|
0
|
1 /*
|
|
|
2 * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
|
|
|
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
|
4 *
|
|
|
5 * This code is free software; you can redistribute it and/or modify it
|
|
|
6 * under the terms of the GNU General Public License version 2 only, as
|
|
|
7 * published by the Free Software Foundation.
|
|
|
8 *
|
|
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT
|
|
|
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
|
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
|
12 * version 2 for more details (a copy is included in the LICENSE file that
|
|
|
13 * accompanied this code).
|
|
|
14 *
|
|
|
15 * You should have received a copy of the GNU General Public License version
|
|
|
16 * 2 along with this work; if not, write to the Free Software Foundation,
|
|
|
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
|
18 *
|
|
|
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
|
20 * CA 95054 USA or visit www.sun.com if you need additional information or
|
|
|
21 * have any questions.
|
|
|
22 *
|
|
|
23 */
|
|
|
24
|
|
|
25 // A space is an abstraction for the "storage units" backing
|
|
|
26 // up the generation abstraction. It includes specific
|
|
|
27 // implementations for keeping track of free and used space,
|
|
|
28 // for iterating over objects and free blocks, etc.
|
|
|
29
|
|
|
30 // Here's the Space hierarchy:
|
|
|
31 //
|
|
|
32 // - Space -- an asbtract base class describing a heap area
|
|
|
33 // - CompactibleSpace -- a space supporting compaction
|
|
|
34 // - CompactibleFreeListSpace -- (used for CMS generation)
|
|
|
35 // - ContiguousSpace -- a compactible space in which all free space
|
|
|
36 // is contiguous
|
|
|
37 // - EdenSpace -- contiguous space used as nursery
|
|
|
38 // - ConcEdenSpace -- contiguous space with a 'soft end safe' allocation
|
|
|
39 // - OffsetTableContigSpace -- contiguous space with a block offset array
|
|
|
40 // that allows "fast" block_start calls
|
|
|
41 // - TenuredSpace -- (used for TenuredGeneration)
|
|
|
42 // - ContigPermSpace -- an offset table contiguous space for perm gen
|
|
|
43
|
|
|
44 // Forward decls.
|
|
|
45 class Space;
|
|
|
46 class BlockOffsetArray;
|
|
|
47 class BlockOffsetArrayContigSpace;
|
|
|
48 class Generation;
|
|
|
49 class CompactibleSpace;
|
|
|
50 class BlockOffsetTable;
|
|
|
51 class GenRemSet;
|
|
|
52 class CardTableRS;
|
|
|
53 class DirtyCardToOopClosure;
|
|
|
54
|
|
|
55
|
|
|
56 // An oop closure that is circumscribed by a filtering memory region.
|
|
|
57 class SpaceMemRegionOopsIterClosure: public virtual OopClosure {
|
|
|
58 OopClosure* cl;
|
|
|
59 MemRegion mr;
|
|
|
60 public:
|
|
|
61 void do_oop(oop* p) {
|
|
|
62 if (mr.contains(p)) {
|
|
|
63 cl->do_oop(p);
|
|
|
64 }
|
|
|
65 }
|
|
|
66 SpaceMemRegionOopsIterClosure(OopClosure* _cl, MemRegion _mr): cl(_cl), mr(_mr) {}
|
|
|
67 };
|
|
|
68
|
|
|
69
|
|
|
70 // A Space describes a heap area. Class Space is an abstract
|
|
|
71 // base class.
|
|
|
72 //
|
|
|
73 // Space supports allocation, size computation and GC support is provided.
|
|
|
74 //
|
|
|
75 // Invariant: bottom() and end() are on page_size boundaries and
|
|
|
76 // bottom() <= top() <= end()
|
|
|
77 // top() is inclusive and end() is exclusive.
|
|
|
78
|
|
|
79 class Space: public CHeapObj {
|
|
|
80 friend class VMStructs;
|
|
|
81 protected:
|
|
|
82 HeapWord* _bottom;
|
|
|
83 HeapWord* _end;
|
|
|
84
|
|
|
85 // Used in support of save_marks()
|
|
|
86 HeapWord* _saved_mark_word;
|
|
|
87
|
|
|
88 MemRegionClosure* _preconsumptionDirtyCardClosure;
|
|
|
89
|
|
|
90 // A sequential tasks done structure. This supports
|
|
|
91 // parallel GC, where we have threads dynamically
|
|
|
92 // claiming sub-tasks from a larger parallel task.
|
|
|
93 SequentialSubTasksDone _par_seq_tasks;
|
|
|
94
|
|
|
95 Space():
|
|
|
96 _bottom(NULL), _end(NULL), _preconsumptionDirtyCardClosure(NULL) { }
|
|
|
97
|
|
|
98 public:
|
|
|
99 // Accessors
|
|
|
100 HeapWord* bottom() const { return _bottom; }
|
|
|
101 HeapWord* end() const { return _end; }
|
|
|
102 virtual void set_bottom(HeapWord* value) { _bottom = value; }
|
|
|
103 virtual void set_end(HeapWord* value) { _end = value; }
|
|
|
104
|
|
|
105 HeapWord* saved_mark_word() const { return _saved_mark_word; }
|
|
|
106 void set_saved_mark_word(HeapWord* p) { _saved_mark_word = p; }
|
|
|
107
|
|
|
108 MemRegionClosure* preconsumptionDirtyCardClosure() const {
|
|
|
109 return _preconsumptionDirtyCardClosure;
|
|
|
110 }
|
|
|
111 void setPreconsumptionDirtyCardClosure(MemRegionClosure* cl) {
|
|
|
112 _preconsumptionDirtyCardClosure = cl;
|
|
|
113 }
|
|
|
114
|
|
|
115 // Returns a subregion of the space containing all the objects in
|
|
|
116 // the space.
|
|
|
117 virtual MemRegion used_region() const { return MemRegion(bottom(), end()); }
|
|
|
118
|
|
|
119 // Returns a region that is guaranteed to contain (at least) all objects
|
|
|
120 // allocated at the time of the last call to "save_marks". If the space
|
|
|
121 // initializes its DirtyCardToOopClosure's specifying the "contig" option
|
|
|
122 // (that is, if the space is contiguous), then this region must contain only
|
|
|
123 // such objects: the memregion will be from the bottom of the region to the
|
|
|
124 // saved mark. Otherwise, the "obj_allocated_since_save_marks" method of
|
|
|
125 // the space must distiguish between objects in the region allocated before
|
|
|
126 // and after the call to save marks.
|
|
|
127 virtual MemRegion used_region_at_save_marks() const {
|
|
|
128 return MemRegion(bottom(), saved_mark_word());
|
|
|
129 }
|
|
|
130
|
|
|
131 // Initialization
|
|
|
132 virtual void initialize(MemRegion mr, bool clear_space);
|
|
|
133 virtual void clear();
|
|
|
134
|
|
|
135 // For detecting GC bugs. Should only be called at GC boundaries, since
|
|
|
136 // some unused space may be used as scratch space during GC's.
