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annotate src/share/vm/memory/space.hpp @ 3456:782e2bb60c41
7052494: Eclipse test fails on JDK 7 b142
Summary: Keep 'ne' test in Counted loop when we can't guarantee during compilation that init < limit.
Reviewed-by: never
author | kvn |
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date | Mon, 20 Jun 2011 16:45:35 -0700 |
parents | f95d63e2154a |
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rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 1997, 2010, 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 #ifndef SHARE_VM_MEMORY_SPACE_HPP |
26 #define SHARE_VM_MEMORY_SPACE_HPP | |
27 | |
28 #include "memory/allocation.hpp" | |
29 #include "memory/blockOffsetTable.hpp" | |
30 #include "memory/cardTableModRefBS.hpp" | |
31 #include "memory/iterator.hpp" | |
32 #include "memory/memRegion.hpp" | |
33 #include "memory/watermark.hpp" | |
34 #include "oops/markOop.hpp" | |
35 #include "runtime/mutexLocker.hpp" | |
36 #include "runtime/prefetch.hpp" | |
37 #include "utilities/workgroup.hpp" | |
38 #ifdef TARGET_OS_FAMILY_linux | |
39 # include "os_linux.inline.hpp" | |
40 #endif | |
41 #ifdef TARGET_OS_FAMILY_solaris | |
42 # include "os_solaris.inline.hpp" | |
43 #endif | |
44 #ifdef TARGET_OS_FAMILY_windows | |
45 # include "os_windows.inline.hpp" | |
46 #endif | |
47 | |
0 | 48 // A space is an abstraction for the "storage units" backing |
49 // up the generation abstraction. It includes specific | |
50 // implementations for keeping track of free and used space, | |
51 // for iterating over objects and free blocks, etc. | |
52 | |
53 // Here's the Space hierarchy: | |
54 // | |
55 // - Space -- an asbtract base class describing a heap area | |
56 // - CompactibleSpace -- a space supporting compaction | |
57 // - CompactibleFreeListSpace -- (used for CMS generation) | |
58 // - ContiguousSpace -- a compactible space in which all free space | |
59 // is contiguous | |
60 // - EdenSpace -- contiguous space used as nursery | |
61 // - ConcEdenSpace -- contiguous space with a 'soft end safe' allocation | |
62 // - OffsetTableContigSpace -- contiguous space with a block offset array | |
63 // that allows "fast" block_start calls | |
64 // - TenuredSpace -- (used for TenuredGeneration) | |
65 // - ContigPermSpace -- an offset table contiguous space for perm gen | |
66 | |
67 // Forward decls. | |
68 class Space; | |
69 class BlockOffsetArray; | |
70 class BlockOffsetArrayContigSpace; | |
71 class Generation; | |
72 class CompactibleSpace; | |
73 class BlockOffsetTable; | |
74 class GenRemSet; | |
75 class CardTableRS; | |
76 class DirtyCardToOopClosure; | |
77 | |
78 // An oop closure that is circumscribed by a filtering memory region. | |
113
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79 class SpaceMemRegionOopsIterClosure: public OopClosure { |
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80 private: |
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81 OopClosure* _cl; |
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82 MemRegion _mr; |
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83 protected: |
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84 template <class T> void do_oop_work(T* p) { |
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85 if (_mr.contains(p)) { |
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86 _cl->do_oop(p); |
0 | 87 } |
88 } | |
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89 public: |
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90 SpaceMemRegionOopsIterClosure(OopClosure* cl, MemRegion mr): |
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91 _cl(cl), _mr(mr) {} |
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92 virtual void do_oop(oop* p); |
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93 virtual void do_oop(narrowOop* p); |
0 | 94 }; |
95 | |
96 // A Space describes a heap area. Class Space is an abstract | |
97 // base class. | |
98 // | |
99 // Space supports allocation, size computation and GC support is provided. | |
100 // | |
101 // Invariant: bottom() and end() are on page_size boundaries and | |
102 // bottom() <= top() <= end() | |
103 // top() is inclusive and end() is exclusive. | |
104 | |
105 class Space: public CHeapObj { | |
106 friend class VMStructs; | |
107 protected: | |
108 HeapWord* _bottom; | |
109 HeapWord* _end; | |
110 | |
111 // Used in support of save_marks() | |
112 HeapWord* _saved_mark_word; | |
113 | |
114 MemRegionClosure* _preconsumptionDirtyCardClosure; | |
115 | |
116 // A sequential tasks done structure. This supports | |
117 // parallel GC, where we have threads dynamically | |
118 // claiming sub-tasks from a larger parallel task. | |
119 SequentialSubTasksDone _par_seq_tasks; | |
120 | |
121 Space(): | |
122 _bottom(NULL), _end(NULL), _preconsumptionDirtyCardClosure(NULL) { } | |
123 | |
124 public: | |
125 // Accessors | |
126 HeapWord* bottom() const { return _bottom; } | |
127 HeapWord* end() const { return _end; } | |
128 virtual void set_bottom(HeapWord* value) { _bottom = value; } | |
129 virtual void set_end(HeapWord* value) { _end = value; } | |
130 | |
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131 virtual HeapWord* saved_mark_word() const { return _saved_mark_word; } |
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132 |
0 | 133 void set_saved_mark_word(HeapWord* p) { _saved_mark_word = p; } |
134 | |
135 MemRegionClosure* preconsumptionDirtyCardClosure() const { | |
136 return _preconsumptionDirtyCardClosure; | |
137 } | |
138 void setPreconsumptionDirtyCardClosure(MemRegionClosure* cl) { | |
139 _preconsumptionDirtyCardClosure = cl; | |
140 } | |
141 | |
142 // Returns a subregion of the space containing all the objects in | |
143 // the space. | |
144 virtual MemRegion used_region() const { return MemRegion(bottom(), end()); } | |
145 | |
146 // Returns a region that is guaranteed to contain (at least) all objects | |
147 // allocated at the time of the last call to "save_marks". If the space | |
148 // initializes its DirtyCardToOopClosure's specifying the "contig" option | |
149 // (that is, if the space is contiguous), then this region must contain only | |
150 // such objects: the memregion will be from the bottom of the region to the | |
151 // saved mark. Otherwise, the "obj_allocated_since_save_marks" method of | |
152 // the space must distiguish between objects in the region allocated before | |
153 // and after the call to save marks. | |
154 virtual MemRegion used_region_at_save_marks() const { | |
155 return MemRegion(bottom(), saved_mark_word()); | |
156 } | |
157 | |
342
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158 // Initialization. |
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159 // "initialize" should be called once on a space, before it is used for |
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160 // any purpose. The "mr" arguments gives the bounds of the space, and |
