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
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
27 #include "gc_implementation/g1/heapRegion.hpp"
28 #include "memory/space.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/java.hpp"
31 #include "services/memTracker.hpp"
32
33 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
34
35 void G1BlockOffsetSharedArrayMappingChangedListener::on_commit(uint start_idx, size_t num_regions) {
36 // Nothing to do. The BOT is hard-wired to be part of the HeapRegion, and we cannot
37 // retrieve it here since this would cause firing of several asserts. The code
38 // exacuted after commit of a region already needs to do some re-initialization of
39 // the HeapRegion, so we combine that.
40 }
41
42 //////////////////////////////////////////////////////////////////////
43 // G1BlockOffsetSharedArray
44 //////////////////////////////////////////////////////////////////////
45
46 G1BlockOffsetSharedArray::G1BlockOffsetSharedArray(MemRegion heap, G1RegionToSpaceMapper* storage) :
47 _reserved(), _end(NULL), _listener(), _offset_array(NULL) {
48
49 _reserved = heap;
50 _end = NULL;
51
52 MemRegion bot_reserved = storage->reserved();
53
54 _offset_array = (u_char*)bot_reserved.start();
55 _end = _reserved.end();
56
57 storage->set_mapping_changed_listener(&_listener);
58
59 if (TraceBlockOffsetTable) {
60 gclog_or_tty->print_cr("G1BlockOffsetSharedArray::G1BlockOffsetSharedArray: ");
61 gclog_or_tty->print_cr(" "
62 " rs.base(): " INTPTR_FORMAT
63 " rs.size(): " INTPTR_FORMAT
64 " rs end(): " INTPTR_FORMAT,
65 bot_reserved.start(), bot_reserved.byte_size(), bot_reserved.end());
66 }
67 }
68
69 bool G1BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const {
70 assert(p >= _reserved.start(), "just checking");
71 size_t delta = pointer_delta(p, _reserved.start());
72 return (delta & right_n_bits(LogN_words)) == (size_t)NoBits;
73 }
74
75 void G1BlockOffsetSharedArray::set_offset_array(HeapWord* left, HeapWord* right, u_char offset) {
76 set_offset_array(index_for(left), index_for(right -1), offset);
77 }
78
79 //////////////////////////////////////////////////////////////////////
80 // G1BlockOffsetArray
81 //////////////////////////////////////////////////////////////////////
82
83 G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array,
84 MemRegion mr, bool init_to_zero) :
85 G1BlockOffsetTable(mr.start(), mr.end()),
86 _unallocated_block(_bottom),
87 _array(array), _gsp(NULL),
88 _init_to_zero(init_to_zero) {
89 assert(_bottom <= _end, "arguments out of order");
90 if (!_init_to_zero) {
91 // initialize cards to point back to mr.start()
92 set_remainder_to_point_to_start(mr.start() + N_words, mr.end());
93 _array->set_offset_array(0, 0); // set first card to 0
94 }
95 }
96
97 void G1BlockOffsetArray::set_space(G1OffsetTableContigSpace* sp) {
98 _gsp = sp;
99 }
100
101 // The arguments follow the normal convention of denoting
102 // a right-open interval: [start, end)
103 void
104 G1BlockOffsetArray:: set_remainder_to_point_to_start(HeapWord* start, HeapWord* end) {
105
106 if (start >= end) {
107 // The start address is equal to the end address (or to
108 // the right of the end address) so there are not cards
109 // that need to be updated..
110 return;
111 }
112
113 // Write the backskip value for each region.
114 //
115 // offset
116 // card 2nd 3rd
117 // | +- 1st | |
118 // v v v v
119 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-
120 // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ...