|
|
|
137 // Default implementation does nothing. We also call this when expanding
|
|
|
138 // a space to satisfy an allocation request. See bug #4668531
|
|
|
139 virtual void mangle_unused_area() {}
|
|
|
140 virtual void mangle_region(MemRegion mr) {}
|
|
|
141
|
|
|
142 // Testers
|
|
|
143 bool is_empty() const { return used() == 0; }
|
|
|
144 bool not_empty() const { return used() > 0; }
|
|
|
145
|
|
|
146 // Returns true iff the given the space contains the
|
|
|
147 // given address as part of an allocated object. For
|
|
|
148 // ceratin kinds of spaces, this might be a potentially
|
|
|
149 // expensive operation. To prevent performance problems
|
|
|
150 // on account of its inadvertent use in product jvm's,
|
|
|
151 // we restrict its use to assertion checks only.
|
|
|
152 virtual bool is_in(const void* p) const;
|
|
|
153
|
|
|
154 // Returns true iff the given reserved memory of the space contains the
|
|
|
155 // given address.
|
|
|
156 bool is_in_reserved(const void* p) const { return _bottom <= p && p < _end; }
|
|
|
157
|
|
|
158 // Returns true iff the given block is not allocated.
|
|
|
159 virtual bool is_free_block(const HeapWord* p) const = 0;
|
|
|
160
|
|
|
161 // Test whether p is double-aligned
|
|
|
162 static bool is_aligned(void* p) {
|
|
|
163 return ((intptr_t)p & (sizeof(double)-1)) == 0;
|
|
|
164 }
|
|
|
165
|
|
|
166 // Size computations. Sizes are in bytes.
|
|
|
167 size_t capacity() const { return byte_size(bottom(), end()); }
|
|
|
168 virtual size_t used() const = 0;
|
|
|
169 virtual size_t free() const = 0;
|
|
|
170
|
|
|
171 // Iterate over all the ref-containing fields of all objects in the
|
|
|
172 // space, calling "cl.do_oop" on each. Fields in objects allocated by
|
|
|
173 // applications of the closure are not included in the iteration.
|
|
|
174 virtual void oop_iterate(OopClosure* cl);
|
|
|
175
|
|
|
176 // Same as above, restricted to the intersection of a memory region and
|
|
|
177 // the space. Fields in objects allocated by applications of the closure
|
|
|
178 // are not included in the iteration.
|
|
|
179 virtual void oop_iterate(MemRegion mr, OopClosure* cl) = 0;
|
|
|
180
|
|
|
181 // Iterate over all objects in the space, calling "cl.do_object" on
|
|
|
182 // each. Objects allocated by applications of the closure are not
|
|
|
183 // included in the iteration.
|
|
|
184 virtual void object_iterate(ObjectClosure* blk) = 0;
|
|
|
185
|
|
|
186 // Iterate over all objects that intersect with mr, calling "cl->do_object"
|
|
|
187 // on each. There is an exception to this: if this closure has already
|
|
|
188 // been invoked on an object, it may skip such objects in some cases. This is
|
|
|
189 // Most likely to happen in an "upwards" (ascending address) iteration of
|
|
|
190 // MemRegions.
|
|
|
191 virtual void object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl);
|
|
|
192
|
|
|
193 // Iterate over as many initialized objects in the space as possible,
|
|
|
194 // calling "cl.do_object_careful" on each. Return NULL if all objects
|
|
|
195 // in the space (at the start of the iteration) were iterated over.
|
|
|
196 // Return an address indicating the extent of the iteration in the
|
|
|
197 // event that the iteration had to return because of finding an
|
|
|
198 // uninitialized object in the space, or if the closure "cl"
|
|
|
199 // signalled early termination.
|
|
|
200 virtual HeapWord* object_iterate_careful(ObjectClosureCareful* cl);
|
|
|
201 virtual HeapWord* object_iterate_careful_m(MemRegion mr,
|
|
|
202 ObjectClosureCareful* cl);
|
|
|
203
|
|
|
204 // Create and return a new dirty card to oop closure. Can be
|
|
|
205 // overriden to return the appropriate type of closure
|
|
|
206 // depending on the type of space in which the closure will
|
|
|
207 // operate. ResourceArea allocated.
|
|
|
208 virtual DirtyCardToOopClosure* new_dcto_cl(OopClosure* cl,
|
|
|
209 CardTableModRefBS::PrecisionStyle precision,
|
|
|
210 HeapWord* boundary = NULL);
|
|
|
211
|
|
|
212 // If "p" is in the space, returns the address of the start of the
|
|
|
213 // "block" that contains "p". We say "block" instead of "object" since
|
|
|
214 // some heaps may not pack objects densely; a chunk may either be an
|
|
|
215 // object or a non-object. If "p" is not in the space, return NULL.
|
|
|
216 virtual HeapWord* block_start(const void* p) const = 0;
|
|
|
217
|
|
|
218 // Requires "addr" to be the start of a chunk, and returns its size.
|
|
|
219 // "addr + size" is required to be the start of a new chunk, or the end
|
|
|
220 // of the active area of the heap.
|
|
|
221 virtual size_t block_size(const HeapWord* addr) const = 0;
|
|
|
222
|
|
|
223 // Requires "addr" to be the start of a block, and returns "TRUE" iff
|
|
|
224 // the block is an object.
|
|
|
225 virtual bool block_is_obj(const HeapWord* addr) const = 0;
|
|
|
226
|
|
|
227 // Requires "addr" to be the start of a block, and returns "TRUE" iff
|
|
|
228 // the block is an object and the object is alive.
|
|
|
229 virtual bool obj_is_alive(const HeapWord* addr) const;
|
|
|
230
|
|
|
231 // Allocation (return NULL if full). Assumes the caller has established
|
|
|
232 // mutually exclusive access to the space.
|
|
|
233 virtual HeapWord* allocate(size_t word_size) = 0;
|
|
|
234
|
|
|
235 // Allocation (return NULL if full). Enforces mutual exclusion internally.
|
|
|
236 virtual HeapWord* par_allocate(size_t word_size) = 0;
|
|
|
237
|
|
|
238 // Returns true if this object has been allocated since a
|
|
|
239 // generation's "save_marks" call.
|
|
|
240 virtual bool obj_allocated_since_save_marks(const oop obj) const = 0;
|
|
|
241
|
|
|
242 // Mark-sweep-compact support: all spaces can update pointers to objects
|
|
|
243 // moving as a part of compaction.
|
|
|
244 virtual void adjust_pointers();
|
|
|
245
|
|
|
246 // PrintHeapAtGC support
|
|
|
247 virtual void print() const;
|
|
|
248 virtual void print_on(outputStream* st) const;
|
|
|
249 virtual void print_short() const;
|
|
|
250 virtual void print_short_on(outputStream* st) const;
|
|
|
251
|
|
|
252
|
|
|
253 // Accessor for parallel sequential tasks.
|
|
|
254 SequentialSubTasksDone* par_seq_tasks() { return &_par_seq_tasks; }
|
|
|
255
|
|
|
256 // IF "this" is a ContiguousSpace, return it, else return NULL.