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161 // the "clear_space" argument should be true unless the memory in "mr" is |
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162 // known to be zeroed. |
263
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163 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); |
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164 |
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165 // The "clear" method must be called on a region that may have |
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166 // had allocation performed in it, but is now to be considered empty. |
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167 virtual void clear(bool mangle_space); |
0 | 168 |
169 // For detecting GC bugs. Should only be called at GC boundaries, since | |
170 // some unused space may be used as scratch space during GC's. | |
171 // Default implementation does nothing. We also call this when expanding | |
172 // a space to satisfy an allocation request. See bug #4668531 | |
173 virtual void mangle_unused_area() {} | |
263
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174 virtual void mangle_unused_area_complete() {} |
0 | 175 virtual void mangle_region(MemRegion mr) {} |
176 | |
177 // Testers | |
178 bool is_empty() const { return used() == 0; } | |
179 bool not_empty() const { return used() > 0; } | |
180 | |
181 // Returns true iff the given the space contains the | |
182 // given address as part of an allocated object. For | |
183 // ceratin kinds of spaces, this might be a potentially | |
184 // expensive operation. To prevent performance problems | |
185 // on account of its inadvertent use in product jvm's, | |
186 // we restrict its use to assertion checks only. | |
187 virtual bool is_in(const void* p) const; | |
188 | |
189 // Returns true iff the given reserved memory of the space contains the | |
190 // given address. | |
191 bool is_in_reserved(const void* p) const { return _bottom <= p && p < _end; } | |
192 | |
193 // Returns true iff the given block is not allocated. | |
194 virtual bool is_free_block(const HeapWord* p) const = 0; | |
195 | |
196 // Test whether p is double-aligned | |
197 static bool is_aligned(void* p) { | |
198 return ((intptr_t)p & (sizeof(double)-1)) == 0; | |
199 } | |
200 | |
201 // Size computations. Sizes are in bytes. | |
202 size_t capacity() const { return byte_size(bottom(), end()); } | |
203 virtual size_t used() const = 0; | |
204 virtual size_t free() const = 0; | |
205 | |
206 // Iterate over all the ref-containing fields of all objects in the | |
207 // space, calling "cl.do_oop" on each. Fields in objects allocated by | |
208 // applications of the closure are not included in the iteration. | |
209 virtual void oop_iterate(OopClosure* cl); | |
210 | |
211 // Same as above, restricted to the intersection of a memory region and | |
212 // the space. Fields in objects allocated by applications of the closure | |
213 // are not included in the iteration. | |
214 virtual void oop_iterate(MemRegion mr, OopClosure* cl) = 0; | |
215 | |
216 // Iterate over all objects in the space, calling "cl.do_object" on | |
217 // each. Objects allocated by applications of the closure are not | |
218 // included in the iteration. | |
219 virtual void object_iterate(ObjectClosure* blk) = 0; | |
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220 // Similar to object_iterate() except only iterates over |
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221 // objects whose internal references point to objects in the space. |
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222 virtual void safe_object_iterate(ObjectClosure* blk) = 0; |
0 | 223 |
224 // Iterate over all objects that intersect with mr, calling "cl->do_object" | |
225 // on each. There is an exception to this: if this closure has already | |
226 // been invoked on an object, it may skip such objects in some cases. This is | |
227 // Most likely to happen in an "upwards" (ascending address) iteration of | |
228 // MemRegions. | |
229 virtual void object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl); | |
230 | |
231 // Iterate over as many initialized objects in the space as possible, | |
232 // calling "cl.do_object_careful" on each. Return NULL if all objects | |
233 // in the space (at the start of the iteration) were iterated over. | |
234 // Return an address indicating the extent of the iteration in the | |
235 // event that the iteration had to return because of finding an | |
236 // uninitialized object in the space, or if the closure "cl" | |
237 // signalled early termination. | |
238 virtual HeapWord* object_iterate_careful(ObjectClosureCareful* cl); | |
239 virtual HeapWord* object_iterate_careful_m(MemRegion mr, | |
240 ObjectClosureCareful* cl); | |
241 | |
242 // Create and return a new dirty card to oop closure. Can be | |
243 // overriden to return the appropriate type of closure | |
244 // depending on the type of space in which the closure will | |
245 // operate. ResourceArea allocated. | |
246 virtual DirtyCardToOopClosure* new_dcto_cl(OopClosure* cl, | |
247 CardTableModRefBS::PrecisionStyle precision, | |
248 HeapWord* boundary = NULL); | |
249 | |
250 // If "p" is in the space, returns the address of the start of the | |
251 // "block" that contains "p". We say "block" instead of "object" since | |
252 // some heaps may not pack objects densely; a chunk may either be an | |
253 // object or a non-object. If "p" is not in the space, return NULL. | |
342
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254 virtual HeapWord* block_start_const(const void* p) const = 0; |
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255 |
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256 // The non-const version may have benevolent side effects on the data |
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257 // structure supporting these calls, possibly speeding up future calls. |
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258 // The default implementation, however, is simply to call the const |
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259 // version. |
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260 inline virtual HeapWord* block_start(const void* p); |
0 | 261 |
262 // Requires "addr" to be the start of a chunk, and returns its size. | |
263 // "addr + size" is required to be the start of a new chunk, or the end | |
264 // of the active area of the heap. | |
265 virtual size_t block_size(const HeapWord* addr) const = 0; | |
266 | |
267 // Requires "addr" to be the start of a block, and returns "TRUE" iff | |
268 // the block is an object. | |
269 virtual bool block_is_obj(const HeapWord* addr) const = 0; | |
270 | |
271 // Requires "addr" to be the start of a block, and returns "TRUE" iff | |
272 // the block is an object and the object is alive. | |