121 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-
122 // 11 19 75
123 // 12
124 //
125 // offset card is the card that points to the start of an object
126 // x - offset value of offset card
127 // 1st - start of first logarithmic region
128 // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1
129 // 2nd - start of second logarithmic region
130 // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8
131 // 3rd - start of third logarithmic region
132 // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64
133 //
134 // integer below the block offset entry is an example of
135 // the index of the entry
136 //
137 // Given an address,
138 // Find the index for the address
139 // Find the block offset table entry
140 // Convert the entry to a back slide
141 // (e.g., with today's, offset = 0x81 =>
142 // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8
143 // Move back N (e.g., 8) entries and repeat with the
144 // value of the new entry
145 //
146 size_t start_card = _array->index_for(start);
147 size_t end_card = _array->index_for(end-1);
148 assert(start ==_array->address_for_index(start_card), "Precondition");
149 assert(end ==_array->address_for_index(end_card)+N_words, "Precondition");
150 set_remainder_to_point_to_start_incl(start_card, end_card); // closed interval
151 }
152
153 // Unlike the normal convention in this code, the argument here denotes
154 // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start()
155 // above.
156 void
157 G1BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card) {
158 if (start_card > end_card) {
159 return;
160 }
161 assert(start_card > _array->index_for(_bottom), "Cannot be first card");
162 assert(_array->offset_array(start_card-1) <= N_words,
163 "Offset card has an unexpected value");
164 size_t start_card_for_region = start_card;
165 u_char offset = max_jubyte;
166 for (int i = 0; i < BlockOffsetArray::N_powers; i++) {
167 // -1 so that the the card with the actual offset is counted. Another -1
168 // so that the reach ends in this region and not at the start
169 // of the next.
170 size_t reach = start_card - 1 + (BlockOffsetArray::power_to_cards_back(i+1) - 1);
171 offset = N_words + i;
172 if (reach >= end_card) {
173 _array->set_offset_array(start_card_for_region, end_card, offset);
174 start_card_for_region = reach + 1;
175 break;
176 }
177 _array->set_offset_array(start_card_for_region, reach, offset);
178 start_card_for_region = reach + 1;
179 }
180 assert(start_card_for_region > end_card, "Sanity check");
181 DEBUG_ONLY(check_all_cards(start_card, end_card);)
182 }
183
184 // The block [blk_start, blk_end) has been allocated;
185 // adjust the block offset table to represent this information;
186 // right-open interval: [blk_start, blk_end)
187 void
188 G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) {
189 mark_block(blk_start, blk_end);
190 allocated(blk_start, blk_end);
191 }
192
193 // Adjust BOT to show that a previously whole block has been split
194 // into two.
195 void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size,
196 size_t left_blk_size) {
197 // Verify that the BOT shows [blk, blk + blk_size) to be one block.
198 verify_single_block(blk, blk_size);
199 // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size)
200 // is one single block.
201 mark_block(blk + left_blk_size, blk + blk_size);
202 }
203
204
205 // Action_mark - update the BOT for the block [blk_start, blk_end).
206 // Current typical use is for splitting a block.
207 // Action_single - update the BOT for an allocation.
208 // Action_verify - BOT verification.
209 void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start,
210 HeapWord* blk_end,
211 Action action) {
212 assert(Universe::heap()->is_in_reserved(blk_start),
213 "reference must be into the heap");
214 assert(Universe::heap()->is_in_reserved(blk_end-1),
215 "limit must be within the heap");
216 // This is optimized to make the test fast, assuming we only rarely
217 // cross boundaries.
218 uintptr_t end_ui = (uintptr_t)(blk_end - 1);
219 uintptr_t start_ui = (uintptr_t)blk_start;
220 // Calculate the last card boundary preceding end of blk
221 intptr_t boundary_before_end = (intptr_t)end_ui;
222 clear_bits(boundary_before_end, right_n_bits(LogN));
223 if (start_ui <= (uintptr_t)boundary_before_end) {
224 // blk starts at or crosses a boundary
225 // Calculate index of card on which blk begins
226 size_t start_index = _array->index_for(blk_start);
227 // Index of card on which blk ends
228 size_t end_index = _array->index_for(blk_end - 1);
229 // Start address of card on which blk begins
230 HeapWord* boundary = _array->address_for_index(start_index);
231 assert(boundary <= blk_start, "blk should start at or after boundary");
232 if (blk_start != boundary) {
233 // blk starts strictly after boundary
234 // adjust card boundary and start_index forward to next card
235 boundary += N_words;
236 start_index++;
237 }
238 assert(start_index <= end_index, "monotonicity of index_for()");
239 assert(boundary <= (HeapWord*)boundary_before_end, "tautology");
240 switch (action) {
241 case Action_mark: {
242 if (init_to_zero()) {
243 _array->set_offset_array(start_index, boundary, blk_start);
244 break;
245 } // Else fall through to the next case
246 }
247 case Action_single: {
248 _array->set_offset_array(start_index, boundary, blk_start);
249 // We have finished marking the "offset card". We need to now
250 // mark the subsequent cards that this blk spans.
