Mercurial > hg > truffle
annotate src/share/vm/memory/blockOffsetTable.cpp @ 6294:b0fc02623974
exclude TestPrograms from JaCoCo processing
author | Doug Simon <doug.simon@oracle.com> |
---|---|
date | Tue, 28 Aug 2012 13:55:11 +0200 |
parents | d2a62e0f25eb |
children | da91efe96a93 |
rev | line source |
---|---|
0 | 1 /* |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
2 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1489
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1489
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1489
diff
changeset
|
21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "gc_interface/collectedHeap.inline.hpp" | |
27 #include "memory/blockOffsetTable.inline.hpp" | |
28 #include "memory/iterator.hpp" | |
29 #include "memory/space.inline.hpp" | |
30 #include "memory/universe.hpp" | |
31 #include "oops/oop.inline.hpp" | |
32 #include "runtime/java.hpp" | |
6197 | 33 #include "services/memTracker.hpp" |
0 | 34 |
35 ////////////////////////////////////////////////////////////////////// | |
36 // BlockOffsetSharedArray | |
37 ////////////////////////////////////////////////////////////////////// | |
38 | |
39 BlockOffsetSharedArray::BlockOffsetSharedArray(MemRegion reserved, | |
40 size_t init_word_size): | |
41 _reserved(reserved), _end(NULL) | |
42 { | |
43 size_t size = compute_size(reserved.word_size()); | |
44 ReservedSpace rs(size); | |
45 if (!rs.is_reserved()) { | |
46 vm_exit_during_initialization("Could not reserve enough space for heap offset array"); | |
47 } | |
6197 | 48 |
49 MemTracker::record_virtual_memory_type((address)rs.base(), mtGC); | |
50 | |
0 | 51 if (!_vs.initialize(rs, 0)) { |
52 vm_exit_during_initialization("Could not reserve enough space for heap offset array"); | |
53 } | |
54 _offset_array = (u_char*)_vs.low_boundary(); | |
55 resize(init_word_size); | |
56 if (TraceBlockOffsetTable) { | |
57 gclog_or_tty->print_cr("BlockOffsetSharedArray::BlockOffsetSharedArray: "); | |
58 gclog_or_tty->print_cr(" " | |
59 " rs.base(): " INTPTR_FORMAT | |
60 " rs.size(): " INTPTR_FORMAT | |
61 " rs end(): " INTPTR_FORMAT, | |
62 rs.base(), rs.size(), rs.base() + rs.size()); | |
63 gclog_or_tty->print_cr(" " | |
64 " _vs.low_boundary(): " INTPTR_FORMAT | |
65 " _vs.high_boundary(): " INTPTR_FORMAT, | |
66 _vs.low_boundary(), | |
67 _vs.high_boundary()); | |
68 } | |
69 } | |
70 | |
71 void BlockOffsetSharedArray::resize(size_t new_word_size) { | |
72 assert(new_word_size <= _reserved.word_size(), "Resize larger than reserved"); | |
73 size_t new_size = compute_size(new_word_size); | |
74 size_t old_size = _vs.committed_size(); | |
75 size_t delta; | |
76 char* high = _vs.high(); | |
77 _end = _reserved.start() + new_word_size; | |
78 if (new_size > old_size) { | |
79 delta = ReservedSpace::page_align_size_up(new_size - old_size); | |
80 assert(delta > 0, "just checking"); | |
81 if (!_vs.expand_by(delta)) { | |
82 // Do better than this for Merlin | |
83 vm_exit_out_of_memory(delta, "offset table expansion"); | |
84 } | |
85 assert(_vs.high() == high + delta, "invalid expansion"); | |
86 } else { | |
87 delta = ReservedSpace::page_align_size_down(old_size - new_size); | |
88 if (delta == 0) return; | |
89 _vs.shrink_by(delta); | |
90 assert(_vs.high() == high - delta, "invalid expansion"); | |
91 } | |
92 } | |
93 | |
94 bool BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const { | |
95 assert(p >= _reserved.start(), "just checking"); | |
96 size_t delta = pointer_delta(p, _reserved.start()); | |
97 return (delta & right_n_bits(LogN_words)) == (size_t)NoBits; | |
98 } | |
99 | |
100 | |
101 void BlockOffsetSharedArray::serialize(SerializeOopClosure* soc, | |
102 HeapWord* start, HeapWord* end) { | |
103 assert(_offset_array[0] == 0, "objects can't cross covered areas"); | |
104 assert(start <= end, "bad address range"); | |
105 size_t start_index = index_for(start); | |
106 size_t end_index = index_for(end-1)+1; | |
107 soc->do_region(&_offset_array[start_index], | |
108 (end_index - start_index) * sizeof(_offset_array[0])); | |
109 } | |
110 | |
111 ////////////////////////////////////////////////////////////////////// | |
112 // BlockOffsetArray | |
113 ////////////////////////////////////////////////////////////////////// | |
114 | |
115 BlockOffsetArray::BlockOffsetArray(BlockOffsetSharedArray* array, | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
116 MemRegion mr, bool init_to_zero_) : |
0 | 117 BlockOffsetTable(mr.start(), mr.end()), |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
118 _array(array) |
0 | 119 { |
