Mon, 28 Jul 2008 15:30:23 -0700
Merge
1 /*
2 * Copyright 2005-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 class ParallelScavengeHeap;
26 class PSAdaptiveSizePolicy;
27 class PSYoungGen;
28 class PSOldGen;
29 class PSPermGen;
30 class ParCompactionManager;
31 class ParallelTaskTerminator;
32 class PSParallelCompact;
33 class GCTaskManager;
34 class GCTaskQueue;
35 class PreGCValues;
36 class MoveAndUpdateClosure;
37 class RefProcTaskExecutor;
39 class SpaceInfo
40 {
41 public:
42 MutableSpace* space() const { return _space; }
44 // Where the free space will start after the collection. Valid only after the
45 // summary phase completes.
46 HeapWord* new_top() const { return _new_top; }
48 // Allows new_top to be set.
49 HeapWord** new_top_addr() { return &_new_top; }
51 // Where the smallest allowable dense prefix ends (used only for perm gen).
52 HeapWord* min_dense_prefix() const { return _min_dense_prefix; }
54 // Where the dense prefix ends, or the compacted region begins.
55 HeapWord* dense_prefix() const { return _dense_prefix; }
57 // The start array for the (generation containing the) space, or NULL if there
58 // is no start array.
59 ObjectStartArray* start_array() const { return _start_array; }
61 void set_space(MutableSpace* s) { _space = s; }
62 void set_new_top(HeapWord* addr) { _new_top = addr; }
63 void set_min_dense_prefix(HeapWord* addr) { _min_dense_prefix = addr; }
64 void set_dense_prefix(HeapWord* addr) { _dense_prefix = addr; }
65 void set_start_array(ObjectStartArray* s) { _start_array = s; }
67 private:
68 MutableSpace* _space;
69 HeapWord* _new_top;
70 HeapWord* _min_dense_prefix;
71 HeapWord* _dense_prefix;
72 ObjectStartArray* _start_array;
73 };
75 class ParallelCompactData
76 {
77 public:
78 // Sizes are in HeapWords, unless indicated otherwise.
79 static const size_t Log2ChunkSize;
80 static const size_t ChunkSize;
81 static const size_t ChunkSizeBytes;
83 // Mask for the bits in a size_t to get an offset within a chunk.
84 static const size_t ChunkSizeOffsetMask;
85 // Mask for the bits in a pointer to get an offset within a chunk.
86 static const size_t ChunkAddrOffsetMask;
87 // Mask for the bits in a pointer to get the address of the start of a chunk.
88 static const size_t ChunkAddrMask;
90 static const size_t Log2BlockSize;
91 static const size_t BlockSize;
92 static const size_t BlockOffsetMask;
93 static const size_t BlockMask;
95 static const size_t BlocksPerChunk;
97 class ChunkData
98 {
99 public:
100 // Destination address of the chunk.
101 HeapWord* destination() const { return _destination; }
103 // The first chunk containing data destined for this chunk.
104 size_t source_chunk() const { return _source_chunk; }
106 // The object (if any) starting in this chunk and ending in a different
107 // chunk that could not be updated during the main (parallel) compaction
108 // phase. This is different from _partial_obj_addr, which is an object that
109 // extends onto a source chunk. However, the two uses do not overlap in
110 // time, so the same field is used to save space.
111 HeapWord* deferred_obj_addr() const { return _partial_obj_addr; }
113 // The starting address of the partial object extending onto the chunk.
114 HeapWord* partial_obj_addr() const { return _partial_obj_addr; }
116 // Size of the partial object extending onto the chunk (words).
117 size_t partial_obj_size() const { return _partial_obj_size; }
119 // Size of live data that lies within this chunk due to objects that start
120 // in this chunk (words). This does not include the partial object
121 // extending onto the chunk (if any), or the part of an object that extends
122 // onto the next chunk (if any).
123 size_t live_obj_size() const { return _dc_and_los & los_mask; }
125 // Total live data that lies within the chunk (words).
126 size_t data_size() const { return partial_obj_size() + live_obj_size(); }
128 // The destination_count is the number of other chunks to which data from
129 // this chunk will be copied. At the end of the summary phase, the valid
130 // values of destination_count are
131 //
132 // 0 - data from the chunk will be compacted completely into itself, or the
133 // chunk is empty. The chunk can be claimed and then filled.
134 // 1 - data from the chunk will be compacted into 1 other chunk; some
135 // data from the chunk may also be compacted into the chunk itself.
136 // 2 - data from the chunk will be copied to 2 other chunks.
137 //
138 // During compaction as chunks are emptied, the destination_count is
139 // decremented (atomically) and when it reaches 0, it can be claimed and
140 // then filled.
141 //
142 // A chunk is claimed for processing by atomically changing the
143 // destination_count to the claimed value (dc_claimed). After a chunk has
144 // been filled, the destination_count should be set to the completed value
145 // (dc_completed).
146 inline uint destination_count() const;
147 inline uint destination_count_raw() const;
149 // The location of the java heap data that corresponds to this chunk.
150 inline HeapWord* data_location() const;
152 // The highest address referenced by objects in this chunk.
153 inline HeapWord* highest_ref() const;
155 // Whether this chunk is available to be claimed, has been claimed, or has
156 // been completed.
157 //
158 // Minor subtlety: claimed() returns true if the chunk is marked
159 // completed(), which is desirable since a chunk must be claimed before it
160 // can be completed.
161 bool available() const { return _dc_and_los < dc_one; }
162 bool claimed() const { return _dc_and_los >= dc_claimed; }
163 bool completed() const { return _dc_and_los >= dc_completed; }
165 // These are not atomic.
166 void set_destination(HeapWord* addr) { _destination = addr; }
167 void set_source_chunk(size_t chunk) { _source_chunk = chunk; }
168 void set_deferred_obj_addr(HeapWord* addr) { _partial_obj_addr = addr; }
169 void set_partial_obj_addr(HeapWord* addr) { _partial_obj_addr = addr; }
170 void set_partial_obj_size(size_t words) {
171 _partial_obj_size = (chunk_sz_t) words;
172 }
174 inline void set_destination_count(uint count);
175 inline void set_live_obj_size(size_t words);
176 inline void set_data_location(HeapWord* addr);
177 inline void set_completed();
178 inline bool claim_unsafe();
180 // These are atomic.
181 inline void add_live_obj(size_t words);
182 inline void set_highest_ref(HeapWord* addr);
183 inline void decrement_destination_count();
184 inline bool claim();
186 private:
187 // The type used to represent object sizes within a chunk.
188 typedef uint chunk_sz_t;
190 // Constants for manipulating the _dc_and_los field, which holds both the
191 // destination count and live obj size. The live obj size lives at the
192 // least significant end so no masking is necessary when adding.
193 static const chunk_sz_t dc_shift; // Shift amount.
194 static const chunk_sz_t dc_mask; // Mask for destination count.
195 static const chunk_sz_t dc_one; // 1, shifted appropriately.
196 static const chunk_sz_t dc_claimed; // Chunk has been claimed.
197 static const chunk_sz_t dc_completed; // Chunk has been completed.
198 static const chunk_sz_t los_mask; // Mask for live obj size.
200 HeapWord* _destination;
201 size_t _source_chunk;
202 HeapWord* _partial_obj_addr;
203 chunk_sz_t _partial_obj_size;
204 chunk_sz_t volatile _dc_and_los;
205 #ifdef ASSERT
206 // These enable optimizations that are only partially implemented. Use
207 // debug builds to prevent the code fragments from breaking.
