Mercurial > hg > graal-jvmci-8
annotate src/share/vm/memory/space.hpp @ 12233:40136aa2cdb1
8010722: assert: failed: heap size is too big for compressed oops
Summary: Use conservative assumptions of required alignment for the various garbage collector components into account when determining the maximum heap size that supports compressed oops. Using this conservative value avoids several circular dependencies in the calculation.
Reviewed-by: stefank, dholmes
author | tschatzl |
---|---|
date | Wed, 11 Sep 2013 16:25:02 +0200 |
parents | 12f651e29f6b |
children | de6a9e811145 bdd155477289 |
rev | line source |
---|---|
0 | 1 /* |
6008 | 2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
845
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
845
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
845
diff
changeset
|
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" | |
8001
db9981fd3124
8005915: Unify SERIALGC and INCLUDE_ALTERNATE_GCS
jprovino
parents:
7448
diff
changeset
|
37 #include "utilities/macros.hpp" |
1972 | 38 #include "utilities/workgroup.hpp" |
39 #ifdef TARGET_OS_FAMILY_linux | |
40 # include "os_linux.inline.hpp" | |
41 #endif | |
42 #ifdef TARGET_OS_FAMILY_solaris | |
43 # include "os_solaris.inline.hpp" | |
44 #endif | |
45 #ifdef TARGET_OS_FAMILY_windows | |
46 # include "os_windows.inline.hpp" | |
47 #endif | |
3960 | 48 #ifdef TARGET_OS_FAMILY_bsd |
49 # include "os_bsd.inline.hpp" | |
50 #endif | |
1972 | 51 |
0 | 52 // A space is an abstraction for the "storage units" backing |
53 // up the generation abstraction. It includes specific | |
54 // implementations for keeping track of free and used space, | |
55 // for iterating over objects and free blocks, etc. | |
56 | |
57 // Here's the Space hierarchy: | |
58 // | |
59 // - Space -- an asbtract base class describing a heap area | |
60 // - CompactibleSpace -- a space supporting compaction | |
61 // - CompactibleFreeListSpace -- (used for CMS generation) | |
62 // - ContiguousSpace -- a compactible space in which all free space | |
63 // is contiguous | |
64 // - EdenSpace -- contiguous space used as nursery | |
65 // - ConcEdenSpace -- contiguous space with a 'soft end safe' allocation | |
66 // - OffsetTableContigSpace -- contiguous space with a block offset array | |
67 // that allows "fast" block_start calls | |
68 // - TenuredSpace -- (used for TenuredGeneration) | |
69 | |
70 // Forward decls. | |
71 class Space; | |
72 class BlockOffsetArray; | |
73 class BlockOffsetArrayContigSpace; | |
74 class Generation; | |
75 class CompactibleSpace; | |
76 class BlockOffsetTable; | |
77 class GenRemSet; | |
78 class CardTableRS; | |
79 class DirtyCardToOopClosure; | |
80 | |
81 // An oop closure that is circumscribed by a filtering memory region. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
82 class SpaceMemRegionOopsIterClosure: public ExtendedOopClosure { |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
83 private: |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
84 ExtendedOopClosure* _cl; |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
85 MemRegion _mr; |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
86 protected: |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
87 template <class T> void do_oop_work(T* p) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
88 if (_mr.contains(p)) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
89 _cl->do_oop(p); |
0 | 90 } |
91 } | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
92 public: |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
93 SpaceMemRegionOopsIterClosure(ExtendedOopClosure* cl, MemRegion mr): |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
94 _cl(cl), _mr(mr) {} |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
95 virtual void do_oop(oop* p); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
96 virtual void do_oop(narrowOop* p); |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
97 virtual bool do_metadata() { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
98 // _cl is of type ExtendedOopClosure instead of OopClosure, so that we can check this. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
99 assert(!_cl->do_metadata(), "I've checked all call paths, this shouldn't happen."); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
100 return false; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
101 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
102 virtual void do_klass(Klass* k) { ShouldNotReachHere(); } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
103 virtual void do_class_loader_data(ClassLoaderData* cld) { ShouldNotReachHere(); } |
0 | 104 }; |
105 | |
106 // A Space describes a heap area. Class Space is an abstract | |
107 // base class. | |
108 // | |
109 // Space supports allocation, size computation and GC support is provided. | |
110 // | |
111 // Invariant: bottom() and end() are on page_size boundaries and | |
112 // bottom() <= top() <= end() | |
113 // top() is inclusive and end() is exclusive. | |
114 | |
6197 | 115 class Space: public CHeapObj<mtGC> { |
0 | 116 friend class VMStructs; |
117 protected: | |
118 HeapWord* _bottom; | |
119 HeapWord* _end; | |
120 | |
121 // Used in support of save_marks() | |
122 HeapWord* _saved_mark_word; | |
123 | |
124 MemRegionClosure* _preconsumptionDirtyCardClosure; | |
125 | |
126 // A sequential tasks done structure. This supports | |
127 // parallel GC, where we have threads dynamically | |
128 // claiming sub-tasks from a larger parallel task. | |
129 SequentialSubTasksDone _par_seq_tasks; | |
130 | |
131 Space(): | |
132 _bottom(NULL), _end(NULL), _preconsumptionDirtyCardClosure(NULL) { } | |
133 | |
134 public: | |
135 // Accessors | |
136 HeapWord* bottom() const { return _bottom; } | |
137 HeapWord* end() const { return _end; } | |
138 virtual void set_bottom(HeapWord* value) { _bottom = value; } | |
139 virtual void set_end(HeapWord* value) { _end = value; } | |
140 | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
141 virtual HeapWord* saved_mark_word() const { return _saved_mark_word; } |
845
df6caf649ff7
6700789: G1: Enable use of compressed oops with G1 heaps
ysr
parents:
579
diff
changeset
|
142 |
0 | 143 void set_saved_mark_word(HeapWord* p) { _saved_mark_word = p; } |
144 | |
145 MemRegionClosure* preconsumptionDirtyCardClosure() const { | |
146 return _preconsumptionDirtyCardClosure; | |
147 } | |
148 void setPreconsumptionDirtyCardClosure(MemRegionClosure* cl) { | |
149 _preconsumptionDirtyCardClosure = cl; | |
150 } | |
151 | |
152 // Returns a subregion of the space containing all the objects in | |
153 // the space. | |
154 virtual MemRegion used_region() const { return MemRegion(bottom(), end()); } | |
155 | |
156 // Returns a region that is guaranteed to contain (at least) all objects | |
157 // allocated at the time of the last call to "save_marks". If the space | |
158 // initializes its DirtyCardToOopClosure's specifying the "contig" option | |
159 // (that is, if the space is contiguous), then this region must contain only | |
