Tue, 11 May 2010 14:35:43 -0700
6931180: Migration to recent versions of MS Platform SDK
6951582: Build problems on win64
Summary: Changes to enable building JDK7 with Microsoft Visual Studio 2010
Reviewed-by: ohair, art, ccheung, dcubed
1 /*
2 * Copyright 2000-2009 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 // The CollectedHeap type requires subtypes to implement a method
26 // "block_start". For some subtypes, notably generational
27 // systems using card-table-based write barriers, the efficiency of this
28 // operation may be important. Implementations of the "BlockOffsetArray"
29 // class may be useful in providing such efficient implementations.
30 //
31 // BlockOffsetTable (abstract)
32 // - BlockOffsetArray (abstract)
33 // - BlockOffsetArrayNonContigSpace
34 // - BlockOffsetArrayContigSpace
35 //
37 class ContiguousSpace;
38 class SerializeOopClosure;
40 //////////////////////////////////////////////////////////////////////////
41 // The BlockOffsetTable "interface"
42 //////////////////////////////////////////////////////////////////////////
43 class BlockOffsetTable VALUE_OBJ_CLASS_SPEC {
44 friend class VMStructs;
45 protected:
46 // These members describe the region covered by the table.
48 // The space this table is covering.
49 HeapWord* _bottom; // == reserved.start
50 HeapWord* _end; // End of currently allocated region.
52 public:
53 // Initialize the table to cover the given space.
54 // The contents of the initial table are undefined.
55 BlockOffsetTable(HeapWord* bottom, HeapWord* end):
56 _bottom(bottom), _end(end) {
57 assert(_bottom <= _end, "arguments out of order");
58 }
60 // Note that the committed size of the covered space may have changed,
61 // so the table size might also wish to change.
62 virtual void resize(size_t new_word_size) = 0;
64 virtual void set_bottom(HeapWord* new_bottom) {
65 assert(new_bottom <= _end, "new_bottom > _end");
66 _bottom = new_bottom;
67 resize(pointer_delta(_end, _bottom));
68 }
70 // Requires "addr" to be contained by a block, and returns the address of
71 // the start of that block.
72 virtual HeapWord* block_start_unsafe(const void* addr) const = 0;
74 // Returns the address of the start of the block containing "addr", or
75 // else "null" if it is covered by no block.
76 HeapWord* block_start(const void* addr) const;
77 };
79 //////////////////////////////////////////////////////////////////////////
80 // One implementation of "BlockOffsetTable," the BlockOffsetArray,
81 // divides the covered region into "N"-word subregions (where
82 // "N" = 2^"LogN". An array with an entry for each such subregion
83 // indicates how far back one must go to find the start of the
84 // chunk that includes the first word of the subregion.
85 //
86 // Each BlockOffsetArray is owned by a Space. However, the actual array
87 // may be shared by several BlockOffsetArrays; this is useful
88 // when a single resizable area (such as a generation) is divided up into
89 // several spaces in which contiguous allocation takes place. (Consider,
90 // for example, the garbage-first generation.)
92 // Here is the shared array type.
93 //////////////////////////////////////////////////////////////////////////
94 // BlockOffsetSharedArray
95 //////////////////////////////////////////////////////////////////////////
96 class BlockOffsetSharedArray: public CHeapObj {
97 friend class BlockOffsetArray;
98 friend class BlockOffsetArrayNonContigSpace;
99 friend class BlockOffsetArrayContigSpace;
100 friend class VMStructs;
102 private:
103 enum SomePrivateConstants {
104 LogN = 9,
105 LogN_words = LogN - LogHeapWordSize,
106 N_bytes = 1 << LogN,
107 N_words = 1 << LogN_words
108 };
110 // The reserved region covered by the shared array.
111 MemRegion _reserved;
113 // End of the current committed region.
114 HeapWord* _end;
116 // Array for keeping offsets for retrieving object start fast given an
117 // address.
118 VirtualSpace _vs;
119 u_char* _offset_array; // byte array keeping backwards offsets
121 protected:
122 // Bounds checking accessors:
123 // For performance these have to devolve to array accesses in product builds.