120 assert(_bottom <= _end, "arguments out of order"); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
121 set_init_to_zero(init_to_zero_); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
122 if (!init_to_zero_) { |
0 | 123 // initialize cards to point back to mr.start() |
124 set_remainder_to_point_to_start(mr.start() + N_words, mr.end()); | |
125 _array->set_offset_array(0, 0); // set first card to 0 | |
126 } | |
127 } | |
128 | |
129 | |
130 // The arguments follow the normal convention of denoting | |
131 // a right-open interval: [start, end) | |
132 void | |
133 BlockOffsetArray:: | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
134 set_remainder_to_point_to_start(HeapWord* start, HeapWord* end, bool reducing) { |
0 | 135 |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
136 check_reducing_assertion(reducing); |
0 | 137 if (start >= end) { |
138 // The start address is equal to the end address (or to | |
139 // the right of the end address) so there are not cards | |
140 // that need to be updated.. | |
141 return; | |
142 } | |
143 | |
144 // Write the backskip value for each region. | |
145 // | |
146 // offset | |
147 // card 2nd 3rd | |
148 // | +- 1st | | | |
149 // v v v v | |
150 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- | |
151 // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ... | |
152 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- | |
153 // 11 19 75 | |
154 // 12 | |
155 // | |
156 // offset card is the card that points to the start of an object | |
157 // x - offset value of offset card | |
158 // 1st - start of first logarithmic region | |
159 // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1 | |
160 // 2nd - start of second logarithmic region | |
161 // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8 | |
162 // 3rd - start of third logarithmic region | |
163 // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64 | |
164 // | |
165 // integer below the block offset entry is an example of | |
166 // the index of the entry | |
167 // | |
168 // Given an address, | |
169 // Find the index for the address | |
170 // Find the block offset table entry | |
171 // Convert the entry to a back slide | |
172 // (e.g., with today's, offset = 0x81 => | |
173 // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8 | |
174 // Move back N (e.g., 8) entries and repeat with the | |
175 // value of the new entry | |
176 // | |
177 size_t start_card = _array->index_for(start); | |
178 size_t end_card = _array->index_for(end-1); | |
179 assert(start ==_array->address_for_index(start_card), "Precondition"); | |
180 assert(end ==_array->address_for_index(end_card)+N_words, "Precondition"); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
181 set_remainder_to_point_to_start_incl(start_card, end_card, reducing); // closed interval |
0 | 182 } |
183 | |
184 | |
185 // Unlike the normal convention in this code, the argument here denotes | |
186 // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start() | |
187 // above. | |
188 void | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
189 BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card, bool reducing) { |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
190 |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
191 check_reducing_assertion(reducing); |
0 | 192 if (start_card > end_card) { |
193 return; | |
194 } | |
195 assert(start_card > _array->index_for(_bottom), "Cannot be first card"); | |
196 assert(_array->offset_array(start_card-1) <= N_words, | |
197 "Offset card has an unexpected value"); | |
198 size_t start_card_for_region = start_card; | |
199 u_char offset = max_jubyte; | |
342 | 200 for (int i = 0; i < N_powers; i++) { |
0 | 201 // -1 so that the the card with the actual offset is counted. Another -1 |
202 // so that the reach ends in this region and not at the start | |
203 // of the next. | |
204 size_t reach = start_card - 1 + (power_to_cards_back(i+1) - 1); | |
205 offset = N_words + i; | |
206 if (reach >= end_card) { | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
207 _array->set_offset_array(start_card_for_region, end_card, offset, reducing); |
0 | 208 start_card_for_region = reach + 1; |
209 break; | |
210 } | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
211 _array->set_offset_array(start_card_for_region, reach, offset, reducing); |
0 | 212 start_card_for_region = reach + 1; |
213 } | |
214 assert(start_card_for_region > end_card, "Sanity check"); | |
215 DEBUG_ONLY(check_all_cards(start_card, end_card);) | |
216 } | |
217 | |
