Mercurial > hg > truffle
annotate src/share/vm/memory/blockOffsetTable.cpp @ 14694:58cf34613a72
8036976: PPC64: implement the template interpreter
Reviewed-by: kvn, coleenp
Contributed-by: axel.siebenborn@sap.com, martin.doerr@sap.com
author | goetz |
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date | Mon, 10 Mar 2014 12:58:02 +0100 |
parents | 63a4eb8bcd23 |
children | 4ca6dc0799b6 |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 2000, 2013, 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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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 | |
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83 vm_exit_out_of_memory(delta, OOM_MMAP_ERROR, "offset table expansion"); |
0 | 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 ////////////////////////////////////////////////////////////////////// | |
102 // BlockOffsetArray | |
103 ////////////////////////////////////////////////////////////////////// | |
104 | |
105 BlockOffsetArray::BlockOffsetArray(BlockOffsetSharedArray* array, | |
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106 MemRegion mr, bool init_to_zero_) : |
0 | 107 BlockOffsetTable(mr.start(), mr.end()), |
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108 _array(array) |
0 | 109 { |
110 assert(_bottom <= _end, "arguments out of order"); | |
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111 set_init_to_zero(init_to_zero_); |
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112 if (!init_to_zero_) { |
0 | 113 // initialize cards to point back to mr.start() |
114 set_remainder_to_point_to_start(mr.start() + N_words, mr.end()); | |
115 _array->set_offset_array(0, 0); // set first card to 0 | |
116 } | |
117 } | |
118 | |
119 | |
120 // The arguments follow the normal convention of denoting | |
121 // a right-open interval: [start, end) | |
122 void | |
123 BlockOffsetArray:: | |
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124 set_remainder_to_point_to_start(HeapWord* start, HeapWord* end, bool reducing) { |
0 | 125 |
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126 check_reducing_assertion(reducing); |
0 | 127 if (start >= end) { |
128 // The start address is equal to the end address (or to | |
129 // the right of the end address) so there are not cards | |
130 // that need to be updated.. | |
131 return; | |
132 } | |
133 | |
134 // Write the backskip value for each region. | |
135 // | |
136 // offset | |
137 // card 2nd 3rd | |
138 // | +- 1st | | | |
139 // v v v v | |
140 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- | |
141 // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ... | |
142 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- | |
143 // 11 19 75 | |
144 // 12 | |
145 // | |
146 // offset card is the card that points to the start of an object | |
147 // x - offset value of offset card | |
148 // 1st - start of first logarithmic region | |
149 // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1 | |
150 // 2nd - start of second logarithmic region | |
151 // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8 | |
152 // 3rd - start of third logarithmic region | |
153 // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64 | |
154 // | |
155 // integer below the block offset entry is an example of | |
156 // the index of the entry | |
157 // | |
158 // Given an address, | |
159 // Find the index for the address | |
160 // Find the block offset table entry | |
161 // Convert the entry to a back slide | |
162 // (e.g., with today's, offset = 0x81 => | |
163 // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8 | |
164 // Move back N (e.g., 8) entries and repeat with the | |
165 // value of the new entry | |
166 // | |
167 size_t start_card = _array->index_for(start); | |
168 size_t end_card = _array->index_for(end-1); | |
169 assert(start ==_array->address_for_index(start_card), "Precondition"); | |
170 assert(end ==_array->address_for_index(end_card)+N_words, "Precondition"); | |