124 u_char offset_array(size_t index) const {
125 assert(index < _vs.committed_size(), "index out of range");
126 return _offset_array[index];
127 }
128 void set_offset_array(size_t index, u_char offset) {
129 assert(index < _vs.committed_size(), "index out of range");
130 _offset_array[index] = offset;
131 }
132 void set_offset_array(size_t index, HeapWord* high, HeapWord* low) {
133 assert(index < _vs.committed_size(), "index out of range");
134 assert(high >= low, "addresses out of order");
135 assert(pointer_delta(high, low) <= N_words, "offset too large");
136 _offset_array[index] = (u_char)pointer_delta(high, low);
137 }
138 void set_offset_array(HeapWord* left, HeapWord* right, u_char offset) {
139 assert(index_for(right - 1) < _vs.committed_size(),
140 "right address out of range");
141 assert(left < right, "Heap addresses out of order");
142 size_t num_cards = pointer_delta(right, left) >> LogN_words;
143 memset(&_offset_array[index_for(left)], offset, num_cards);
144 }
146 void set_offset_array(size_t left, size_t right, u_char offset) {
147 assert(right < _vs.committed_size(), "right address out of range");
148 assert(left <= right, "indexes out of order");
149 size_t num_cards = right - left + 1;
150 memset(&_offset_array[left], offset, num_cards);
151 }
153 void check_offset_array(size_t index, HeapWord* high, HeapWord* low) const {
154 assert(index < _vs.committed_size(), "index out of range");
155 assert(high >= low, "addresses out of order");
156 assert(pointer_delta(high, low) <= N_words, "offset too large");
157 assert(_offset_array[index] == pointer_delta(high, low),
158 "Wrong offset");
159 }
161 bool is_card_boundary(HeapWord* p) const;
163 // Return the number of slots needed for an offset array
164 // that covers mem_region_words words.
165 // We always add an extra slot because if an object
166 // ends on a card boundary we put a 0 in the next
167 // offset array slot, so we want that slot always
168 // to be reserved.
170 size_t compute_size(size_t mem_region_words) {
171 size_t number_of_slots = (mem_region_words / N_words) + 1;
172 return ReservedSpace::allocation_align_size_up(number_of_slots);
173 }
175 public:
176 // Initialize the table to cover from "base" to (at least)
177 // "base + init_word_size". In the future, the table may be expanded
178 // (see "resize" below) up to the size of "_reserved" (which must be at
179 // least "init_word_size".) The contents of the initial table are
180 // undefined; it is the responsibility of the constituent
181 // BlockOffsetTable(s) to initialize cards.
182 BlockOffsetSharedArray(MemRegion reserved, size_t init_word_size);
184 // Notes a change in the committed size of the region covered by the
185 // table. The "new_word_size" may not be larger than the size of the
186 // reserved region this table covers.
187 void resize(size_t new_word_size);
189 void set_bottom(HeapWord* new_bottom);
191 // Updates all the BlockOffsetArray's sharing this shared array to
192 // reflect the current "top"'s of their spaces.
193 void update_offset_arrays(); // Not yet implemented!
195 // Return the appropriate index into "_offset_array" for "p".
196 size_t index_for(const void* p) const;
198 // Return the address indicating the start of the region corresponding to
199 // "index" in "_offset_array".
200 HeapWord* address_for_index(size_t index) const;
202 // Return the address "p" incremented by the size of
203 // a region. This method does not align the address
204 // returned to the start of a region. It is a simple
205 // primitive.
206 HeapWord* inc_by_region_size(HeapWord* p) const { return p + N_words; }
208 // Shared space support
209 void serialize(SerializeOopClosure* soc, HeapWord* start, HeapWord* end);
210 };
212 //////////////////////////////////////////////////////////////////////////
213 // The BlockOffsetArray whose subtypes use the BlockOffsetSharedArray.