251 if (start_index < end_index) {
252 HeapWord* rem_st = _array->address_for_index(start_index) + N_words;
253 HeapWord* rem_end = _array->address_for_index(end_index) + N_words;
254 set_remainder_to_point_to_start(rem_st, rem_end);
255 }
256 break;
257 }
258 case Action_check: {
259 _array->check_offset_array(start_index, boundary, blk_start);
260 // We have finished checking the "offset card". We need to now
261 // check the subsequent cards that this blk spans.
262 check_all_cards(start_index + 1, end_index);
263 break;
264 }
265 default:
266 ShouldNotReachHere();
267 }
268 }
269 }
270
271 // The card-interval [start_card, end_card] is a closed interval; this
272 // is an expensive check -- use with care and only under protection of
273 // suitable flag.
274 void G1BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const {
275
276 if (end_card < start_card) {
277 return;
278 }
279 guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card");
280 for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) {
281 u_char entry = _array->offset_array(c);
282 if (c - start_card > BlockOffsetArray::power_to_cards_back(1)) {
283 guarantee(entry > N_words,
284 err_msg("Should be in logarithmic region - "
285 "entry: %u, "
286 "_array->offset_array(c): %u, "
287 "N_words: %u",
288 (uint)entry, (uint)_array->offset_array(c), (uint)N_words));
289 }
290 size_t backskip = BlockOffsetArray::entry_to_cards_back(entry);
291 size_t landing_card = c - backskip;
292 guarantee(landing_card >= (start_card - 1), "Inv");
293 if (landing_card >= start_card) {
294 guarantee(_array->offset_array(landing_card) <= entry,
295 err_msg("Monotonicity - landing_card offset: %u, "
296 "entry: %u",
297 (uint)_array->offset_array(landing_card), (uint)entry));
298 } else {
299 guarantee(landing_card == start_card - 1, "Tautology");
300 // Note that N_words is the maximum offset value
301 guarantee(_array->offset_array(landing_card) <= N_words,
302 err_msg("landing card offset: %u, "
303 "N_words: %u",
304 (uint)_array->offset_array(landing_card), (uint)N_words));
305 }
306 }
307 }
308
309 // The range [blk_start, blk_end) represents a single contiguous block
310 // of storage; modify the block offset table to represent this
311 // information; Right-open interval: [blk_start, blk_end)
312 // NOTE: this method does _not_ adjust _unallocated_block.
313 void
314 G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) {
315 do_block_internal(blk_start, blk_end, Action_single);
316 }
317
318 // Mark the BOT such that if [blk_start, blk_end) straddles a card
319 // boundary, the card following the first such boundary is marked
320 // with the appropriate offset.
321 // NOTE: this method does _not_ adjust _unallocated_block or
322 // any cards subsequent to the first one.
323 void
324 G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) {
325 do_block_internal(blk_start, blk_end, Action_mark);
326 }
327
328 HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) {
329 assert(_bottom <= addr && addr < _end,
330 "addr must be covered by this Array");
331 // Must read this exactly once because it can be modified by parallel
332 // allocation.
333 HeapWord* ub = _unallocated_block;
334 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
335 assert(ub < _end, "tautology (see above)");
336 return ub;
337 }
338 // Otherwise, find the block start using the table.
339 HeapWord* q = block_at_or_preceding(addr, false, 0);
340 return forward_to_block_containing_addr(q, addr);
341 }
342
343 // This duplicates a little code from the above: unavoidable.
344 HeapWord*
345 G1BlockOffsetArray::block_start_unsafe_const(const void* addr) const {
346 assert(_bottom <= addr && addr < _end,
347 "addr must be covered by this Array");
348 // Must read this exactly once because it can be modified by parallel
349 // allocation.
