Tue, 19 Aug 2014 02:05:49 -0700
8044406: JVM crash with JDK8 (build 1.8.0-b132) with G1 GC
Summary: Fill the last card that has been allocated into with a dummy object
Reviewed-by: tschatzl, mgerdin
1 /*
2 * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
27 #include "memory/space.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "runtime/java.hpp"
30 #include "services/memTracker.hpp"
32 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
34 //////////////////////////////////////////////////////////////////////
35 // G1BlockOffsetSharedArray
36 //////////////////////////////////////////////////////////////////////
38 G1BlockOffsetSharedArray::G1BlockOffsetSharedArray(MemRegion reserved,
39 size_t init_word_size) :
40 _reserved(reserved), _end(NULL)
41 {
42 size_t size = compute_size(reserved.word_size());
43 ReservedSpace rs(ReservedSpace::allocation_align_size_up(size));
44 if (!rs.is_reserved()) {
45 vm_exit_during_initialization("Could not reserve enough space for heap offset array");
46 }
47 if (!_vs.initialize(rs, 0)) {
48 vm_exit_during_initialization("Could not reserve enough space for heap offset array");
49 }
51 MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
53 _offset_array = (u_char*)_vs.low_boundary();
54 resize(init_word_size);
55 if (TraceBlockOffsetTable) {
56 gclog_or_tty->print_cr("G1BlockOffsetSharedArray::G1BlockOffsetSharedArray: ");
57 gclog_or_tty->print_cr(" "
58 " rs.base(): " INTPTR_FORMAT
59 " rs.size(): " INTPTR_FORMAT
60 " rs end(): " INTPTR_FORMAT,
61 rs.base(), rs.size(), rs.base() + rs.size());
62 gclog_or_tty->print_cr(" "
63 " _vs.low_boundary(): " INTPTR_FORMAT
64 " _vs.high_boundary(): " INTPTR_FORMAT,
65 _vs.low_boundary(),
66 _vs.high_boundary());
67 }
68 }
70 void G1BlockOffsetSharedArray::resize(size_t new_word_size) {
71 assert(new_word_size <= _reserved.word_size(), "Resize larger than reserved");
72 size_t new_size = compute_size(new_word_size);
73 size_t old_size = _vs.committed_size();
74 size_t delta;
75 char* high = _vs.high();
76 _end = _reserved.start() + new_word_size;
77 if (new_size > old_size) {
78 delta = ReservedSpace::page_align_size_up(new_size - old_size);
79 assert(delta > 0, "just checking");
80 if (!_vs.expand_by(delta)) {
81 // Do better than this for Merlin
82 vm_exit_out_of_memory(delta, OOM_MMAP_ERROR, "offset table expansion");
83 }
84 assert(_vs.high() == high + delta, "invalid expansion");
85 // Initialization of the contents is left to the
86 // G1BlockOffsetArray that uses it.
87 } else {
88 delta = ReservedSpace::page_align_size_down(old_size - new_size);
89 if (delta == 0) return;
90 _vs.shrink_by(delta);
91 assert(_vs.high() == high - delta, "invalid expansion");
92 }
93 }
95 bool G1BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const {
96 assert(p >= _reserved.start(), "just checking");
97 size_t delta = pointer_delta(p, _reserved.start());
98 return (delta & right_n_bits(LogN_words)) == (size_t)NoBits;
99 }
102 //////////////////////////////////////////////////////////////////////
103 // G1BlockOffsetArray
104 //////////////////////////////////////////////////////////////////////
106 G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array,
107 MemRegion mr, bool init_to_zero) :
108 G1BlockOffsetTable(mr.start(), mr.end()),
109 _unallocated_block(_bottom),
110 _array(array), _csp(NULL),
111 _init_to_zero(init_to_zero) {
112 assert(_bottom <= _end, "arguments out of order");
113 if (!_init_to_zero) {
114 // initialize cards to point back to mr.start()
115 set_remainder_to_point_to_start(mr.start() + N_words, mr.end());
116 _array->set_offset_array(0, 0); // set first card to 0
117 }
118 }
120 void G1BlockOffsetArray::set_space(Space* sp) {
121 _sp = sp;
122 _csp = sp->toContiguousSpace();
123 }
125 // The arguments follow the normal convention of denoting
126 // a right-open interval: [start, end)
127 void
128 G1BlockOffsetArray:: set_remainder_to_point_to_start(HeapWord* start, HeapWord* end) {
130 if (start >= end) {
131 // The start address is equal to the end address (or to
132 // the right of the end address) so there are not cards
133 // that need to be updated..