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171 set_remainder_to_point_to_start_incl(start_card, end_card, reducing); // closed interval |
0 | 172 } |
173 | |
174 | |
175 // Unlike the normal convention in this code, the argument here denotes | |
176 // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start() | |
177 // above. | |
178 void | |
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179 BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card, bool reducing) { |
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180 |
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181 check_reducing_assertion(reducing); |
0 | 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; | |
342 | 190 for (int i = 0; i < N_powers; i++) { |
0 | 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 + (power_to_cards_back(i+1) - 1); | |
195 offset = N_words + i; | |
196 if (reach >= end_card) { | |
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197 _array->set_offset_array(start_card_for_region, end_card, offset, reducing); |
0 | 198 start_card_for_region = reach + 1; |
199 break; | |
200 } | |
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201 _array->set_offset_array(start_card_for_region, reach, offset, reducing); |
0 | 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 } | |
207 | |
208 // The card-interval [start_card, end_card] is a closed interval; this | |
209 // is an expensive check -- use with care and only under protection of | |
210 // suitable flag. | |
211 void BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const { | |
212 | |
213 if (end_card < start_card) { | |
214 return; | |
215 } | |
216 guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card"); | |
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217 u_char last_entry = N_words; |
0 | 218 for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) { |
219 u_char entry = _array->offset_array(c); | |
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220 guarantee(entry >= last_entry, "Monotonicity"); |
0 | 221 if (c - start_card > power_to_cards_back(1)) { |
222 guarantee(entry > N_words, "Should be in logarithmic region"); | |
223 } | |
224 size_t backskip = entry_to_cards_back(entry); | |
225 size_t landing_card = c - backskip; | |
226 guarantee(landing_card >= (start_card - 1), "Inv"); | |
227 if (landing_card >= start_card) { | |
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228 guarantee(_array->offset_array(landing_card) <= entry, "Monotonicity"); |
0 | 229 } else { |
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230 guarantee(landing_card == (start_card - 1), "Tautology"); |
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231 // Note that N_words is the maximum offset value |
0 | 232 guarantee(_array->offset_array(landing_card) <= N_words, "Offset value"); |
233 } | |
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234 last_entry = entry; // remember for monotonicity test |
0 | 235 } |
236 } | |
237 | |
238 | |
239 void | |
240 BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) { | |
241 assert(blk_start != NULL && blk_end > blk_start, | |
242 "phantom block"); | |
243 single_block(blk_start, blk_end); | |
244 } | |
245 | |
246 // Action_mark - update the BOT for the block [blk_start, blk_end). | |
247 // Current typical use is for splitting a block. | |
248 // Action_single - udpate the BOT for an allocation. | |
249 // Action_verify - BOT verification. | |
250 void | |
251 BlockOffsetArray::do_block_internal(HeapWord* blk_start, | |
252 HeapWord* blk_end, | |
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253 Action action, bool reducing) { |
0 | 254 assert(Universe::heap()->is_in_reserved(blk_start), |
255 "reference must be into the heap"); | |
256 assert(Universe::heap()->is_in_reserved(blk_end-1), | |
257 "limit must be within the heap"); | |
258 // This is optimized to make the test fast, assuming we only rarely | |
259 // cross boundaries. | |
260 uintptr_t end_ui = (uintptr_t)(blk_end - 1); | |
261 uintptr_t start_ui = (uintptr_t)blk_start; | |