350 HeapWord* ub = _unallocated_block;
351 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
352 assert(ub < _end, "tautology (see above)");
353 return ub;
354 }
355 // Otherwise, find the block start using the table.
356 HeapWord* q = block_at_or_preceding(addr, false, 0);
357 HeapWord* n = q + block_size(q);
358 return forward_to_block_containing_addr_const(q, n, addr);
359 }
360
361
362 HeapWord*
363 G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q,
364 HeapWord* n,
365 const void* addr) {
366 // We're not in the normal case. We need to handle an important subcase
367 // here: LAB allocation. An allocation previously recorded in the
368 // offset table was actually a lab allocation, and was divided into
369 // several objects subsequently. Fix this situation as we answer the
370 // query, by updating entries as we cross them.
371
372 // If the fist object's end q is at the card boundary. Start refining
373 // with the corresponding card (the value of the entry will be basically
374 // set to 0). If the object crosses the boundary -- start from the next card.
375 size_t n_index = _array->index_for(n);
376 size_t next_index = _array->index_for(n) + !_array->is_card_boundary(n);
377 // Calculate a consistent next boundary. If "n" is not at the boundary
378 // already, step to the boundary.
379 HeapWord* next_boundary = _array->address_for_index(n_index) +
380 (n_index == next_index ? 0 : N_words);
381 assert(next_boundary <= _array->_end,
382 err_msg("next_boundary is beyond the end of the covered region "
383 " next_boundary " PTR_FORMAT " _array->_end " PTR_FORMAT,
384 next_boundary, _array->_end));
385 if (addr >= gsp()->top()) return gsp()->top();
386 while (next_boundary < addr) {
387 while (n <= next_boundary) {
388 q = n;
389 oop obj = oop(q);
390 if (obj->klass_or_null() == NULL) return q;
391 n += block_size(q);
392 }
393 assert(q <= next_boundary && n > next_boundary, "Consequence of loop");
394 // [q, n) is the block that crosses the boundary.
395 alloc_block_work2(&next_boundary, &next_index, q, n);
396 }
397 return forward_to_block_containing_addr_const(q, n, addr);
398 }
399
400 HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const {
401 assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
402
403 assert(_bottom <= addr && addr < _end,
404 "addr must be covered by this Array");
405 // Must read this exactly once because it can be modified by parallel
406 // allocation.
407 HeapWord* ub = _unallocated_block;
408 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
409 assert(ub < _end, "tautology (see above)");
410 return ub;
411 }
412
413 // Otherwise, find the block start using the table, but taking
414 // care (cf block_start_unsafe() above) not to parse any objects/blocks
415 // on the cards themselves.
416 size_t index = _array->index_for(addr);
417 assert(_array->address_for_index(index) == addr,
418 "arg should be start of card");
419
420 HeapWord* q = (HeapWord*)addr;
421 uint offset;
422 do {
423 offset = _array->offset_array(index--);
424 q -= offset;
425 } while (offset == N_words);
426 assert(q <= addr, "block start should be to left of arg");
427 return q;
428 }
429
430 // Note that the committed size of the covered space may have changed,
431 // so the table size might also wish to change.
432 void G1BlockOffsetArray::resize(size_t new_word_size) {
433 HeapWord* new_end = _bottom + new_word_size;
434 if (_end < new_end && !init_to_zero()) {
435 // verify that the old and new boundaries are also card boundaries
436 assert(_array->is_card_boundary(_end),
437 "_end not a card boundary");
438 assert(_array->is_card_boundary(new_end),
439 "new _end would not be a card boundary");
440 // set all the newly added cards
441 _array->set_offset_array(_end, new_end, N_words);
442 }
443 _end = new_end; // update _end
444 }
445
446 void G1BlockOffsetArray::set_region(MemRegion mr) {
447 _bottom = mr.start();
448 _end = mr.end();
449 }
450
451 //
452 // threshold_
453 // | _index_
454 // v v
455 // +-------+-------+-------+-------+-------+
456 // | i-1 | i | i+1 | i+2 | i+3 |
457 // +-------+-------+-------+-------+-------+
458 // ( ^ ]
459 // block-start
460 //
461 void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_,
462 HeapWord* blk_start, HeapWord* blk_end) {
463 // For efficiency, do copy-in/copy-out.