134 return;
135 }
137 // Write the backskip value for each region.
138 //
139 // offset
140 // card 2nd 3rd
141 // | +- 1st | |
142 // v v v v
143 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-
144 // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ...
145 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-
146 // 11 19 75
147 // 12
148 //
149 // offset card is the card that points to the start of an object
150 // x - offset value of offset card
151 // 1st - start of first logarithmic region
152 // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1
153 // 2nd - start of second logarithmic region
154 // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8
155 // 3rd - start of third logarithmic region
156 // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64
157 //
158 // integer below the block offset entry is an example of
159 // the index of the entry
160 //
161 // Given an address,
162 // Find the index for the address
163 // Find the block offset table entry
164 // Convert the entry to a back slide
165 // (e.g., with today's, offset = 0x81 =>
166 // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8
167 // Move back N (e.g., 8) entries and repeat with the
168 // value of the new entry
169 //
170 size_t start_card = _array->index_for(start);
171 size_t end_card = _array->index_for(end-1);
172 assert(start ==_array->address_for_index(start_card), "Precondition");
173 assert(end ==_array->address_for_index(end_card)+N_words, "Precondition");
174 set_remainder_to_point_to_start_incl(start_card, end_card); // closed interval
175 }
177 // Unlike the normal convention in this code, the argument here denotes
178 // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start()
179 // above.
180 void
181 G1BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card) {
182 if (start_card > end_card) {
183 return;
184 }
185 assert(start_card > _array->index_for(_bottom), "Cannot be first card");
186 assert(_array->offset_array(start_card-1) <= N_words,
187 "Offset card has an unexpected value");
188 size_t start_card_for_region = start_card;
189 u_char offset = max_jubyte;
190 for (int i = 0; i < BlockOffsetArray::N_powers; i++) {
191 // -1 so that the the card with the actual offset is counted. Another -1
192 // so that the reach ends in this region and not at the start
193 // of the next.
194 size_t reach = start_card - 1 + (BlockOffsetArray::power_to_cards_back(i+1) - 1);
195 offset = N_words + i;
196 if (reach >= end_card) {
197 _array->set_offset_array(start_card_for_region, end_card, offset);
198 start_card_for_region = reach + 1;
199 break;
200 }
201 _array->set_offset_array(start_card_for_region, reach, offset);
202 start_card_for_region = reach + 1;
203 }
204 assert(start_card_for_region > end_card, "Sanity check");
205 DEBUG_ONLY(check_all_cards(start_card, end_card);)
206 }
208 // The block [blk_start, blk_end) has been allocated;
209 // adjust the block offset table to represent this information;
210 // right-open interval: [blk_start, blk_end)
211 void
212 G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) {
213 mark_block(blk_start, blk_end);
214 allocated(blk_start, blk_end);
215 }
217 // Adjust BOT to show that a previously whole block has been split
218 // into two.
219 void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size,
220 size_t left_blk_size) {
221 // Verify that the BOT shows [blk, blk + blk_size) to be one block.
222 verify_single_block(blk, blk_size);
223 // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size)
224 // is one single block.
225 mark_block(blk + left_blk_size, blk + blk_size);
226 }
229 // Action_mark - update the BOT for the block [blk_start, blk_end).
230 // Current typical use is for splitting a block.
231 // Action_single - update the BOT for an allocation.
232 // Action_verify - BOT verification.
233 void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start,
234 HeapWord* blk_end,
235 Action action) {
236 assert(Universe::heap()->is_in_reserved(blk_start),
237 "reference must be into the heap");
238 assert(Universe::heap()->is_in_reserved(blk_end-1),
239 "limit must be within the heap");
240 // This is optimized to make the test fast, assuming we only rarely
241 // cross boundaries.