208 HeapWord* _data_location;
209 HeapWord* _highest_ref;
210 #endif // #ifdef ASSERT
212 #ifdef ASSERT
213 public:
214 uint _pushed; // 0 until chunk is pushed onto a worker's stack
215 private:
216 #endif
217 };
219 // 'Blocks' allow shorter sections of the bitmap to be searched. Each Block
220 // holds an offset, which is the amount of live data in the Chunk to the left
221 // of the first live object in the Block. This amount of live data will
222 // include any object extending into the block. The first block in
223 // a chunk does not include any partial object extending into the
224 // the chunk.
225 //
226 // The offset also encodes the
227 // 'parity' of the first 1 bit in the Block: a positive offset means the
228 // first 1 bit marks the start of an object, a negative offset means the first
229 // 1 bit marks the end of an object.
230 class BlockData
231 {
232 public:
233 typedef short int blk_ofs_t;
235 blk_ofs_t offset() const { return _offset >= 0 ? _offset : -_offset; }
236 blk_ofs_t raw_offset() const { return _offset; }
237 void set_first_is_start_bit(bool v) { _first_is_start_bit = v; }
239 #if 0
240 // The need for this method was anticipated but it is
241 // never actually used. Do not include it for now. If
242 // it is needed, consider the problem of what is passed
243 // as "v". To avoid warning errors the method set_start_bit_offset()
244 // was changed to take a size_t as the parameter and to do the
245 // check for the possible overflow. Doing the cast in these
246 // methods better limits the potential problems because of
247 // the size of the field to this class.
248 void set_raw_offset(blk_ofs_t v) { _offset = v; }
249 #endif
250 void set_start_bit_offset(size_t val) {
251 assert(val >= 0, "sanity");
252 _offset = (blk_ofs_t) val;
253 assert(val == (size_t) _offset, "Value is too large");
254 _first_is_start_bit = true;
255 }
256 void set_end_bit_offset(size_t val) {
257 assert(val >= 0, "sanity");
258 _offset = (blk_ofs_t) val;
259 assert(val == (size_t) _offset, "Value is too large");
260 _offset = - _offset;
261 _first_is_start_bit = false;
262 }
263 bool first_is_start_bit() {
264 assert(_set_phase > 0, "Not initialized");
265 return _first_is_start_bit;
266 }
267 bool first_is_end_bit() {
268 assert(_set_phase > 0, "Not initialized");
269 return !_first_is_start_bit;
270 }
272 private:
273 blk_ofs_t _offset;
274 // This is temporary until the mark_bitmap is separated into
275 // a start bit array and an end bit array.
276 bool _first_is_start_bit;
277 #ifdef ASSERT
278 short _set_phase;
279 static short _cur_phase;
280 public:
281 static void set_cur_phase(short v) { _cur_phase = v; }
282 #endif
283 };
285 public:
286 ParallelCompactData();
287 bool initialize(MemRegion covered_region);
289 size_t chunk_count() const { return _chunk_count; }
291 // Convert chunk indices to/from ChunkData pointers.
292 inline ChunkData* chunk(size_t chunk_idx) const;
293 inline size_t chunk(const ChunkData* const chunk_ptr) const;
295 // Returns true if the given address is contained within the chunk
296 bool chunk_contains(size_t chunk_index, HeapWord* addr);
298 size_t block_count() const { return _block_count; }
299 inline BlockData* block(size_t n) const;
301 // Returns true if the given block is in the given chunk.
302 static bool chunk_contains_block(size_t chunk_index, size_t block_index);
304 void add_obj(HeapWord* addr, size_t len);
305 void add_obj(oop p, size_t len) { add_obj((HeapWord*)p, len); }
307 // Fill in the chunks covering [beg, end) so that no data moves; i.e., the
308 // destination of chunk n is simply the start of chunk n. The argument beg
309 // must be chunk-aligned; end need not be.
310 void summarize_dense_prefix(HeapWord* beg, HeapWord* end);
312 bool summarize(HeapWord* target_beg, HeapWord* target_end,
313 HeapWord* source_beg, HeapWord* source_end,
314 HeapWord** target_next, HeapWord** source_next = 0);
316 void clear();
317 void clear_range(size_t beg_chunk, size_t end_chunk);
318 void clear_range(HeapWord* beg, HeapWord* end) {
319 clear_range(addr_to_chunk_idx(beg), addr_to_chunk_idx(end));
320 }
322 // Return the number of words between addr and the start of the chunk
323 // containing addr.
324 inline size_t chunk_offset(const HeapWord* addr) const;
326 // Convert addresses to/from a chunk index or chunk pointer.
327 inline size_t addr_to_chunk_idx(const HeapWord* addr) const;
328 inline ChunkData* addr_to_chunk_ptr(const HeapWord* addr) const;
329 inline HeapWord* chunk_to_addr(size_t chunk) const;
330 inline HeapWord* chunk_to_addr(size_t chunk, size_t offset) const;
331 inline HeapWord* chunk_to_addr(const ChunkData* chunk) const;
333 inline HeapWord* chunk_align_down(HeapWord* addr) const;
334 inline HeapWord* chunk_align_up(HeapWord* addr) const;
335 inline bool is_chunk_aligned(HeapWord* addr) const;
337 // Analogous to chunk_offset() for blocks.
338 size_t block_offset(const HeapWord* addr) const;
339 size_t addr_to_block_idx(const HeapWord* addr) const;
340 size_t addr_to_block_idx(const oop obj) const {
341 return addr_to_block_idx((HeapWord*) obj);
342 }
343 inline BlockData* addr_to_block_ptr(const HeapWord* addr) const;
344 inline HeapWord* block_to_addr(size_t block) const;
346 // Return the address one past the end of the partial object.
347 HeapWord* partial_obj_end(size_t chunk_idx) const;
349 // Return the new location of the object p after the
350 // the compaction.
351 HeapWord* calc_new_pointer(HeapWord* addr);
353 // Same as calc_new_pointer() using blocks.
354 HeapWord* block_calc_new_pointer(HeapWord* addr);
356 // Same as calc_new_pointer() using chunks.
357 HeapWord* chunk_calc_new_pointer(HeapWord* addr);
359 HeapWord* calc_new_pointer(oop p) {
360 return calc_new_pointer((HeapWord*) p);
361 }
363 // Return the updated address for the given klass
364 klassOop calc_new_klass(klassOop);
366 // Given a block returns true if the partial object for the
367 // corresponding chunk ends in the block. Returns false, otherwise
368 // If there is no partial object, returns false.