|
|
|
257 virtual ContiguousSpace* toContiguousSpace() {
|
|
|
258 return NULL;
|
|
|
259 }
|
|
|
260
|
|
|
261 // Debugging
|
|
|
262 virtual void verify(bool allow_dirty) const = 0;
|
|
|
263 };
|
|
|
264
|
|
|
265 // A MemRegionClosure (ResourceObj) whose "do_MemRegion" function applies an
|
|
|
266 // OopClosure to (the addresses of) all the ref-containing fields that could
|
|
|
267 // be modified by virtue of the given MemRegion being dirty. (Note that
|
|
|
268 // because of the imprecise nature of the write barrier, this may iterate
|
|
|
269 // over oops beyond the region.)
|
|
|
270 // This base type for dirty card to oop closures handles memory regions
|
|
|
271 // in non-contiguous spaces with no boundaries, and should be sub-classed
|
|
|
272 // to support other space types. See ContiguousDCTOC for a sub-class
|
|
|
273 // that works with ContiguousSpaces.
|
|
|
274
|
|
|
275 class DirtyCardToOopClosure: public MemRegionClosureRO {
|
|
|
276 protected:
|
|
|
277 OopClosure* _cl;
|
|
|
278 Space* _sp;
|
|
|
279 CardTableModRefBS::PrecisionStyle _precision;
|
|
|
280 HeapWord* _boundary; // If non-NULL, process only non-NULL oops
|
|
|
281 // pointing below boundary.
|
|
|
282 HeapWord* _min_done; // ObjHeadPreciseArray precision requires
|
|
|
283 // a downwards traversal; this is the
|
|
|
284 // lowest location already done (or,
|
|
|
285 // alternatively, the lowest address that
|
|
|
286 // shouldn't be done again. NULL means infinity.)
|
|
|
287 NOT_PRODUCT(HeapWord* _last_bottom;)
|
|
|
288
|
|
|
289 // Get the actual top of the area on which the closure will
|
|
|
290 // operate, given where the top is assumed to be (the end of the
|
|
|
291 // memory region passed to do_MemRegion) and where the object
|
|
|
292 // at the top is assumed to start. For example, an object may
|
|
|
293 // start at the top but actually extend past the assumed top,
|
|
|
294 // in which case the top becomes the end of the object.
|
|
|
295 virtual HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj);
|
|
|
296
|
|
|
297 // Walk the given memory region from bottom to (actual) top
|
|
|
298 // looking for objects and applying the oop closure (_cl) to
|
|
|
299 // them. The base implementation of this treats the area as
|
|
|
300 // blocks, where a block may or may not be an object. Sub-
|
|
|
301 // classes should override this to provide more accurate
|
|
|
302 // or possibly more efficient walking.
|
|
|
303 virtual void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top);
|
|
|
304
|
|
|
305 public:
|
|
|
306 DirtyCardToOopClosure(Space* sp, OopClosure* cl,
|
|
|
307 CardTableModRefBS::PrecisionStyle precision,
|
|
|
308 HeapWord* boundary) :
|
|
|
309 _sp(sp), _cl(cl), _precision(precision), _boundary(boundary),
|
|
|
310 _min_done(NULL) {
|
|
|
311 NOT_PRODUCT(_last_bottom = NULL;)
|
|
|
312 }
|
|
|
313
|
|
|
314 void do_MemRegion(MemRegion mr);
|
|
|
315
|
|
|
316 void set_min_done(HeapWord* min_done) {
|
|
|
317 _min_done = min_done;
|
|
|
318 }
|
|
|
319 #ifndef PRODUCT
|
|
|
320 void set_last_bottom(HeapWord* last_bottom) {
|
|
|
321 _last_bottom = last_bottom;
|
|
|
322 }
|
|
|
323 #endif
|
|
|
324 };
|
|
|
325
|
|
|
326 // A structure to represent a point at which objects are being copied
|
|
|
327 // during compaction.
|
|
|
328 class CompactPoint : public StackObj {
|
|
|
329 public:
|
|
|
330 Generation* gen;
|
|
|
331 CompactibleSpace* space;
|
|
|
332 HeapWord* threshold;
|
|
|
333 CompactPoint(Generation* _gen, CompactibleSpace* _space,
|
|
|
334 HeapWord* _threshold) :
|
|
|
335 gen(_gen), space(_space), threshold(_threshold) {}
|
|
|
336 };
|
|
|
337
|
|
|
338
|
|
|
339 // A space that supports compaction operations. This is usually, but not
|
|
|
340 // necessarily, a space that is normally contiguous. But, for example, a
|
|
|
341 // free-list-based space whose normal collection is a mark-sweep without
|
|
|
342 // compaction could still support compaction in full GC's.
|
|
|
343
|
|
|
344 class CompactibleSpace: public Space {
|
|
|
345 friend class VMStructs;
|
|
|
346 friend class CompactibleFreeListSpace;
|
|
|
347 friend class CompactingPermGenGen;
|
|
|
348 friend class CMSPermGenGen;
|
|
|
349 private:
|
|
|
350 HeapWord* _compaction_top;
|
|
|
351 CompactibleSpace* _next_compaction_space;
|
|
|
352
|
|
|
353 public:
|
|
|
354 virtual void initialize(MemRegion mr, bool clear_space);
|
|
|
355
|
|
|
356 // Used temporarily during a compaction phase to hold the value
|
|
|
357 // top should have when compaction is complete.
|
|
|
358 HeapWord* compaction_top() const { return _compaction_top; }
|
|
|
359
|
|
|
360 void set_compaction_top(HeapWord* value) {
|
|
|
361 assert(value == NULL || (value >= bottom() && value <= end()),
|
|
|
362 "should point inside space");
|
|
|
363 _compaction_top = value;
|
|
|
364 }
|
|
|
365
|
|
|
366 // Perform operations on the space needed after a compaction
|
|
|
367 // has been performed.
|
|
|
368 virtual void reset_after_compaction() {}
|
|
|
369
|
|
|
370 // Returns the next space (in the current generation) to be compacted in
|
|
|
371 // the global compaction order. Also is used to select the next
|
|
|
372 // space into which to compact.
|
|
|
373
|
|
|
374 virtual CompactibleSpace* next_compaction_space() const {
|
|
|
375 return _next_compaction_space;
|
|
|
376 }
|
|
|
377
|
|
|
378 void set_next_compaction_space(CompactibleSpace* csp) {
|
|
|
379 _next_compaction_space = csp;
|
|
|
380 }
|
|
|
381
|
|
|
382 // MarkSweep support phase2
|
|
|
383
|
|
|
384 // Start the process of compaction of the current space: compute
|
|
|
385 // post-compaction addresses, and insert forwarding pointers. The fields
|
|
|
386 // "cp->gen" and "cp->compaction_space" are the generation and space into
|
|
|
387 // which we are currently compacting. This call updates "cp" as necessary,
|
|
|
388 // and leaves the "compaction_top" of the final value of
|
|
|
389 // "cp->compaction_space" up-to-date. Offset tables may be updated in
|
|
|
390 // this phase as if the final copy had occurred; if so, "cp->threshold"
|
|
|
391 // indicates when the next such action should be taken.
