(GC_typed_mark_proc_index, env+1);
415 : }
416 0 : return(mark_stack_ptr);
417 : }
418 :
419 : /* Return the size of the object described by d. It would be faster to */
420 : /* store this directly, or to compute it as part of */
421 : /* GC_push_complex_descriptor, but hopefully it doesn't matter. */
422 0 : STATIC word GC_descr_obj_size(complex_descriptor *d)
423 : {
424 0 : switch(d -> TAG) {
425 : case LEAF_TAG:
426 0 : return(d -> ld.ld_nelements * d -> ld.ld_size);
427 : case ARRAY_TAG:
428 0 : return(d -> ad.ad_nelements
429 0 : * GC_descr_obj_size(d -> ad.ad_element_descr));
430 : case SEQUENCE_TAG:
431 0 : return(GC_descr_obj_size(d -> sd.sd_first)
432 0 : + GC_descr_obj_size(d -> sd.sd_second));
433 : default:
434 0 : ABORT("Bad complex descriptor");
435 0 : /*NOTREACHED*/ return 0; /*NOTREACHED*/
436 : }
437 : }
438 :
439 : /* Push descriptors for the object at addr with complex descriptor d */
440 : /* onto the mark stack. Return 0 if the mark stack overflowed. */
441 0 : STATIC mse * GC_push_complex_descriptor(word *addr, complex_descriptor *d,
442 : mse *msp, mse *msl)
443 : {
444 0 : register ptr_t current = (ptr_t) addr;
445 : register word nelements;
446 : register word sz;
447 : register word i;
448 :
449 0 : switch(d -> TAG) {
450 : case LEAF_TAG:
451 : {
452 0 : register GC_descr descr = d -> ld.ld_descriptor;
453 :
454 0 : nelements = d -> ld.ld_nelements;
455 0 : if (msl - msp <= (ptrdiff_t)nelements) return(0);
456 0 : sz = d -> ld.ld_size;
457 0 : for (i = 0; i < nelements; i++) {
458 0 : msp++;
459 0 : msp -> mse_start = current;
460 0 : msp -> mse_descr = descr;
461 0 : current += sz;
462 : }
463 0 : return(msp);
464 : }
465 : case ARRAY_TAG:
466 : {
467 0 : register complex_descriptor *descr = d -> ad.ad_element_descr;
468 :
469 0 : nelements = d -> ad.ad_nelements;
470 0 : sz = GC_descr_obj_size(descr);
471 0 : for (i = 0; i < nelements; i++) {
472 0 : msp = GC_push_complex_descriptor((word *)current, descr,
473 : msp, msl);
474 0 : if (msp == 0) return(0);
475 0 : current += sz;
476 : }
477 0 : return(msp);
478 : }
479 : case SEQUENCE_TAG:
480 : {
481 0 : sz = GC_descr_obj_size(d -> sd.sd_first);
482 0 : msp = GC_push_complex_descriptor((word *)current, d -> sd.sd_first,
483 : msp, msl);
484 0 : if (msp == 0) return(0);
485 0 : current += sz;
486 0 : msp = GC_push_complex_descriptor((word *)current, d -> sd.sd_second,
487 : msp, msl);
488 0 : return(msp);
489 : }
490 : default:
491 0 : ABORT("Bad complex descriptor");
492 0 : /*NOTREACHED*/ return 0; /*NOTREACHED*/
493 : }
494 : }
495 :
496 : /*ARGSUSED*/
497 0 : STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
498 : mse * mark_stack_limit, word env)
499 : {
500 0 : hdr * hhdr = HDR(addr);
501 0 : size_t sz = hhdr -> hb_sz;
502 0 : size_t nwords = BYTES_TO_WORDS(sz);
503 0 : complex_descriptor * descr = (complex_descriptor *)(addr[nwords-1]);
504 0 : mse * orig_mark_stack_ptr = mark_stack_ptr;
505 : mse * new_mark_stack_ptr;
506 :
507 0 : if (descr == 0) {
508 : /* Found a reference to a free list entry. Ignore it. */
509 0 : return(orig_mark_stack_ptr);
510 : }
511 : /* In use counts were already updated when array descriptor was */
512 : /* pushed. Here we only replace it by subobject descriptors, so */
513 : /* no update is necessary. */
514 0 : new_mark_stack_ptr = GC_push_complex_descriptor(addr, descr,
515 : mark_stack_ptr,
516 : mark_stack_limit-1);
517 0 : if (new_mark_stack_ptr == 0) {