218 // The card-interval [start_card, end_card] is a closed interval; this | |
219 // is an expensive check -- use with care and only under protection of | |
220 // suitable flag. | |
221 void BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const { | |
222 | |
223 if (end_card < start_card) { | |
224 return; | |
225 } | |
226 guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card"); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
227 u_char last_entry = N_words; |
0 | 228 for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) { |
229 u_char entry = _array->offset_array(c); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
230 guarantee(entry >= last_entry, "Monotonicity"); |
0 | 231 if (c - start_card > power_to_cards_back(1)) { |
232 guarantee(entry > N_words, "Should be in logarithmic region"); | |
233 } | |
234 size_t backskip = entry_to_cards_back(entry); | |
235 size_t landing_card = c - backskip; | |
236 guarantee(landing_card >= (start_card - 1), "Inv"); | |
237 if (landing_card >= start_card) { | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
238 guarantee(_array->offset_array(landing_card) <= entry, "Monotonicity"); |
0 | 239 } else { |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
240 guarantee(landing_card == (start_card - 1), "Tautology"); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
241 // Note that N_words is the maximum offset value |
0 | 242 guarantee(_array->offset_array(landing_card) <= N_words, "Offset value"); |
243 } | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
244 last_entry = entry; // remember for monotonicity test |
0 | 245 } |
246 } | |
247 | |
248 | |
249 void | |
250 BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) { | |
251 assert(blk_start != NULL && blk_end > blk_start, | |
252 "phantom block"); | |
253 single_block(blk_start, blk_end); | |
254 } | |
255 | |
256 // Action_mark - update the BOT for the block [blk_start, blk_end). | |
257 // Current typical use is for splitting a block. | |
258 // Action_single - udpate the BOT for an allocation. | |
259 // Action_verify - BOT verification. | |
260 void | |
261 BlockOffsetArray::do_block_internal(HeapWord* blk_start, | |
262 HeapWord* blk_end, | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
263 Action action, bool reducing) { |
0 | 264 assert(Universe::heap()->is_in_reserved(blk_start), |
265 "reference must be into the heap"); | |
266 assert(Universe::heap()->is_in_reserved(blk_end-1), | |
267 "limit must be within the heap"); | |
268 // This is optimized to make the test fast, assuming we only rarely | |
269 // cross boundaries. | |
270 uintptr_t end_ui = (uintptr_t)(blk_end - 1); | |
271 uintptr_t start_ui = (uintptr_t)blk_start; | |
272 // Calculate the last card boundary preceding end of blk | |
273 intptr_t boundary_before_end = (intptr_t)end_ui; | |
274 clear_bits(boundary_before_end, right_n_bits(LogN)); | |
275 if (start_ui <= (uintptr_t)boundary_before_end) { | |
276 // blk starts at or crosses a boundary | |
277 // Calculate index of card on which blk begins | |
278 size_t start_index = _array->index_for(blk_start); | |
279 // Index of card on which blk ends | |
280 size_t end_index = _array->index_for(blk_end - 1); | |
281 // Start address of card on which blk begins | |
282 HeapWord* boundary = _array->address_for_index(start_index); | |
283 assert(boundary <= blk_start, "blk should start at or after boundary"); | |
284 if (blk_start != boundary) { | |
285 // blk starts strictly after boundary | |
286 // adjust card boundary and start_index forward to next card | |
287 boundary += N_words; | |
288 start_index++; | |
289 } | |
290 assert(start_index <= end_index, "monotonicity of index_for()"); | |
291 assert(boundary <= (HeapWord*)boundary_before_end, "tautology"); | |
292 switch (action) { | |
293 case Action_mark: { | |
294 if (init_to_zero()) { | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
295 _array->set_offset_array(start_index, boundary, blk_start, reducing); |
0 | 296 break; |
297 } // Else fall through to the next case | |
298 } | |
299 case Action_single: { | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
300 _array->set_offset_array(start_index, boundary, blk_start, reducing); |
0 | 301 // We have finished marking the "offset card". We need to now |
302 // mark the subsequent cards that this blk spans. | |
303 if (start_index < end_index) { | |
304 HeapWord* rem_st = _array->address_for_index(start_index) + N_words; | |
305 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
306 set_remainder_to_point_to_start(rem_st, rem_end, reducing); |