|
|
|
392 virtual void prepare_for_compaction(CompactPoint* cp);
|
|
|
393 // MarkSweep support phase3
|
|
|
394 virtual void adjust_pointers();
|
|
|
395 // MarkSweep support phase4
|
|
|
396 virtual void compact();
|
|
|
397
|
|
|
398 // The maximum percentage of objects that can be dead in the compacted
|
|
|
399 // live part of a compacted space ("deadwood" support.)
|
|
|
400 virtual int allowed_dead_ratio() const { return 0; };
|
|
|
401
|
|
|
402 // Some contiguous spaces may maintain some data structures that should
|
|
|
403 // be updated whenever an allocation crosses a boundary. This function
|
|
|
404 // returns the first such boundary.
|
|
|
405 // (The default implementation returns the end of the space, so the
|
|
|
406 // boundary is never crossed.)
|
|
|
407 virtual HeapWord* initialize_threshold() { return end(); }
|
|
|
408
|
|
|
409 // "q" is an object of the given "size" that should be forwarded;
|
|
|
410 // "cp" names the generation ("gen") and containing "this" (which must
|
|
|
411 // also equal "cp->space"). "compact_top" is where in "this" the
|
|
|
412 // next object should be forwarded to. If there is room in "this" for
|
|
|
413 // the object, insert an appropriate forwarding pointer in "q".
|
|
|
414 // If not, go to the next compaction space (there must
|
|
|
415 // be one, since compaction must succeed -- we go to the first space of
|
|
|
416 // the previous generation if necessary, updating "cp"), reset compact_top
|
|
|
417 // and then forward. In either case, returns the new value of "compact_top".
|
|
|
418 // If the forwarding crosses "cp->threshold", invokes the "cross_threhold"
|
|
|
419 // function of the then-current compaction space, and updates "cp->threshold
|
|
|
420 // accordingly".
|
|
|
421 virtual HeapWord* forward(oop q, size_t size, CompactPoint* cp,
|
|
|
422 HeapWord* compact_top);
|
|
|
423
|
|
|
424 // Return a size with adjusments as required of the space.
|
|
|
425 virtual size_t adjust_object_size_v(size_t size) const { return size; }
|
|
|
426
|
|
|
427 protected:
|
|
|
428 // Used during compaction.
|
|
|
429 HeapWord* _first_dead;
|
|
|
430 HeapWord* _end_of_live;
|
|
|
431
|
|
|
432 // Minimum size of a free block.
|
|
|
433 virtual size_t minimum_free_block_size() const = 0;
|
|
|
434
|
|
|
435 // This the function is invoked when an allocation of an object covering
|
|
|
436 // "start" to "end occurs crosses the threshold; returns the next
|
|
|
437 // threshold. (The default implementation does nothing.)
|
|
|
438 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* the_end) {
|
|
|
439 return end();
|
|
|
440 }
|
|
|
441
|
|
|
442 // Requires "allowed_deadspace_words > 0", that "q" is the start of a
|
|
|
443 // free block of the given "word_len", and that "q", were it an object,
|
|
|
444 // would not move if forwared. If the size allows, fill the free
|
|
|
445 // block with an object, to prevent excessive compaction. Returns "true"
|
|
|
446 // iff the free region was made deadspace, and modifies
|
|
|
447 // "allowed_deadspace_words" to reflect the number of available deadspace
|
|
|
448 // words remaining after this operation.
|
|
|
449 bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q,
|
|
|
450 size_t word_len);
|
|
|
451 };
|
|
|
452
|
|
|
453 #define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size) { \
|
|
|
454 /* Compute the new addresses for the live objects and store it in the mark \
|
|
|
455 * Used by universe::mark_sweep_phase2() \
|
|
|
456 */ \
|
|
|
457 HeapWord* compact_top; /* This is where we are currently compacting to. */ \
|
|
|
458 \
|
|
|
459 /* We're sure to be here before any objects are compacted into this \
|
|
|
460 * space, so this is a good time to initialize this: \
|
|
|
461 */ \
|
|
|
462 set_compaction_top(bottom()); \
|
|
|
463 \
|
|
|
464 if (cp->space == NULL) { \
|
|
|
465 assert(cp->gen != NULL, "need a generation"); \
|
|
|
466 assert(cp->threshold == NULL, "just checking"); \
|
|
|
467 assert(cp->gen->first_compaction_space() == this, "just checking"); \
|
|
|
468 cp->space = cp->gen->first_compaction_space(); \
|
|
|
469 compact_top = cp->space->bottom(); \
|
|
|
470 cp->space->set_compaction_top(compact_top); \
|
|
|
471 cp->threshold = cp->space->initialize_threshold(); \
|
|
|
472 } else { \
|
|
|
473 compact_top = cp->space->compaction_top(); \
|
|
|
474 } \
|
|
|
475 \
|
|
|
476 /* We allow some amount of garbage towards the bottom of the space, so \
|
|
|
477 * we don't start compacting before there is a significant gain to be made.\
|
|
|
478 * Occasionally, we want to ensure a full compaction, which is determined \
|
|
|
479 * by the MarkSweepAlwaysCompactCount parameter. \
|
|
|
480 */ \
|
|
|
481 int invocations = SharedHeap::heap()->perm_gen()->stat_record()->invocations;\
|
|
|
482 bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0); \
|
|
|
483 \
|
|
|
484 size_t allowed_deadspace = 0; \
|
|
|
485 if (skip_dead) { \
|
|
|
486 int ratio = allowed_dead_ratio(); \
|
|
|
487 allowed_deadspace = (capacity() * ratio / 100) / HeapWordSize; \
|
|
|
488 } \
|
|
|
489 \
|
|
|
490 HeapWord* q = bottom(); \
|
|
|
491 HeapWord* t = scan_limit(); \
|
|
|
492 \
|
|
|
493 HeapWord* end_of_live= q; /* One byte beyond the last byte of the last \
|
|
|
494 live object. */ \
|
|
|
495 HeapWord* first_dead = end();/* The first dead object. */ \
|
|
|
496 LiveRange* liveRange = NULL; /* The current live range, recorded in the \
|
|
|
497 first header of preceding free area. */ \
|
|
|
498 _first_dead = first_dead; \
|
|
|
499 \
|
|
|