369 bool partial_obj_ends_in_block(size_t block_index);
371 // Returns the block index for the block
372 static size_t block_idx(BlockData* block);
374 #ifdef ASSERT
375 void verify_clear(const PSVirtualSpace* vspace);
376 void verify_clear();
377 #endif // #ifdef ASSERT
379 private:
380 bool initialize_block_data(size_t region_size);
381 bool initialize_chunk_data(size_t region_size);
382 PSVirtualSpace* create_vspace(size_t count, size_t element_size);
384 private:
385 HeapWord* _region_start;
386 #ifdef ASSERT
387 HeapWord* _region_end;
388 #endif // #ifdef ASSERT
390 PSVirtualSpace* _chunk_vspace;
391 ChunkData* _chunk_data;
392 size_t _chunk_count;
394 PSVirtualSpace* _block_vspace;
395 BlockData* _block_data;
396 size_t _block_count;
397 };
399 inline uint
400 ParallelCompactData::ChunkData::destination_count_raw() const
401 {
402 return _dc_and_los & dc_mask;
403 }
405 inline uint
406 ParallelCompactData::ChunkData::destination_count() const
407 {
408 return destination_count_raw() >> dc_shift;
409 }
411 inline void
412 ParallelCompactData::ChunkData::set_destination_count(uint count)
413 {
414 assert(count <= (dc_completed >> dc_shift), "count too large");
415 const chunk_sz_t live_sz = (chunk_sz_t) live_obj_size();
416 _dc_and_los = (count << dc_shift) | live_sz;
417 }
419 inline void ParallelCompactData::ChunkData::set_live_obj_size(size_t words)
420 {
421 assert(words <= los_mask, "would overflow");
422 _dc_and_los = destination_count_raw() | (chunk_sz_t)words;
423 }
425 inline void ParallelCompactData::ChunkData::decrement_destination_count()
426 {
427 assert(_dc_and_los < dc_claimed, "already claimed");
428 assert(_dc_and_los >= dc_one, "count would go negative");
429 Atomic::add((int)dc_mask, (volatile int*)&_dc_and_los);
430 }
432 inline HeapWord* ParallelCompactData::ChunkData::data_location() const
433 {
434 DEBUG_ONLY(return _data_location;)
435 NOT_DEBUG(return NULL;)
436 }
438 inline HeapWord* ParallelCompactData::ChunkData::highest_ref() const
439 {
440 DEBUG_ONLY(return _highest_ref;)
441 NOT_DEBUG(return NULL;)
442 }
444 inline void ParallelCompactData::ChunkData::set_data_location(HeapWord* addr)
445 {
446 DEBUG_ONLY(_data_location = addr;)
447 }
449 inline void ParallelCompactData::ChunkData::set_completed()
450 {
451 assert(claimed(), "must be claimed first");
452 _dc_and_los = dc_completed | (chunk_sz_t) live_obj_size();
453 }
455 // MT-unsafe claiming of a chunk. Should only be used during single threaded
456 // execution.
457 inline bool ParallelCompactData::ChunkData::claim_unsafe()
458 {
459 if (available()) {
460 _dc_and_los |= dc_claimed;
461 return true;
462 }
463 return false;
464 }
466 inline void ParallelCompactData::ChunkData::add_live_obj(size_t words)
467 {
468 assert(words <= (size_t)los_mask - live_obj_size(), "overflow");
469 Atomic::add((int) words, (volatile int*) &_dc_and_los);
470 }
472 inline void ParallelCompactData::ChunkData::set_highest_ref(HeapWord* addr)
473 {
474 #ifdef ASSERT
475 HeapWord* tmp = _highest_ref;
476 while (addr > tmp) {
477 tmp = (HeapWord*)Atomic::cmpxchg_ptr(addr, &_highest_ref, tmp);
478 }
479 #endif // #ifdef ASSERT
480 }
482 inline bool ParallelCompactData::ChunkData::claim()
483 {
484 const int los = (int) live_obj_size();
485 const int old = Atomic::cmpxchg(dc_claimed | los,
486 (volatile int*) &_dc_and_los, los);
487 return old == los;
488 }
490 inline ParallelCompactData::ChunkData*
491 ParallelCompactData::chunk(size_t chunk_idx) const
492 {
493 assert(chunk_idx <= chunk_count(), "bad arg");
494 return _chunk_data + chunk_idx;
495 }
497 inline size_t
498 ParallelCompactData::chunk(const ChunkData* const chunk_ptr) const
499 {
500 assert(chunk_ptr >= _chunk_data, "bad arg");
501 assert(chunk_ptr <= _chunk_data + chunk_count(), "bad arg");
502 return pointer_delta(chunk_ptr, _chunk_data, sizeof(ChunkData));
503 }
505 inline ParallelCompactData::BlockData*
506 ParallelCompactData::block(size_t n) const {
507 assert(n < block_count(), "bad arg");
508 return _block_data + n;
509 }
511 inline size_t
512 ParallelCompactData::chunk_offset(const HeapWord* addr) const
513 {
514 assert(addr >= _region_start, "bad addr");
515 assert(addr <= _region_end, "bad addr");
516 return (size_t(addr) & ChunkAddrOffsetMask) >> LogHeapWordSize;
517 }
519 inline size_t
520 ParallelCompactData::addr_to_chunk_idx(const HeapWord* addr) const
521 {
522 assert(addr >= _region_start, "bad addr");
523 assert(addr <= _region_end, "bad addr");
524 return pointer_delta(addr, _region_start) >> Log2ChunkSize;
525 }
527 inline ParallelCompactData::ChunkData*
528 ParallelCompactData::addr_to_chunk_ptr(const HeapWord* addr) const
529 {
530 return chunk(addr_to_chunk_idx(addr));
531 }
533 inline HeapWord*
534 ParallelCompactData::chunk_to_addr(size_t chunk) const
535 {
536 assert(chunk <= _chunk_count, "chunk out of range");
537 return _region_start + (chunk << Log2ChunkSize);
538 }
540 inline HeapWord*
541 ParallelCompactData::chunk_to_addr(const ChunkData* chunk) const
542 {
543 return chunk_to_addr(pointer_delta(chunk, _chunk_data, sizeof(ChunkData)));
544 }
546 inline HeapWord*
547 ParallelCompactData::chunk_to_addr(size_t chunk, size_t offset) const
548 {
549 assert(chunk <= _chunk_count, "chunk out of range");
550 assert(offset < ChunkSize, "offset too big"); // This may be too strict.
551 return chunk_to_addr(chunk) + offset;
552 }
554 inline HeapWord*
555 ParallelCompactData::chunk_align_down(HeapWord* addr) const
556 {
557 assert(addr >= _region_start, "bad addr");
558 assert(addr < _region_end + ChunkSize, "bad addr");
559 return (HeapWord*)(size_t(addr) & ChunkAddrMask);
560 }
562 inline HeapWord*
563 ParallelCompactData::chunk_align_up(HeapWord* addr) const
564 {
565 assert(addr >= _region_start, "bad addr");
566 assert(addr <= _region_end, "bad addr");
567 return chunk_align_down(addr + ChunkSizeOffsetMask);
568 }
570 inline bool
571 ParallelCompactData::is_chunk_aligned(HeapWord* addr) const
572 {
573 return chunk_offset(addr) == 0;
574 }
576 inline size_t
577 ParallelCompactData::block_offset(const HeapWord* addr) const
578 {
579 assert(addr >= _region_start, "bad addr");
580 assert(addr <= _region_end, "bad addr");
581 return pointer_delta(addr, _region_start) & BlockOffsetMask;
582 }
584 inline size_t
585 ParallelCompactData::addr_to_block_idx(const HeapWord* addr) const
586 {
587 assert(addr >= _region_start, "bad addr");
588 assert(addr <= _region_end, "bad addr");
589 return pointer_delta(addr, _region_start) >> Log2BlockSize;
590 }
592 inline ParallelCompactData::BlockData*
593 ParallelCompactData::addr_to_block_ptr(const HeapWord* addr) const
594 {
595 return block(addr_to_block_idx(addr));
596 }
598 inline HeapWord*
599 ParallelCompactData::block_to_addr(size_t block) const
600 {
601 assert(block < _block_count, "block out of range");
602 return _region_start + (block << Log2BlockSize);
603 }
605 // Abstract closure for use with ParMarkBitMap::iterate(), which will invoke the
606 // do_addr() method.