0 | 307 } |
308 break; | |
309 } | |
310 case Action_check: { | |
311 _array->check_offset_array(start_index, boundary, blk_start); | |
312 // We have finished checking the "offset card". We need to now | |
313 // check the subsequent cards that this blk spans. | |
314 check_all_cards(start_index + 1, end_index); | |
315 break; | |
316 } | |
317 default: | |
318 ShouldNotReachHere(); | |
319 } | |
320 } | |
321 } | |
322 | |
323 // The range [blk_start, blk_end) represents a single contiguous block | |
324 // of storage; modify the block offset table to represent this | |
325 // information; Right-open interval: [blk_start, blk_end) | |
326 // NOTE: this method does _not_ adjust _unallocated_block. | |
327 void | |
328 BlockOffsetArray::single_block(HeapWord* blk_start, | |
329 HeapWord* blk_end) { | |
330 do_block_internal(blk_start, blk_end, Action_single); | |
331 } | |
332 | |
333 void BlockOffsetArray::verify() const { | |
334 // For each entry in the block offset table, verify that | |
335 // the entry correctly finds the start of an object at the | |
336 // first address covered by the block or to the left of that | |
337 // first address. | |
338 | |
339 size_t next_index = 1; | |
340 size_t last_index = last_active_index(); | |
341 | |
342 // Use for debugging. Initialize to NULL to distinguish the | |
343 // first iteration through the while loop. | |
344 HeapWord* last_p = NULL; | |
345 HeapWord* last_start = NULL; | |
346 oop last_o = NULL; | |
347 | |
348 while (next_index <= last_index) { | |
349 // Use an address past the start of the address for | |
350 // the entry. | |
351 HeapWord* p = _array->address_for_index(next_index) + 1; | |
352 if (p >= _end) { | |
353 // That's all of the allocated block table. | |
354 return; | |
355 } | |
356 // block_start() asserts that start <= p. | |
357 HeapWord* start = block_start(p); | |
358 // First check if the start is an allocated block and only | |
359 // then if it is a valid object. | |
360 oop o = oop(start); | |
361 assert(!Universe::is_fully_initialized() || | |
362 _sp->is_free_block(start) || | |
363 o->is_oop_or_null(), "Bad object was found"); | |
364 next_index++; | |
365 last_p = p; | |
366 last_start = start; | |
367 last_o = o; | |
368 } | |
369 } | |
370 | |
371 ////////////////////////////////////////////////////////////////////// | |
372 // BlockOffsetArrayNonContigSpace | |
373 ////////////////////////////////////////////////////////////////////// | |
374 | |
375 // The block [blk_start, blk_end) has been allocated; | |
376 // adjust the block offset table to represent this information; | |
377 // NOTE: Clients of BlockOffsetArrayNonContigSpace: consider using | |
378 // the somewhat more lightweight split_block() or | |
379 // (when init_to_zero()) mark_block() wherever possible. | |
380 // right-open interval: [blk_start, blk_end) | |
381 void | |
382 BlockOffsetArrayNonContigSpace::alloc_block(HeapWord* blk_start, | |
383 HeapWord* blk_end) { | |
384 assert(blk_start != NULL && blk_end > blk_start, | |
385 "phantom block"); | |
386 single_block(blk_start, blk_end); | |
387 allocated(blk_start, blk_end); | |
388 } | |
389 | |
390 // Adjust BOT to show that a previously whole block has been split | |
391 // into two. We verify the BOT for the first part (prefix) and | |
392 // update the BOT for the second part (suffix). | |
393 // blk is the start of the block | |
394 // blk_size is the size of the original block | |
395 // left_blk_size is the size of the first part of the split | |
396 void BlockOffsetArrayNonContigSpace::split_block(HeapWord* blk, | |
397 size_t blk_size, | |
398 size_t left_blk_size) { | |
399 // Verify that the BOT shows [blk, blk + blk_size) to be one block. | |
400 verify_single_block(blk, blk_size); | |
401 // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size) | |
402 // is one single block. | |
403 assert(blk_size > 0, "Should be positive"); | |
404 assert(left_blk_size > 0, "Should be positive"); | |
405 assert(left_blk_size < blk_size, "Not a split"); | |
406 | |
407 // Start addresses of prefix block and suffix block. | |
408 HeapWord* pref_addr = blk; | |
409 HeapWord* suff_addr = blk + left_blk_size; | |
410 HeapWord* end_addr = blk + blk_size; | |
411 | |
412 // Indices for starts of prefix block and suffix block. | |
413 size_t pref_index = _array->index_for(pref_addr); | |
414 if (_array->address_for_index(pref_index) != pref_addr) { | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
415 // pref_addr does not begin pref_index |
0 | 416 pref_index++; |
417 } | |
418 | |