500 const intx interval = PrefetchScanIntervalInBytes; \
|
|
|
501 \
|
|
|
502 while (q < t) { \
|
|
|
503 assert(!block_is_obj(q) || \
|
|
|
504 oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || \
|
|
|
505 oop(q)->mark()->has_bias_pattern(), \
|
|
|
506 "these are the only valid states during a mark sweep"); \
|
|
|
507 if (block_is_obj(q) && oop(q)->is_gc_marked()) { \
|
|
|
508 /* prefetch beyond q */ \
|
|
|
509 Prefetch::write(q, interval); \
|
|
|
510 /* size_t size = oop(q)->size(); changing this for cms for perm gen */\
|
|
|
511 size_t size = block_size(q); \
|
|
|
512 compact_top = cp->space->forward(oop(q), size, cp, compact_top); \
|
|
|
513 q += size; \
|
|
|
514 end_of_live = q; \
|
|
|
515 } else { \
|
|
|
516 /* run over all the contiguous dead objects */ \
|
|
|
517 HeapWord* end = q; \
|
|
|
518 do { \
|
|
|
519 /* prefetch beyond end */ \
|
|
|
520 Prefetch::write(end, interval); \
|
|
|
521 end += block_size(end); \
|
|
|
522 } while (end < t && (!block_is_obj(end) || !oop(end)->is_gc_marked()));\
|
|
|
523 \
|
|
|
524 /* see if we might want to pretend this object is alive so that \
|
|
|
525 * we don't have to compact quite as often. \
|
|
|
526 */ \
|
|
|
527 if (allowed_deadspace > 0 && q == compact_top) { \
|
|
|
528 size_t sz = pointer_delta(end, q); \
|
|
|
529 if (insert_deadspace(allowed_deadspace, q, sz)) { \
|
|
|
530 compact_top = cp->space->forward(oop(q), sz, cp, compact_top); \
|
|
|
531 q = end; \
|
|
|
532 end_of_live = end; \
|
|
|
533 continue; \
|
|
|
534 } \
|
|
|
535 } \
|
|
|
536 \
|
|
|
537 /* otherwise, it really is a free region. */ \
|
|
|
538 \
|
|
|
539 /* for the previous LiveRange, record the end of the live objects. */ \
|
|
|
540 if (liveRange) { \
|
|
|
541 liveRange->set_end(q); \
|
|
|
542 } \
|
|
|
543 \
|
|
|
544 /* record the current LiveRange object. \
|
|
|
545 * liveRange->start() is overlaid on the mark word. \
|
|
|
546 */ \
|
|
|
547 liveRange = (LiveRange*)q; \
|
|
|
548 liveRange->set_start(end); \
|
|
|
549 liveRange->set_end(end); \
|
|
|
550 \
|
|
|
551 /* see if this is the first dead region. */ \
|
|
|
552 if (q < first_dead) { \
|
|
|
553 first_dead = q; \
|
|
|
554 } \
|
|
|
555 \
|
|
|
556 /* move on to the next object */ \
|
|
|
557 q = end; \
|
|
|
558 } \
|
|
|
559 } \
|
|
|
560 \
|
|
|
561 assert(q == t, "just checking"); \
|
|
|
562 if (liveRange != NULL) { \
|
|
|
563 liveRange->set_end(q); \
|
|
|
564 } \
|
|
|
565 _end_of_live = end_of_live; \
|
|
|
566 if (end_of_live < first_dead) { \
|
|
|
567 first_dead = end_of_live; \
|
|
|
568 } \
|
|
|
569 _first_dead = first_dead; \
|
|
|
570 \
|
|
|
571 /* save the compaction_top of the compaction space. */ \
|
|
|
572 cp->space->set_compaction_top(compact_top); \
|
|
|
573 }
|
|
|
574
|
|
|
575 #define SCAN_AND_ADJUST_POINTERS(adjust_obj_size) { \
|
|
|
576 /* adjust all the interior pointers to point at the new locations of objects \
|
|
|
577 * Used by MarkSweep::mark_sweep_phase3() */ \
|
|
|
578 \
|
|
|
579 HeapWord* q = bottom(); \
|
|
|
580 HeapWord* t = _end_of_live; /* Established by "prepare_for_compaction". */ \
|
|
|
581 \
|
|
|
582 assert(_first_dead <= _end_of_live, "Stands to reason, no?"); \
|
|
|
583 \
|
|
|
584 if (q < t && _first_dead > q && \
|
|
|
585 !oop(q)->is_gc_marked()) { \
|
|
|
586 /* we have a chunk of the space which hasn't moved and we've \
|
|
|
587 * reinitialized the mark word during the previous pass, so we can't \
|
|
|
588 * use is_gc_marked for the traversal. */ \
|
|
|
589 HeapWord* end = _first_dead; \
|
|
|
590 \
|
|
|
591 while (q < end) { \
|
|
|
592 /* I originally tried to conjoin "block_start(q) == q" to the \
|
|
|
593 * assertion below, but that doesn't work, because you can't \
|
|
|
594 * accurately traverse previous objects to get to the current one \
|
|
|
595 * after their pointers (including pointers into permGen) have been \
|
|
|
596 * updated, until the actual compaction is done. dld, 4/00 */ \
|
|
|
597 assert(block_is_obj(q), \
|
|
|
598 "should be at block boundaries, and should be looking at objs"); \
|
|
|
599 \
|
|
|
600 debug_only(MarkSweep::track_interior_pointers(oop(q))); \
|
|
|
601 \
|
|
|
602 /* point all the oops to the new location */ \
|
|
|
603 size_t size = oop(q)->adjust_pointers(); \
|
|
|
604 size = adjust_obj_size(size); \
|
|
|
605 \
|
|
|
606 debug_only(MarkSweep::check_interior_pointers()); \
|
|
|
607 \
|
|
|
608 debug_only(MarkSweep::validate_live_oop(oop(q), size)); \
|
|
|
609 \
|
|
|
610 q += size; \
|
|
|
611 } \
|
|
|
612 \
|
|
|
613 if (_first_dead == t) { \
|
|
|
614 q = t; \
|
|
|
615 } else { \
|
|
|
616 /* $$$ This is funky. Using this to read the previously written \
|
|
|
617 * LiveRange. See also use below. */ \
|
|
|
618 q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); \
|
|
|
619 } \
|
|
|
620 } \
|
|
|
621 \
|
|
|
622 const intx interval = PrefetchScanIntervalInBytes; \
|
|
|
623 \
|
|
|
624 debug_only(HeapWord* prev_q = NULL); \
|
|
|
625 while (q < t) { \
|
|
|
626 /* prefetch beyond q */ \
|
|
|
627 Prefetch::write(q, interval); \
|
|
|
628 if (oop(q)->is_gc_marked()) { \
|
|
|
629 /* q is alive */ \
|
|
|
630 debug_only(MarkSweep::track_interior_pointers(oop(q))); \
|
|
|
631 /* point all the oops to the new location */ \
|
|
|
632 size_t size = oop(q)->adjust_pointers(); \
|
|
|
633 size = adjust_obj_size(size); \
|
|
|
634 debug_only(MarkSweep::check_interior_pointers()); \
|
|
|
635 debug_only(MarkSweep::validate_live_oop(oop(q), size)); \
|
|
|
636 debug_only(prev_q = q); \
|
|
|
637 q += size; \
|
|
|
638 } else { \
|
|
|