262 // Calculate the last card boundary preceding end of blk | |
263 intptr_t boundary_before_end = (intptr_t)end_ui; | |
264 clear_bits(boundary_before_end, right_n_bits(LogN)); | |
265 if (start_ui <= (uintptr_t)boundary_before_end) { | |
266 // blk starts at or crosses a boundary | |
267 // Calculate index of card on which blk begins | |
268 size_t start_index = _array->index_for(blk_start); | |
269 // Index of card on which blk ends | |
270 size_t end_index = _array->index_for(blk_end - 1); | |
271 // Start address of card on which blk begins | |
272 HeapWord* boundary = _array->address_for_index(start_index); | |
273 assert(boundary <= blk_start, "blk should start at or after boundary"); | |
274 if (blk_start != boundary) { | |
275 // blk starts strictly after boundary | |
276 // adjust card boundary and start_index forward to next card | |
277 boundary += N_words; | |
278 start_index++; | |
279 } | |
280 assert(start_index <= end_index, "monotonicity of index_for()"); | |
281 assert(boundary <= (HeapWord*)boundary_before_end, "tautology"); | |
282 switch (action) { | |
283 case Action_mark: { | |
284 if (init_to_zero()) { | |
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285 _array->set_offset_array(start_index, boundary, blk_start, reducing); |
0 | 286 break; |
287 } // Else fall through to the next case | |
288 } | |
289 case Action_single: { | |
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290 _array->set_offset_array(start_index, boundary, blk_start, reducing); |
0 | 291 // We have finished marking the "offset card". We need to now |
292 // mark the subsequent cards that this blk spans. | |
293 if (start_index < end_index) { | |
294 HeapWord* rem_st = _array->address_for_index(start_index) + N_words; | |
295 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; | |
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296 set_remainder_to_point_to_start(rem_st, rem_end, reducing); |
0 | 297 } |
298 break; | |
299 } | |
300 case Action_check: { | |
301 _array->check_offset_array(start_index, boundary, blk_start); | |
302 // We have finished checking the "offset card". We need to now | |
303 // check the subsequent cards that this blk spans. | |
304 check_all_cards(start_index + 1, end_index); | |
305 break; | |
306 } | |
307 default: | |
308 ShouldNotReachHere(); | |
309 } | |
310 } | |
311 } | |
312 | |
313 // The range [blk_start, blk_end) represents a single contiguous block | |
314 // of storage; modify the block offset table to represent this | |
315 // information; Right-open interval: [blk_start, blk_end) | |
316 // NOTE: this method does _not_ adjust _unallocated_block. | |
317 void | |
318 BlockOffsetArray::single_block(HeapWord* blk_start, | |
319 HeapWord* blk_end) { | |
320 do_block_internal(blk_start, blk_end, Action_single); | |
321 } | |
322 | |
323 void BlockOffsetArray::verify() const { | |
324 // For each entry in the block offset table, verify that | |
325 // the entry correctly finds the start of an object at the | |
326 // first address covered by the block or to the left of that | |
327 // first address. | |
328 | |
329 size_t next_index = 1; | |
330 size_t last_index = last_active_index(); | |
331 | |
332 // Use for debugging. Initialize to NULL to distinguish the | |
333 // first iteration through the while loop. | |
334 HeapWord* last_p = NULL; | |
335 HeapWord* last_start = NULL; | |
336 oop last_o = NULL; | |
337 | |
338 while (next_index <= last_index) { | |
339 // Use an address past the start of the address for | |
340 // the entry. | |
341 HeapWord* p = _array->address_for_index(next_index) + 1; | |
342 if (p >= _end) { | |
343 // That's all of the allocated block table. | |
344 return; | |
345 } | |
346 // block_start() asserts that start <= p. | |
347 HeapWord* start = block_start(p); | |
348 // First check if the start is an allocated block and only | |
349 // then if it is a valid object. | |
350 oop o = oop(start); | |
351 assert(!Universe::is_fully_initialized() || | |
352 _sp->is_free_block(start) || | |