607 //
608 // The closure is initialized with the number of heap words to process
609 // (words_remaining()), and becomes 'full' when it reaches 0. The do_addr()
610 // methods in subclasses should update the total as words are processed. Since
611 // only one subclass actually uses this mechanism to terminate iteration, the
612 // default initial value is > 0. The implementation is here and not in the
613 // single subclass that uses it to avoid making is_full() virtual, and thus
614 // adding a virtual call per live object.
616 class ParMarkBitMapClosure: public StackObj {
617 public:
618 typedef ParMarkBitMap::idx_t idx_t;
619 typedef ParMarkBitMap::IterationStatus IterationStatus;
621 public:
622 inline ParMarkBitMapClosure(ParMarkBitMap* mbm, ParCompactionManager* cm,
623 size_t words = max_uintx);
625 inline ParCompactionManager* compaction_manager() const;
626 inline ParMarkBitMap* bitmap() const;
627 inline size_t words_remaining() const;
628 inline bool is_full() const;
629 inline HeapWord* source() const;
631 inline void set_source(HeapWord* addr);
633 virtual IterationStatus do_addr(HeapWord* addr, size_t words) = 0;
635 protected:
636 inline void decrement_words_remaining(size_t words);
638 private:
639 ParMarkBitMap* const _bitmap;
640 ParCompactionManager* const _compaction_manager;
641 DEBUG_ONLY(const size_t _initial_words_remaining;) // Useful in debugger.
642 size_t _words_remaining; // Words left to copy.
644 protected:
645 HeapWord* _source; // Next addr that would be read.
646 };
648 inline
649 ParMarkBitMapClosure::ParMarkBitMapClosure(ParMarkBitMap* bitmap,
650 ParCompactionManager* cm,
651 size_t words):
652 _bitmap(bitmap), _compaction_manager(cm)
653 #ifdef ASSERT
654 , _initial_words_remaining(words)
655 #endif
656 {
657 _words_remaining = words;
658 _source = NULL;
659 }
661 inline ParCompactionManager* ParMarkBitMapClosure::compaction_manager() const {
662 return _compaction_manager;
663 }
665 inline ParMarkBitMap* ParMarkBitMapClosure::bitmap() const {
666 return _bitmap;
667 }
669 inline size_t ParMarkBitMapClosure::words_remaining() const {
670 return _words_remaining;
671 }
673 inline bool ParMarkBitMapClosure::is_full() const {
674 return words_remaining() == 0;
675 }
677 inline HeapWord* ParMarkBitMapClosure::source() const {
678 return _source;
679 }
681 inline void ParMarkBitMapClosure::set_source(HeapWord* addr) {
682 _source = addr;
683 }
685 inline void ParMarkBitMapClosure::decrement_words_remaining(size_t words) {
686 assert(_words_remaining >= words, "processed too many words");
687 _words_remaining -= words;
688 }
690 // Closure for updating the block data during the summary phase.
691 class BitBlockUpdateClosure: public ParMarkBitMapClosure {
692 // ParallelCompactData::BlockData::blk_ofs_t _live_data_left;
693 size_t _live_data_left;
694 size_t _cur_block;
695 HeapWord* _chunk_start;
696 HeapWord* _chunk_end;
697 size_t _chunk_index;
699 public:
700 BitBlockUpdateClosure(ParMarkBitMap* mbm,
701 ParCompactionManager* cm,
702 size_t chunk_index);
704 size_t cur_block() { return _cur_block; }
705 size_t chunk_index() { return _chunk_index; }
706 size_t live_data_left() { return _live_data_left; }
707 // Returns true the first bit in the current block (cur_block) is
708 // a start bit.
709 // Returns true if the current block is within the chunk for the closure;
710 bool chunk_contains_cur_block();
712 // Set the chunk index and related chunk values for
713 // a new chunk.
714 void reset_chunk(size_t chunk_index);
716 virtual IterationStatus do_addr(HeapWord* addr, size_t words);
717 };
719 // The UseParallelOldGC collector is a stop-the-world garbage
720 // collector that does parts of the collection using parallel threads.
721 // The collection includes the tenured generation and the young
722 // generation. The permanent generation is collected at the same
723 // time as the other two generations but the permanent generation
724 // is collect by a single GC thread. The permanent generation is
725 // collected serially because of the requirement that during the
726 // processing of a klass AAA, any objects reference by AAA must
727 // already have been processed. This requirement is enforced by
728 // a left (lower address) to right (higher address) sliding compaction.
729 //
730 // There are four phases of the collection.
731 //
732 // - marking phase
733 // - summary phase
734 // - compacting phase
735 // - clean up phase
736 //
737 // Roughly speaking these phases correspond, respectively, to
738 // - mark all the live objects
739 // - calculate the destination of each object at the end of the collection
740 // - move the objects to their destination
741 // - update some references and reinitialize some variables
742 //
743 // These three phases are invoked in PSParallelCompact::invoke_no_policy().
744 // The marking phase is implemented in PSParallelCompact::marking_phase()
745 // and does a complete marking of the heap.
746 // The summary phase is implemented in PSParallelCompact::summary_phase().
747 // The move and update phase is implemented in PSParallelCompact::compact().
748 //
749 // A space that is being collected is divided into chunks and with
750 // each chunk is associated an object of type ParallelCompactData.
751 // Each chunk is of a fixed size and typically will contain more than
752 // 1 object and may have parts of objects at the front and back of the
753 // chunk.
754 //
755 // chunk -----+---------------------+----------
756 // objects covered [ AAA )[ BBB )[ CCC )[ DDD )
757 //
758 // The marking phase does a complete marking of all live objects in the
759 // heap. The marking also compiles the size of the data for
760 // all live objects covered by the chunk. This size includes the
761 // part of any live object spanning onto the chunk (part of AAA
762 // if it is live) from the front, all live objects contained in the chunk
763 // (BBB and/or CCC if they are live), and the part of any live objects
764 // covered by the chunk that extends off the chunk (part of DDD if it is
765 // live). The marking phase uses multiple GC threads and marking is
766 // done in a bit array of type ParMarkBitMap. The marking of the
767 // bit map is done atomically as is the accumulation of the size of the
768 // live objects covered by a chunk.
769 //
770 // The summary phase calculates the total live data to the left of
771 // each chunk XXX. Based on that total and the bottom of the space,
772 // it can calculate the starting location of the live data in XXX.
773 // The summary phase calculates for each chunk XXX quantites such as
774 //
775 // - the amount of live data at the beginning of a chunk from an object
776 // entering the chunk.
777 // - the location of the first live data on the chunk
778 // - a count of the number of chunks receiving live data from XXX.
779 //
780 // See ParallelCompactData for precise details. The summary phase also
781 // calculates the dense prefix for the compaction. The dense prefix
782 // is a portion at the beginning of the space that is not moved. The
783 // objects in the dense prefix do need to have their object references
784 // updated. See method summarize_dense_prefix().
785 //
786 // The summary phase is done using 1 GC thread.
787 //
788 // The compaction phase moves objects to their new location and updates
789 // all references in the object.
790 //
791 // A current exception is that objects that cross a chunk boundary
792 // are moved but do not have their references updated. References are
793 // not updated because it cannot easily be determined if the klass
794 // pointer KKK for the object AAA has been updated. KKK likely resides
795 // in a chunk to the left of the chunk containing AAA. These AAA's
796 // have there references updated at the end in a clean up phase.