419 size_t suff_index = _array->index_for(suff_addr); | |
420 if (_array->address_for_index(suff_index) != suff_addr) { | |
421 // suff_addr does not begin suff_index | |
422 suff_index++; | |
423 } | |
424 | |
425 // Definition: A block B, denoted [B_start, B_end) __starts__ | |
426 // a card C, denoted [C_start, C_end), where C_start and C_end | |
427 // are the heap addresses that card C covers, iff | |
428 // B_start <= C_start < B_end. | |
429 // | |
430 // We say that a card C "is started by" a block B, iff | |
431 // B "starts" C. | |
432 // | |
433 // Note that the cardinality of the set of cards {C} | |
434 // started by a block B can be 0, 1, or more. | |
435 // | |
436 // Below, pref_index and suff_index are, respectively, the | |
437 // first (least) card indices that the prefix and suffix of | |
438 // the split start; end_index is one more than the index of | |
439 // the last (greatest) card that blk starts. | |
440 size_t end_index = _array->index_for(end_addr - 1) + 1; | |
441 | |
442 // Calculate the # cards that the prefix and suffix affect. | |
443 size_t num_pref_cards = suff_index - pref_index; | |
444 | |
445 size_t num_suff_cards = end_index - suff_index; | |
446 // Change the cards that need changing | |
447 if (num_suff_cards > 0) { | |
448 HeapWord* boundary = _array->address_for_index(suff_index); | |
449 // Set the offset card for suffix block | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
450 _array->set_offset_array(suff_index, boundary, suff_addr, true /* reducing */); |
0 | 451 // Change any further cards that need changing in the suffix |
452 if (num_pref_cards > 0) { | |
453 if (num_pref_cards >= num_suff_cards) { | |
454 // Unilaterally fix all of the suffix cards: closed card | |
455 // index interval in args below. | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
456 set_remainder_to_point_to_start_incl(suff_index + 1, end_index - 1, true /* reducing */); |
0 | 457 } else { |
458 // Unilaterally fix the first (num_pref_cards - 1) following | |
459 // the "offset card" in the suffix block. | |
460 set_remainder_to_point_to_start_incl(suff_index + 1, | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
461 suff_index + num_pref_cards - 1, true /* reducing */); |
0 | 462 // Fix the appropriate cards in the remainder of the |
463 // suffix block -- these are the last num_pref_cards | |
464 // cards in each power block of the "new" range plumbed | |
465 // from suff_addr. | |
466 bool more = true; | |
467 uint i = 1; | |
468 while (more && (i < N_powers)) { | |
469 size_t back_by = power_to_cards_back(i); | |
470 size_t right_index = suff_index + back_by - 1; | |
471 size_t left_index = right_index - num_pref_cards + 1; | |
472 if (right_index >= end_index - 1) { // last iteration | |
473 right_index = end_index - 1; | |
474 more = false; | |
475 } | |
476 if (back_by > num_pref_cards) { | |
477 // Fill in the remainder of this "power block", if it | |
478 // is non-null. | |
479 if (left_index <= right_index) { | |
480 _array->set_offset_array(left_index, right_index, | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
481 N_words + i - 1, true /* reducing */); |
0 | 482 } else { |
483 more = false; // we are done | |
484 } | |
485 i++; | |
486 break; | |
487 } | |
488 i++; | |
489 } | |
490 while (more && (i < N_powers)) { | |
491 size_t back_by = power_to_cards_back(i); | |
492 size_t right_index = suff_index + back_by - 1; | |
493 size_t left_index = right_index - num_pref_cards + 1; | |
494 if (right_index >= end_index - 1) { // last iteration | |
495 right_index = end_index - 1; | |
496 if (left_index > right_index) { | |
497 break; | |
498 } | |
499 more = false; | |
500 } | |
501 assert(left_index <= right_index, "Error"); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
502 _array->set_offset_array(left_index, right_index, N_words + i - 1, true /* reducing */); |
0 | 503 i++; |
504 } | |
505 } | |
506 } // else no more cards to fix in suffix | |
507 } // else nothing needs to be done | |
508 // Verify that we did the right thing | |
509 verify_single_block(pref_addr, left_blk_size); | |
510 verify_single_block(suff_addr, blk_size - left_blk_size); | |
511 } | |
512 | |
513 | |
514 // Mark the BOT such that if [blk_start, blk_end) straddles a card | |
515 // boundary, the card following the first such boundary is marked | |
516 // with the appropriate offset. | |
517 // NOTE: this method does _not_ adjust _unallocated_block or | |
518 // any cards subsequent to the first one. | |
519 void | |