160 // such objects: the memregion will be from the bottom of the region to the | |
161 // saved mark. Otherwise, the "obj_allocated_since_save_marks" method of | |
162 // the space must distiguish between objects in the region allocated before | |
163 // and after the call to save marks. | |
164 virtual MemRegion used_region_at_save_marks() const { | |
165 return MemRegion(bottom(), saved_mark_word()); | |
166 } | |
167 | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
168 // Initialization. |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
169 // "initialize" should be called once on a space, before it is used for |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
170 // any purpose. The "mr" arguments gives the bounds of the space, and |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
171 // the "clear_space" argument should be true unless the memory in "mr" is |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
172 // known to be zeroed. |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
173 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
174 |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
175 // The "clear" method must be called on a region that may have |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
176 // had allocation performed in it, but is now to be considered empty. |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
177 virtual void clear(bool mangle_space); |
0 | 178 |
179 // For detecting GC bugs. Should only be called at GC boundaries, since | |
180 // some unused space may be used as scratch space during GC's. | |
181 // Default implementation does nothing. We also call this when expanding | |
182 // a space to satisfy an allocation request. See bug #4668531 | |
183 virtual void mangle_unused_area() {} | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
184 virtual void mangle_unused_area_complete() {} |
0 | 185 virtual void mangle_region(MemRegion mr) {} |
186 | |
187 // Testers | |
188 bool is_empty() const { return used() == 0; } | |
189 bool not_empty() const { return used() > 0; } | |
190 | |
191 // Returns true iff the given the space contains the | |
192 // given address as part of an allocated object. For | |
193 // ceratin kinds of spaces, this might be a potentially | |
194 // expensive operation. To prevent performance problems | |
195 // on account of its inadvertent use in product jvm's, | |
196 // we restrict its use to assertion checks only. | |
4708 | 197 virtual bool is_in(const void* p) const = 0; |
0 | 198 |
199 // Returns true iff the given reserved memory of the space contains the | |
200 // given address. | |
201 bool is_in_reserved(const void* p) const { return _bottom <= p && p < _end; } | |
202 | |
203 // Returns true iff the given block is not allocated. | |
204 virtual bool is_free_block(const HeapWord* p) const = 0; | |
205 | |
206 // Test whether p is double-aligned | |
207 static bool is_aligned(void* p) { | |
208 return ((intptr_t)p & (sizeof(double)-1)) == 0; | |
209 } | |
210 | |
211 // Size computations. Sizes are in bytes. | |
212 size_t capacity() const { return byte_size(bottom(), end()); } | |
213 virtual size_t used() const = 0; | |
214 virtual size_t free() const = 0; | |
215 | |
216 // Iterate over all the ref-containing fields of all objects in the | |
217 // space, calling "cl.do_oop" on each. Fields in objects allocated by | |
218 // applications of the closure are not included in the iteration. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
219 virtual void oop_iterate(ExtendedOopClosure* cl); |
0 | 220 |
221 // Same as above, restricted to the intersection of a memory region and | |
222 // the space. Fields in objects allocated by applications of the closure | |
223 // are not included in the iteration. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
224 virtual void oop_iterate(MemRegion mr, ExtendedOopClosure* cl) = 0; |
0 | 225 |
226 // Iterate over all objects in the space, calling "cl.do_object" on | |
227 // each. Objects allocated by applications of the closure are not | |
228 // included in the iteration. | |
229 virtual void object_iterate(ObjectClosure* blk) = 0; | |
517
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
438
diff
changeset
|
230 // Similar to object_iterate() except only iterates over |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
438
diff
changeset
|
231 // objects whose internal references point to objects in the space. |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
438
diff
changeset
|
232 virtual void safe_object_iterate(ObjectClosure* blk) = 0; |
0 | 233 |
234 // Iterate over all objects that intersect with mr, calling "cl->do_object" | |
235 // on each. There is an exception to this: if this closure has already | |
236 // been invoked on an object, it may skip such objects in some cases. This is | |
237 // Most likely to happen in an "upwards" (ascending address) iteration of | |
238 // MemRegions. | |
239 virtual void object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl); | |
240 | |
241 // Iterate over as many initialized objects in the space as possible, | |
242 // calling "cl.do_object_careful" on each. Return NULL if all objects | |
243 // in the space (at the start of the iteration) were iterated over. | |
244 // Return an address indicating the extent of the iteration in the | |
245 // event that the iteration had to return because of finding an | |
246 // uninitialized object in the space, or if the closure "cl" | |
247 // signalled early termination. | |
248 virtual HeapWord* object_iterate_careful(ObjectClosureCareful* cl); | |
249 virtual HeapWord* object_iterate_careful_m(MemRegion mr, | |
250 ObjectClosureCareful* cl); | |
251 | |
252 // Create and return a new dirty card to oop closure. Can be | |
253 // overriden to return the appropriate type of closure | |
254 // depending on the type of space in which the closure will | |
255 // operate. ResourceArea allocated. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
256 virtual DirtyCardToOopClosure* new_dcto_cl(ExtendedOopClosure* cl, |
0 | 257 CardTableModRefBS::PrecisionStyle precision, |
258 HeapWord* boundary = NULL); | |
259 | |
260 // If "p" is in the space, returns the address of the start of the | |
261 // "block" that contains "p". We say "block" instead of "object" since | |
262 // some heaps may not pack objects densely; a chunk may either be an | |
263 // object or a non-object. If "p" is not in the space, return NULL. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
264 virtual HeapWord* block_start_const(const void* p) const = 0; |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
265 |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
266 // The non-const version may have benevolent side effects on the data |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
267 // structure supporting these calls, possibly speeding up future calls. |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