273 virtual bool obj_is_alive(const HeapWord* addr) const; | |
274 | |
275 // Allocation (return NULL if full). Assumes the caller has established | |
276 // mutually exclusive access to the space. | |
277 virtual HeapWord* allocate(size_t word_size) = 0; | |
278 | |
279 // Allocation (return NULL if full). Enforces mutual exclusion internally. | |
280 virtual HeapWord* par_allocate(size_t word_size) = 0; | |
281 | |
282 // Returns true if this object has been allocated since a | |
283 // generation's "save_marks" call. | |
284 virtual bool obj_allocated_since_save_marks(const oop obj) const = 0; | |
285 | |
286 // Mark-sweep-compact support: all spaces can update pointers to objects | |
287 // moving as a part of compaction. | |
288 virtual void adjust_pointers(); | |
289 | |
290 // PrintHeapAtGC support | |
291 virtual void print() const; | |
292 virtual void print_on(outputStream* st) const; | |
293 virtual void print_short() const; | |
294 virtual void print_short_on(outputStream* st) const; | |
295 | |
296 | |
297 // Accessor for parallel sequential tasks. | |
298 SequentialSubTasksDone* par_seq_tasks() { return &_par_seq_tasks; } | |
299 | |
300 // IF "this" is a ContiguousSpace, return it, else return NULL. | |
301 virtual ContiguousSpace* toContiguousSpace() { | |
302 return NULL; | |
303 } | |
304 | |
305 // Debugging | |
306 virtual void verify(bool allow_dirty) const = 0; | |
307 }; | |
308 | |
309 // A MemRegionClosure (ResourceObj) whose "do_MemRegion" function applies an | |
310 // OopClosure to (the addresses of) all the ref-containing fields that could | |
311 // be modified by virtue of the given MemRegion being dirty. (Note that | |
312 // because of the imprecise nature of the write barrier, this may iterate | |
313 // over oops beyond the region.) | |
314 // This base type for dirty card to oop closures handles memory regions | |
315 // in non-contiguous spaces with no boundaries, and should be sub-classed | |
316 // to support other space types. See ContiguousDCTOC for a sub-class | |
317 // that works with ContiguousSpaces. | |
318 | |
319 class DirtyCardToOopClosure: public MemRegionClosureRO { | |
320 protected: | |
321 OopClosure* _cl; | |
322 Space* _sp; | |
323 CardTableModRefBS::PrecisionStyle _precision; | |
324 HeapWord* _boundary; // If non-NULL, process only non-NULL oops | |
325 // pointing below boundary. | |
342
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326 HeapWord* _min_done; // ObjHeadPreciseArray precision requires |
0 | 327 // a downwards traversal; this is the |
328 // lowest location already done (or, | |
329 // alternatively, the lowest address that | |
330 // shouldn't be done again. NULL means infinity.) | |
331 NOT_PRODUCT(HeapWord* _last_bottom;) | |
342
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332 NOT_PRODUCT(HeapWord* _last_explicit_min_done;) |
0 | 333 |
334 // Get the actual top of the area on which the closure will | |
335 // operate, given where the top is assumed to be (the end of the | |
336 // memory region passed to do_MemRegion) and where the object | |
337 // at the top is assumed to start. For example, an object may | |
338 // start at the top but actually extend past the assumed top, | |
339 // in which case the top becomes the end of the object. | |
340 virtual HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj); | |
341 | |
342 // Walk the given memory region from bottom to (actual) top | |
343 // looking for objects and applying the oop closure (_cl) to | |
344 // them. The base implementation of this treats the area as | |
345 // blocks, where a block may or may not be an object. Sub- | |
346 // classes should override this to provide more accurate | |
347 // or possibly more efficient walking. | |
348 virtual void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); | |
349 | |
350 public: | |
351 DirtyCardToOopClosure(Space* sp, OopClosure* cl, | |
352 CardTableModRefBS::PrecisionStyle precision, | |
353 HeapWord* boundary) : | |
354 _sp(sp), _cl(cl), _precision(precision), _boundary(boundary), | |
355 _min_done(NULL) { | |
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356 NOT_PRODUCT(_last_bottom = NULL); |
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357 NOT_PRODUCT(_last_explicit_min_done = NULL); |
0 | 358 } |
359 | |
360 void do_MemRegion(MemRegion mr); | |
361 | |
362 void set_min_done(HeapWord* min_done) { | |
363 _min_done = min_done; | |
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364 NOT_PRODUCT(_last_explicit_min_done = _min_done); |
0 | 365 } |
366 #ifndef PRODUCT | |
367 void set_last_bottom(HeapWord* last_bottom) { | |
368 _last_bottom = last_bottom; | |
369 } | |
370 #endif | |
371 }; | |
372 | |
373 // A structure to represent a point at which objects are being copied | |
374 // during compaction. | |
375 class CompactPoint : public StackObj { | |
376 public: | |
377 Generation* gen; | |
378 CompactibleSpace* space; | |
379 HeapWord* threshold; | |
380 CompactPoint(Generation* _gen, CompactibleSpace* _space, | |
381 HeapWord* _threshold) : | |
382 gen(_gen), space(_space), threshold(_threshold) {} | |
383 }; | |
384 | |
385 | |
386 // A space that supports compaction operations. This is usually, but not | |
387 // necessarily, a space that is normally contiguous. But, for example, a | |
388 // free-list-based space whose normal collection is a mark-sweep without | |
389 // compaction could still support compaction in full GC's. | |
390 | |
391 class CompactibleSpace: public Space { | |
392 friend class VMStructs; | |
393 friend class CompactibleFreeListSpace; | |
394 friend class CompactingPermGenGen; | |
395 friend class CMSPermGenGen; | |
396 private: | |
397 HeapWord* _compaction_top; | |
398 CompactibleSpace* _next_compaction_space; | |
399 | |
400 public: | |
347
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401 CompactibleSpace() : |
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402 _compaction_top(NULL), _next_compaction_space(NULL) {} |
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403 |
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404 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); |
356 | 405 virtual void clear(bool mangle_space); |
0 | 406 |
407 // Used temporarily during a compaction phase to hold the value | |
408 // top should have when compaction is complete. | |
409 HeapWord* compaction_top() const { return _compaction_top; } | |
410 | |
411 void set_compaction_top(HeapWord* value) { | |
412 assert(value == NULL || (value >= bottom() && value <= end()), | |
413 "should point inside space"); | |
414 _compaction_top = value; | |
415 } | |
416 | |
417 // Perform operations on the space needed after a compaction | |
418 // has been performed. | |
419 virtual void reset_after_compaction() {} | |
420 | |
421 // Returns the next space (in the current generation) to be compacted in | |
422 // the global compaction order. Also is used to select the next | |