797 // See the method PSParallelCompact::update_deferred_objects(). An
798 // alternate strategy is being investigated for this deferral of updating.
799 //
800 // Compaction is done on a chunk basis. A chunk that is ready to be
801 // filled is put on a ready list and GC threads take chunk off the list
802 // and fill them. A chunk is ready to be filled if it
803 // empty of live objects. Such a chunk may have been initially
804 // empty (only contained
805 // dead objects) or may have had all its live objects copied out already.
806 // A chunk that compacts into itself is also ready for filling. The
807 // ready list is initially filled with empty chunks and chunks compacting
808 // into themselves. There is always at least 1 chunk that can be put on
809 // the ready list. The chunks are atomically added and removed from
810 // the ready list.
811 //
812 class PSParallelCompact : AllStatic {
813 public:
814 // Convenient access to type names.
815 typedef ParMarkBitMap::idx_t idx_t;
816 typedef ParallelCompactData::ChunkData ChunkData;
817 typedef ParallelCompactData::BlockData BlockData;
819 typedef enum {
820 perm_space_id, old_space_id, eden_space_id,
821 from_space_id, to_space_id, last_space_id
822 } SpaceId;
824 public:
825 // Inline closure decls
826 //
827 class IsAliveClosure: public BoolObjectClosure {
828 public:
829 virtual void do_object(oop p);
830 virtual bool do_object_b(oop p);
831 };
833 class KeepAliveClosure: public OopClosure {
834 private:
835 ParCompactionManager* _compaction_manager;
836 protected:
837 template <class T> inline void do_oop_work(T* p);
838 public:
839 KeepAliveClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
840 virtual void do_oop(oop* p);
841 virtual void do_oop(narrowOop* p);
842 };
844 // Current unused
845 class FollowRootClosure: public OopsInGenClosure {
846 private:
847 ParCompactionManager* _compaction_manager;
848 public:
849 FollowRootClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
850 virtual void do_oop(oop* p);
851 virtual void do_oop(narrowOop* p);
852 virtual const bool do_nmethods() const { return true; }
853 };
855 class FollowStackClosure: public VoidClosure {
856 private:
857 ParCompactionManager* _compaction_manager;
858 public:
859 FollowStackClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
860 virtual void do_void();
861 };
863 class AdjustPointerClosure: public OopsInGenClosure {
864 private:
865 bool _is_root;
866 public:
867 AdjustPointerClosure(bool is_root) : _is_root(is_root) { }
868 virtual void do_oop(oop* p);
869 virtual void do_oop(narrowOop* p);
870 };
872 // Closure for verifying update of pointers. Does not
873 // have any side effects.
874 class VerifyUpdateClosure: public ParMarkBitMapClosure {
875 const MutableSpace* _space; // Is this ever used?
877 public:
878 VerifyUpdateClosure(ParCompactionManager* cm, const MutableSpace* sp) :
879 ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm), _space(sp)
880 { }
882 virtual IterationStatus do_addr(HeapWord* addr, size_t words);
884 const MutableSpace* space() { return _space; }
885 };
887 // Closure for updating objects altered for debug checking
888 class ResetObjectsClosure: public ParMarkBitMapClosure {
889 public:
890 ResetObjectsClosure(ParCompactionManager* cm):
891 ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm)
892 { }
894 virtual IterationStatus do_addr(HeapWord* addr, size_t words);
895 };
897 friend class KeepAliveClosure;
898 friend class FollowStackClosure;
899 friend class AdjustPointerClosure;
900 friend class FollowRootClosure;
901 friend class instanceKlassKlass;
902 friend class RefProcTaskProxy;
904 private:
905 static elapsedTimer _accumulated_time;
906 static unsigned int _total_invocations;
907 static unsigned int _maximum_compaction_gc_num;
908 static jlong _time_of_last_gc; // ms
909 static CollectorCounters* _counters;
910 static ParMarkBitMap _mark_bitmap;
911 static ParallelCompactData _summary_data;
912 static IsAliveClosure _is_alive_closure;
913 static SpaceInfo _space_info[last_space_id];
914 static bool _print_phases;
915 static AdjustPointerClosure _adjust_root_pointer_closure;
916 static AdjustPointerClosure _adjust_pointer_closure;
918 // Reference processing (used in ...follow_contents)
919 static ReferenceProcessor* _ref_processor;
921 // Updated location of intArrayKlassObj.
922 static klassOop _updated_int_array_klass_obj;
924 // Values computed at initialization and used by dead_wood_limiter().
925 static double _dwl_mean;
926 static double _dwl_std_dev;
927 static double _dwl_first_term;
928 static double _dwl_adjustment;
929 #ifdef ASSERT
930 static bool _dwl_initialized;
931 #endif // #ifdef ASSERT
933 private:
934 // Closure accessors
935 static OopClosure* adjust_pointer_closure() { return (OopClosure*)&_adjust_pointer_closure; }
936 static OopClosure* adjust_root_pointer_closure() { return (OopClosure*)&_adjust_root_pointer_closure; }
937 static BoolObjectClosure* is_alive_closure() { return (BoolObjectClosure*)&_is_alive_closure; }
939 static void initialize_space_info();
941 // Return true if details about individual phases should be printed.
942 static inline bool print_phases();
944 // Clear the marking bitmap and summary data that cover the specified space.
945 static void clear_data_covering_space(SpaceId id);
947 static void pre_compact(PreGCValues* pre_gc_values);
948 static void post_compact();
950 // Mark live objects
951 static void marking_phase(ParCompactionManager* cm,
952 bool maximum_heap_compaction);
953 static void follow_stack(ParCompactionManager* cm);
954 static void follow_weak_klass_links(ParCompactionManager* cm);
956 template <class T> static inline void adjust_pointer(T* p, bool is_root);
957 static void adjust_root_pointer(oop* p) { adjust_pointer(p, true); }
959 template <class T>
960 static inline void follow_root(ParCompactionManager* cm, T* p);
962 // Compute the dense prefix for the designated space. This is an experimental
963 // implementation currently not used in production.
964 static HeapWord* compute_dense_prefix_via_density(const SpaceId id,
965 bool maximum_compaction);
967 // Methods used to compute the dense prefix.
969 // Compute the value of the normal distribution at x = density. The mean and
970 // standard deviation are values saved by initialize_dead_wood_limiter().
971 static inline double normal_distribution(double density);
973 // Initialize the static vars used by dead_wood_limiter().
974 static void initialize_dead_wood_limiter();
976 // Return the percentage of space that can be treated as "dead wood" (i.e.,
977 // not reclaimed).
978 static double dead_wood_limiter(double density, size_t min_percent);
980 // Find the first (left-most) chunk in the range [beg, end) that has at least
981 // dead_words of dead space to the left. The argument beg must be the first
982 // chunk in the space that is not completely live.
983 static ChunkData* dead_wood_limit_chunk(const ChunkData* beg,
984 const ChunkData* end,
985 size_t dead_words);
987 // Return a pointer to the first chunk in the range [beg, end) that is not
988 // completely full.
989 static ChunkData* first_dead_space_chunk(const ChunkData* beg,
990 const ChunkData* end);
992 // Return a value indicating the benefit or 'yield' if the compacted region
993 // were to start (or equivalently if the dense prefix were to end) at the
994 // candidate chunk. Higher values are better.