353 o->is_oop_or_null(), "Bad object was found"); | |
354 next_index++; | |
355 last_p = p; | |
356 last_start = start; | |
357 last_o = o; | |
358 } | |
359 } | |
360 | |
361 ////////////////////////////////////////////////////////////////////// | |
362 // BlockOffsetArrayNonContigSpace | |
363 ////////////////////////////////////////////////////////////////////// | |
364 | |
365 // The block [blk_start, blk_end) has been allocated; | |
366 // adjust the block offset table to represent this information; | |
367 // NOTE: Clients of BlockOffsetArrayNonContigSpace: consider using | |
368 // the somewhat more lightweight split_block() or | |
369 // (when init_to_zero()) mark_block() wherever possible. | |
370 // right-open interval: [blk_start, blk_end) | |
371 void | |
372 BlockOffsetArrayNonContigSpace::alloc_block(HeapWord* blk_start, | |
373 HeapWord* blk_end) { | |
374 assert(blk_start != NULL && blk_end > blk_start, | |
375 "phantom block"); | |
376 single_block(blk_start, blk_end); | |
377 allocated(blk_start, blk_end); | |
378 } | |
379 | |
380 // Adjust BOT to show that a previously whole block has been split | |
381 // into two. We verify the BOT for the first part (prefix) and | |
382 // update the BOT for the second part (suffix). | |
383 // blk is the start of the block | |
384 // blk_size is the size of the original block | |
385 // left_blk_size is the size of the first part of the split | |
386 void BlockOffsetArrayNonContigSpace::split_block(HeapWord* blk, | |
387 size_t blk_size, | |
388 size_t left_blk_size) { | |
389 // Verify that the BOT shows [blk, blk + blk_size) to be one block. | |
390 verify_single_block(blk, blk_size); | |
391 // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size) | |
392 // is one single block. | |
393 assert(blk_size > 0, "Should be positive"); | |
394 assert(left_blk_size > 0, "Should be positive"); | |
395 assert(left_blk_size < blk_size, "Not a split"); | |
396 | |
397 // Start addresses of prefix block and suffix block. | |
398 HeapWord* pref_addr = blk; | |
399 HeapWord* suff_addr = blk + left_blk_size; | |
400 HeapWord* end_addr = blk + blk_size; | |
401 | |
402 // Indices for starts of prefix block and suffix block. | |
403 size_t pref_index = _array->index_for(pref_addr); | |
404 if (_array->address_for_index(pref_index) != pref_addr) { | |
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405 // pref_addr does not begin pref_index |
0 | 406 pref_index++; |
407 } | |
408 | |
409 size_t suff_index = _array->index_for(suff_addr); | |
410 if (_array->address_for_index(suff_index) != suff_addr) { | |
411 // suff_addr does not begin suff_index | |
412 suff_index++; | |
413 } | |
414 | |
415 // Definition: A block B, denoted [B_start, B_end) __starts__ | |
416 // a card C, denoted [C_start, C_end), where C_start and C_end | |
417 // are the heap addresses that card C covers, iff | |
418 // B_start <= C_start < B_end. | |
419 // | |
420 // We say that a card C "is started by" a block B, iff | |
421 // B "starts" C. | |
422 // | |
423 // Note that the cardinality of the set of cards {C} | |
424 // started by a block B can be 0, 1, or more. | |
425 // | |
426 // Below, pref_index and suff_index are, respectively, the | |
427 // first (least) card indices that the prefix and suffix of | |
428 // the split start; end_index is one more than the index of | |
429 // the last (greatest) card that blk starts. | |
430 size_t end_index = _array->index_for(end_addr - 1) + 1; | |
431 | |
432 // Calculate the # cards that the prefix and suffix affect. | |
433 size_t num_pref_cards = suff_index - pref_index; | |
434 | |
435 size_t num_suff_cards = end_index - suff_index; | |
436 // Change the cards that need changing | |
437 if (num_suff_cards > 0) { | |
438 HeapWord* boundary = _array->address_for_index(suff_index); | |
439 // Set the offset card for suffix block | |
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440 _array->set_offset_array(suff_index, boundary, suff_addr, true /* reducing */); |
0 | 441 // Change any further cards that need changing in the suffix |