423 // space into which to compact. | |
424 | |
425 virtual CompactibleSpace* next_compaction_space() const { | |
426 return _next_compaction_space; | |
427 } | |
428 | |
429 void set_next_compaction_space(CompactibleSpace* csp) { | |
430 _next_compaction_space = csp; | |
431 } | |
432 | |
433 // MarkSweep support phase2 | |
434 | |
435 // Start the process of compaction of the current space: compute | |
436 // post-compaction addresses, and insert forwarding pointers. The fields | |
437 // "cp->gen" and "cp->compaction_space" are the generation and space into | |
438 // which we are currently compacting. This call updates "cp" as necessary, | |
439 // and leaves the "compaction_top" of the final value of | |
440 // "cp->compaction_space" up-to-date. Offset tables may be updated in | |
441 // this phase as if the final copy had occurred; if so, "cp->threshold" | |
442 // indicates when the next such action should be taken. | |
443 virtual void prepare_for_compaction(CompactPoint* cp); | |
444 // MarkSweep support phase3 | |
445 virtual void adjust_pointers(); | |
446 // MarkSweep support phase4 | |
447 virtual void compact(); | |
448 | |
449 // The maximum percentage of objects that can be dead in the compacted | |
450 // live part of a compacted space ("deadwood" support.) | |
438 | 451 virtual size_t allowed_dead_ratio() const { return 0; }; |
0 | 452 |
453 // Some contiguous spaces may maintain some data structures that should | |
454 // be updated whenever an allocation crosses a boundary. This function | |
455 // returns the first such boundary. | |
456 // (The default implementation returns the end of the space, so the | |
457 // boundary is never crossed.) | |
458 virtual HeapWord* initialize_threshold() { return end(); } | |
459 | |
460 // "q" is an object of the given "size" that should be forwarded; | |
461 // "cp" names the generation ("gen") and containing "this" (which must | |
462 // also equal "cp->space"). "compact_top" is where in "this" the | |
463 // next object should be forwarded to. If there is room in "this" for | |
464 // the object, insert an appropriate forwarding pointer in "q". | |
465 // If not, go to the next compaction space (there must | |
466 // be one, since compaction must succeed -- we go to the first space of | |
467 // the previous generation if necessary, updating "cp"), reset compact_top | |
468 // and then forward. In either case, returns the new value of "compact_top". | |
469 // If the forwarding crosses "cp->threshold", invokes the "cross_threhold" | |
470 // function of the then-current compaction space, and updates "cp->threshold | |
471 // accordingly". | |
472 virtual HeapWord* forward(oop q, size_t size, CompactPoint* cp, | |
473 HeapWord* compact_top); | |
474 | |
475 // Return a size with adjusments as required of the space. | |
476 virtual size_t adjust_object_size_v(size_t size) const { return size; } | |
477 | |
478 protected: | |
479 // Used during compaction. | |
480 HeapWord* _first_dead; | |
481 HeapWord* _end_of_live; | |
482 | |
483 // Minimum size of a free block. | |
484 virtual size_t minimum_free_block_size() const = 0; | |
485 | |
486 // This the function is invoked when an allocation of an object covering | |
487 // "start" to "end occurs crosses the threshold; returns the next | |
488 // threshold. (The default implementation does nothing.) | |
489 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* the_end) { | |
490 return end(); | |
491 } | |
492 | |
493 // Requires "allowed_deadspace_words > 0", that "q" is the start of a | |
494 // free block of the given "word_len", and that "q", were it an object, | |
495 // would not move if forwared. If the size allows, fill the free | |
496 // block with an object, to prevent excessive compaction. Returns "true" | |
497 // iff the free region was made deadspace, and modifies | |
498 // "allowed_deadspace_words" to reflect the number of available deadspace | |
499 // words remaining after this operation. | |
500 bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q, | |
501 size_t word_len); | |
502 }; | |
503 | |
504 #define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size) { \ | |
505 /* Compute the new addresses for the live objects and store it in the mark \ | |
506 * Used by universe::mark_sweep_phase2() \ | |
507 */ \ | |
508 HeapWord* compact_top; /* This is where we are currently compacting to. */ \ | |
509 \ | |
510 /* We're sure to be here before any objects are compacted into this \ | |
511 * space, so this is a good time to initialize this: \ | |
512 */ \ | |
513 set_compaction_top(bottom()); \ | |
514 \ | |
515 if (cp->space == NULL) { \ | |
516 assert(cp->gen != NULL, "need a generation"); \ | |
517 assert(cp->threshold == NULL, "just checking"); \ | |
518 assert(cp->gen->first_compaction_space() == this, "just checking"); \ | |
519 cp->space = cp->gen->first_compaction_space(); \ | |
520 compact_top = cp->space->bottom(); \ | |
521 cp->space->set_compaction_top(compact_top); \ | |
522 cp->threshold = cp->space->initialize_threshold(); \ | |
523 } else { \ | |
524 compact_top = cp->space->compaction_top(); \ | |
525 } \ | |
526 \ | |
527 /* We allow some amount of garbage towards the bottom of the space, so \ | |
528 * we don't start compacting before there is a significant gain to be made.\ | |
529 * Occasionally, we want to ensure a full compaction, which is determined \ | |
530 * by the MarkSweepAlwaysCompactCount parameter. \ | |
531 */ \ | |
532 int invocations = SharedHeap::heap()->perm_gen()->stat_record()->invocations;\ | |
533 bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0); \ | |
534 \ | |
535 size_t allowed_deadspace = 0; \ | |
536 if (skip_dead) { \ | |
438 | 537 const size_t ratio = allowed_dead_ratio(); \ |
0 | 538 allowed_deadspace = (capacity() * ratio / 100) / HeapWordSize; \ |
539 } \ | |
540 \ | |
541 HeapWord* q = bottom(); \ | |
542 HeapWord* t = scan_limit(); \ | |
543 \ | |
544 HeapWord* end_of_live= q; /* One byte beyond the last byte of the last \ | |
545 live object. */ \ | |
546 HeapWord* first_dead = end();/* The first dead object. */ \ | |
547 LiveRange* liveRange = NULL; /* The current live range, recorded in the \ | |
548 first header of preceding free area. */ \ | |
549 _first_dead = first_dead; \ | |
550 \ | |
551 const intx interval = PrefetchScanIntervalInBytes; \ | |
552 \ | |
553 while (q < t) { \ | |
554 assert(!block_is_obj(q) || \ | |
555 oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || \ | |
556 oop(q)->mark()->has_bias_pattern(), \ | |
557 "these are the only valid states during a mark sweep"); \ | |
558 if (block_is_obj(q) && oop(q)->is_gc_marked()) { \ | |
559 /* prefetch beyond q */ \ | |
560 Prefetch::write(q, interval); \ | |
561 /* size_t size = oop(q)->size(); changing this for cms for perm gen */\ | |
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562 size_t size = block_size(q); \ |