268 // The default implementation, however, is simply to call the const |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
269 // version. |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
270 inline virtual HeapWord* block_start(const void* p); |
0 | 271 |
272 // Requires "addr" to be the start of a chunk, and returns its size. | |
273 // "addr + size" is required to be the start of a new chunk, or the end | |
274 // of the active area of the heap. | |
275 virtual size_t block_size(const HeapWord* addr) const = 0; | |
276 | |
277 // Requires "addr" to be the start of a block, and returns "TRUE" iff | |
278 // the block is an object. | |
279 virtual bool block_is_obj(const HeapWord* addr) const = 0; | |
280 | |
281 // Requires "addr" to be the start of a block, and returns "TRUE" iff | |
282 // the block is an object and the object is alive. | |
283 virtual bool obj_is_alive(const HeapWord* addr) const; | |
284 | |
285 // Allocation (return NULL if full). Assumes the caller has established | |
286 // mutually exclusive access to the space. | |
287 virtual HeapWord* allocate(size_t word_size) = 0; | |
288 | |
289 // Allocation (return NULL if full). Enforces mutual exclusion internally. | |
290 virtual HeapWord* par_allocate(size_t word_size) = 0; | |
291 | |
292 // Returns true if this object has been allocated since a | |
293 // generation's "save_marks" call. | |
294 virtual bool obj_allocated_since_save_marks(const oop obj) const = 0; | |
295 | |
296 // Mark-sweep-compact support: all spaces can update pointers to objects | |
297 // moving as a part of compaction. | |
298 virtual void adjust_pointers(); | |
299 | |
300 // PrintHeapAtGC support | |
301 virtual void print() const; | |
302 virtual void print_on(outputStream* st) const; | |
303 virtual void print_short() const; | |
304 virtual void print_short_on(outputStream* st) const; | |
305 | |
306 | |
307 // Accessor for parallel sequential tasks. | |
308 SequentialSubTasksDone* par_seq_tasks() { return &_par_seq_tasks; } | |
309 | |
310 // IF "this" is a ContiguousSpace, return it, else return NULL. | |
311 virtual ContiguousSpace* toContiguousSpace() { | |
312 return NULL; | |
313 } | |
314 | |
315 // Debugging | |
6008 | 316 virtual void verify() const = 0; |
0 | 317 }; |
318 | |
319 // A MemRegionClosure (ResourceObj) whose "do_MemRegion" function applies an | |
320 // OopClosure to (the addresses of) all the ref-containing fields that could | |
321 // be modified by virtue of the given MemRegion being dirty. (Note that | |
322 // because of the imprecise nature of the write barrier, this may iterate | |
323 // over oops beyond the region.) | |
324 // This base type for dirty card to oop closures handles memory regions | |
325 // in non-contiguous spaces with no boundaries, and should be sub-classed | |
326 // to support other space types. See ContiguousDCTOC for a sub-class | |
327 // that works with ContiguousSpaces. | |
328 | |
329 class DirtyCardToOopClosure: public MemRegionClosureRO { | |
330 protected: | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
331 ExtendedOopClosure* _cl; |
0 | 332 Space* _sp; |
333 CardTableModRefBS::PrecisionStyle _precision; | |
334 HeapWord* _boundary; // If non-NULL, process only non-NULL oops | |
335 // pointing below boundary. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
336 HeapWord* _min_done; // ObjHeadPreciseArray precision requires |
0 | 337 // a downwards traversal; this is the |
338 // lowest location already done (or, | |
339 // alternatively, the lowest address that | |
340 // shouldn't be done again. NULL means infinity.) | |
341 NOT_PRODUCT(HeapWord* _last_bottom;) | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
342 NOT_PRODUCT(HeapWord* _last_explicit_min_done;) |
0 | 343 |
344 // Get the actual top of the area on which the closure will | |
345 // operate, given where the top is assumed to be (the end of the | |
346 // memory region passed to do_MemRegion) and where the object | |
347 // at the top is assumed to start. For example, an object may | |
348 // start at the top but actually extend past the assumed top, | |
349 // in which case the top becomes the end of the object. | |
350 virtual HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj); | |
351 | |
352 // Walk the given memory region from bottom to (actual) top | |
353 // looking for objects and applying the oop closure (_cl) to | |
354 // them. The base implementation of this treats the area as | |
355 // blocks, where a block may or may not be an object. Sub- | |
356 // classes should override this to provide more accurate | |
357 // or possibly more efficient walking. | |
358 virtual void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); | |
359 | |
360 public: | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
361 DirtyCardToOopClosure(Space* sp, ExtendedOopClosure* cl, |
0 | 362 CardTableModRefBS::PrecisionStyle precision, |
363 HeapWord* boundary) : | |
364 _sp(sp), _cl(cl), _precision(precision), _boundary(boundary), | |
365 _min_done(NULL) { | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
366 NOT_PRODUCT(_last_bottom = NULL); |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
367 NOT_PRODUCT(_last_explicit_min_done = NULL); |
0 | 368 } |
369 | |
370 void do_MemRegion(MemRegion mr); | |
371 | |
372 void set_min_done(HeapWord* min_done) { | |
373 _min_done = min_done; | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
374 NOT_PRODUCT(_last_explicit_min_done = _min_done); |
0 | 375 } |
376 #ifndef PRODUCT | |
377 void set_last_bottom(HeapWord* last_bottom) { | |
378 _last_bottom = last_bottom; | |
379 } | |
380 #endif | |
381 }; | |
382 | |
383 // A structure to represent a point at which objects are being copied | |
384 // during compaction. | |
385 class CompactPoint : public StackObj { | |
386 public: | |
387 Generation* gen; | |
388 CompactibleSpace* space; | |
389 HeapWord* threshold; | |
390 CompactPoint(Generation* _gen, CompactibleSpace* _space, | |
391 HeapWord* _threshold) : | |
392 gen(_gen), space(_space), threshold(_threshold) {} | |
393 }; | |
394 | |
395 | |
396 // A space that supports compaction operations. This is usually, but not | |
397 // necessarily, a space that is normally contiguous. But, for example, a | |
398 // free-list-based space whose normal collection is a mark-sweep without | |
399 // compaction could still support compaction in full GC's. | |
400 | |
401 class CompactibleSpace: public Space { | |
402 friend class VMStructs; | |
403 friend class CompactibleFreeListSpace; | |
404 private: | |
405 HeapWord* _compaction_top; | |
406 CompactibleSpace* _next_compaction_space; | |
407 | |
408 public: | |
347
60fb9c4db4e6
6718086: CMS assert: _concurrent_iteration_safe_limit update missed
ysr
parents:
342
diff
changeset
|
409 CompactibleSpace() : |
60fb9c4db4e6
6718086: CMS assert: _concurrent_iteration_safe_limit update missed
ysr
parents:
342
diff
changeset
|
410 _compaction_top(NULL), _next_compaction_space(NULL) {} |
60fb9c4db4e6