442 if (num_pref_cards > 0) { | |
443 if (num_pref_cards >= num_suff_cards) { | |
444 // Unilaterally fix all of the suffix cards: closed card | |
445 // index interval in args below. | |
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446 set_remainder_to_point_to_start_incl(suff_index + 1, end_index - 1, true /* reducing */); |
0 | 447 } else { |
448 // Unilaterally fix the first (num_pref_cards - 1) following | |
449 // the "offset card" in the suffix block. | |
450 set_remainder_to_point_to_start_incl(suff_index + 1, | |
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451 suff_index + num_pref_cards - 1, true /* reducing */); |
0 | 452 // Fix the appropriate cards in the remainder of the |
453 // suffix block -- these are the last num_pref_cards | |
454 // cards in each power block of the "new" range plumbed | |
455 // from suff_addr. | |
456 bool more = true; | |
457 uint i = 1; | |
458 while (more && (i < N_powers)) { | |
459 size_t back_by = power_to_cards_back(i); | |
460 size_t right_index = suff_index + back_by - 1; | |
461 size_t left_index = right_index - num_pref_cards + 1; | |
462 if (right_index >= end_index - 1) { // last iteration | |
463 right_index = end_index - 1; | |
464 more = false; | |
465 } | |
466 if (back_by > num_pref_cards) { | |
467 // Fill in the remainder of this "power block", if it | |
468 // is non-null. | |
469 if (left_index <= right_index) { | |
470 _array->set_offset_array(left_index, right_index, | |
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471 N_words + i - 1, true /* reducing */); |
0 | 472 } else { |
473 more = false; // we are done | |
474 } | |
475 i++; | |
476 break; | |
477 } | |
478 i++; | |
479 } | |
480 while (more && (i < N_powers)) { | |
481 size_t back_by = power_to_cards_back(i); | |
482 size_t right_index = suff_index + back_by - 1; | |
483 size_t left_index = right_index - num_pref_cards + 1; | |
484 if (right_index >= end_index - 1) { // last iteration | |
485 right_index = end_index - 1; | |
486 if (left_index > right_index) { | |
487 break; | |
488 } | |
489 more = false; | |
490 } | |
491 assert(left_index <= right_index, "Error"); | |
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492 _array->set_offset_array(left_index, right_index, N_words + i - 1, true /* reducing */); |
0 | 493 i++; |
494 } | |
495 } | |
496 } // else no more cards to fix in suffix | |
497 } // else nothing needs to be done | |
498 // Verify that we did the right thing | |
499 verify_single_block(pref_addr, left_blk_size); | |
500 verify_single_block(suff_addr, blk_size - left_blk_size); | |
501 } | |
502 | |
503 | |
504 // Mark the BOT such that if [blk_start, blk_end) straddles a card | |
505 // boundary, the card following the first such boundary is marked | |
506 // with the appropriate offset. | |
507 // NOTE: this method does _not_ adjust _unallocated_block or | |
508 // any cards subsequent to the first one. | |
509 void | |
510 BlockOffsetArrayNonContigSpace::mark_block(HeapWord* blk_start, | |
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511 HeapWord* blk_end, bool reducing) { |
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512 do_block_internal(blk_start, blk_end, Action_mark, reducing); |
0 | 513 } |
514 | |
515 HeapWord* BlockOffsetArrayNonContigSpace::block_start_unsafe( | |
516 const void* addr) const { | |
517 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
518 assert(_bottom <= addr && addr < _end, | |
519 "addr must be covered by this Array"); | |
520 // Must read this exactly once because it can be modified by parallel | |
521 // allocation. | |
522 HeapWord* ub = _unallocated_block; | |
523 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { | |
524 assert(ub < _end, "tautology (see above)"); | |
525 return ub; | |
526 } | |
527 | |
528 // Otherwise, find the block start using the table. | |
529 size_t index = _array->index_for(addr); | |
530 HeapWord* q = _array->address_for_index(index); | |
531 | |
532 uint offset = _array->offset_array(index); // Extend u_char to uint. | |