0 | 563 compact_top = cp->space->forward(oop(q), size, cp, compact_top); \ |
564 q += size; \ | |
565 end_of_live = q; \ | |
566 } else { \ | |
567 /* run over all the contiguous dead objects */ \ | |
568 HeapWord* end = q; \ | |
569 do { \ | |
570 /* prefetch beyond end */ \ | |
571 Prefetch::write(end, interval); \ | |
572 end += block_size(end); \ | |
573 } while (end < t && (!block_is_obj(end) || !oop(end)->is_gc_marked()));\ | |
574 \ | |
575 /* see if we might want to pretend this object is alive so that \ | |
576 * we don't have to compact quite as often. \ | |
577 */ \ | |
578 if (allowed_deadspace > 0 && q == compact_top) { \ | |
579 size_t sz = pointer_delta(end, q); \ | |
580 if (insert_deadspace(allowed_deadspace, q, sz)) { \ | |
581 compact_top = cp->space->forward(oop(q), sz, cp, compact_top); \ | |
582 q = end; \ | |
583 end_of_live = end; \ | |
584 continue; \ | |
585 } \ | |
586 } \ | |
587 \ | |
588 /* otherwise, it really is a free region. */ \ | |
589 \ | |
590 /* for the previous LiveRange, record the end of the live objects. */ \ | |
591 if (liveRange) { \ | |
592 liveRange->set_end(q); \ | |
593 } \ | |
594 \ | |
595 /* record the current LiveRange object. \ | |
596 * liveRange->start() is overlaid on the mark word. \ | |
597 */ \ | |
598 liveRange = (LiveRange*)q; \ | |
599 liveRange->set_start(end); \ | |
600 liveRange->set_end(end); \ | |
601 \ | |
602 /* see if this is the first dead region. */ \ | |
603 if (q < first_dead) { \ | |
604 first_dead = q; \ | |
605 } \ | |
606 \ | |
607 /* move on to the next object */ \ | |
608 q = end; \ | |
609 } \ | |
610 } \ | |
611 \ | |
612 assert(q == t, "just checking"); \ | |
613 if (liveRange != NULL) { \ | |
614 liveRange->set_end(q); \ | |
615 } \ | |
616 _end_of_live = end_of_live; \ | |
617 if (end_of_live < first_dead) { \ | |
618 first_dead = end_of_live; \ | |
619 } \ | |
620 _first_dead = first_dead; \ | |
621 \ | |
622 /* save the compaction_top of the compaction space. */ \ | |
623 cp->space->set_compaction_top(compact_top); \ | |
624 } | |
625 | |
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626 #define SCAN_AND_ADJUST_POINTERS(adjust_obj_size) { \ |
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627 /* adjust all the interior pointers to point at the new locations of objects \ |
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628 * Used by MarkSweep::mark_sweep_phase3() */ \ |
0 | 629 \ |
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630 HeapWord* q = bottom(); \ |
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631 HeapWord* t = _end_of_live; /* Established by "prepare_for_compaction". */ \ |
0 | 632 \ |
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633 assert(_first_dead <= _end_of_live, "Stands to reason, no?"); \ |
0 | 634 \ |
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635 if (q < t && _first_dead > q && \ |
0 | 636 !oop(q)->is_gc_marked()) { \ |
637 /* we have a chunk of the space which hasn't moved and we've \ | |
638 * reinitialized the mark word during the previous pass, so we can't \ | |
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639 * use is_gc_marked for the traversal. */ \ |
0 | 640 HeapWord* end = _first_dead; \ |
641 \ | |
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642 while (q < end) { \ |
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643 /* I originally tried to conjoin "block_start(q) == q" to the \ |
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644 * assertion below, but that doesn't work, because you can't \ |
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645 * accurately traverse previous objects to get to the current one \ |
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646 * after their pointers (including pointers into permGen) have been \ |
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647 * updated, until the actual compaction is done. dld, 4/00 */ \ |
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648 assert(block_is_obj(q), \ |
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649 "should be at block boundaries, and should be looking at objs"); \ |
0 | 650 \ |
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651 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q))); \ |
0 | 652 \ |
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653 /* point all the oops to the new location */ \ |
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654 size_t size = oop(q)->adjust_pointers(); \ |
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655 size = adjust_obj_size(size); \ |
0 | 656 \ |
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657 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers()); \ |
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658 \ |
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659 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size)); \ |
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660 \ |
0 | 661 q += size; \ |
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662 } \ |
0 | 663 \ |
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664 if (_first_dead == t) { \ |
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665 q = t; \ |
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666 } else { \ |
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667 /* $$$ This is funky. Using this to read the previously written \ |
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668 * LiveRange. See also use below. */ \ |
0 | 669 q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); \ |
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670 } \ |
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671 } \ |
0 | 672 \ |
673 const intx interval = PrefetchScanIntervalInBytes; \ | |
674 \ | |
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675 debug_only(HeapWord* prev_q = NULL); \ |
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676 while (q < t) { \ |
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677 /* prefetch beyond q */ \ |
0 | 678 Prefetch::write(q, interval); \ |
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679 if (oop(q)->is_gc_marked()) { \ |
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680 /* q is alive */ \ |
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681 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q))); \ |
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682 /* point all the oops to the new location */ \ |
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683 size_t size = oop(q)->adjust_pointers(); \ |
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684 size = adjust_obj_size(size); \ |
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685 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers()); \ |
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686 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size)); \ |
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687 debug_only(prev_q = q); \ |