520 BlockOffsetArrayNonContigSpace::mark_block(HeapWord* blk_start, | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
521 HeapWord* blk_end, bool reducing) { |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
522 do_block_internal(blk_start, blk_end, Action_mark, reducing); |
0 | 523 } |
524 | |
525 HeapWord* BlockOffsetArrayNonContigSpace::block_start_unsafe( | |
526 const void* addr) const { | |
527 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
528 assert(_bottom <= addr && addr < _end, | |
529 "addr must be covered by this Array"); | |
530 // Must read this exactly once because it can be modified by parallel | |
531 // allocation. | |
532 HeapWord* ub = _unallocated_block; | |
533 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { | |
534 assert(ub < _end, "tautology (see above)"); | |
535 return ub; | |
536 } | |
537 | |
538 // Otherwise, find the block start using the table. | |
539 size_t index = _array->index_for(addr); | |
540 HeapWord* q = _array->address_for_index(index); | |
541 | |
542 uint offset = _array->offset_array(index); // Extend u_char to uint. | |
543 while (offset >= N_words) { | |
544 // The excess of the offset from N_words indicates a power of Base | |
545 // to go back by. | |
546 size_t n_cards_back = entry_to_cards_back(offset); | |
547 q -= (N_words * n_cards_back); | |
3359
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
548 assert(q >= _sp->bottom(), |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
549 err_msg("q = " PTR_FORMAT " crossed below bottom = " PTR_FORMAT, |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
550 q, _sp->bottom())); |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
551 assert(q < _sp->end(), |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
552 err_msg("q = " PTR_FORMAT " crossed above end = " PTR_FORMAT, |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
553 q, _sp->end())); |
0 | 554 index -= n_cards_back; |
555 offset = _array->offset_array(index); | |
556 } | |
557 assert(offset < N_words, "offset too large"); | |
558 index--; | |
559 q -= offset; | |
3359
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
560 assert(q >= _sp->bottom(), |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
561 err_msg("q = " PTR_FORMAT " crossed below bottom = " PTR_FORMAT, |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
562 q, _sp->bottom())); |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
563 assert(q < _sp->end(), |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
564 err_msg("q = " PTR_FORMAT " crossed above end = " PTR_FORMAT, |
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
565 q, _sp->end())); |
0 | 566 HeapWord* n = q; |
567 | |
568 while (n <= addr) { | |
569 debug_only(HeapWord* last = q); // for debugging | |
570 q = n; | |
571 n += _sp->block_size(n); | |
3359
7d64aa23eb96
7043891: CMS: assert(_whole_heap.contains(p)) failed: out of bounds access to card marking array
ysr
parents:
1972
diff
changeset
|
572 assert(n > q, |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
573 err_msg("Looping at n = " PTR_FORMAT " with last = " PTR_FORMAT"," |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
574 " while querying blk_start(" PTR_FORMAT ")" |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
575 " on _sp = [" PTR_FORMAT "," PTR_FORMAT ")", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
576 n, last, addr, _sp->bottom(), _sp->end())); |
0 | 577 } |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
578 assert(q <= addr, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
579 err_msg("wrong order for current (" INTPTR_FORMAT ")" " <= arg (" INTPTR_FORMAT ")", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
580 q, addr)); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
581 assert(addr <= n, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
582 err_msg("wrong order for arg (" INTPTR_FORMAT ") <= next (" INTPTR_FORMAT ")", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3359
diff
changeset
|
583 addr, n)); |
0 | 584 return q; |
585 } | |
586 | |
587 HeapWord* BlockOffsetArrayNonContigSpace::block_start_careful( | |
588 const void* addr) const { | |
589 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
590 | |
591 assert(_bottom <= addr && addr < _end, | |
592 "addr must be covered by this Array"); | |
593 // Must read this exactly once because it can be modified by parallel | |
594 // allocation. | |
595 HeapWord* ub = _unallocated_block; | |
596 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { | |
597 assert(ub < _end, "tautology (see above)"); | |
598 return ub; | |
599 } | |