6718086: CMS assert: _concurrent_iteration_safe_limit update missed
ysr
parents:
342
diff
changeset
|
411 |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
412 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); |
356 | 413 virtual void clear(bool mangle_space); |
0 | 414 |
415 // Used temporarily during a compaction phase to hold the value | |
416 // top should have when compaction is complete. | |
417 HeapWord* compaction_top() const { return _compaction_top; } | |
418 | |
419 void set_compaction_top(HeapWord* value) { | |
420 assert(value == NULL || (value >= bottom() && value <= end()), | |
421 "should point inside space"); | |
422 _compaction_top = value; | |
423 } | |
424 | |
425 // Perform operations on the space needed after a compaction | |
426 // has been performed. | |
427 virtual void reset_after_compaction() {} | |
428 | |
429 // Returns the next space (in the current generation) to be compacted in | |
430 // the global compaction order. Also is used to select the next | |
431 // space into which to compact. | |
432 | |
433 virtual CompactibleSpace* next_compaction_space() const { | |
434 return _next_compaction_space; | |
435 } | |
436 | |
437 void set_next_compaction_space(CompactibleSpace* csp) { | |
438 _next_compaction_space = csp; | |
439 } | |
440 | |
441 // MarkSweep support phase2 | |
442 | |
443 // Start the process of compaction of the current space: compute | |
444 // post-compaction addresses, and insert forwarding pointers. The fields | |
445 // "cp->gen" and "cp->compaction_space" are the generation and space into | |
446 // which we are currently compacting. This call updates "cp" as necessary, | |
447 // and leaves the "compaction_top" of the final value of | |
448 // "cp->compaction_space" up-to-date. Offset tables may be updated in | |
449 // this phase as if the final copy had occurred; if so, "cp->threshold" | |
450 // indicates when the next such action should be taken. | |
451 virtual void prepare_for_compaction(CompactPoint* cp); | |
452 // MarkSweep support phase3 | |
453 virtual void adjust_pointers(); | |
454 // MarkSweep support phase4 | |
455 virtual void compact(); | |
456 | |
457 // The maximum percentage of objects that can be dead in the compacted | |
458 // live part of a compacted space ("deadwood" support.) | |
438 | 459 virtual size_t allowed_dead_ratio() const { return 0; }; |
0 | 460 |
461 // Some contiguous spaces may maintain some data structures that should | |
462 // be updated whenever an allocation crosses a boundary. This function | |
463 // returns the first such boundary. | |
464 // (The default implementation returns the end of the space, so the | |
465 // boundary is never crossed.) | |
466 virtual HeapWord* initialize_threshold() { return end(); } | |
467 | |
468 // "q" is an object of the given "size" that should be forwarded; | |
469 // "cp" names the generation ("gen") and containing "this" (which must | |
470 // also equal "cp->space"). "compact_top" is where in "this" the | |
471 // next object should be forwarded to. If there is room in "this" for | |
472 // the object, insert an appropriate forwarding pointer in "q". | |
473 // If not, go to the next compaction space (there must | |
474 // be one, since compaction must succeed -- we go to the first space of | |
475 // the previous generation if necessary, updating "cp"), reset compact_top | |
476 // and then forward. In either case, returns the new value of "compact_top". | |
477 // If the forwarding crosses "cp->threshold", invokes the "cross_threhold" | |
478 // function of the then-current compaction space, and updates "cp->threshold | |
479 // accordingly". | |
480 virtual HeapWord* forward(oop q, size_t size, CompactPoint* cp, | |
481 HeapWord* compact_top); | |
482 | |
483 // Return a size with adjusments as required of the space. | |
484 virtual size_t adjust_object_size_v(size_t size) const { return size; } | |
485 | |
486 protected: | |
487 // Used during compaction. | |
488 HeapWord* _first_dead; | |
489 HeapWord* _end_of_live; | |
490 | |
491 // Minimum size of a free block. | |
492 virtual size_t minimum_free_block_size() const = 0; | |
493 | |
494 // This the function is invoked when an allocation of an object covering | |
495 // "start" to "end occurs crosses the threshold; returns the next | |
496 // threshold. (The default implementation does nothing.) | |
497 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* the_end) { | |
498 return end(); | |
499 } | |
500 | |
501 // Requires "allowed_deadspace_words > 0", that "q" is the start of a | |
502 // free block of the given "word_len", and that "q", were it an object, | |
503 // would not move if forwared. If the size allows, fill the free | |
504 // block with an object, to prevent excessive compaction. Returns "true" | |
505 // iff the free region was made deadspace, and modifies | |
506 // "allowed_deadspace_words" to reflect the number of available deadspace | |
507 // words remaining after this operation. | |
508 bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q, | |
509 size_t word_len); | |
510 }; | |
511 | |
512 #define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size) { \ | |
513 /* Compute the new addresses for the live objects and store it in the mark \ | |
514 * Used by universe::mark_sweep_phase2() \ | |
515 */ \ | |
516 HeapWord* compact_top; /* This is where we are currently compacting to. */ \ | |
517 \ | |
518 /* We're sure to be here before any objects are compacted into this \ | |
519 * space, so this is a good time to initialize this: \ | |
520 */ \ | |
521 set_compaction_top(bottom()); \ | |
522 \ | |
523 if (cp->space == NULL) { \ | |
524 assert(cp->gen != NULL, "need a generation"); \ | |
525 assert(cp->threshold == NULL, "just checking"); \ | |
526 assert(cp->gen->first_compaction_space() == this, "just checking"); \ | |
527 cp->space = cp->gen->first_compaction_space(); \ | |
528 compact_top = cp->space->bottom(); \ | |
529 cp->space->set_compaction_top(compact_top); \ | |
530 cp->threshold = cp->space->initialize_threshold(); \ | |
531 } else { \ | |
532 compact_top = cp->space->compaction_top(); \ | |
533 } \ | |
534 \ | |
535 /* We allow some amount of garbage towards the bottom of the space, so \ | |
536 * we don't start compacting before there is a significant gain to be made.\ | |
537 * Occasionally, we want to ensure a full compaction, which is determined \ | |
538 * by the MarkSweepAlwaysCompactCount parameter. \ | |
539 */ \ | |
10287
12f651e29f6b
6843347: Boundary values in some public GC options cause crashes
tschatzl
parents:
8001
diff
changeset
|
540 uint invocations = MarkSweep::total_invocations(); \ |
12f651e29f6b
6843347: Boundary values in some public GC options cause crashes
tschatzl
parents:
8001
diff
changeset
|
541 bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0); \ |
0 | 542 \ |
543 size_t allowed_deadspace = 0; \ | |
544 if (skip_dead) { \ | |
438 | 545 const size_t ratio = allowed_dead_ratio(); \ |
0 | 546 allowed_deadspace = (capacity() * ratio / 100) / HeapWordSize; \ |