0 | 688 q += size; \ |
356 | 689 } else { \ |
690 /* q is not a live object, so its mark should point at the next \ | |
691 * live object */ \ | |
692 debug_only(prev_q = q); \ | |
693 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \ | |
694 assert(q > prev_q, "we should be moving forward through memory"); \ | |
695 } \ | |
696 } \ | |
0 | 697 \ |
356 | 698 assert(q == t, "just checking"); \ |
0 | 699 } |
700 | |
356 | 701 #define SCAN_AND_COMPACT(obj_size) { \ |
0 | 702 /* Copy all live objects to their new location \ |
356 | 703 * Used by MarkSweep::mark_sweep_phase4() */ \ |
0 | 704 \ |
356 | 705 HeapWord* q = bottom(); \ |
706 HeapWord* const t = _end_of_live; \ | |
707 debug_only(HeapWord* prev_q = NULL); \ | |
0 | 708 \ |
356 | 709 if (q < t && _first_dead > q && \ |
0 | 710 !oop(q)->is_gc_marked()) { \ |
356 | 711 debug_only( \ |
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712 /* we have a chunk of the space which hasn't moved and we've reinitialized \ |
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713 * the mark word during the previous pass, so we can't use is_gc_marked for \ |
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714 * the traversal. */ \ |
356 | 715 HeapWord* const end = _first_dead; \ |
716 \ | |
717 while (q < end) { \ | |
0 | 718 size_t size = obj_size(q); \ |
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719 assert(!oop(q)->is_gc_marked(), \ |
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720 "should be unmarked (special dense prefix handling)"); \ |
356 | 721 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, q)); \ |
722 debug_only(prev_q = q); \ | |
0 | 723 q += size; \ |
356 | 724 } \ |
725 ) /* debug_only */ \ | |
726 \ | |
727 if (_first_dead == t) { \ | |
728 q = t; \ | |
729 } else { \ | |
730 /* $$$ Funky */ \ | |
731 q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); \ | |
732 } \ | |
733 } \ | |
0 | 734 \ |
356 | 735 const intx scan_interval = PrefetchScanIntervalInBytes; \ |
736 const intx copy_interval = PrefetchCopyIntervalInBytes; \ | |
737 while (q < t) { \ | |
738 if (!oop(q)->is_gc_marked()) { \ | |
739 /* mark is pointer to next marked oop */ \ | |
740 debug_only(prev_q = q); \ | |
741 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \ | |
742 assert(q > prev_q, "we should be moving forward through memory"); \ | |
743 } else { \ | |
744 /* prefetch beyond q */ \ | |
0 | 745 Prefetch::read(q, scan_interval); \ |
746 \ | |
747 /* size and destination */ \ | |
748 size_t size = obj_size(q); \ | |
749 HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); \ | |
750 \ | |
356 | 751 /* prefetch beyond compaction_top */ \ |
0 | 752 Prefetch::write(compaction_top, copy_interval); \ |
753 \ | |
356 | 754 /* copy object and reinit its mark */ \ |
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755 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, \ |
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756 compaction_top)); \ |
356 | 757 assert(q != compaction_top, "everything in this pass should be moving"); \ |
758 Copy::aligned_conjoint_words(q, compaction_top, size); \ | |
759 oop(compaction_top)->init_mark(); \ | |
760 assert(oop(compaction_top)->klass() != NULL, "should have a class"); \ | |
0 | 761 \ |
356 | 762 debug_only(prev_q = q); \ |
0 | 763 q += size; \ |
356 | 764 } \ |
765 } \ | |
0 | 766 \ |
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767 /* Let's remember if we were empty before we did the compaction. */ \ |
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768 bool was_empty = used_region().is_empty(); \ |
0 | 769 /* Reset space after compaction is complete */ \ |
356 | 770 reset_after_compaction(); \ |
0 | 771 /* We do this clear, below, since it has overloaded meanings for some */ \ |
772 /* space subtypes. For example, OffsetTableContigSpace's that were */ \ | |
773 /* compacted into will have had their offset table thresholds updated */ \ | |
774 /* continuously, but those that weren't need to have their thresholds */ \ | |
775 /* re-initialized. Also mangles unused area for debugging. */ \ | |
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776 if (used_region().is_empty()) { \ |
356 | 777 if (!was_empty) clear(SpaceDecorator::Mangle); \ |
0 | 778 } else { \ |
779 if (ZapUnusedHeapArea) mangle_unused_area(); \ | |
780 } \ | |
781 } | |
782 | |
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783 class GenSpaceMangler; |
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784 |
0 | 785 // A space in which the free area is contiguous. It therefore supports |
786 // faster allocation, and compaction. | |
787 class ContiguousSpace: public CompactibleSpace { | |
788 friend class OneContigSpaceCardGeneration; | |
789 friend class VMStructs; | |
790 protected: | |
791 HeapWord* _top; | |
792 HeapWord* _concurrent_iteration_safe_limit; | |
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793 // A helper for mangling the unused area of the space in debug builds. |
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794 GenSpaceMangler* _mangler; |
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795 |
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796 GenSpaceMangler* mangler() { return _mangler; } |
0 | 797 |
798 // Allocation helpers (return NULL if full). | |
799 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value); | |
800 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value); | |
801 | |
802 public: | |
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803 ContiguousSpace(); |
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804 ~ContiguousSpace(); |
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805 |
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806 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); |
356 | 807 virtual void clear(bool mangle_space); |
0 | 808 |
809 // Accessors | |
810 HeapWord* top() const { return _top; } | |
811 void set_top(HeapWord* value) { _top = value; } | |
812 | |
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813 virtual void set_saved_mark() { _saved_mark_word = top(); } |
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814 void reset_saved_mark() { _saved_mark_word = bottom(); } |
0 | 815 |
816 WaterMark bottom_mark() { return WaterMark(this, bottom()); } | |
817 WaterMark top_mark() { return WaterMark(this, top()); } | |
818 WaterMark saved_mark() { return WaterMark(this, saved_mark_word()); } | |
819 bool saved_mark_at_top() const { return saved_mark_word() == top(); } | |
820 | |
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821 // In debug mode mangle (write it with a particular bit |
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822 // pattern) the unused part of a space. |
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823 |
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824 // Used to save the an address in a space for later use during mangling. |