995 //
996 // The value is based on the amount of space reclaimed vs. the costs of (a)
997 // updating references in the dense prefix plus (b) copying objects and
998 // updating references in the compacted region.
999 static inline double reclaimed_ratio(const ChunkData* const candidate,
1000 HeapWord* const bottom,
1001 HeapWord* const top,
1002 HeapWord* const new_top);
1004 // Compute the dense prefix for the designated space.
1005 static HeapWord* compute_dense_prefix(const SpaceId id,
1006 bool maximum_compaction);
1008 // Return true if dead space crosses onto the specified Chunk; bit must be the
1009 // bit index corresponding to the first word of the Chunk.
1010 static inline bool dead_space_crosses_boundary(const ChunkData* chunk,
1011 idx_t bit);
1013 // Summary phase utility routine to fill dead space (if any) at the dense
1014 // prefix boundary. Should only be called if the the dense prefix is
1015 // non-empty.
1016 static void fill_dense_prefix_end(SpaceId id);
1018 static void summarize_spaces_quick();
1019 static void summarize_space(SpaceId id, bool maximum_compaction);
1020 static void summary_phase(ParCompactionManager* cm, bool maximum_compaction);
1022 static bool block_first_offset(size_t block_index, idx_t* block_offset_ptr);
1024 // Fill in the BlockData
1025 static void summarize_blocks(ParCompactionManager* cm,
1026 SpaceId first_compaction_space_id);
1028 // The space that is compacted after space_id.
1029 static SpaceId next_compaction_space_id(SpaceId space_id);
1031 // Adjust addresses in roots. Does not adjust addresses in heap.
1032 static void adjust_roots();
1034 // Serial code executed in preparation for the compaction phase.
1035 static void compact_prologue();
1037 // Move objects to new locations.
1038 static void compact_perm(ParCompactionManager* cm);
1039 static void compact();
1041 // Add available chunks to the stack and draining tasks to the task queue.
1042 static void enqueue_chunk_draining_tasks(GCTaskQueue* q,
1043 uint parallel_gc_threads);
1045 // Add dense prefix update tasks to the task queue.
1046 static void enqueue_dense_prefix_tasks(GCTaskQueue* q,
1047 uint parallel_gc_threads);
1049 // Add chunk stealing tasks to the task queue.
1050 static void enqueue_chunk_stealing_tasks(
1051 GCTaskQueue* q,
1052 ParallelTaskTerminator* terminator_ptr,
1053 uint parallel_gc_threads);
1055 // For debugging only - compacts the old gen serially
1056 static void compact_serial(ParCompactionManager* cm);
1058 // If objects are left in eden after a collection, try to move the boundary
1059 // and absorb them into the old gen. Returns true if eden was emptied.
1060 static bool absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
1061 PSYoungGen* young_gen,
1062 PSOldGen* old_gen);
1064 // Reset time since last full gc
1065 static void reset_millis_since_last_gc();
1067 protected:
1068 #ifdef VALIDATE_MARK_SWEEP
1069 static GrowableArray<void*>* _root_refs_stack;
1070 static GrowableArray<oop> * _live_oops;
1071 static GrowableArray<oop> * _live_oops_moved_to;
1072 static GrowableArray<size_t>* _live_oops_size;
1073 static size_t _live_oops_index;
1074 static size_t _live_oops_index_at_perm;
1075 static GrowableArray<void*>* _other_refs_stack;
1076 static GrowableArray<void*>* _adjusted_pointers;
1077 static bool _pointer_tracking;
1078 static bool _root_tracking;
1080 // The following arrays are saved since the time of the last GC and
1081 // assist in tracking down problems where someone has done an errant
1082 // store into the heap, usually to an oop that wasn't properly
1083 // handleized across a GC. If we crash or otherwise fail before the
1084 // next GC, we can query these arrays to find out the object we had
1085 // intended to do the store to (assuming it is still alive) and the
1086 // offset within that object. Covered under RecordMarkSweepCompaction.
1087 static GrowableArray<HeapWord*> * _cur_gc_live_oops;
1088 static GrowableArray<HeapWord*> * _cur_gc_live_oops_moved_to;
1089 static GrowableArray<size_t>* _cur_gc_live_oops_size;
1090 static GrowableArray<HeapWord*> * _last_gc_live_oops;
1091 static GrowableArray<HeapWord*> * _last_gc_live_oops_moved_to;
1092 static GrowableArray<size_t>* _last_gc_live_oops_size;
1093 #endif
1095 public:
1096 class MarkAndPushClosure: public OopClosure {
1097 private:
1098 ParCompactionManager* _compaction_manager;
1099 public:
1100 MarkAndPushClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
1101 virtual void do_oop(oop* p);
1102 virtual void do_oop(narrowOop* p);
1103 virtual const bool do_nmethods() const { return true; }
1104 };
1106 PSParallelCompact();
1108 // Convenient accessor for Universe::heap().
1109 static ParallelScavengeHeap* gc_heap() {
1110 return (ParallelScavengeHeap*)Universe::heap();
1111 }
1113 static void invoke(bool maximum_heap_compaction);
1114 static void invoke_no_policy(bool maximum_heap_compaction);
1116 static void post_initialize();
1117 // Perform initialization for PSParallelCompact that requires
1118 // allocations. This should be called during the VM initialization
1119 // at a pointer where it would be appropriate to return a JNI_ENOMEM
1120 // in the event of a failure.
1121 static bool initialize();
1123 // Public accessors
1124 static elapsedTimer* accumulated_time() { return &_accumulated_time; }
1125 static unsigned int total_invocations() { return _total_invocations; }
1126 static CollectorCounters* counters() { return _counters; }
1128 // Used to add tasks
1129 static GCTaskManager* const gc_task_manager();
1130 static klassOop updated_int_array_klass_obj() {
1131 return _updated_int_array_klass_obj;
1132 }
1134 // Marking support
1135 static inline bool mark_obj(oop obj);
1136 // Check mark and maybe push on marking stack
1137 template <class T> static inline void mark_and_push(ParCompactionManager* cm,
1138 T* p);
1140 // Compaction support.
1141 // Return true if p is in the range [beg_addr, end_addr).
1142 static inline bool is_in(HeapWord* p, HeapWord* beg_addr, HeapWord* end_addr);
1143 static inline bool is_in(oop* p, HeapWord* beg_addr, HeapWord* end_addr);
1145 // Convenience wrappers for per-space data kept in _space_info.
1146 static inline MutableSpace* space(SpaceId space_id);
1147 static inline HeapWord* new_top(SpaceId space_id);
1148 static inline HeapWord* dense_prefix(SpaceId space_id);
1149 static inline ObjectStartArray* start_array(SpaceId space_id);
1151 // Return true if the klass should be updated.
1152 static inline bool should_update_klass(klassOop k);
1154 // Move and update the live objects in the specified space.
1155 static void move_and_update(ParCompactionManager* cm, SpaceId space_id);
1157 // Process the end of the given chunk range in the dense prefix.
1158 // This includes saving any object not updated.
1159 static void dense_prefix_chunks_epilogue(ParCompactionManager* cm,
1160 size_t chunk_start_index,
1161 size_t chunk_end_index,
1162 idx_t exiting_object_offset,
1163 idx_t chunk_offset_start,
1164 idx_t chunk_offset_end);
1166 // Update a chunk in the dense prefix. For each live object
1167 // in the chunk, update it's interior references. For each
1168 // dead object, fill it with deadwood. Dead space at the end
1169 // of a chunk range will be filled to the start of the next
1170 // live object regardless of the chunk_index_end. None of the
1171 // objects in the dense prefix move and dead space is dead
1172 // (holds only dead objects that don't need any processing), so
1173 // dead space can be filled in any order.