533 while (offset >= N_words) { | |
534 // The excess of the offset from N_words indicates a power of Base | |
535 // to go back by. | |
536 size_t n_cards_back = entry_to_cards_back(offset); | |
537 q -= (N_words * n_cards_back); | |
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538 assert(q >= _sp->bottom(), |
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539 err_msg("q = " PTR_FORMAT " crossed below bottom = " PTR_FORMAT, |
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540 q, _sp->bottom())); |
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541 assert(q < _sp->end(), |
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542 err_msg("q = " PTR_FORMAT " crossed above end = " PTR_FORMAT, |
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543 q, _sp->end())); |
0 | 544 index -= n_cards_back; |
545 offset = _array->offset_array(index); | |
546 } | |
547 assert(offset < N_words, "offset too large"); | |
548 index--; | |
549 q -= offset; | |
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550 assert(q >= _sp->bottom(), |
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551 err_msg("q = " PTR_FORMAT " crossed below bottom = " PTR_FORMAT, |
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552 q, _sp->bottom())); |
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553 assert(q < _sp->end(), |
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554 err_msg("q = " PTR_FORMAT " crossed above end = " PTR_FORMAT, |
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555 q, _sp->end())); |
0 | 556 HeapWord* n = q; |
557 | |
558 while (n <= addr) { | |
559 debug_only(HeapWord* last = q); // for debugging | |
560 q = n; | |
561 n += _sp->block_size(n); | |
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562 assert(n > q, |
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563 err_msg("Looping at n = " PTR_FORMAT " with last = " PTR_FORMAT"," |
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564 " while querying blk_start(" PTR_FORMAT ")" |
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565 " on _sp = [" PTR_FORMAT "," PTR_FORMAT ")", |
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566 n, last, addr, _sp->bottom(), _sp->end())); |
0 | 567 } |
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568 assert(q <= addr, |
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569 err_msg("wrong order for current (" INTPTR_FORMAT ")" " <= arg (" INTPTR_FORMAT ")", |
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570 q, addr)); |
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571 assert(addr <= n, |
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572 err_msg("wrong order for arg (" INTPTR_FORMAT ") <= next (" INTPTR_FORMAT ")", |
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573 addr, n)); |
0 | 574 return q; |
575 } | |
576 | |
577 HeapWord* BlockOffsetArrayNonContigSpace::block_start_careful( | |
578 const void* addr) const { | |
579 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
580 | |
581 assert(_bottom <= addr && addr < _end, | |
582 "addr must be covered by this Array"); | |
583 // Must read this exactly once because it can be modified by parallel | |
584 // allocation. | |
585 HeapWord* ub = _unallocated_block; | |
586 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { | |
587 assert(ub < _end, "tautology (see above)"); | |
588 return ub; | |
589 } | |
590 | |
591 // Otherwise, find the block start using the table, but taking | |
592 // care (cf block_start_unsafe() above) not to parse any objects/blocks | |
14309 | 593 // on the cards themselves. |
0 | 594 size_t index = _array->index_for(addr); |
595 assert(_array->address_for_index(index) == addr, | |
596 "arg should be start of card"); | |
597 | |
598 HeapWord* q = (HeapWord*)addr; | |
599 uint offset; | |
600 do { | |
601 offset = _array->offset_array(index); | |
602 if (offset < N_words) { | |
603 q -= offset; | |
604 } else { | |
605 size_t n_cards_back = entry_to_cards_back(offset); | |