214 //////////////////////////////////////////////////////////////////////////
215 class BlockOffsetArray: public BlockOffsetTable {
216 friend class VMStructs;
217 friend class G1BlockOffsetArray; // temp. until we restructure and cleanup
218 protected:
219 // The following enums are used by do_block_internal() below
220 enum Action {
221 Action_single, // BOT records a single block (see single_block())
222 Action_mark, // BOT marks the start of a block (see mark_block())
223 Action_check // Check that BOT records block correctly
224 // (see verify_single_block()).
225 };
227 enum SomePrivateConstants {
228 N_words = BlockOffsetSharedArray::N_words,
229 LogN = BlockOffsetSharedArray::LogN,
230 // entries "e" of at least N_words mean "go back by Base^(e-N_words)."
231 // All entries are less than "N_words + N_powers".
232 LogBase = 4,
233 Base = (1 << LogBase),
234 N_powers = 14
235 };
237 static size_t power_to_cards_back(uint i) {
238 return (size_t)(1 << (LogBase * i));
239 }
240 static size_t power_to_words_back(uint i) {
241 return power_to_cards_back(i) * N_words;
242 }
243 static size_t entry_to_cards_back(u_char entry) {
244 assert(entry >= N_words, "Precondition");
245 return power_to_cards_back(entry - N_words);
246 }
247 static size_t entry_to_words_back(u_char entry) {
248 assert(entry >= N_words, "Precondition");
249 return power_to_words_back(entry - N_words);
250 }
252 // The shared array, which is shared with other BlockOffsetArray's
253 // corresponding to different spaces within a generation or span of
254 // memory.
255 BlockOffsetSharedArray* _array;
257 // The space that owns this subregion.
258 Space* _sp;
260 // If true, array entries are initialized to 0; otherwise, they are
261 // initialized to point backwards to the beginning of the covered region.
262 bool _init_to_zero;
264 // Sets the entries
265 // corresponding to the cards starting at "start" and ending at "end"
266 // to point back to the card before "start": the interval [start, end)
267 // is right-open.
268 void set_remainder_to_point_to_start(HeapWord* start, HeapWord* end);
269 // Same as above, except that the args here are a card _index_ interval
270 // that is closed: [start_index, end_index]
271 void set_remainder_to_point_to_start_incl(size_t start, size_t end);
273 // A helper function for BOT adjustment/verification work
274 void do_block_internal(HeapWord* blk_start, HeapWord* blk_end, Action action);
276 public:
277 // The space may not have its bottom and top set yet, which is why the
278 // region is passed as a parameter. If "init_to_zero" is true, the
279 // elements of the array are initialized to zero. Otherwise, they are
280 // initialized to point backwards to the beginning.
281 BlockOffsetArray(BlockOffsetSharedArray* array, MemRegion mr,
282 bool init_to_zero);
284 // Note: this ought to be part of the constructor, but that would require
285 // "this" to be passed as a parameter to a member constructor for
286 // the containing concrete subtype of Space.
287 // This would be legal C++, but MS VC++ doesn't allow it.
288 void set_space(Space* sp) { _sp = sp; }
290 // Resets the covered region to the given "mr".
291 void set_region(MemRegion mr) {
292 _bottom = mr.start();
293 _end = mr.end();
294 }
296 // Note that the committed size of the covered space may have changed,
297 // so the table size might also wish to change.
298 virtual void resize(size_t new_word_size) {
299 HeapWord* new_end = _bottom + new_word_size;
300 if (_end < new_end && !init_to_zero()) {
301 // verify that the old and new boundaries are also card boundaries
302 assert(_array->is_card_boundary(_end),
303 "_end not a card boundary");
304 assert(_array->is_card_boundary(new_end),
305 "new _end would not be a card boundary");
306 // set all the newly added cards
307 _array->set_offset_array(_end, new_end, N_words);
308 }
309 _end = new_end; // update _end
310 }
312 // Adjust the BOT to show that it has a single block in the
313 // range [blk_start, blk_start + size). All necessary BOT
314 // cards are adjusted, but _unallocated_block isn't.