600 | |
601 // Otherwise, find the block start using the table, but taking | |
602 // care (cf block_start_unsafe() above) not to parse any objects/blocks | |
603 // on the cards themsleves. | |
604 size_t index = _array->index_for(addr); | |
605 assert(_array->address_for_index(index) == addr, | |
606 "arg should be start of card"); | |
607 | |
608 HeapWord* q = (HeapWord*)addr; | |
609 uint offset; | |
610 do { | |
611 offset = _array->offset_array(index); | |
612 if (offset < N_words) { | |
613 q -= offset; | |
614 } else { | |
615 size_t n_cards_back = entry_to_cards_back(offset); | |
616 q -= (n_cards_back * N_words); | |
617 index -= n_cards_back; | |
618 } | |
619 } while (offset >= N_words); | |
620 assert(q <= addr, "block start should be to left of arg"); | |
621 return q; | |
622 } | |
623 | |
624 #ifndef PRODUCT | |
625 // Verification & debugging - ensure that the offset table reflects the fact | |
626 // that the block [blk_start, blk_end) or [blk, blk + size) is a | |
627 // single block of storage. NOTE: can't const this because of | |
628 // call to non-const do_block_internal() below. | |
629 void BlockOffsetArrayNonContigSpace::verify_single_block( | |
630 HeapWord* blk_start, HeapWord* blk_end) { | |
631 if (VerifyBlockOffsetArray) { | |
632 do_block_internal(blk_start, blk_end, Action_check); | |
633 } | |
634 } | |
635 | |
636 void BlockOffsetArrayNonContigSpace::verify_single_block( | |
637 HeapWord* blk, size_t size) { | |
638 verify_single_block(blk, blk + size); | |
639 } | |
640 | |
641 // Verify that the given block is before _unallocated_block | |
642 void BlockOffsetArrayNonContigSpace::verify_not_unallocated( | |
643 HeapWord* blk_start, HeapWord* blk_end) const { | |
644 if (BlockOffsetArrayUseUnallocatedBlock) { | |
645 assert(blk_start < blk_end, "Block inconsistency?"); | |
646 assert(blk_end <= _unallocated_block, "_unallocated_block problem"); | |
647 } | |
648 } | |
649 | |
650 void BlockOffsetArrayNonContigSpace::verify_not_unallocated( | |
651 HeapWord* blk, size_t size) const { | |
652 verify_not_unallocated(blk, blk + size); | |
653 } | |
654 #endif // PRODUCT | |
655 | |
656 size_t BlockOffsetArrayNonContigSpace::last_active_index() const { | |
657 if (_unallocated_block == _bottom) { | |
658 return 0; | |
659 } else { | |
660 return _array->index_for(_unallocated_block - 1); | |
661 } | |
662 } | |
663 | |
664 ////////////////////////////////////////////////////////////////////// | |
665 // BlockOffsetArrayContigSpace | |
666 ////////////////////////////////////////////////////////////////////// | |
667 | |
668 HeapWord* BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) const { | |
669 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
670 | |
671 // Otherwise, find the block start using the table. | |
672 assert(_bottom <= addr && addr < _end, | |
673 "addr must be covered by this Array"); | |
674 size_t index = _array->index_for(addr); | |
675 // We must make sure that the offset table entry we use is valid. If | |
676 // "addr" is past the end, start at the last known one and go forward. | |
677 index = MIN2(index, _next_offset_index-1); | |
678 HeapWord* q = _array->address_for_index(index); | |
679 | |
680 uint offset = _array->offset_array(index); // Extend u_char to uint. | |
681 while (offset > N_words) { | |
682 // The excess of the offset from N_words indicates a power of Base | |
683 // to go back by. | |
684 size_t n_cards_back = entry_to_cards_back(offset); | |
685 q -= (N_words * n_cards_back); | |
686 assert(q >= _sp->bottom(), "Went below bottom!"); | |
687 index -= n_cards_back; | |
688 offset = _array->offset_array(index); | |
689 } | |
690 while (offset == N_words) { | |
691 assert(q >= _sp->bottom(), "Went below bottom!"); | |
692 q -= N_words; | |
693 index--; | |
694 offset = _array->offset_array(index); | |
695 } | |
696 assert(offset < N_words, "offset too large"); | |
697 q -= offset; | |
698 HeapWord* n = q; | |
699 | |
700 while (n <= addr) { | |
701 debug_only(HeapWord* last = q); // for debugging | |
702 q = n; | |
703 n += _sp->block_size(n); | |
704 } | |
705 assert(q <= addr, "wrong order for current and arg"); | |
706 assert(addr <= n, "wrong order for arg and next"); | |
707 return q; | |
708 } | |
709 | |
710 // | |
711 // _next_offset_threshold | |
712 // | _next_offset_index | |
713 // v v | |
714 // +-------+-------+-------+-------+-------+ | |
715 // | i-1 | i | i+1 | i+2 | i+3 | | |
716 // +-------+-------+-------+-------+-------+ | |
717 // ( ^ ] | |
718 // block-start | |
719 // | |
720 | |