547 } \ | |
548 \ | |
549 HeapWord* q = bottom(); \ | |
550 HeapWord* t = scan_limit(); \ | |
551 \ | |
552 HeapWord* end_of_live= q; /* One byte beyond the last byte of the last \ | |
553 live object. */ \ | |
554 HeapWord* first_dead = end();/* The first dead object. */ \ | |
555 LiveRange* liveRange = NULL; /* The current live range, recorded in the \ | |
556 first header of preceding free area. */ \ | |
557 _first_dead = first_dead; \ | |
558 \ | |
559 const intx interval = PrefetchScanIntervalInBytes; \ | |
560 \ | |
561 while (q < t) { \ | |
562 assert(!block_is_obj(q) || \ | |
563 oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || \ | |
564 oop(q)->mark()->has_bias_pattern(), \ | |
565 "these are the only valid states during a mark sweep"); \ | |
566 if (block_is_obj(q) && oop(q)->is_gc_marked()) { \ | |
567 /* prefetch beyond q */ \ | |
568 Prefetch::write(q, interval); \ | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
569 size_t size = block_size(q); \ |
0 | 570 compact_top = cp->space->forward(oop(q), size, cp, compact_top); \ |
571 q += size; \ | |
572 end_of_live = q; \ | |
573 } else { \ | |
574 /* run over all the contiguous dead objects */ \ | |
575 HeapWord* end = q; \ | |
576 do { \ | |
577 /* prefetch beyond end */ \ | |
578 Prefetch::write(end, interval); \ | |
579 end += block_size(end); \ | |
580 } while (end < t && (!block_is_obj(end) || !oop(end)->is_gc_marked()));\ | |
581 \ | |
582 /* see if we might want to pretend this object is alive so that \ | |
583 * we don't have to compact quite as often. \ | |
584 */ \ | |
585 if (allowed_deadspace > 0 && q == compact_top) { \ | |
586 size_t sz = pointer_delta(end, q); \ | |
587 if (insert_deadspace(allowed_deadspace, q, sz)) { \ | |
588 compact_top = cp->space->forward(oop(q), sz, cp, compact_top); \ | |
589 q = end; \ | |
590 end_of_live = end; \ | |
591 continue; \ | |
592 } \ | |
593 } \ | |
594 \ | |
595 /* otherwise, it really is a free region. */ \ | |
596 \ | |
597 /* for the previous LiveRange, record the end of the live objects. */ \ | |
598 if (liveRange) { \ | |
599 liveRange->set_end(q); \ | |
600 } \ | |
601 \ | |
602 /* record the current LiveRange object. \ | |
603 * liveRange->start() is overlaid on the mark word. \ | |
604 */ \ | |
605 liveRange = (LiveRange*)q; \ | |
606 liveRange->set_start(end); \ | |
607 liveRange->set_end(end); \ | |
608 \ | |
609 /* see if this is the first dead region. */ \ | |
610 if (q < first_dead) { \ | |
611 first_dead = q; \ | |
612 } \ | |
613 \ | |
614 /* move on to the next object */ \ | |
615 q = end; \ | |
616 } \ | |
617 } \ | |
618 \ | |
619 assert(q == t, "just checking"); \ | |
620 if (liveRange != NULL) { \ | |
621 liveRange->set_end(q); \ | |
622 } \ | |
623 _end_of_live = end_of_live; \ | |
624 if (end_of_live < first_dead) { \ | |
625 first_dead = end_of_live; \ | |
626 } \ | |
627 _first_dead = first_dead; \ | |
628 \ | |
629 /* save the compaction_top of the compaction space. */ \ | |
630 cp->space->set_compaction_top(compact_top); \ | |
631 } | |
632 | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
633 #define SCAN_AND_ADJUST_POINTERS(adjust_obj_size) { \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
634 /* adjust all the interior pointers to point at the new locations of objects \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
635 * Used by MarkSweep::mark_sweep_phase3() */ \ |
0 | 636 \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
637 HeapWord* q = bottom(); \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
638 HeapWord* t = _end_of_live; /* Established by "prepare_for_compaction". */ \ |
0 | 639 \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
640 assert(_first_dead <= _end_of_live, "Stands to reason, no?"); \ |
0 | 641 \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
642 if (q < t && _first_dead > q && \ |
0 | 643 !oop(q)->is_gc_marked()) { \ |
644 /* we have a chunk of the space which hasn't moved and we've \ | |
645 * reinitialized the mark word during the previous pass, so we can't \ | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
646 * use is_gc_marked for the traversal. */ \ |
0 | 647 HeapWord* end = _first_dead; \ |
648 \ | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
649 while (q < end) { \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
650 /* I originally tried to conjoin "block_start(q) == q" to the \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
651 * assertion below, but that doesn't work, because you can't \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
652 * accurately traverse previous objects to get to the current one \ |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
653 * after their pointers have been \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
654 * updated, until the actual compaction is done. dld, 4/00 */ \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
655 assert(block_is_obj(q), \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
656 "should be at block boundaries, and should be looking at objs"); \ |
0 | 657 \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
658 /* point all the oops to the new location */ \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
659 size_t size = oop(q)->adjust_pointers(); \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
660 size = adjust_obj_size(size); \ |
0 | 661 \ |
662 q += size; \ | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
663 } \ |
0 | 664 \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
665 if (_first_dead == t) { \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
666 q = t; \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
667 } else { \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
668 /* $$$ This is funky. Using this to read the previously written \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
669 * LiveRange. See also use below. */ \ |
0 | 670 q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
671 } \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
672 } \ |
0 | 673 \ |
674 const intx interval = PrefetchScanIntervalInBytes; \ | |
675 \ | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
676 debug_only(HeapWord* prev_q = NULL); \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
677 while (q < t) { \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
678 /* prefetch beyond q */ \ |
0 | 679 Prefetch::write(q, interval); \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
680 if (oop(q)->is_gc_marked()) { \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
681 /* q is alive */ \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
682 /* point all the oops to the new location */ \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
683 size_t size = oop(q)->adjust_pointers(); \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
684 size = adjust_obj_size(size); \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
685 debug_only(prev_q = q); \ |
0 | 686 q += size; \ |
356 | 687 } else { \ |