639 /* q is not a live object, so its mark should point at the next \
|
|
|
640 * live object */ \
|
|
|
641 debug_only(prev_q = q); \
|
|
|
642 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \
|
|
|
643 assert(q > prev_q, "we should be moving forward through memory"); \
|
|
|
644 } \
|
|
|
645 } \
|
|
|
646 \
|
|
|
647 assert(q == t, "just checking"); \
|
|
|
648 }
|
|
|
649
|
|
|
650 #define SCAN_AND_COMPACT(obj_size) { \
|
|
|
651 /* Copy all live objects to their new location \
|
|
|
652 * Used by MarkSweep::mark_sweep_phase4() */ \
|
|
|
653 \
|
|
|
654 HeapWord* q = bottom(); \
|
|
|
655 HeapWord* const t = _end_of_live; \
|
|
|
656 debug_only(HeapWord* prev_q = NULL); \
|
|
|
657 \
|
|
|
658 if (q < t && _first_dead > q && \
|
|
|
659 !oop(q)->is_gc_marked()) { \
|
|
|
660 debug_only( \
|
|
|
661 /* we have a chunk of the space which hasn't moved and we've reinitialized the \
|
|
|
662 * mark word during the previous pass, so we can't use is_gc_marked for the \
|
|
|
663 * traversal. */ \
|
|
|
664 HeapWord* const end = _first_dead; \
|
|
|
665 \
|
|
|
666 while (q < end) { \
|
|
|
667 size_t size = obj_size(q); \
|
|
|
668 assert(!oop(q)->is_gc_marked(), "should be unmarked (special dense prefix handling)"); \
|
|
|
669 debug_only(MarkSweep::live_oop_moved_to(q, size, q)); \
|
|
|
670 debug_only(prev_q = q); \
|
|
|
671 q += size; \
|
|
|
672 } \
|
|
|
673 ) /* debug_only */ \
|
|
|
674 \
|
|
|
675 if (_first_dead == t) { \
|
|
|
676 q = t; \
|
|
|
677 } else { \
|
|
|
678 /* $$$ Funky */ \
|
|
|
679 q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); \
|
|
|
680 } \
|
|
|
681 } \
|
|
|
682 \
|
|
|
683 const intx scan_interval = PrefetchScanIntervalInBytes; \
|
|
|
684 const intx copy_interval = PrefetchCopyIntervalInBytes; \
|
|
|
685 while (q < t) { \
|
|
|
686 if (!oop(q)->is_gc_marked()) { \
|
|
|
687 /* mark is pointer to next marked oop */ \
|
|
|
688 debug_only(prev_q = q); \
|
|
|
689 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \
|
|
|
690 assert(q > prev_q, "we should be moving forward through memory"); \
|
|
|
691 } else { \
|
|
|
692 /* prefetch beyond q */ \
|
|
|
693 Prefetch::read(q, scan_interval); \
|
|
|
694 \
|
|
|
695 /* size and destination */ \
|
|
|
696 size_t size = obj_size(q); \
|
|
|
697 HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); \
|
|
|
698 \
|
|
|
699 /* prefetch beyond compaction_top */ \
|
|
|
700 Prefetch::write(compaction_top, copy_interval); \
|
|
|
701 \
|
|
|
702 /* copy object and reinit its mark */ \
|
|
|
703 debug_only(MarkSweep::live_oop_moved_to(q, size, compaction_top)); \
|
|
|
704 assert(q != compaction_top, "everything in this pass should be moving"); \
|
|
|
705 Copy::aligned_conjoint_words(q, compaction_top, size); \
|
|
|
706 oop(compaction_top)->init_mark(); \
|
|
|
707 assert(oop(compaction_top)->klass() != NULL, "should have a class"); \
|
|
|
708 \
|
|
|
709 debug_only(prev_q = q); \
|
|
|
710 q += size; \
|
|
|
711 } \
|
|
|
712 } \
|
|
|
713 \
|
|
|
714 /* Reset space after compaction is complete */ \
|
|
|
715 reset_after_compaction(); \
|
|
|
716 /* We do this clear, below, since it has overloaded meanings for some */ \
|
|
|
717 /* space subtypes. For example, OffsetTableContigSpace's that were */ \
|
|
|
718 /* compacted into will have had their offset table thresholds updated */ \
|
|
|
719 /* continuously, but those that weren't need to have their thresholds */ \
|
|
|
720 /* re-initialized. Also mangles unused area for debugging. */ \
|
|
|
721 if (is_empty()) { \
|
|
|
722 clear(); \
|
|
|
723 } else { \
|
|
|
724 if (ZapUnusedHeapArea) mangle_unused_area(); \
|
|
|
725 } \
|
|
|
726 }
|
|
|
727
|
|
|
728 // A space in which the free area is contiguous. It therefore supports
|
|
|
729 // faster allocation, and compaction.
|
|
|
730 class ContiguousSpace: public CompactibleSpace {
|
|
|
731 friend class OneContigSpaceCardGeneration;
|
|
|
732 friend class VMStructs;
|
|
|
733 protected:
|
|
|
734 HeapWord* _top;
|
|
|
735 HeapWord* _concurrent_iteration_safe_limit;
|
|
|
736
|
|
|
737 // Allocation helpers (return NULL if full).
|
|
|
738 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value);
|
|
|
739 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value);
|
|
|
740
|
|
|
741 public:
|
|
|
742 virtual void initialize(MemRegion mr, bool clear_space);
|
|
|
743
|
|
|
744 // Accessors
|
|
|
745 HeapWord* top() const { return _top; }
|
|
|
746 void set_top(HeapWord* value) { _top = value; }
|
|
|
747
|
|
|
748 void set_saved_mark() { _saved_mark_word = top(); }
|
|
|
749 void reset_saved_mark() { _saved_mark_word = bottom(); }
|
|
|
750
|
|
|
751 virtual void clear();
|
|
|
752
|
|
|
753 WaterMark bottom_mark() { return WaterMark(this, bottom()); }
|
|
|
754 WaterMark top_mark() { return WaterMark(this, top()); }
|
|
|
755 WaterMark saved_mark() { return WaterMark(this, saved_mark_word()); }
|
|
|
756 bool saved_mark_at_top() const { return saved_mark_word() == top(); }
|
|
|
757
|
|
|
758 void mangle_unused_area();
|
|
|
759 void mangle_region(MemRegion mr);
|
|
|
760
|
|
|
761 // Size computations: sizes in bytes.
|
|
|
762 size_t capacity() const { return byte_size(bottom(), end()); }
|
|
|
763 size_t used() const { return byte_size(bottom(), top()); }
|
|
|
764 size_t free() const { return byte_size(top(), end()); }
|
|
|
765
|
|
|
766 // Override from space.
|
|
|
767 bool is_in(const void* p) const;
|
|
|
768
|
|
|
769 virtual bool is_free_block(const HeapWord* p) const;
|
|
|
770
|
|
|
771 // In a contiguous space we have a more obvious bound on what parts
|
|
|
772 // contain objects.