464 HeapWord* threshold = *threshold_;
465 size_t index = *index_;
466
467 assert(blk_start != NULL && blk_end > blk_start,
468 "phantom block");
469 assert(blk_end > threshold, "should be past threshold");
470 assert(blk_start <= threshold, "blk_start should be at or before threshold");
471 assert(pointer_delta(threshold, blk_start) <= N_words,
472 "offset should be <= BlockOffsetSharedArray::N");
473 assert(Universe::heap()->is_in_reserved(blk_start),
474 "reference must be into the heap");
475 assert(Universe::heap()->is_in_reserved(blk_end-1),
476 "limit must be within the heap");
477 assert(threshold == _array->_reserved.start() + index*N_words,
478 "index must agree with threshold");
479
480 DEBUG_ONLY(size_t orig_index = index;)
481
482 // Mark the card that holds the offset into the block. Note
483 // that _next_offset_index and _next_offset_threshold are not
484 // updated until the end of this method.
485 _array->set_offset_array(index, threshold, blk_start);
486
487 // We need to now mark the subsequent cards that this blk spans.
488
489 // Index of card on which blk ends.
490 size_t end_index = _array->index_for(blk_end - 1);
491
492 // Are there more cards left to be updated?
493 if (index + 1 <= end_index) {
494 HeapWord* rem_st = _array->address_for_index(index + 1);
495 // Calculate rem_end this way because end_index
496 // may be the last valid index in the covered region.
497 HeapWord* rem_end = _array->address_for_index(end_index) + N_words;
498 set_remainder_to_point_to_start(rem_st, rem_end);
499 }
500
501 index = end_index + 1;
502 // Calculate threshold_ this way because end_index
503 // may be the last valid index in the covered region.
504 threshold = _array->address_for_index(end_index) + N_words;
505 assert(threshold >= blk_end, "Incorrect offset threshold");
506
507 // index_ and threshold_ updated here.
508 *threshold_ = threshold;
509 *index_ = index;
510
511 #ifdef ASSERT
512 // The offset can be 0 if the block starts on a boundary. That
513 // is checked by an assertion above.
514 size_t start_index = _array->index_for(blk_start);
515 HeapWord* boundary = _array->address_for_index(start_index);
516 assert((_array->offset_array(orig_index) == 0 &&
517 blk_start == boundary) ||
518 (_array->offset_array(orig_index) > 0 &&
519 _array->offset_array(orig_index) <= N_words),
520 err_msg("offset array should have been set - "
521 "orig_index offset: %u, "
522 "blk_start: " PTR_FORMAT ", "
523 "boundary: " PTR_FORMAT,
524 (uint)_array->offset_array(orig_index),
525 blk_start, boundary));
526 for (size_t j = orig_index + 1; j <= end_index; j++) {
527 assert(_array->offset_array(j) > 0 &&
528 _array->offset_array(j) <=
529 (u_char) (N_words+BlockOffsetArray::N_powers-1),
530 err_msg("offset array should have been set - "
531 "%u not > 0 OR %u not <= %u",
532 (uint) _array->offset_array(j),
533 (uint) _array->offset_array(j),
534 (uint) (N_words+BlockOffsetArray::N_powers-1)));
535 }
536 #endif
537 }
538
539 bool
540 G1BlockOffsetArray::verify_for_object(HeapWord* obj_start,
541 size_t word_size) const {
542 size_t first_card = _array->index_for(obj_start);
543 size_t last_card = _array->index_for(obj_start + word_size - 1);
544 if (!_array->is_card_boundary(obj_start)) {
545 // If the object is not on a card boundary the BOT entry of the
546 // first card should point to another object so we should not
547 // check that one.