1174 static void update_and_deadwood_in_dense_prefix(ParCompactionManager* cm,
1175 SpaceId space_id,
1176 size_t chunk_index_start,
1177 size_t chunk_index_end);
1179 // Return the address of the count + 1st live word in the range [beg, end).
1180 static HeapWord* skip_live_words(HeapWord* beg, HeapWord* end, size_t count);
1182 // Return the address of the word to be copied to dest_addr, which must be
1183 // aligned to a chunk boundary.
1184 static HeapWord* first_src_addr(HeapWord* const dest_addr,
1185 size_t src_chunk_idx);
1187 // Determine the next source chunk, set closure.source() to the start of the
1188 // new chunk return the chunk index. Parameter end_addr is the address one
1189 // beyond the end of source range just processed. If necessary, switch to a
1190 // new source space and set src_space_id (in-out parameter) and src_space_top
1191 // (out parameter) accordingly.
1192 static size_t next_src_chunk(MoveAndUpdateClosure& closure,
1193 SpaceId& src_space_id,
1194 HeapWord*& src_space_top,
1195 HeapWord* end_addr);
1197 // Decrement the destination count for each non-empty source chunk in the
1198 // range [beg_chunk, chunk(chunk_align_up(end_addr))).
1199 static void decrement_destination_counts(ParCompactionManager* cm,
1200 size_t beg_chunk,
1201 HeapWord* end_addr);
1203 // Fill a chunk, copying objects from one or more source chunks.
1204 static void fill_chunk(ParCompactionManager* cm, size_t chunk_idx);
1205 static void fill_and_update_chunk(ParCompactionManager* cm, size_t chunk) {
1206 fill_chunk(cm, chunk);
1207 }
1209 // Update the deferred objects in the space.
1210 static void update_deferred_objects(ParCompactionManager* cm, SpaceId id);
1212 // Mark pointer and follow contents.
1213 template <class T>
1214 static inline void mark_and_follow(ParCompactionManager* cm, T* p);
1216 static ParMarkBitMap* mark_bitmap() { return &_mark_bitmap; }
1217 static ParallelCompactData& summary_data() { return _summary_data; }
1219 static inline void adjust_pointer(oop* p) { adjust_pointer(p, false); }
1220 static inline void adjust_pointer(narrowOop* p) { adjust_pointer(p, false); }
1222 template <class T>
1223 static inline void adjust_pointer(T* p,
1224 HeapWord* beg_addr,
1225 HeapWord* end_addr);
1227 // Reference Processing
1228 static ReferenceProcessor* const ref_processor() { return _ref_processor; }
1230 // Return the SpaceId for the given address.
1231 static SpaceId space_id(HeapWord* addr);
1233 // Time since last full gc (in milliseconds).
1234 static jlong millis_since_last_gc();
1236 #ifdef VALIDATE_MARK_SWEEP
1237 static void track_adjusted_pointer(void* p, bool isroot);
1238 static void check_adjust_pointer(void* p);
1239 static void track_interior_pointers(oop obj);
1240 static void check_interior_pointers();
1242 static void reset_live_oop_tracking(bool at_perm);
1243 static void register_live_oop(oop p, size_t size);
1244 static void validate_live_oop(oop p, size_t size);
1245 static void live_oop_moved_to(HeapWord* q, size_t size, HeapWord* compaction_top);
1246 static void compaction_complete();
1248 // Querying operation of RecordMarkSweepCompaction results.
1249 // Finds and prints the current base oop and offset for a word
1250 // within an oop that was live during the last GC. Helpful for
1251 // tracking down heap stomps.
1252 static void print_new_location_of_heap_address(HeapWord* q);
1253 #endif // #ifdef VALIDATE_MARK_SWEEP
1255 // Call backs for class unloading
1256 // Update subklass/sibling/implementor links at end of marking.
1257 static void revisit_weak_klass_link(ParCompactionManager* cm, Klass* k);
1259 #ifndef PRODUCT
1260 // Debugging support.
1261 static const char* space_names[last_space_id];
1262 static void print_chunk_ranges();
1263 static void print_dense_prefix_stats(const char* const algorithm,
1264 const SpaceId id,
1265 const bool maximum_compaction,
1266 HeapWord* const addr);
1267 #endif // #ifndef PRODUCT
1269 #ifdef ASSERT
1270 // Verify that all the chunks have been emptied.
1271 static void verify_complete(SpaceId space_id);
1272 #endif // #ifdef ASSERT
1273 };
1275 inline bool PSParallelCompact::mark_obj(oop obj) {
1276 const int obj_size = obj->size();
1277 if (mark_bitmap()->mark_obj(obj, obj_size)) {
1278 _summary_data.add_obj(obj, obj_size);
1279 return true;
1280 } else {
1281 return false;
1282 }
1283 }
1285 template <class T>
1286 inline void PSParallelCompact::follow_root(ParCompactionManager* cm, T* p) {
1287 assert(!Universe::heap()->is_in_reserved(p),
1288 "roots shouldn't be things within the heap");
1289 #ifdef VALIDATE_MARK_SWEEP
1290 if (ValidateMarkSweep) {
1291 guarantee(!_root_refs_stack->contains(p), "should only be in here once");
1292 _root_refs_stack->push(p);
1293 }
1294 #endif
1295 T heap_oop = oopDesc::load_heap_oop(p);
1296 if (!oopDesc::is_null(heap_oop)) {
1297 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
1298 if (mark_bitmap()->is_unmarked(obj)) {
1299 if (mark_obj(obj)) {
1300 obj->follow_contents(cm);
1301 }
1302 }
1303 }
1304 follow_stack(cm);
1305 }
1307 template <class T>
1308 inline void PSParallelCompact::mark_and_follow(ParCompactionManager* cm,
1309 T* p) {
1310 T heap_oop = oopDesc::load_heap_oop(p);
1311 if (!oopDesc::is_null(heap_oop)) {
1312 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
1313 if (mark_bitmap()->is_unmarked(obj)) {
1314 if (mark_obj(obj)) {
1315 obj->follow_contents(cm);
1316 }
1317 }
1318 }
1319 }
1321 template <class T>
1322 inline void PSParallelCompact::mark_and_push(ParCompactionManager* cm, T* p) {
1323 T heap_oop = oopDesc::load_heap_oop(p);
1324 if (!oopDesc::is_null(heap_oop)) {
1325 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
1326 if (mark_bitmap()->is_unmarked(obj)) {
1327 if (mark_obj(obj)) {
1328 // This thread marked the object and owns the subsequent processing of it.
1329 cm->save_for_scanning(obj);
1330 }
1331 }
1332 }
1333 }
1335 template <class T>
1336 inline void PSParallelCompact::adjust_pointer(T* p, bool isroot) {
1337 T heap_oop = oopDesc::load_heap_oop(p);
1338 if (!oopDesc::is_null(heap_oop)) {
1339 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
1340 oop new_obj = (oop)summary_data().calc_new_pointer(obj);
1341 assert(new_obj != NULL || // is forwarding ptr?
1342 obj->is_shared(), // never forwarded?
1343 "should be forwarded");
1344 // Just always do the update unconditionally?