315 void single_block(HeapWord* blk_start, HeapWord* blk_end);
316 void single_block(HeapWord* blk, size_t size) {
317 single_block(blk, blk + size);
318 }
320 // When the alloc_block() call returns, the block offset table should
321 // have enough information such that any subsequent block_start() call
322 // with an argument equal to an address that is within the range
323 // [blk_start, blk_end) would return the value blk_start, provided
324 // there have been no calls in between that reset this information
325 // (e.g. see BlockOffsetArrayNonContigSpace::single_block() call
326 // for an appropriate range covering the said interval).
327 // These methods expect to be called with [blk_start, blk_end)
328 // representing a block of memory in the heap.
329 virtual void alloc_block(HeapWord* blk_start, HeapWord* blk_end);
330 void alloc_block(HeapWord* blk, size_t size) {
331 alloc_block(blk, blk + size);
332 }
334 // If true, initialize array slots with no allocated blocks to zero.
335 // Otherwise, make them point back to the front.
336 bool init_to_zero() { return _init_to_zero; }
338 // Debugging
339 // Return the index of the last entry in the "active" region.
340 virtual size_t last_active_index() const = 0;
341 // Verify the block offset table
342 void verify() const;
343 void check_all_cards(size_t left_card, size_t right_card) const;
344 };
346 ////////////////////////////////////////////////////////////////////////////
347 // A subtype of BlockOffsetArray that takes advantage of the fact
348 // that its underlying space is a NonContiguousSpace, so that some
349 // specialized interfaces can be made available for spaces that
350 // manipulate the table.
351 ////////////////////////////////////////////////////////////////////////////
352 class BlockOffsetArrayNonContigSpace: public BlockOffsetArray {
353 friend class VMStructs;
354 private:
355 // The portion [_unallocated_block, _sp.end()) of the space that
356 // is a single block known not to contain any objects.
357 // NOTE: See BlockOffsetArrayUseUnallocatedBlock flag.
358 HeapWord* _unallocated_block;
360 public:
361 BlockOffsetArrayNonContigSpace(BlockOffsetSharedArray* array, MemRegion mr):
362 BlockOffsetArray(array, mr, false),
363 _unallocated_block(_bottom) { }
365 // accessor
366 HeapWord* unallocated_block() const {
367 assert(BlockOffsetArrayUseUnallocatedBlock,
368 "_unallocated_block is not being maintained");
369 return _unallocated_block;
370 }
372 void set_unallocated_block(HeapWord* block) {
373 assert(BlockOffsetArrayUseUnallocatedBlock,
374 "_unallocated_block is not being maintained");
375 assert(block >= _bottom && block <= _end, "out of range");
376 _unallocated_block = block;
377 }
379 // These methods expect to be called with [blk_start, blk_end)
380 // representing a block of memory in the heap.
381 void alloc_block(HeapWord* blk_start, HeapWord* blk_end);
382 void alloc_block(HeapWord* blk, size_t size) {
383 alloc_block(blk, blk + size);
384 }
386 // The following methods are useful and optimized for a
387 // non-contiguous space.
389 // Given a block [blk_start, blk_start + full_blk_size), and
390 // a left_blk_size < full_blk_size, adjust the BOT to show two
391 // blocks [blk_start, blk_start + left_blk_size) and
392 // [blk_start + left_blk_size, blk_start + full_blk_size).
393 // It is assumed (and verified in the non-product VM) that the
394 // BOT was correct for the original block.
395 void split_block(HeapWord* blk_start, size_t full_blk_size,
396 size_t left_blk_size);
398 // Adjust BOT to show that it has a block in the range
399 // [blk_start, blk_start + size). Only the first card
400 // of BOT is touched. It is assumed (and verified in the
401 // non-product VM) that the remaining cards of the block
402 // are correct.
403 void mark_block(HeapWord* blk_start, HeapWord* blk_end);
404 void mark_block(HeapWord* blk, size_t size) {
405 mark_block(blk, blk + size);
406 }
408 // Adjust _unallocated_block to indicate that a particular
409 // block has been newly allocated or freed. It is assumed (and
410 // verified in the non-product VM) that the BOT is correct for
411 // the given block.