688 /* q is not a live object, so its mark should point at the next \ | |
689 * live object */ \ | |
690 debug_only(prev_q = q); \ | |
691 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \ | |
692 assert(q > prev_q, "we should be moving forward through memory"); \ | |
693 } \ | |
694 } \ | |
0 | 695 \ |
356 | 696 assert(q == t, "just checking"); \ |
0 | 697 } |
698 | |
356 | 699 #define SCAN_AND_COMPACT(obj_size) { \ |
0 | 700 /* Copy all live objects to their new location \ |
356 | 701 * Used by MarkSweep::mark_sweep_phase4() */ \ |
0 | 702 \ |
356 | 703 HeapWord* q = bottom(); \ |
704 HeapWord* const t = _end_of_live; \ | |
705 debug_only(HeapWord* prev_q = NULL); \ | |
0 | 706 \ |
356 | 707 if (q < t && _first_dead > q && \ |
0 | 708 !oop(q)->is_gc_marked()) { \ |
356 | 709 debug_only( \ |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
710 /* we have a chunk of the space which hasn't moved and we've reinitialized \ |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
711 * the mark word during the previous pass, so we can't use is_gc_marked for \ |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
712 * the traversal. */ \ |
356 | 713 HeapWord* const end = _first_dead; \ |
714 \ | |
715 while (q < end) { \ | |
0 | 716 size_t size = obj_size(q); \ |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
717 assert(!oop(q)->is_gc_marked(), \ |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
718 "should be unmarked (special dense prefix handling)"); \ |
356 | 719 debug_only(prev_q = q); \ |
0 | 720 q += size; \ |
356 | 721 } \ |
722 ) /* debug_only */ \ | |
723 \ | |
724 if (_first_dead == t) { \ | |
725 q = t; \ | |
726 } else { \ | |
727 /* $$$ Funky */ \ | |
728 q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); \ | |
729 } \ | |
730 } \ | |
0 | 731 \ |
356 | 732 const intx scan_interval = PrefetchScanIntervalInBytes; \ |
733 const intx copy_interval = PrefetchCopyIntervalInBytes; \ | |
734 while (q < t) { \ | |
735 if (!oop(q)->is_gc_marked()) { \ | |
736 /* mark is pointer to next marked oop */ \ | |
737 debug_only(prev_q = q); \ | |
738 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \ | |
739 assert(q > prev_q, "we should be moving forward through memory"); \ | |
740 } else { \ | |
741 /* prefetch beyond q */ \ | |
0 | 742 Prefetch::read(q, scan_interval); \ |
743 \ | |
744 /* size and destination */ \ | |
745 size_t size = obj_size(q); \ | |
746 HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); \ | |
747 \ | |
356 | 748 /* prefetch beyond compaction_top */ \ |
0 | 749 Prefetch::write(compaction_top, copy_interval); \ |
750 \ | |
356 | 751 /* copy object and reinit its mark */ \ |
752 assert(q != compaction_top, "everything in this pass should be moving"); \ | |
753 Copy::aligned_conjoint_words(q, compaction_top, size); \ | |
754 oop(compaction_top)->init_mark(); \ | |
755 assert(oop(compaction_top)->klass() != NULL, "should have a class"); \ | |
0 | 756 \ |
356 | 757 debug_only(prev_q = q); \ |
0 | 758 q += size; \ |
356 | 759 } \ |
760 } \ | |
0 | 761 \ |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
762 /* Let's remember if we were empty before we did the compaction. */ \ |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
763 bool was_empty = used_region().is_empty(); \ |
0 | 764 /* Reset space after compaction is complete */ \ |
356 | 765 reset_after_compaction(); \ |
0 | 766 /* We do this clear, below, since it has overloaded meanings for some */ \ |
767 /* space subtypes. For example, OffsetTableContigSpace's that were */ \ | |
768 /* compacted into will have had their offset table thresholds updated */ \ | |
769 /* continuously, but those that weren't need to have their thresholds */ \ | |
770 /* re-initialized. Also mangles unused area for debugging. */ \ | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
771 if (used_region().is_empty()) { \ |
356 | 772 if (!was_empty) clear(SpaceDecorator::Mangle); \ |
0 | 773 } else { \ |
774 if (ZapUnusedHeapArea) mangle_unused_area(); \ | |
775 } \ | |
776 } | |
777 | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
778 class GenSpaceMangler; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
779 |
0 | 780 // A space in which the free area is contiguous. It therefore supports |
781 // faster allocation, and compaction. | |
782 class ContiguousSpace: public CompactibleSpace { | |
783 friend class OneContigSpaceCardGeneration; | |
784 friend class VMStructs; | |
785 protected: | |
786 HeapWord* _top; | |
787 HeapWord* _concurrent_iteration_safe_limit; | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
788 // A helper for mangling the unused area of the space in debug builds. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
789 GenSpaceMangler* _mangler; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
790 |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
791 GenSpaceMangler* mangler() { return _mangler; } |
0 | 792 |
793 // Allocation helpers (return NULL if full). | |
794 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value); | |
795 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value); | |
796 | |
797 public: | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
798 ContiguousSpace(); |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
799 ~ContiguousSpace(); |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
800 |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
801 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); |
356 | 802 virtual void clear(bool mangle_space); |
0 | 803 |
804 // Accessors | |
805 HeapWord* top() const { return _top; } | |
806 void set_top(HeapWord* value) { _top = value; } | |
807 | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
808 virtual void set_saved_mark() { _saved_mark_word = top(); } |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
809 void reset_saved_mark() { _saved_mark_word = bottom(); } |
0 | 810 |
811 WaterMark bottom_mark() { return WaterMark(this, bottom()); } | |
812 WaterMark top_mark() { return WaterMark(this, top()); } | |
813 WaterMark saved_mark() { return WaterMark(this, saved_mark_word()); } | |
814 bool saved_mark_at_top() const { return saved_mark_word() == top(); } | |
815 | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
816 // In debug mode mangle (write it with a particular bit |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
817 // pattern) the unused part of a space. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
818 |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
819 // Used to save the an address in a space for later use during mangling. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
820 void set_top_for_allocations(HeapWord* v) PRODUCT_RETURN; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
821 // Used to save the space's current top for later use during mangling. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
822 void set_top_for_allocations() PRODUCT_RETURN; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
823 |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