1345 if (new_obj != NULL) {
1346 assert(Universe::heap()->is_in_reserved(new_obj),
1347 "should be in object space");
1348 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
1349 }
1350 }
1351 VALIDATE_MARK_SWEEP_ONLY(track_adjusted_pointer(p, isroot));
1352 }
1354 template <class T>
1355 inline void PSParallelCompact::KeepAliveClosure::do_oop_work(T* p) {
1356 #ifdef VALIDATE_MARK_SWEEP
1357 if (ValidateMarkSweep) {
1358 if (!Universe::heap()->is_in_reserved(p)) {
1359 _root_refs_stack->push(p);
1360 } else {
1361 _other_refs_stack->push(p);
1362 }
1363 }
1364 #endif
1365 mark_and_push(_compaction_manager, p);
1366 }
1368 inline bool PSParallelCompact::print_phases() {
1369 return _print_phases;
1370 }
1372 inline double PSParallelCompact::normal_distribution(double density) {
1373 assert(_dwl_initialized, "uninitialized");
1374 const double squared_term = (density - _dwl_mean) / _dwl_std_dev;
1375 return _dwl_first_term * exp(-0.5 * squared_term * squared_term);
1376 }
1378 inline bool
1379 PSParallelCompact::dead_space_crosses_boundary(const ChunkData* chunk,
1380 idx_t bit)
1381 {
1382 assert(bit > 0, "cannot call this for the first bit/chunk");
1383 assert(_summary_data.chunk_to_addr(chunk) == _mark_bitmap.bit_to_addr(bit),
1384 "sanity check");
1386 // Dead space crosses the boundary if (1) a partial object does not extend
1387 // onto the chunk, (2) an object does not start at the beginning of the chunk,
1388 // and (3) an object does not end at the end of the prior chunk.
1389 return chunk->partial_obj_size() == 0 &&
1390 !_mark_bitmap.is_obj_beg(bit) &&
1391 !_mark_bitmap.is_obj_end(bit - 1);
1392 }
1394 inline bool
1395 PSParallelCompact::is_in(HeapWord* p, HeapWord* beg_addr, HeapWord* end_addr) {
1396 return p >= beg_addr && p < end_addr;
1397 }
1399 inline bool
1400 PSParallelCompact::is_in(oop* p, HeapWord* beg_addr, HeapWord* end_addr) {
1401 return is_in((HeapWord*)p, beg_addr, end_addr);
1402 }
1404 inline MutableSpace* PSParallelCompact::space(SpaceId id) {
1405 assert(id < last_space_id, "id out of range");
1406 return _space_info[id].space();
1407 }
1409 inline HeapWord* PSParallelCompact::new_top(SpaceId id) {
1410 assert(id < last_space_id, "id out of range");
1411 return _space_info[id].new_top();
1412 }
1414 inline HeapWord* PSParallelCompact::dense_prefix(SpaceId id) {
1415 assert(id < last_space_id, "id out of range");
1416 return _space_info[id].dense_prefix();
1417 }
1419 inline ObjectStartArray* PSParallelCompact::start_array(SpaceId id) {
1420 assert(id < last_space_id, "id out of range");
1421 return _space_info[id].start_array();
1422 }
1424 inline bool PSParallelCompact::should_update_klass(klassOop k) {
1425 return ((HeapWord*) k) >= dense_prefix(perm_space_id);
1426 }
1428 template <class T>
1429 inline void PSParallelCompact::adjust_pointer(T* p,
1430 HeapWord* beg_addr,
1431 HeapWord* end_addr) {
1432 if (is_in((HeapWord*)p, beg_addr, end_addr)) {
1433 adjust_pointer(p);
1434 }
1435 }
1437 class MoveAndUpdateClosure: public ParMarkBitMapClosure {
1438 public:
1439 inline MoveAndUpdateClosure(ParMarkBitMap* bitmap, ParCompactionManager* cm,
1440 ObjectStartArray* start_array,
1441 HeapWord* destination, size_t words);
1443 // Accessors.
1444 HeapWord* destination() const { return _destination; }
1446 // If the object will fit (size <= words_remaining()), copy it to the current
1447 // destination, update the interior oops and the start array and return either
1448 // full (if the closure is full) or incomplete. If the object will not fit,
1449 // return would_overflow.
1450 virtual IterationStatus do_addr(HeapWord* addr, size_t size);
1452 // Copy enough words to fill this closure, starting at source(). Interior
1453 // oops and the start array are not updated. Return full.
1454 IterationStatus copy_until_full();
1456 // Copy enough words to fill this closure or to the end of an object,
1457 // whichever is smaller, starting at source(). Interior oops and the start
1458 // array are not updated.
1459 void copy_partial_obj();
1461 protected:
1462 // Update variables to indicate that word_count words were processed.
1463 inline void update_state(size_t word_count);
1465 protected:
1466 ObjectStartArray* const _start_array;
1467 HeapWord* _destination; // Next addr to be written.
1468 };
1470 inline
1471 MoveAndUpdateClosure::MoveAndUpdateClosure(ParMarkBitMap* bitmap,
1472 ParCompactionManager* cm,
1473 ObjectStartArray* start_array,
1474 HeapWord* destination,
1475 size_t words) :
1476 ParMarkBitMapClosure(bitmap, cm, words), _start_array(start_array)
1477 {
1478 _destination = destination;
1479 }
1481 inline void MoveAndUpdateClosure::update_state(size_t words)
1482 {
1483 decrement_words_remaining(words);
1484 _source += words;
1485 _destination += words;
1486 }
1488 class UpdateOnlyClosure: public ParMarkBitMapClosure {
1489 private:
1490 const PSParallelCompact::SpaceId _space_id;
1491 ObjectStartArray* const _start_array;
1493 public:
1494 UpdateOnlyClosure(ParMarkBitMap* mbm,
1495 ParCompactionManager* cm,
1496 PSParallelCompact::SpaceId space_id);
1498 // Update the object.
1499 virtual IterationStatus do_addr(HeapWord* addr, size_t words);
1501 inline void do_addr(HeapWord* addr);
1502 };
1504 inline void UpdateOnlyClosure::do_addr(HeapWord* addr)
1505 {
1506 _start_array->allocate_block(addr);
1507 oop(addr)->update_contents(compaction_manager());
1508 }
1510 class FillClosure: public ParMarkBitMapClosure {
1511 public:
1512 FillClosure(ParCompactionManager* cm, PSParallelCompact::SpaceId space_id) :
1513 ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm),
1514 _space_id(space_id),
1515 _start_array(PSParallelCompact::start_array(space_id)) {
1516 assert(_space_id == PSParallelCompact::perm_space_id ||
1517 _space_id == PSParallelCompact::old_space_id,
1518 "cannot use FillClosure in the young gen");
1519 assert(bitmap() != NULL, "need a bitmap");
1520 assert(_start_array != NULL, "need a start array");
1521 }
1523 void fill_region(HeapWord* addr, size_t size) {
1524 MemRegion region(addr, size);
1525 SharedHeap::fill_region_with_object(region);
1526 _start_array->allocate_block(addr);
1527 }
1529 virtual IterationStatus do_addr(HeapWord* addr, size_t size) {
1530 fill_region(addr, size);
1531 return ParMarkBitMap::incomplete;
1532 }
1534 private:
1535 const PSParallelCompact::SpaceId _space_id;
1536 ObjectStartArray* const _start_array;
1537 };