518 : /* Doesn't fit. Conservatively push the whole array as a unit */
519 : /* and request a mark stack expansion. */
520 : /* This cannot cause a mark stack overflow, since it replaces */
521 : /* the original array entry. */
522 0 : GC_mark_stack_too_small = TRUE;
523 0 : new_mark_stack_ptr = orig_mark_stack_ptr + 1;
524 0 : new_mark_stack_ptr -> mse_start = (ptr_t)addr;
525 0 : new_mark_stack_ptr -> mse_descr = sz | GC_DS_LENGTH;
526 : } else {
527 : /* Push descriptor itself */
528 0 : new_mark_stack_ptr++;
529 0 : new_mark_stack_ptr -> mse_start = (ptr_t)(addr + nwords - 1);
530 0 : new_mark_stack_ptr -> mse_descr = sizeof(word) | GC_DS_LENGTH;
531 : }
532 0 : return new_mark_stack_ptr;
533 : }
534 :
535 0 : GC_API GC_descr GC_CALL GC_make_descriptor(GC_bitmap bm, size_t len)
536 : {
537 0 : signed_word last_set_bit = len - 1;
538 : GC_descr result;
539 : signed_word i;
540 : # define HIGH_BIT (((word)1) << (WORDSZ - 1))
541 :
542 0 : if (!GC_explicit_typing_initialized) GC_init_explicit_typing();
543 0 : while (last_set_bit >= 0 && !GC_get_bit(bm, last_set_bit))
544 0 : last_set_bit--;
545 0 : if (last_set_bit < 0) return(0 /* no pointers */);
546 : # if ALIGNMENT == CPP_WORDSZ/8
547 : {
548 0 : register GC_bool all_bits_set = TRUE;
549 0 : for (i = 0; i < last_set_bit; i++) {
550 0 : if (!GC_get_bit(bm, i)) {
551 0 : all_bits_set = FALSE;
552 0 : break;
553 : }
554 : }
555 0 : if (all_bits_set) {
556 : /* An initial section contains all pointers. Use length descriptor. */
557 0 : return (WORDS_TO_BYTES(last_set_bit+1) | GC_DS_LENGTH);
558 : }
559 : }
560 : # endif
561 0 : if ((word)last_set_bit < BITMAP_BITS) {
562 : /* Hopefully the common case. */
563 : /* Build bitmap descriptor (with bits reversed) */
564 0 : result = HIGH_BIT;
565 0 : for (i = last_set_bit - 1; i >= 0; i--) {
566 0 : result >>= 1;
567 0 : if (GC_get_bit(bm, i)) result |= HIGH_BIT;
568 : }
569 0 : result |= GC_DS_BITMAP;
570 0 : return(result);
571 : } else {
572 : signed_word index;
573 :
574 0 : index = GC_add_ext_descriptor(bm, (word)last_set_bit+1);
575 0 : if (index == -1) return(WORDS_TO_BYTES(last_set_bit+1) | GC_DS_LENGTH);
576 : /* Out of memory: use conservative */
577 : /* approximation. */
578 0 : result = GC_MAKE_PROC(GC_typed_mark_proc_index, (word)index);
579 0 : return result;
580 : }
581 : }
582 :
583 0 : GC_API void * GC_CALL GC_malloc_explicitly_typed(size_t lb, GC_descr d)
584 : {
585 : ptr_t op;
586 : ptr_t * opp;
587 : size_t lg;
588 : DCL_LOCK_STATE;
589 :
590 0 : lb += TYPD_EXTRA_BYTES;
591 0 : if(SMALL_OBJ(lb)) {
592 0 : lg = GC_size_map[lb];
593 0 : opp = &(GC_eobjfreelist[lg]);
594 0 : LOCK();
595 0 : if( (op = *opp) == 0 ) {
596 0 : UNLOCK();
597 0 : op = (ptr_t)GENERAL_MALLOC((word)lb, GC_explicit_kind);
598 0 : if (0 == op) return 0;
599 0 : lg = GC_size_map[lb]; /* May have been uninitialized. */
600 : } else {
601 0 : *opp = obj_link(op);
602 0 : obj_link(op) = 0;
603 0 : GC_bytes_allocd += GRANULES_TO_BYTES(lg);
604 0 : UNLOCK();
605 : }
606 0 : ((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
607 : } else {
608 0 : op = (ptr_t)GENERAL_MALLOC((word)lb, GC_explicit_kind);
609 0 : if (op != NULL) {
610 0 : lg = BYTES_TO_GRANULES(GC_size(op));
611 0 : ((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
612 : }
613 : }
614 0 : return((void *) op);
615 : }
616 :
617 0 : GC_API void * GC_CALL GC_malloc_explicitly_typed_ignore_off_page(size_t lb,
618 : GC_descr d)