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825 void set_top_for_allocations(HeapWord* v) PRODUCT_RETURN; |
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826 // Used to save the space's current top for later use during mangling. |
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827 void set_top_for_allocations() PRODUCT_RETURN; |
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828 |
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829 // Mangle regions in the space from the current top up to the |
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830 // previously mangled part of the space. |
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831 void mangle_unused_area() PRODUCT_RETURN; |
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832 // Mangle [top, end) |
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833 void mangle_unused_area_complete() PRODUCT_RETURN; |
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834 // Mangle the given MemRegion. |
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835 void mangle_region(MemRegion mr) PRODUCT_RETURN; |
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836 |
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837 // Do some sparse checking on the area that should have been mangled. |
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838 void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN; |
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839 // Check the complete area that should have been mangled. |
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840 // This code may be NULL depending on the macro DEBUG_MANGLING. |
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841 void check_mangled_unused_area_complete() PRODUCT_RETURN; |
0 | 842 |
843 // Size computations: sizes in bytes. | |
844 size_t capacity() const { return byte_size(bottom(), end()); } | |
845 size_t used() const { return byte_size(bottom(), top()); } | |
846 size_t free() const { return byte_size(top(), end()); } | |
847 | |
848 // Override from space. | |
849 bool is_in(const void* p) const; | |
850 | |
851 virtual bool is_free_block(const HeapWord* p) const; | |
852 | |
853 // In a contiguous space we have a more obvious bound on what parts | |
854 // contain objects. | |
855 MemRegion used_region() const { return MemRegion(bottom(), top()); } | |
856 | |
857 MemRegion used_region_at_save_marks() const { | |
858 return MemRegion(bottom(), saved_mark_word()); | |
859 } | |
860 | |
861 // Allocation (return NULL if full) | |
862 virtual HeapWord* allocate(size_t word_size); | |
863 virtual HeapWord* par_allocate(size_t word_size); | |
864 | |
865 virtual bool obj_allocated_since_save_marks(const oop obj) const { | |
866 return (HeapWord*)obj >= saved_mark_word(); | |
867 } | |
868 | |
869 // Iteration | |
870 void oop_iterate(OopClosure* cl); | |
871 void oop_iterate(MemRegion mr, OopClosure* cl); | |
872 void object_iterate(ObjectClosure* blk); | |
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873 // For contiguous spaces this method will iterate safely over objects |
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874 // in the space (i.e., between bottom and top) when at a safepoint. |
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875 void safe_object_iterate(ObjectClosure* blk); |
0 | 876 void object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl); |
877 // iterates on objects up to the safe limit | |
878 HeapWord* object_iterate_careful(ObjectClosureCareful* cl); | |
879 inline HeapWord* concurrent_iteration_safe_limit(); | |
880 // changes the safe limit, all objects from bottom() to the new | |
881 // limit should be properly initialized | |
882 inline void set_concurrent_iteration_safe_limit(HeapWord* new_limit); | |
883 | |
884 #ifndef SERIALGC | |
885 // In support of parallel oop_iterate. | |
886 #define ContigSpace_PAR_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ | |
887 void par_oop_iterate(MemRegion mr, OopClosureType* blk); | |
888 | |
889 ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DECL) | |
890 #undef ContigSpace_PAR_OOP_ITERATE_DECL | |
891 #endif // SERIALGC | |
892 | |
893 // Compaction support | |
894 virtual void reset_after_compaction() { | |
895 assert(compaction_top() >= bottom() && compaction_top() <= end(), "should point inside space"); | |
896 set_top(compaction_top()); | |
897 // set new iteration safe limit | |
898 set_concurrent_iteration_safe_limit(compaction_top()); | |
899 } | |
900 virtual size_t minimum_free_block_size() const { return 0; } | |
901 | |
902 // Override. | |
903 DirtyCardToOopClosure* new_dcto_cl(OopClosure* cl, | |
904 CardTableModRefBS::PrecisionStyle precision, | |
905 HeapWord* boundary = NULL); | |
906 | |
907 // Apply "blk->do_oop" to the addresses of all reference fields in objects | |
908 // starting with the _saved_mark_word, which was noted during a generation's | |
909 // save_marks and is required to denote the head of an object. | |
910 // Fields in objects allocated by applications of the closure | |
911 // *are* included in the iteration. | |
912 // Updates _saved_mark_word to point to just after the last object | |
913 // iterated over. | |
914 #define ContigSpace_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ | |
915 void oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk); | |
916 | |
917 ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DECL) | |
918 #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DECL | |
919 | |
920 // Same as object_iterate, but starting from "mark", which is required | |
921 // to denote the start of an object. Objects allocated by | |
922 // applications of the closure *are* included in the iteration. | |
923 virtual void object_iterate_from(WaterMark mark, ObjectClosure* blk); | |
924 | |
925 // Very inefficient implementation. | |
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926 virtual HeapWord* block_start_const(const void* p) const; |
0 | 927 size_t block_size(const HeapWord* p) const; |
928 // If a block is in the allocated area, it is an object. | |
929 bool block_is_obj(const HeapWord* p) const { return p < top(); } | |
930 | |
931 // Addresses for inlined allocation | |
932 HeapWord** top_addr() { return &_top; } | |
933 HeapWord** end_addr() { return &_end; } | |
934 | |
935 // Overrides for more efficient compaction support. | |
936 void prepare_for_compaction(CompactPoint* cp); | |
937 | |
938 // PrintHeapAtGC support. | |
939 virtual void print_on(outputStream* st) const; | |
940 | |
941 // Checked dynamic downcasts. | |
942 virtual ContiguousSpace* toContiguousSpace() { | |
943 return this; | |
944 } | |
945 | |
946 // Debugging | |
947 virtual void verify(bool allow_dirty) const; | |
948 | |
949 // Used to increase collection frequency. "factor" of 0 means entire | |
950 // space. | |
951 void allocate_temporary_filler(int factor); | |