242 uintptr_t end_ui = (uintptr_t)(blk_end - 1);
243 uintptr_t start_ui = (uintptr_t)blk_start;
244 // Calculate the last card boundary preceding end of blk
245 intptr_t boundary_before_end = (intptr_t)end_ui;
246 clear_bits(boundary_before_end, right_n_bits(LogN));
247 if (start_ui <= (uintptr_t)boundary_before_end) {
248 // blk starts at or crosses a boundary
249 // Calculate index of card on which blk begins
250 size_t start_index = _array->index_for(blk_start);
251 // Index of card on which blk ends
252 size_t end_index = _array->index_for(blk_end - 1);
253 // Start address of card on which blk begins
254 HeapWord* boundary = _array->address_for_index(start_index);
255 assert(boundary <= blk_start, "blk should start at or after boundary");
256 if (blk_start != boundary) {
257 // blk starts strictly after boundary
258 // adjust card boundary and start_index forward to next card
259 boundary += N_words;
260 start_index++;
261 }
262 assert(start_index <= end_index, "monotonicity of index_for()");
263 assert(boundary <= (HeapWord*)boundary_before_end, "tautology");
264 switch (action) {
265 case Action_mark: {
266 if (init_to_zero()) {
267 _array->set_offset_array(start_index, boundary, blk_start);
268 break;
269 } // Else fall through to the next case
270 }
271 case Action_single: {
272 _array->set_offset_array(start_index, boundary, blk_start);
273 // We have finished marking the "offset card". We need to now
274 // mark the subsequent cards that this blk spans.
275 if (start_index < end_index) {
276 HeapWord* rem_st = _array->address_for_index(start_index) + N_words;
277 HeapWord* rem_end = _array->address_for_index(end_index) + N_words;
278 set_remainder_to_point_to_start(rem_st, rem_end);
279 }
280 break;
281 }
282 case Action_check: {
283 _array->check_offset_array(start_index, boundary, blk_start);
284 // We have finished checking the "offset card". We need to now
285 // check the subsequent cards that this blk spans.
286 check_all_cards(start_index + 1, end_index);
287 break;
288 }
289 default:
290 ShouldNotReachHere();
291 }
292 }
293 }
295 // The card-interval [start_card, end_card] is a closed interval; this
296 // is an expensive check -- use with care and only under protection of
297 // suitable flag.
298 void G1BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const {
300 if (end_card < start_card) {
301 return;
302 }
303 guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card");
304 for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) {
305 u_char entry = _array->offset_array(c);
306 if (c - start_card > BlockOffsetArray::power_to_cards_back(1)) {
307 guarantee(entry > N_words,
308 err_msg("Should be in logarithmic region - "
309 "entry: " UINT32_FORMAT ", "
310 "_array->offset_array(c): " UINT32_FORMAT ", "
311 "N_words: " UINT32_FORMAT,
312 entry, _array->offset_array(c), N_words));
313 }
314 size_t backskip = BlockOffsetArray::entry_to_cards_back(entry);
315 size_t landing_card = c - backskip;
316 guarantee(landing_card >= (start_card - 1), "Inv");
317 if (landing_card >= start_card) {
318 guarantee(_array->offset_array(landing_card) <= entry,
319 err_msg("Monotonicity - landing_card offset: " UINT32_FORMAT ", "
320 "entry: " UINT32_FORMAT,
321 _array->offset_array(landing_card), entry));
322 } else {
323 guarantee(landing_card == start_card - 1, "Tautology");
324 // Note that N_words is the maximum offset value
325 guarantee(_array->offset_array(landing_card) <= N_words,
326 err_msg("landing card offset: " UINT32_FORMAT ", "
327 "N_words: " UINT32_FORMAT,
328 _array->offset_array(landing_card), N_words));
329 }
330 }
331 }
333 // The range [blk_start, blk_end) represents a single contiguous block
334 // of storage; modify the block offset table to represent this
335 // information; Right-open interval: [blk_start, blk_end)
336 // NOTE: this method does _not_ adjust _unallocated_block.
337 void
338 G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) {
339 do_block_internal(blk_start, blk_end, Action_single);
340 }
342 // Mark the BOT such that if [blk_start, blk_end) straddles a card
343 // boundary, the card following the first such boundary is marked
344 // with the appropriate offset.
345 // NOTE: this method does _not_ adjust _unallocated_block or
346 // any cards subsequent to the first one.
347 void
348 G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) {
349 do_block_internal(blk_start, blk_end, Action_mark);
350 }
352 HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) {
353 assert(_bottom <= addr && addr < _end,
354 "addr must be covered by this Array");
355 // Must read this exactly once because it can be modified by parallel
356 // allocation.