606 q -= (n_cards_back * N_words); | |
607 index -= n_cards_back; | |
608 } | |
609 } while (offset >= N_words); | |
610 assert(q <= addr, "block start should be to left of arg"); | |
611 return q; | |
612 } | |
613 | |
614 #ifndef PRODUCT | |
615 // Verification & debugging - ensure that the offset table reflects the fact | |
616 // that the block [blk_start, blk_end) or [blk, blk + size) is a | |
617 // single block of storage. NOTE: can't const this because of | |
618 // call to non-const do_block_internal() below. | |
619 void BlockOffsetArrayNonContigSpace::verify_single_block( | |
620 HeapWord* blk_start, HeapWord* blk_end) { | |
621 if (VerifyBlockOffsetArray) { | |
622 do_block_internal(blk_start, blk_end, Action_check); | |
623 } | |
624 } | |
625 | |
626 void BlockOffsetArrayNonContigSpace::verify_single_block( | |
627 HeapWord* blk, size_t size) { | |
628 verify_single_block(blk, blk + size); | |
629 } | |
630 | |
631 // Verify that the given block is before _unallocated_block | |
632 void BlockOffsetArrayNonContigSpace::verify_not_unallocated( | |
633 HeapWord* blk_start, HeapWord* blk_end) const { | |
634 if (BlockOffsetArrayUseUnallocatedBlock) { | |
635 assert(blk_start < blk_end, "Block inconsistency?"); | |
636 assert(blk_end <= _unallocated_block, "_unallocated_block problem"); | |
637 } | |
638 } | |
639 | |
640 void BlockOffsetArrayNonContigSpace::verify_not_unallocated( | |
641 HeapWord* blk, size_t size) const { | |
642 verify_not_unallocated(blk, blk + size); | |
643 } | |
644 #endif // PRODUCT | |
645 | |
646 size_t BlockOffsetArrayNonContigSpace::last_active_index() const { | |
647 if (_unallocated_block == _bottom) { | |
648 return 0; | |
649 } else { | |
650 return _array->index_for(_unallocated_block - 1); | |
651 } | |
652 } | |
653 | |
654 ////////////////////////////////////////////////////////////////////// | |
655 // BlockOffsetArrayContigSpace | |
656 ////////////////////////////////////////////////////////////////////// | |
657 | |
658 HeapWord* BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) const { | |
659 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
660 | |
661 // Otherwise, find the block start using the table. | |
662 assert(_bottom <= addr && addr < _end, | |
663 "addr must be covered by this Array"); | |
664 size_t index = _array->index_for(addr); | |
665 // We must make sure that the offset table entry we use is valid. If | |
666 // "addr" is past the end, start at the last known one and go forward. | |
667 index = MIN2(index, _next_offset_index-1); | |
668 HeapWord* q = _array->address_for_index(index); | |
669 | |
670 uint offset = _array->offset_array(index); // Extend u_char to uint. | |
671 while (offset > N_words) { | |
672 // The excess of the offset from N_words indicates a power of Base | |
673 // to go back by. | |
674 size_t n_cards_back = entry_to_cards_back(offset); | |
675 q -= (N_words * n_cards_back); | |
676 assert(q >= _sp->bottom(), "Went below bottom!"); | |
677 index -= n_cards_back; | |
678 offset = _array->offset_array(index); | |
679 } | |
680 while (offset == N_words) { | |
681 assert(q >= _sp->bottom(), "Went below bottom!"); | |
682 q -= N_words; | |
683 index--; | |
684 offset = _array->offset_array(index); | |
685 } | |
686 assert(offset < N_words, "offset too large"); | |
687 q -= offset; | |
688 HeapWord* n = q; | |
689 | |
690 while (n <= addr) { | |
691 debug_only(HeapWord* last = q); // for debugging | |
692 q = n; | |
693 n += _sp->block_size(n); | |
694 } | |
695 assert(q <= addr, "wrong order for current and arg"); | |
696 assert(addr <= n, "wrong order for arg and next"); | |
697 return q; | |
698 } | |
699 | |
700 // | |
701 // _next_offset_threshold | |
702 // | _next_offset_index | |
703 // v v | |
704 // +-------+-------+-------+-------+-------+ | |
705 // | i-1 | i | i+1 | i+2 | i+3 | | |
706 // +-------+-------+-------+-------+-------+ | |
707 // ( ^ ] | |
708 // block-start | |
709 // | |
710 | |
711 void BlockOffsetArrayContigSpace::alloc_block_work(HeapWord* blk_start, | |