|
|
|
773 MemRegion used_region() const { return MemRegion(bottom(), top()); }
|
|
|
774
|
|
|
775 MemRegion used_region_at_save_marks() const {
|
|
|
776 return MemRegion(bottom(), saved_mark_word());
|
|
|
777 }
|
|
|
778
|
|
|
779 // Allocation (return NULL if full)
|
|
|
780 virtual HeapWord* allocate(size_t word_size);
|
|
|
781 virtual HeapWord* par_allocate(size_t word_size);
|
|
|
782
|
|
|
783 virtual bool obj_allocated_since_save_marks(const oop obj) const {
|
|
|
784 return (HeapWord*)obj >= saved_mark_word();
|
|
|
785 }
|
|
|
786
|
|
|
787 // Iteration
|
|
|
788 void oop_iterate(OopClosure* cl);
|
|
|
789 void oop_iterate(MemRegion mr, OopClosure* cl);
|
|
|
790 void object_iterate(ObjectClosure* blk);
|
|
|
791 void object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl);
|
|
|
792 // iterates on objects up to the safe limit
|
|
|
793 HeapWord* object_iterate_careful(ObjectClosureCareful* cl);
|
|
|
794 inline HeapWord* concurrent_iteration_safe_limit();
|
|
|
795 // changes the safe limit, all objects from bottom() to the new
|
|
|
796 // limit should be properly initialized
|
|
|
797 inline void set_concurrent_iteration_safe_limit(HeapWord* new_limit);
|
|
|
798
|
|
|
799 #ifndef SERIALGC
|
|
|
800 // In support of parallel oop_iterate.
|
|
|
801 #define ContigSpace_PAR_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
|
|
|
802 void par_oop_iterate(MemRegion mr, OopClosureType* blk);
|
|
|
803
|
|
|
804 ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DECL)
|
|
|
805 #undef ContigSpace_PAR_OOP_ITERATE_DECL
|
|
|
806 #endif // SERIALGC
|
|
|
807
|
|
|
808 // Compaction support
|
|
|
809 virtual void reset_after_compaction() {
|
|
|
810 assert(compaction_top() >= bottom() && compaction_top() <= end(), "should point inside space");
|
|
|
811 set_top(compaction_top());
|
|
|
812 // set new iteration safe limit
|
|
|
813 set_concurrent_iteration_safe_limit(compaction_top());
|
|
|
814 }
|
|
|
815 virtual size_t minimum_free_block_size() const { return 0; }
|
|
|
816
|
|
|
817 // Override.
|
|
|
818 DirtyCardToOopClosure* new_dcto_cl(OopClosure* cl,
|
|
|
819 CardTableModRefBS::PrecisionStyle precision,
|
|
|
820 HeapWord* boundary = NULL);
|
|
|
821
|
|
|
822 // Apply "blk->do_oop" to the addresses of all reference fields in objects
|
|
|
823 // starting with the _saved_mark_word, which was noted during a generation's
|
|
|
824 // save_marks and is required to denote the head of an object.
|
|
|
825 // Fields in objects allocated by applications of the closure
|
|
|
826 // *are* included in the iteration.
|
|
|
827 // Updates _saved_mark_word to point to just after the last object
|
|
|
828 // iterated over.
|
|
|
829 #define ContigSpace_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
|
|
|
830 void oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk);
|
|
|
831
|
|
|
832 ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DECL)
|
|
|
833 #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DECL
|
|
|
834
|
|
|
835 // Same as object_iterate, but starting from "mark", which is required
|
|
|
836 // to denote the start of an object. Objects allocated by
|
|
|
837 // applications of the closure *are* included in the iteration.
|
|
|
838 virtual void object_iterate_from(WaterMark mark, ObjectClosure* blk);
|
|
|
839
|
|
|
840 // Very inefficient implementation.
|
|
|
841 virtual HeapWord* block_start(const void* p) const;
|
|
|
842 size_t block_size(const HeapWord* p) const;
|
|
|
843 // If a block is in the allocated area, it is an object.
|
|
|
844 bool block_is_obj(const HeapWord* p) const { return p < top(); }
|
|
|
845
|
|
|
846 // Addresses for inlined allocation
|
|
|
847 HeapWord** top_addr() { return &_top; }
|
|
|
848 HeapWord** end_addr() { return &_end; }
|
|
|
849
|
|
|
850 // Overrides for more efficient compaction support.
|
|
|
851 void prepare_for_compaction(CompactPoint* cp);
|
|
|
852
|
|
|
853 // PrintHeapAtGC support.
|
|
|
854 virtual void print_on(outputStream* st) const;
|
|
|
855
|
|
|
856 // Checked dynamic downcasts.
|
|
|
857 virtual ContiguousSpace* toContiguousSpace() {
|
|
|
858 return this;
|
|
|
859 }
|
|
|
860
|
|
|
861 // Debugging
|
|
|
862 virtual void verify(bool allow_dirty) const;
|
|
|
863
|
|
|
864 // Used to increase collection frequency. "factor" of 0 means entire
|
|
|
865 // space.
|
|
|
866 void allocate_temporary_filler(int factor);
|
|
|
867
|
|
|
868 };
|
|
|
869
|
|
|
870
|
|
|
871 // A dirty card to oop closure that does filtering.
|
|
|
872 // It knows how to filter out objects that are outside of the _boundary.
|
|
|
873 class Filtering_DCTOC : public DirtyCardToOopClosure {
|
|
|
874 protected:
|
|
|
875 // Override.
|
|
|
876 void walk_mem_region(MemRegion mr,
|
|
|
877 HeapWord* bottom, HeapWord* top);
|
|
|
878
|
|
|
879 // Walk the given memory region, from bottom to top, applying
|
|
|
880 // the given oop closure to (possibly) all objects found. The
|
|
|
881 // given oop closure may or may not be the same as the oop
|
|
|
882 // closure with which this closure was created, as it may
|
|
|
883 // be a filtering closure which makes use of the _boundary.
|
|
|
884 // We offer two signatures, so the FilteringClosure static type is
|
|
|
885 // apparent.
|
|
|
886 virtual void walk_mem_region_with_cl(MemRegion mr,
|
|
|
887 HeapWord* bottom, HeapWord* top,
|
|
|
888 OopClosure* cl) = 0;
|
|
|
889 virtual void walk_mem_region_with_cl(MemRegion mr,
|
|
|
890 HeapWord* bottom, HeapWord* top,
|
|
|
891 FilteringClosure* cl) = 0;
|
|
|
892
|
|
|
893 public:
|
|
|
894 Filtering_DCTOC(Space* sp, OopClosure* cl,
|
|
|
895 CardTableModRefBS::PrecisionStyle precision,
|
|
|
896 HeapWord* boundary) :
|
|
|
897 DirtyCardToOopClosure(sp, cl, precision, boundary) {}
|
|
|
898 };
|
|
|
899
|
|
|
900 // A dirty card to oop closure for contiguous spaces
|
|
|
901 // (ContiguousSpace and sub-classes).
|
|
|
902 // It is a FilteringClosure, as defined above, and it knows:
|
|
|
903 //
|
|
|
904 // 1. That the actual top of any area in a memory region
|
|
|
905 // contained by the space is bounded by the end of the contiguous
|
|
|
906 // region of the space.