824 // Mangle regions in the space from the current top up to the |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
825 // previously mangled part of the space. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
826 void mangle_unused_area() PRODUCT_RETURN; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
827 // Mangle [top, end) |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
828 void mangle_unused_area_complete() PRODUCT_RETURN; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
829 // Mangle the given MemRegion. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
830 void mangle_region(MemRegion mr) PRODUCT_RETURN; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
831 |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
832 // Do some sparse checking on the area that should have been mangled. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
833 void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN; |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
834 // Check the complete area that should have been mangled. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
835 // This code may be NULL depending on the macro DEBUG_MANGLING. |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
836 void check_mangled_unused_area_complete() PRODUCT_RETURN; |
0 | 837 |
838 // Size computations: sizes in bytes. | |
839 size_t capacity() const { return byte_size(bottom(), end()); } | |
840 size_t used() const { return byte_size(bottom(), top()); } | |
841 size_t free() const { return byte_size(top(), end()); } | |
842 | |
843 // Override from space. | |
844 bool is_in(const void* p) const; | |
845 | |
846 virtual bool is_free_block(const HeapWord* p) const; | |
847 | |
848 // In a contiguous space we have a more obvious bound on what parts | |
849 // contain objects. | |
850 MemRegion used_region() const { return MemRegion(bottom(), top()); } | |
851 | |
852 MemRegion used_region_at_save_marks() const { | |
853 return MemRegion(bottom(), saved_mark_word()); | |
854 } | |
855 | |
856 // Allocation (return NULL if full) | |
857 virtual HeapWord* allocate(size_t word_size); | |
858 virtual HeapWord* par_allocate(size_t word_size); | |
859 | |
860 virtual bool obj_allocated_since_save_marks(const oop obj) const { | |
861 return (HeapWord*)obj >= saved_mark_word(); | |
862 } | |
863 | |
864 // Iteration | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
865 void oop_iterate(ExtendedOopClosure* cl); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
866 void oop_iterate(MemRegion mr, ExtendedOopClosure* cl); |
0 | 867 void object_iterate(ObjectClosure* blk); |
517
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
438
diff
changeset
|
868 // For contiguous spaces this method will iterate safely over objects |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
438
diff
changeset
|
869 // in the space (i.e., between bottom and top) when at a safepoint. |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
438
diff
changeset
|
870 void safe_object_iterate(ObjectClosure* blk); |
0 | 871 void object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl); |
872 // iterates on objects up to the safe limit | |
873 HeapWord* object_iterate_careful(ObjectClosureCareful* cl); | |
6048
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
874 HeapWord* concurrent_iteration_safe_limit() { |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
875 assert(_concurrent_iteration_safe_limit <= top(), |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
876 "_concurrent_iteration_safe_limit update missed"); |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
877 return _concurrent_iteration_safe_limit; |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
878 } |
0 | 879 // changes the safe limit, all objects from bottom() to the new |
880 // limit should be properly initialized | |
6048
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
881 void set_concurrent_iteration_safe_limit(HeapWord* new_limit) { |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
882 assert(new_limit <= top(), "uninitialized objects in the safe range"); |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
883 _concurrent_iteration_safe_limit = new_limit; |
a05a695ea044
7167437: Can't build on linux without precompiled headers
stefank
parents:
6008
diff
changeset
|
884 } |
0 | 885 |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
886 |
8001
db9981fd3124
8005915: Unify SERIALGC and INCLUDE_ALTERNATE_GCS
jprovino
parents:
7448
diff
changeset
|
887 #if INCLUDE_ALL_GCS |
0 | 888 // In support of parallel oop_iterate. |
889 #define ContigSpace_PAR_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ | |
890 void par_oop_iterate(MemRegion mr, OopClosureType* blk); | |
891 | |
892 ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DECL) | |
893 #undef ContigSpace_PAR_OOP_ITERATE_DECL | |
8001
db9981fd3124
8005915: Unify SERIALGC and INCLUDE_ALTERNATE_GCS
jprovino
parents:
7448
diff
changeset
|
894 #endif // INCLUDE_ALL_GCS |
0 | 895 |
896 // Compaction support | |
897 virtual void reset_after_compaction() { | |
898 assert(compaction_top() >= bottom() && compaction_top() <= end(), "should point inside space"); | |
899 set_top(compaction_top()); | |
900 // set new iteration safe limit | |
901 set_concurrent_iteration_safe_limit(compaction_top()); | |
902 } | |
903 virtual size_t minimum_free_block_size() const { return 0; } | |
904 | |
905 // Override. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
906 DirtyCardToOopClosure* new_dcto_cl(ExtendedOopClosure* cl, |
0 | 907 CardTableModRefBS::PrecisionStyle precision, |
908 HeapWord* boundary = NULL); | |
909 | |
910 // Apply "blk->do_oop" to the addresses of all reference fields in objects | |
911 // starting with the _saved_mark_word, which was noted during a generation's | |
912 // save_marks and is required to denote the head of an object. | |
913 // Fields in objects allocated by applications of the closure | |
914 // *are* included in the iteration. | |
915 // Updates _saved_mark_word to point to just after the last object | |
916 // iterated over. | |
917 #define ContigSpace_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ | |
918 void oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk); | |
919 | |
920 ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DECL) | |
921 #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DECL | |
922 | |
923 // Same as object_iterate, but starting from "mark", which is required | |
924 // to denote the start of an object. Objects allocated by | |
925 // applications of the closure *are* included in the iteration. | |
926 virtual void object_iterate_from(WaterMark mark, ObjectClosure* blk); | |
927 | |
928 // Very inefficient implementation. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
929 virtual HeapWord* block_start_const(const void* p) const; |
0 | 930 size_t block_size(const HeapWord* p) const; |
931 // If a block is in the allocated area, it is an object. | |
932 bool block_is_obj(const HeapWord* p) const { return p < top(); } | |