712 HeapWord* blk_end) { | |
713 assert(blk_start != NULL && blk_end > blk_start, | |
714 "phantom block"); | |
715 assert(blk_end > _next_offset_threshold, | |
716 "should be past threshold"); | |
717 assert(blk_start <= _next_offset_threshold, | |
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718 "blk_start should be at or before threshold"); |
0 | 719 assert(pointer_delta(_next_offset_threshold, blk_start) <= N_words, |
720 "offset should be <= BlockOffsetSharedArray::N"); | |
721 assert(Universe::heap()->is_in_reserved(blk_start), | |
722 "reference must be into the heap"); | |
723 assert(Universe::heap()->is_in_reserved(blk_end-1), | |
724 "limit must be within the heap"); | |
725 assert(_next_offset_threshold == | |
726 _array->_reserved.start() + _next_offset_index*N_words, | |
727 "index must agree with threshold"); | |
728 | |
729 debug_only(size_t orig_next_offset_index = _next_offset_index;) | |
730 | |
731 // Mark the card that holds the offset into the block. Note | |
732 // that _next_offset_index and _next_offset_threshold are not | |
733 // updated until the end of this method. | |
734 _array->set_offset_array(_next_offset_index, | |
735 _next_offset_threshold, | |
736 blk_start); | |
737 | |
738 // We need to now mark the subsequent cards that this blk spans. | |
739 | |
740 // Index of card on which blk ends. | |
741 size_t end_index = _array->index_for(blk_end - 1); | |
742 | |
743 // Are there more cards left to be updated? | |
744 if (_next_offset_index + 1 <= end_index) { | |
745 HeapWord* rem_st = _array->address_for_index(_next_offset_index + 1); | |
746 // Calculate rem_end this way because end_index | |
747 // may be the last valid index in the covered region. | |
748 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; | |
749 set_remainder_to_point_to_start(rem_st, rem_end); | |
750 } | |
751 | |
752 // _next_offset_index and _next_offset_threshold updated here. | |
753 _next_offset_index = end_index + 1; | |
754 // Calculate _next_offset_threshold this way because end_index | |
755 // may be the last valid index in the covered region. | |
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756 _next_offset_threshold = _array->address_for_index(end_index) + N_words; |
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757 assert(_next_offset_threshold >= blk_end, "Incorrect offset threshold"); |
0 | 758 |
759 #ifdef ASSERT | |
760 // The offset can be 0 if the block starts on a boundary. That | |
761 // is checked by an assertion above. | |
762 size_t start_index = _array->index_for(blk_start); | |
763 HeapWord* boundary = _array->address_for_index(start_index); | |
764 assert((_array->offset_array(orig_next_offset_index) == 0 && | |
765 blk_start == boundary) || | |
766 (_array->offset_array(orig_next_offset_index) > 0 && | |
767 _array->offset_array(orig_next_offset_index) <= N_words), | |
768 "offset array should have been set"); | |
769 for (size_t j = orig_next_offset_index + 1; j <= end_index; j++) { | |
770 assert(_array->offset_array(j) > 0 && | |
771 _array->offset_array(j) <= (u_char) (N_words+N_powers-1), | |
772 "offset array should have been set"); | |
773 } | |
774 #endif | |
775 } | |
776 | |
777 HeapWord* BlockOffsetArrayContigSpace::initialize_threshold() { | |
778 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), | |
779 "just checking"); | |
780 _next_offset_index = _array->index_for(_bottom); | |
781 _next_offset_index++; | |
782 _next_offset_threshold = | |
783 _array->address_for_index(_next_offset_index); | |
784 return _next_offset_threshold; | |
785 } | |
786 | |
787 void BlockOffsetArrayContigSpace::zero_bottom_entry() { | |
788 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), | |
789 "just checking"); | |
790 size_t bottom_index = _array->index_for(_bottom); | |
791 _array->set_offset_array(bottom_index, 0); | |
792 } | |
793 | |
794 size_t BlockOffsetArrayContigSpace::last_active_index() const { | |
795 size_t result = _next_offset_index - 1; | |
796 return result >= 0 ? result : 0; | |
797 } |