357 HeapWord* ub = _unallocated_block;
358 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
359 assert(ub < _end, "tautology (see above)");
360 return ub;
361 }
362 // Otherwise, find the block start using the table.
363 HeapWord* q = block_at_or_preceding(addr, false, 0);
364 return forward_to_block_containing_addr(q, addr);
365 }
367 // This duplicates a little code from the above: unavoidable.
368 HeapWord*
369 G1BlockOffsetArray::block_start_unsafe_const(const void* addr) const {
370 assert(_bottom <= addr && addr < _end,
371 "addr must be covered by this Array");
372 // Must read this exactly once because it can be modified by parallel
373 // allocation.
374 HeapWord* ub = _unallocated_block;
375 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
376 assert(ub < _end, "tautology (see above)");
377 return ub;
378 }
379 // Otherwise, find the block start using the table.
380 HeapWord* q = block_at_or_preceding(addr, false, 0);
381 HeapWord* n = q + _sp->block_size(q);
382 return forward_to_block_containing_addr_const(q, n, addr);
383 }
386 HeapWord*
387 G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q,
388 HeapWord* n,
389 const void* addr) {
390 // We're not in the normal case. We need to handle an important subcase
391 // here: LAB allocation. An allocation previously recorded in the
392 // offset table was actually a lab allocation, and was divided into
393 // several objects subsequently. Fix this situation as we answer the
394 // query, by updating entries as we cross them.
396 // If the fist object's end q is at the card boundary. Start refining
397 // with the corresponding card (the value of the entry will be basically
398 // set to 0). If the object crosses the boundary -- start from the next card.
399 size_t n_index = _array->index_for(n);
400 size_t next_index = _array->index_for(n) + !_array->is_card_boundary(n);
401 // Calculate a consistent next boundary. If "n" is not at the boundary
402 // already, step to the boundary.
403 HeapWord* next_boundary = _array->address_for_index(n_index) +
404 (n_index == next_index ? 0 : N_words);
405 assert(next_boundary <= _array->_end,
406 err_msg("next_boundary is beyond the end of the covered region "
407 " next_boundary " PTR_FORMAT " _array->_end " PTR_FORMAT,
408 next_boundary, _array->_end));
409 if (csp() != NULL) {
410 if (addr >= csp()->top()) return csp()->top();
411 while (next_boundary < addr) {
412 while (n <= next_boundary) {
413 q = n;
414 oop obj = oop(q);
415 if (obj->klass_or_null() == NULL) return q;
416 n += obj->size();
417 }
418 assert(q <= next_boundary && n > next_boundary, "Consequence of loop");
419 // [q, n) is the block that crosses the boundary.
420 alloc_block_work2(&next_boundary, &next_index, q, n);
421 }
422 } else {
423 while (next_boundary < addr) {
424 while (n <= next_boundary) {
425 q = n;
426 oop obj = oop(q);
427 if (obj->klass_or_null() == NULL) return q;
428 n += _sp->block_size(q);
429 }
430 assert(q <= next_boundary && n > next_boundary, "Consequence of loop");
431 // [q, n) is the block that crosses the boundary.
432 alloc_block_work2(&next_boundary, &next_index, q, n);
433 }
434 }
435 return forward_to_block_containing_addr_const(q, n, addr);
436 }
438 HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const {
439 assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
441 assert(_bottom <= addr && addr < _end,
442 "addr must be covered by this Array");
443 // Must read this exactly once because it can be modified by parallel
444 // allocation.
445 HeapWord* ub = _unallocated_block;
446 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
447 assert(ub < _end, "tautology (see above)");
448 return ub;
449 }
451 // Otherwise, find the block start using the table, but taking
452 // care (cf block_start_unsafe() above) not to parse any objects/blocks
453 // on the cards themsleves.
454 size_t index = _array->index_for(addr);
455 assert(_array->address_for_index(index) == addr,
456 "arg should be start of card");
458 HeapWord* q = (HeapWord*)addr;
459 uint offset;
460 do {
461 offset = _array->offset_array(index--);
462 q -= offset;
463 } while (offset == N_words);
464 assert(q <= addr, "block start should be to left of arg");
465 return q;
466 }
468 // Note that the committed size of the covered space may have changed,
469 // so the table size might also wish to change.