412 void allocated(HeapWord* blk_start, HeapWord* blk_end) {
413 // Verify that the BOT shows [blk, blk + blk_size) to be one block.
414 verify_single_block(blk_start, blk_end);
415 if (BlockOffsetArrayUseUnallocatedBlock) {
416 _unallocated_block = MAX2(_unallocated_block, blk_end);
417 }
418 }
420 void allocated(HeapWord* blk, size_t size) {
421 allocated(blk, blk + size);
422 }
424 void freed(HeapWord* blk_start, HeapWord* blk_end);
425 void freed(HeapWord* blk, size_t size) {
426 freed(blk, blk + size);
427 }
429 HeapWord* block_start_unsafe(const void* addr) const;
431 // Requires "addr" to be the start of a card and returns the
432 // start of the block that contains the given address.
433 HeapWord* block_start_careful(const void* addr) const;
436 // Verification & debugging: ensure that the offset table reflects
437 // the fact that the block [blk_start, blk_end) or [blk, blk + size)
438 // is a single block of storage. NOTE: can't const this because of
439 // call to non-const do_block_internal() below.
440 void verify_single_block(HeapWord* blk_start, HeapWord* blk_end)
441 PRODUCT_RETURN;
442 void verify_single_block(HeapWord* blk, size_t size) PRODUCT_RETURN;
444 // Verify that the given block is before _unallocated_block
445 void verify_not_unallocated(HeapWord* blk_start, HeapWord* blk_end)
446 const PRODUCT_RETURN;
447 void verify_not_unallocated(HeapWord* blk, size_t size)
448 const PRODUCT_RETURN;
450 // Debugging support
451 virtual size_t last_active_index() const;
452 };
454 ////////////////////////////////////////////////////////////////////////////
455 // A subtype of BlockOffsetArray that takes advantage of the fact
456 // that its underlying space is a ContiguousSpace, so that its "active"
457 // region can be more efficiently tracked (than for a non-contiguous space).
458 ////////////////////////////////////////////////////////////////////////////
459 class BlockOffsetArrayContigSpace: public BlockOffsetArray {
460 friend class VMStructs;
461 private:
462 // allocation boundary at which offset array must be updated
463 HeapWord* _next_offset_threshold;
464 size_t _next_offset_index; // index corresponding to that boundary
466 // Work function when allocation start crosses threshold.
467 void alloc_block_work(HeapWord* blk_start, HeapWord* blk_end);
469 public:
470 BlockOffsetArrayContigSpace(BlockOffsetSharedArray* array, MemRegion mr):
471 BlockOffsetArray(array, mr, true) {
472 _next_offset_threshold = NULL;
473 _next_offset_index = 0;
474 }
476 void set_contig_space(ContiguousSpace* sp) { set_space((Space*)sp); }
478 // Initialize the threshold for an empty heap.
479 HeapWord* initialize_threshold();
480 // Zero out the entry for _bottom (offset will be zero)
481 void zero_bottom_entry();
483 // Return the next threshold, the point at which the table should be
484 // updated.
485 HeapWord* threshold() const { return _next_offset_threshold; }
487 // In general, these methods expect to be called with
488 // [blk_start, blk_end) representing a block of memory in the heap.
489 // In this implementation, however, we are OK even if blk_start and/or
490 // blk_end are NULL because NULL is represented as 0, and thus
491 // never exceeds the "_next_offset_threshold".
492 void alloc_block(HeapWord* blk_start, HeapWord* blk_end) {
493 if (blk_end > _next_offset_threshold) {
494 alloc_block_work(blk_start, blk_end);
495 }
496 }
497 void alloc_block(HeapWord* blk, size_t size) {
498 alloc_block(blk, blk + size);
499 }
501 HeapWord* block_start_unsafe(const void* addr) const;
503 void serialize(SerializeOopClosure* soc);
505 // Debugging support
506 virtual size_t last_active_index() const;
507 };