952 | |
953 }; | |
954 | |
955 | |
956 // A dirty card to oop closure that does filtering. | |
957 // It knows how to filter out objects that are outside of the _boundary. | |
958 class Filtering_DCTOC : public DirtyCardToOopClosure { | |
959 protected: | |
960 // Override. | |
961 void walk_mem_region(MemRegion mr, | |
962 HeapWord* bottom, HeapWord* top); | |
963 | |
964 // Walk the given memory region, from bottom to top, applying | |
965 // the given oop closure to (possibly) all objects found. The | |
966 // given oop closure may or may not be the same as the oop | |
967 // closure with which this closure was created, as it may | |
968 // be a filtering closure which makes use of the _boundary. | |
969 // We offer two signatures, so the FilteringClosure static type is | |
970 // apparent. | |
971 virtual void walk_mem_region_with_cl(MemRegion mr, | |
972 HeapWord* bottom, HeapWord* top, | |
973 OopClosure* cl) = 0; | |
974 virtual void walk_mem_region_with_cl(MemRegion mr, | |
975 HeapWord* bottom, HeapWord* top, | |
976 FilteringClosure* cl) = 0; | |
977 | |
978 public: | |
979 Filtering_DCTOC(Space* sp, OopClosure* cl, | |
980 CardTableModRefBS::PrecisionStyle precision, | |
981 HeapWord* boundary) : | |
982 DirtyCardToOopClosure(sp, cl, precision, boundary) {} | |
983 }; | |
984 | |
985 // A dirty card to oop closure for contiguous spaces | |
986 // (ContiguousSpace and sub-classes). | |
987 // It is a FilteringClosure, as defined above, and it knows: | |
988 // | |
989 // 1. That the actual top of any area in a memory region | |
990 // contained by the space is bounded by the end of the contiguous | |
991 // region of the space. | |
992 // 2. That the space is really made up of objects and not just | |
993 // blocks. | |
994 | |
995 class ContiguousSpaceDCTOC : public Filtering_DCTOC { | |
996 protected: | |
997 // Overrides. | |
998 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj); | |
999 | |
1000 virtual void walk_mem_region_with_cl(MemRegion mr, | |
1001 HeapWord* bottom, HeapWord* top, | |
1002 OopClosure* cl); | |
1003 virtual void walk_mem_region_with_cl(MemRegion mr, | |
1004 HeapWord* bottom, HeapWord* top, | |
1005 FilteringClosure* cl); | |
1006 | |
1007 public: | |
1008 ContiguousSpaceDCTOC(ContiguousSpace* sp, OopClosure* cl, | |
1009 CardTableModRefBS::PrecisionStyle precision, | |
1010 HeapWord* boundary) : | |
1011 Filtering_DCTOC(sp, cl, precision, boundary) | |
1012 {} | |
1013 }; | |
1014 | |
1015 | |
1016 // Class EdenSpace describes eden-space in new generation. | |
1017 | |
1018 class DefNewGeneration; | |
1019 | |
1020 class EdenSpace : public ContiguousSpace { | |
1021 friend class VMStructs; | |
1022 private: | |
1023 DefNewGeneration* _gen; | |
1024 | |
1025 // _soft_end is used as a soft limit on allocation. As soft limits are | |
1026 // reached, the slow-path allocation code can invoke other actions and then | |
1027 // adjust _soft_end up to a new soft limit or to end(). | |
1028 HeapWord* _soft_end; | |
1029 | |
1030 public: | |
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1031 EdenSpace(DefNewGeneration* gen) : |
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1032 _gen(gen), _soft_end(NULL) {} |
0 | 1033 |
1034 // Get/set just the 'soft' limit. | |
1035 HeapWord* soft_end() { return _soft_end; } | |
1036 HeapWord** soft_end_addr() { return &_soft_end; } | |
1037 void set_soft_end(HeapWord* value) { _soft_end = value; } | |
1038 | |
1039 // Override. | |
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1040 void clear(bool mangle_space); |
0 | 1041 |
1042 // Set both the 'hard' and 'soft' limits (_end and _soft_end). | |
1043 void set_end(HeapWord* value) { | |
1044 set_soft_end(value); | |
1045 ContiguousSpace::set_end(value); | |
1046 } | |
1047 | |
1048 // Allocation (return NULL if full) | |
1049 HeapWord* allocate(size_t word_size); | |
1050 HeapWord* par_allocate(size_t word_size); | |
1051 }; | |
1052 | |
1053 // Class ConcEdenSpace extends EdenSpace for the sake of safe | |
1054 // allocation while soft-end is being modified concurrently | |
1055 | |
1056 class ConcEdenSpace : public EdenSpace { | |
1057 public: | |
1058 ConcEdenSpace(DefNewGeneration* gen) : EdenSpace(gen) { } | |
1059 | |
1060 // Allocation (return NULL if full) | |
1061 HeapWord* par_allocate(size_t word_size); | |
1062 }; | |
1063 | |
1064 | |
1065 // A ContigSpace that Supports an efficient "block_start" operation via | |
1066 // a BlockOffsetArray (whose BlockOffsetSharedArray may be shared with | |
1067 // other spaces.) This is the abstract base class for old generation | |
1068 // (tenured, perm) spaces. | |
1069 | |
1070 class OffsetTableContigSpace: public ContiguousSpace { | |
1071 friend class VMStructs; | |
1072 protected: | |
1073 BlockOffsetArrayContigSpace _offsets; | |
1074 Mutex _par_alloc_lock; | |
1075 | |
1076 public: | |
1077 // Constructor | |
1078 OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray, | |
1079 MemRegion mr); | |
1080 | |
1081 void set_bottom(HeapWord* value); | |
1082 void set_end(HeapWord* value); | |
1083 | |
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1084 void clear(bool mangle_space); |
0 | 1085 |
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1086 inline HeapWord* block_start_const(const void* p) const; |
0 | 1087 |
1088 // Add offset table update. | |
1089 virtual inline HeapWord* allocate(size_t word_size); | |
1090 inline HeapWord* par_allocate(size_t word_size); | |
1091 | |
1092 // MarkSweep support phase3 | |
1093 virtual HeapWord* initialize_threshold(); | |
1094 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); | |
1095 | |
1096 virtual void print_on(outputStream* st) const; | |
1097 | |
1098 // Debugging | |
1099 void verify(bool allow_dirty) const; | |
1100 | |
1101 // Shared space support | |
1102 void serialize_block_offset_array_offsets(SerializeOopClosure* soc); | |
1103 }; | |
1104 | |
1105 | |
1106 // Class TenuredSpace is used by TenuredGeneration | |
1107 | |
1108 class TenuredSpace: public OffsetTableContigSpace { | |
1109 friend class VMStructs; | |
1110 protected: | |
1111 // Mark sweep support | |
438 | 1112 size_t allowed_dead_ratio() const; |
0 | 1113 public: |
1114 // Constructor | |
1115 TenuredSpace(BlockOffsetSharedArray* sharedOffsetArray, | |
1116 MemRegion mr) : | |
1117 OffsetTableContigSpace(sharedOffsetArray, mr) {} | |
1118 }; | |
1119 | |
1120 | |
1121 // Class ContigPermSpace is used by CompactingPermGen | |
1122 | |
1123 class ContigPermSpace: public OffsetTableContigSpace { | |
1124 friend class VMStructs; | |
1125 protected: | |
1126 // Mark sweep support | |
438 | 1127 size_t allowed_dead_ratio() const; |
0 | 1128 public: |
1129 // Constructor | |
1130 ContigPermSpace(BlockOffsetSharedArray* sharedOffsetArray, MemRegion mr) : | |
1131 OffsetTableContigSpace(sharedOffsetArray, mr) {} | |
1132 }; | |
1972 | 1133 |
1134 #endif // SHARE_VM_MEMORY_SPACE_HPP |