470 void G1BlockOffsetArray::resize(size_t new_word_size) {
471 HeapWord* new_end = _bottom + new_word_size;
472 if (_end < new_end && !init_to_zero()) {
473 // verify that the old and new boundaries are also card boundaries
474 assert(_array->is_card_boundary(_end),
475 "_end not a card boundary");
476 assert(_array->is_card_boundary(new_end),
477 "new _end would not be a card boundary");
478 // set all the newly added cards
479 _array->set_offset_array(_end, new_end, N_words);
480 }
481 _end = new_end; // update _end
482 }
484 void G1BlockOffsetArray::set_region(MemRegion mr) {
485 _bottom = mr.start();
486 _end = mr.end();
487 }
489 //
490 // threshold_
491 // | _index_
492 // v v
493 // +-------+-------+-------+-------+-------+
494 // | i-1 | i | i+1 | i+2 | i+3 |
495 // +-------+-------+-------+-------+-------+
496 // ( ^ ]
497 // block-start
498 //
499 void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_,
500 HeapWord* blk_start, HeapWord* blk_end) {
501 // For efficiency, do copy-in/copy-out.
502 HeapWord* threshold = *threshold_;
503 size_t index = *index_;
505 assert(blk_start != NULL && blk_end > blk_start,
506 "phantom block");
507 assert(blk_end > threshold, "should be past threshold");
508 assert(blk_start <= threshold, "blk_start should be at or before threshold");
509 assert(pointer_delta(threshold, blk_start) <= N_words,
510 "offset should be <= BlockOffsetSharedArray::N");
511 assert(Universe::heap()->is_in_reserved(blk_start),
512 "reference must be into the heap");
513 assert(Universe::heap()->is_in_reserved(blk_end-1),
514 "limit must be within the heap");
515 assert(threshold == _array->_reserved.start() + index*N_words,
516 "index must agree with threshold");
518 DEBUG_ONLY(size_t orig_index = index;)
520 // Mark the card that holds the offset into the block. Note
521 // that _next_offset_index and _next_offset_threshold are not
522 // updated until the end of this method.
523 _array->set_offset_array(index, threshold, blk_start);
525 // We need to now mark the subsequent cards that this blk spans.
527 // Index of card on which blk ends.
528 size_t end_index = _array->index_for(blk_end - 1);
530 // Are there more cards left to be updated?
531 if (index + 1 <= end_index) {
532 HeapWord* rem_st = _array->address_for_index(index + 1);
533 // Calculate rem_end this way because end_index
534 // may be the last valid index in the covered region.
535 HeapWord* rem_end = _array->address_for_index(end_index) + N_words;
536 set_remainder_to_point_to_start(rem_st, rem_end);
537 }
539 index = end_index + 1;
540 // Calculate threshold_ this way because end_index
541 // may be the last valid index in the covered region.
542 threshold = _array->address_for_index(end_index) + N_words;
543 assert(threshold >= blk_end, "Incorrect offset threshold");
545 // index_ and threshold_ updated here.
546 *threshold_ = threshold;
547 *index_ = index;
549 #ifdef ASSERT
550 // The offset can be 0 if the block starts on a boundary. That
551 // is checked by an assertion above.
552 size_t start_index = _array->index_for(blk_start);
553 HeapWord* boundary = _array->address_for_index(start_index);
554 assert((_array->offset_array(orig_index) == 0 &&
555 blk_start == boundary) ||
556 (_array->offset_array(orig_index) > 0 &&
557 _array->offset_array(orig_index) <= N_words),
558 err_msg("offset array should have been set - "
559 "orig_index offset: " UINT32_FORMAT ", "
560 "blk_start: " PTR_FORMAT ", "
561 "boundary: " PTR_FORMAT,
562 _array->offset_array(orig_index),
563 blk_start, boundary));
564 for (size_t j = orig_index + 1; j <= end_index; j++) {
565 assert(_array->offset_array(j) > 0 &&
566 _array->offset_array(j) <=
567 (u_char) (N_words+BlockOffsetArray::N_powers-1),
568 err_msg("offset array should have been set - "
569 UINT32_FORMAT " not > 0 OR "
570 UINT32_FORMAT " not <= " UINT32_FORMAT,
571 _array->offset_array(j),
572 _array->offset_array(j),
573 (u_char) (N_words+BlockOffsetArray::N_powers-1)));
574 }
575 #endif
576 }
578 bool
579 G1BlockOffsetArray::verify_for_object(HeapWord* obj_start,
580 size_t word_size) const {
581 size_t first_card = _array->index_for(obj_start);
582 size_t last_card = _array->index_for(obj_start + word_size - 1);
583 if (!_array->is_card_boundary(obj_start)) {
584 // If the object is not on a card boundary the BOT entry of the
585 // first card should point to another object so we should not
586 // check that one.