|
|
|
907 // 2. That the space is really made up of objects and not just
|
|
|
908 // blocks.
|
|
|
909
|
|
|
910 class ContiguousSpaceDCTOC : public Filtering_DCTOC {
|
|
|
911 protected:
|
|
|
912 // Overrides.
|
|
|
913 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj);
|
|
|
914
|
|
|
915 virtual void walk_mem_region_with_cl(MemRegion mr,
|
|
|
916 HeapWord* bottom, HeapWord* top,
|
|
|
917 OopClosure* cl);
|
|
|
918 virtual void walk_mem_region_with_cl(MemRegion mr,
|
|
|
919 HeapWord* bottom, HeapWord* top,
|
|
|
920 FilteringClosure* cl);
|
|
|
921
|
|
|
922 public:
|
|
|
923 ContiguousSpaceDCTOC(ContiguousSpace* sp, OopClosure* cl,
|
|
|
924 CardTableModRefBS::PrecisionStyle precision,
|
|
|
925 HeapWord* boundary) :
|
|
|
926 Filtering_DCTOC(sp, cl, precision, boundary)
|
|
|
927 {}
|
|
|
928 };
|
|
|
929
|
|
|
930
|
|
|
931 // Class EdenSpace describes eden-space in new generation.
|
|
|
932
|
|
|
933 class DefNewGeneration;
|
|
|
934
|
|
|
935 class EdenSpace : public ContiguousSpace {
|
|
|
936 friend class VMStructs;
|
|
|
937 private:
|
|
|
938 DefNewGeneration* _gen;
|
|
|
939
|
|
|
940 // _soft_end is used as a soft limit on allocation. As soft limits are
|
|
|
941 // reached, the slow-path allocation code can invoke other actions and then
|
|
|
942 // adjust _soft_end up to a new soft limit or to end().
|
|
|
943 HeapWord* _soft_end;
|
|
|
944
|
|
|
945 public:
|
|
|
946 EdenSpace(DefNewGeneration* gen) : _gen(gen) { _soft_end = NULL; }
|
|
|
947
|
|
|
948 // Get/set just the 'soft' limit.
|
|
|
949 HeapWord* soft_end() { return _soft_end; }
|
|
|
950 HeapWord** soft_end_addr() { return &_soft_end; }
|
|
|
951 void set_soft_end(HeapWord* value) { _soft_end = value; }
|
|
|
952
|
|
|
953 // Override.
|
|
|
954 void clear();
|
|
|
955
|
|
|
956 // Set both the 'hard' and 'soft' limits (_end and _soft_end).
|
|
|
957 void set_end(HeapWord* value) {
|
|
|
958 set_soft_end(value);
|
|
|
959 ContiguousSpace::set_end(value);
|
|
|
960 }
|
|
|
961
|
|
|
962 // Allocation (return NULL if full)
|
|
|
963 HeapWord* allocate(size_t word_size);
|
|
|
964 HeapWord* par_allocate(size_t word_size);
|
|
|
965 };
|
|
|
966
|
|
|
967 // Class ConcEdenSpace extends EdenSpace for the sake of safe
|
|
|
968 // allocation while soft-end is being modified concurrently
|
|
|
969
|
|
|
970 class ConcEdenSpace : public EdenSpace {
|
|
|
971 public:
|
|
|
972 ConcEdenSpace(DefNewGeneration* gen) : EdenSpace(gen) { }
|
|
|
973
|
|
|
974 // Allocation (return NULL if full)
|
|
|
975 HeapWord* par_allocate(size_t word_size);
|
|
|
976 };
|
|
|
977
|
|
|
978
|
|
|
979 // A ContigSpace that Supports an efficient "block_start" operation via
|
|
|
980 // a BlockOffsetArray (whose BlockOffsetSharedArray may be shared with
|
|
|
981 // other spaces.) This is the abstract base class for old generation
|
|
|
982 // (tenured, perm) spaces.
|
|
|
983
|
|
|
984 class OffsetTableContigSpace: public ContiguousSpace {
|
|
|
985 friend class VMStructs;
|
|
|
986 protected:
|
|
|
987 BlockOffsetArrayContigSpace _offsets;
|
|
|
988 Mutex _par_alloc_lock;
|
|
|
989
|
|
|
990 public:
|
|
|
991 // Constructor
|
|
|
992 OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray,
|
|
|
993 MemRegion mr);
|
|
|
994
|
|
|
995 void set_bottom(HeapWord* value);
|
|
|
996 void set_end(HeapWord* value);
|
|
|
997
|
|
|
998 void clear();
|
|
|
999
|
|
|
1000 inline HeapWord* block_start(const void* p) const;
|
|
|
1001
|
|
|
1002 // Add offset table update.
|
|
|
1003 virtual inline HeapWord* allocate(size_t word_size);
|
|
|
1004 inline HeapWord* par_allocate(size_t word_size);
|
|
|
1005
|
|
|
1006 // MarkSweep support phase3
|
|
|
1007 virtual HeapWord* initialize_threshold();
|
|
|
1008 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end);
|
|
|
1009
|
|
|
1010 virtual void print_on(outputStream* st) const;
|
|
|
1011
|
|
|
1012 // Debugging
|
|
|
1013 void verify(bool allow_dirty) const;
|
|
|
1014
|
|
|
1015 // Shared space support
|
|
|
1016 void serialize_block_offset_array_offsets(SerializeOopClosure* soc);
|
|
|
1017 };
|
|
|
1018
|
|
|
1019
|
|
|
1020 // Class TenuredSpace is used by TenuredGeneration
|
|
|
1021
|
|
|
1022 class TenuredSpace: public OffsetTableContigSpace {
|
|
|
1023 friend class VMStructs;
|
|
|
1024 protected:
|
|
|
1025 // Mark sweep support
|
|
|
1026 int allowed_dead_ratio() const;
|
|
|
1027 public:
|
|
|
1028 // Constructor
|
|
|
1029 TenuredSpace(BlockOffsetSharedArray* sharedOffsetArray,
|
|
|
1030 MemRegion mr) :
|
|
|
1031 OffsetTableContigSpace(sharedOffsetArray, mr) {}
|
|
|
1032 };
|
|
|
1033
|
|
|
1034
|
|
|
1035 // Class ContigPermSpace is used by CompactingPermGen
|
|
|
1036
|
|
|
1037 class ContigPermSpace: public OffsetTableContigSpace {
|
|
|
1038 friend class VMStructs;
|
|
|
1039 protected:
|
|
|
1040 // Mark sweep support
|
|
|
1041 int allowed_dead_ratio() const;
|
|
|
1042 public:
|
|
|
1043 // Constructor
|
|
|
1044 ContigPermSpace(BlockOffsetSharedArray* sharedOffsetArray, MemRegion mr) :
|
|
|
1045 OffsetTableContigSpace(sharedOffsetArray, mr) {}
|
|
|
1046 };
|