721 void BlockOffsetArrayContigSpace::alloc_block_work(HeapWord* blk_start, | |
722 HeapWord* blk_end) { | |
723 assert(blk_start != NULL && blk_end > blk_start, | |
724 "phantom block"); | |
725 assert(blk_end > _next_offset_threshold, | |
726 "should be past threshold"); | |
727 assert(blk_start <= _next_offset_threshold, | |
1489
cff162798819
6888953: some calls to function-like macros are missing semicolons
jcoomes
parents:
342
diff
changeset
|
728 "blk_start should be at or before threshold"); |
0 | 729 assert(pointer_delta(_next_offset_threshold, blk_start) <= N_words, |
730 "offset should be <= BlockOffsetSharedArray::N"); | |
731 assert(Universe::heap()->is_in_reserved(blk_start), | |
732 "reference must be into the heap"); | |
733 assert(Universe::heap()->is_in_reserved(blk_end-1), | |
734 "limit must be within the heap"); | |
735 assert(_next_offset_threshold == | |
736 _array->_reserved.start() + _next_offset_index*N_words, | |
737 "index must agree with threshold"); | |
738 | |
739 debug_only(size_t orig_next_offset_index = _next_offset_index;) | |
740 | |
741 // Mark the card that holds the offset into the block. Note | |
742 // that _next_offset_index and _next_offset_threshold are not | |
743 // updated until the end of this method. | |
744 _array->set_offset_array(_next_offset_index, | |
745 _next_offset_threshold, | |
746 blk_start); | |
747 | |
748 // We need to now mark the subsequent cards that this blk spans. | |
749 | |
750 // Index of card on which blk ends. | |
751 size_t end_index = _array->index_for(blk_end - 1); | |
752 | |
753 // Are there more cards left to be updated? | |
754 if (_next_offset_index + 1 <= end_index) { | |
755 HeapWord* rem_st = _array->address_for_index(_next_offset_index + 1); | |
756 // Calculate rem_end this way because end_index | |
757 // may be the last valid index in the covered region. | |
758 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; | |
759 set_remainder_to_point_to_start(rem_st, rem_end); | |
760 } | |
761 | |
762 // _next_offset_index and _next_offset_threshold updated here. | |
763 _next_offset_index = end_index + 1; | |
764 // Calculate _next_offset_threshold this way because end_index | |
765 // may be the last valid index in the covered region. | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
766 _next_offset_threshold = _array->address_for_index(end_index) + N_words; |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1552
diff
changeset
|
767 assert(_next_offset_threshold >= blk_end, "Incorrect offset threshold"); |
0 | 768 |
769 #ifdef ASSERT | |
770 // The offset can be 0 if the block starts on a boundary. That | |
771 // is checked by an assertion above. | |
772 size_t start_index = _array->index_for(blk_start); | |
773 HeapWord* boundary = _array->address_for_index(start_index); | |
774 assert((_array->offset_array(orig_next_offset_index) == 0 && | |
775 blk_start == boundary) || | |
776 (_array->offset_array(orig_next_offset_index) > 0 && | |
777 _array->offset_array(orig_next_offset_index) <= N_words), | |
778 "offset array should have been set"); | |
779 for (size_t j = orig_next_offset_index + 1; j <= end_index; j++) { | |
780 assert(_array->offset_array(j) > 0 && | |
781 _array->offset_array(j) <= (u_char) (N_words+N_powers-1), | |
782 "offset array should have been set"); | |
783 } | |
784 #endif | |
785 } | |
786 | |
787 HeapWord* BlockOffsetArrayContigSpace::initialize_threshold() { | |
788 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), | |
789 "just checking"); | |
790 _next_offset_index = _array->index_for(_bottom); | |
791 _next_offset_index++; | |
792 _next_offset_threshold = | |
793 _array->address_for_index(_next_offset_index); | |
794 return _next_offset_threshold; | |
795 } | |
796 | |
797 void BlockOffsetArrayContigSpace::zero_bottom_entry() { | |
798 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), | |
799 "just checking"); | |
800 size_t bottom_index = _array->index_for(_bottom); | |
801 _array->set_offset_array(bottom_index, 0); | |
802 } | |
803 | |
804 | |
805 void BlockOffsetArrayContigSpace::serialize(SerializeOopClosure* soc) { | |
806 if (soc->reading()) { | |
807 // Null these values so that the serializer won't object to updating them. | |
808 _next_offset_threshold = NULL; | |
809 _next_offset_index = 0; | |
810 } | |
811 soc->do_ptr(&_next_offset_threshold); | |
812 soc->do_size_t(&_next_offset_index); | |
813 } | |
814 | |
815 size_t BlockOffsetArrayContigSpace::last_active_index() const { | |
816 size_t result = _next_offset_index - 1; | |
817 return result >= 0 ? result : 0; | |
818 } |