619 : {
620 : ptr_t op;
621 : ptr_t * opp;
622 : size_t lg;
623 : DCL_LOCK_STATE;
624 :
625 0 : lb += TYPD_EXTRA_BYTES;
626 0 : if( SMALL_OBJ(lb) ) {
627 0 : lg = GC_size_map[lb];
628 0 : opp = &(GC_eobjfreelist[lg]);
629 0 : LOCK();
630 0 : if( (op = *opp) == 0 ) {
631 0 : UNLOCK();
632 0 : op = (ptr_t)GENERAL_MALLOC_IOP(lb, GC_explicit_kind);
633 0 : if (0 == op) return 0;
634 0 : lg = GC_size_map[lb]; /* May have been uninitialized. */
635 : } else {
636 0 : *opp = obj_link(op);
637 0 : obj_link(op) = 0;
638 0 : GC_bytes_allocd += GRANULES_TO_BYTES(lg);
639 0 : UNLOCK();
640 : }
641 0 : ((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
642 : } else {
643 0 : op = (ptr_t)GENERAL_MALLOC_IOP(lb, GC_explicit_kind);
644 0 : if (op != NULL) {
645 0 : lg = BYTES_TO_WORDS(GC_size(op));
646 0 : ((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
647 : }
648 : }
649 0 : return((void *) op);
650 : }
651 :
652 0 : GC_API void * GC_CALL GC_calloc_explicitly_typed(size_t n, size_t lb,
653 : GC_descr d)
654 : {
655 : ptr_t op;
656 : ptr_t * opp;
657 : size_t lg;
658 : GC_descr simple_descr;
659 : complex_descriptor *complex_descr;
660 : register int descr_type;
661 : struct LeafDescriptor leaf;
662 : DCL_LOCK_STATE;
663 :
664 0 : descr_type = GC_make_array_descriptor((word)n, (word)lb, d,
665 : &simple_descr, &complex_descr, &leaf);
666 0 : switch(descr_type) {
667 0 : case NO_MEM: return(0);
668 0 : case SIMPLE: return(GC_malloc_explicitly_typed(n*lb, simple_descr));
669 : case LEAF:
670 0 : lb *= n;
671 0 : lb += sizeof(struct LeafDescriptor) + TYPD_EXTRA_BYTES;
672 0 : break;
673 : case COMPLEX:
674 0 : lb *= n;
675 0 : lb += TYPD_EXTRA_BYTES;
676 : break;
677 : }
678 0 : if( SMALL_OBJ(lb) ) {
679 0 : lg = GC_size_map[lb];
680 0 : opp = &(GC_arobjfreelist[lg]);
681 0 : LOCK();
682 0 : if( (op = *opp) == 0 ) {
683 0 : UNLOCK();
684 0 : op = (ptr_t)GENERAL_MALLOC((word)lb, GC_array_kind);
685 0 : if (0 == op) return(0);
686 0 : lg = GC_size_map[lb]; /* May have been uninitialized. */
687 : } else {
688 0 : *opp = obj_link(op);
689 0 : obj_link(op) = 0;
690 0 : GC_bytes_allocd += GRANULES_TO_BYTES(lg);
691 0 : UNLOCK();
692 : }
693 : } else {
694 0 : op = (ptr_t)GENERAL_MALLOC((word)lb, GC_array_kind);
695 0 : if (0 == op) return(0);
696 0 : lg = BYTES_TO_GRANULES(GC_size(op));
697 : }
698 0 : if (descr_type == LEAF) {
699 : /* Set up the descriptor inside the object itself. */
700 : volatile struct LeafDescriptor * lp =
701 : (struct LeafDescriptor *)
702 : ((word *)op
703 0 : + GRANULES_TO_WORDS(lg)
704 0 : - (BYTES_TO_WORDS(sizeof(struct LeafDescriptor)) + 1));
705 :
706 0 : lp -> ld_tag = LEAF_TAG;
707 0 : lp -> ld_size = leaf.ld_size;
708 0 : lp -> ld_nelements = leaf.ld_nelements;
709 0 : lp -> ld_descriptor = leaf.ld_descriptor;
710 0 : ((volatile word *)op)[GRANULES_TO_WORDS(lg) - 1] = (word)lp;
711 : } else {
712 0 : size_t lw = GRANULES_TO_WORDS(lg);
713 :
714 0 : ((word *)op)[lw - 1] = (word)complex_descr;
715 : /* Make sure the descriptor is cleared once there is any danger */
716 : /* it may have been collected. */
717 0 : if (GC_general_register_disappearing_link((void * *)((word *)op+lw-1),
718 : op) == GC_NO_MEMORY) {
719 : /* Couldn't register it due to lack of memory. Punt. */
720 : /* This will probably fail too, but gives the recovery code */
721 : /* a chance. */
722 0 : return(GC_malloc(n*lb));
723 : }
724 : }
725 0 : return((void *) op);
726 : }
|