587 first_card += 1;
588 }
589 for (size_t card = first_card; card <= last_card; card += 1) {
590 HeapWord* card_addr = _array->address_for_index(card);
591 HeapWord* block_start = block_start_const(card_addr);
592 if (block_start != obj_start) {
593 gclog_or_tty->print_cr("block start: "PTR_FORMAT" is incorrect - "
594 "card index: "SIZE_FORMAT" "
595 "card addr: "PTR_FORMAT" BOT entry: %u "
596 "obj: "PTR_FORMAT" word size: "SIZE_FORMAT" "
597 "cards: ["SIZE_FORMAT","SIZE_FORMAT"]",
598 block_start, card, card_addr,
599 _array->offset_array(card),
600 obj_start, word_size, first_card, last_card);
601 return false;
602 }
603 }
604 return true;
605 }
607 #ifndef PRODUCT
608 void
609 G1BlockOffsetArray::print_on(outputStream* out) {
610 size_t from_index = _array->index_for(_bottom);
611 size_t to_index = _array->index_for(_end);
612 out->print_cr(">> BOT for area ["PTR_FORMAT","PTR_FORMAT") "
613 "cards ["SIZE_FORMAT","SIZE_FORMAT")",
614 _bottom, _end, from_index, to_index);
615 for (size_t i = from_index; i < to_index; ++i) {
616 out->print_cr(" entry "SIZE_FORMAT_W(8)" | "PTR_FORMAT" : %3u",
617 i, _array->address_for_index(i),
618 (uint) _array->offset_array(i));
619 }
620 }
621 #endif // !PRODUCT
623 //////////////////////////////////////////////////////////////////////
624 // G1BlockOffsetArrayContigSpace
625 //////////////////////////////////////////////////////////////////////
627 HeapWord*
628 G1BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) {
629 assert(_bottom <= addr && addr < _end,
630 "addr must be covered by this Array");
631 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
632 return forward_to_block_containing_addr(q, addr);
633 }
635 HeapWord*
636 G1BlockOffsetArrayContigSpace::
637 block_start_unsafe_const(const void* addr) const {
638 assert(_bottom <= addr && addr < _end,
639 "addr must be covered by this Array");
640 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
641 HeapWord* n = q + _sp->block_size(q);
642 return forward_to_block_containing_addr_const(q, n, addr);
643 }
645 G1BlockOffsetArrayContigSpace::
646 G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array,
647 MemRegion mr) :
648 G1BlockOffsetArray(array, mr, true)
649 {
650 _next_offset_threshold = NULL;
651 _next_offset_index = 0;
652 }
654 HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold() {
655 assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
656 "just checking");
657 _next_offset_index = _array->index_for(_bottom);
658 _next_offset_index++;
659 _next_offset_threshold =
660 _array->address_for_index(_next_offset_index);
661 return _next_offset_threshold;
662 }
664 void G1BlockOffsetArrayContigSpace::zero_bottom_entry() {
665 assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
666 "just checking");
667 size_t bottom_index = _array->index_for(_bottom);
668 assert(_array->address_for_index(bottom_index) == _bottom,
669 "Precondition of call");
670 _array->set_offset_array(bottom_index, 0);
671 }
673 void
674 G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_top) {
675 assert(new_top <= _end, "_end should have already been updated");
677 // The first BOT entry should have offset 0.
678 zero_bottom_entry();
679 initialize_threshold();
680 alloc_block(_bottom, new_top);
681 }
683 #ifndef PRODUCT
684 void
685 G1BlockOffsetArrayContigSpace::print_on(outputStream* out) {
686 G1BlockOffsetArray::print_on(out);
687 out->print_cr(" next offset threshold: "PTR_FORMAT, _next_offset_threshold);
688 out->print_cr(" next offset index: "SIZE_FORMAT, _next_offset_index);
689 }
690 #endif // !PRODUCT