933 | |
934 // Addresses for inlined allocation | |
935 HeapWord** top_addr() { return &_top; } | |
936 HeapWord** end_addr() { return &_end; } | |
937 | |
938 // Overrides for more efficient compaction support. | |
939 void prepare_for_compaction(CompactPoint* cp); | |
940 | |
941 // PrintHeapAtGC support. | |
942 virtual void print_on(outputStream* st) const; | |
943 | |
944 // Checked dynamic downcasts. | |
945 virtual ContiguousSpace* toContiguousSpace() { | |
946 return this; | |
947 } | |
948 | |
949 // Debugging | |
6008 | 950 virtual void verify() const; |
0 | 951 |
952 // Used to increase collection frequency. "factor" of 0 means entire | |
953 // space. | |
954 void allocate_temporary_filler(int factor); | |
955 | |
956 }; | |
957 | |
958 | |
959 // A dirty card to oop closure that does filtering. | |
960 // It knows how to filter out objects that are outside of the _boundary. | |
961 class Filtering_DCTOC : public DirtyCardToOopClosure { | |
962 protected: | |
963 // Override. | |
964 void walk_mem_region(MemRegion mr, | |
965 HeapWord* bottom, HeapWord* top); | |
966 | |
967 // Walk the given memory region, from bottom to top, applying | |
968 // the given oop closure to (possibly) all objects found. The | |
969 // given oop closure may or may not be the same as the oop | |
970 // closure with which this closure was created, as it may | |
971 // be a filtering closure which makes use of the _boundary. | |
972 // We offer two signatures, so the FilteringClosure static type is | |
973 // apparent. | |
974 virtual void walk_mem_region_with_cl(MemRegion mr, | |
975 HeapWord* bottom, HeapWord* top, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
976 ExtendedOopClosure* cl) = 0; |
0 | 977 virtual void walk_mem_region_with_cl(MemRegion mr, |
978 HeapWord* bottom, HeapWord* top, | |
979 FilteringClosure* cl) = 0; | |
980 | |
981 public: | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
982 Filtering_DCTOC(Space* sp, ExtendedOopClosure* cl, |
0 | 983 CardTableModRefBS::PrecisionStyle precision, |
984 HeapWord* boundary) : | |
985 DirtyCardToOopClosure(sp, cl, precision, boundary) {} | |
986 }; | |
987 | |
988 // A dirty card to oop closure for contiguous spaces | |
989 // (ContiguousSpace and sub-classes). | |
990 // It is a FilteringClosure, as defined above, and it knows: | |
991 // | |
992 // 1. That the actual top of any area in a memory region | |
993 // contained by the space is bounded by the end of the contiguous | |
994 // region of the space. | |
995 // 2. That the space is really made up of objects and not just | |
996 // blocks. | |
997 | |
998 class ContiguousSpaceDCTOC : public Filtering_DCTOC { | |
999 protected: | |
1000 // Overrides. | |
1001 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj); | |
1002 | |
1003 virtual void walk_mem_region_with_cl(MemRegion mr, | |
1004 HeapWord* bottom, HeapWord* top, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1005 ExtendedOopClosure* cl); |
0 | 1006 virtual void walk_mem_region_with_cl(MemRegion mr, |
1007 HeapWord* bottom, HeapWord* top, | |
1008 FilteringClosure* cl); | |
1009 | |
1010 public: | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1011 ContiguousSpaceDCTOC(ContiguousSpace* sp, ExtendedOopClosure* cl, |
0 | 1012 CardTableModRefBS::PrecisionStyle precision, |
1013 HeapWord* boundary) : | |
1014 Filtering_DCTOC(sp, cl, precision, boundary) | |
1015 {} | |
1016 }; | |
1017 | |
1018 | |
1019 // Class EdenSpace describes eden-space in new generation. | |
1020 | |
1021 class DefNewGeneration; | |
1022 | |
1023 class EdenSpace : public ContiguousSpace { | |
1024 friend class VMStructs; | |
1025 private: | |
1026 DefNewGeneration* _gen; | |
1027 | |
1028 // _soft_end is used as a soft limit on allocation. As soft limits are | |
1029 // reached, the slow-path allocation code can invoke other actions and then | |
1030 // adjust _soft_end up to a new soft limit or to end(). | |
1031 HeapWord* _soft_end; | |
1032 | |
1033 public: | |
347
60fb9c4db4e6
6718086: CMS assert: _concurrent_iteration_safe_limit update missed
ysr
parents:
342
diff
changeset
|
1034 EdenSpace(DefNewGeneration* gen) : |
60fb9c4db4e6
6718086: CMS assert: _concurrent_iteration_safe_limit update missed
ysr
parents:
342
diff
changeset
|
1035 _gen(gen), _soft_end(NULL) {} |
0 | 1036 |
1037 // Get/set just the 'soft' limit. | |
1038 HeapWord* soft_end() { return _soft_end; } | |
1039 HeapWord** soft_end_addr() { return &_soft_end; } | |
1040 void set_soft_end(HeapWord* value) { _soft_end = value; } | |
1041 | |
1042 // Override. | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
1043 void clear(bool mangle_space); |
0 | 1044 |
1045 // Set both the 'hard' and 'soft' limits (_end and _soft_end). | |
1046 void set_end(HeapWord* value) { | |
1047 set_soft_end(value); | |
1048 ContiguousSpace::set_end(value); | |
1049 } | |
1050 | |
1051 // Allocation (return NULL if full) | |
1052 HeapWord* allocate(size_t word_size); | |
1053 HeapWord* par_allocate(size_t word_size); | |
1054 }; | |
1055 | |
1056 // Class ConcEdenSpace extends EdenSpace for the sake of safe | |
1057 // allocation while soft-end is being modified concurrently | |
1058 | |
1059 class ConcEdenSpace : public EdenSpace { | |
1060 public: | |
1061 ConcEdenSpace(DefNewGeneration* gen) : EdenSpace(gen) { } | |
1062 | |
1063 // Allocation (return NULL if full) | |
1064 HeapWord* par_allocate(size_t word_size); | |
1065 }; | |
1066 | |
1067 | |
1068 // A ContigSpace that Supports an efficient "block_start" operation via | |
1069 // a BlockOffsetArray (whose BlockOffsetSharedArray may be shared with | |
1070 // other spaces.) This is the abstract base class for old generation | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1071 // (tenured) spaces. |
0 | 1072 |
1073 class OffsetTableContigSpace: public ContiguousSpace { | |
1074 friend class VMStructs; | |
1075 protected: | |
1076 BlockOffsetArrayContigSpace _offsets; | |
1077 Mutex _par_alloc_lock; | |
1078 | |
1079 public: | |
1080 // Constructor | |
1081 OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray, | |
1082 MemRegion mr); | |
1083 | |
1084 void set_bottom(HeapWord* value); | |
1085 void set_end(HeapWord* value); | |
1086 | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
1087 void clear(bool mangle_space); |
0 | 1088 |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
1089 inline HeapWord* block_start_const(const void* p) const; |
0 | 1090 |
1091 // Add offset table update. | |
1092 virtual inline HeapWord* allocate(size_t word_size); | |
1093 inline HeapWord* par_allocate(size_t word_size); | |
1094 | |
1095 // MarkSweep support phase3 | |
1096 virtual HeapWord* initialize_threshold(); | |
1097 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); | |
1098 | |
1099 virtual void print_on(outputStream* st) const; | |
1100 | |
1101 // Debugging | |
6008 | 1102 void verify() const; |
0 | 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 }; | |
1972 | 1119 #endif // SHARE_VM_MEMORY_SPACE_HPP |