548 first_card += 1;
549 }
550 for (size_t card = first_card; card <= last_card; card += 1) {
551 HeapWord* card_addr = _array->address_for_index(card);
552 HeapWord* block_start = block_start_const(card_addr);
553 if (block_start != obj_start) {
554 gclog_or_tty->print_cr("block start: "PTR_FORMAT" is incorrect - "
555 "card index: "SIZE_FORMAT" "
556 "card addr: "PTR_FORMAT" BOT entry: %u "
557 "obj: "PTR_FORMAT" word size: "SIZE_FORMAT" "
558 "cards: ["SIZE_FORMAT","SIZE_FORMAT"]",
559 block_start, card, card_addr,
560 _array->offset_array(card),
561 obj_start, word_size, first_card, last_card);
562 return false;
563 }
564 }
565 return true;
566 }
567
568 #ifndef PRODUCT
569 void
570 G1BlockOffsetArray::print_on(outputStream* out) {
571 size_t from_index = _array->index_for(_bottom);
572 size_t to_index = _array->index_for(_end);
573 out->print_cr(">> BOT for area ["PTR_FORMAT","PTR_FORMAT") "
574 "cards ["SIZE_FORMAT","SIZE_FORMAT")",
575 _bottom, _end, from_index, to_index);
576 for (size_t i = from_index; i < to_index; ++i) {
577 out->print_cr(" entry "SIZE_FORMAT_W(8)" | "PTR_FORMAT" : %3u",
578 i, _array->address_for_index(i),
579 (uint) _array->offset_array(i));
580 }
581 }
582 #endif // !PRODUCT
583
584 //////////////////////////////////////////////////////////////////////
585 // G1BlockOffsetArrayContigSpace
586 //////////////////////////////////////////////////////////////////////
587
588 HeapWord*
589 G1BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) {
590 assert(_bottom <= addr && addr < _end,
591 "addr must be covered by this Array");
592 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
593 return forward_to_block_containing_addr(q, addr);
594 }
595
596 HeapWord*
597 G1BlockOffsetArrayContigSpace::
598 block_start_unsafe_const(const void* addr) const {
599 assert(_bottom <= addr && addr < _end,
600 "addr must be covered by this Array");
601 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
602 HeapWord* n = q + block_size(q);
603 return forward_to_block_containing_addr_const(q, n, addr);
604 }
605
606 G1BlockOffsetArrayContigSpace::
607 G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array,
608 MemRegion mr) :
609 G1BlockOffsetArray(array, mr, true)
610 {
611 _next_offset_threshold = NULL;
612 _next_offset_index = 0;
613 }
614
615 HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold_raw() {
616 assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
617 "just checking");
618 _next_offset_index = _array->index_for_raw(_bottom);
619 _next_offset_index++;
620 _next_offset_threshold =
621 _array->address_for_index_raw(_next_offset_index);
622 return _next_offset_threshold;
623 }
624
625 void G1BlockOffsetArrayContigSpace::zero_bottom_entry_raw() {
626 assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
627 "just checking");
628 size_t bottom_index = _array->index_for_raw(_bottom);
629 assert(_array->address_for_index_raw(bottom_index) == _bottom,
630 "Precondition of call");
631 _array->set_offset_array_raw(bottom_index, 0);
632 }
633
634 HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold() {
635 assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
636 "just checking");
637 _next_offset_index = _array->index_for(_bottom);
638 _next_offset_index++;
639 _next_offset_threshold =
640 _array->address_for_index(_next_offset_index);
641 return _next_offset_threshold;
642 }
643
644 void G1BlockOffsetArrayContigSpace::zero_bottom_entry() {
645 assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
646 "just checking");
647 size_t bottom_index = _array->index_for(_bottom);
648 assert(_array->address_for_index(bottom_index) == _bottom,
649 "Precondition of call");
650 _array->set_offset_array(bottom_index, 0);
651 }
652
653 void
654 G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_top) {
655 assert(new_top <= _end, "_end should have already been updated");
656
657 // The first BOT entry should have offset 0.
658 reset_bot();
659 alloc_block(_bottom, new_top);
660 }
661
662 #ifndef PRODUCT
663 void
664 G1BlockOffsetArrayContigSpace::print_on(outputStream* out) {
665 G1BlockOffsetArray::print_on(out);
666 out->print_cr(" next offset threshold: "PTR_FORMAT, _next_offset_threshold);
667 out->print_cr(" next offset index: "SIZE_FORMAT, _next_offset_index);
668 }
669 #endif // !PRODUCT