Mercurial > hg > graal-compiler

comparison src/share/vm/memory/defNewGeneration.hpp @ 0:a61af66fc99e jdk7-b24

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children ba764ed4b6f2
comparison
equal deleted inserted replaced
-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 2001-2007 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 class EdenSpace;
26 class ContiguousSpace;
27
28 // DefNewGeneration is a young generation containing eden, from- and
29 // to-space.
30
31 class DefNewGeneration: public Generation {
32 friend class VMStructs;
33
34 protected:
35 Generation* _next_gen;
36 int _tenuring_threshold; // Tenuring threshold for next collection.
37 ageTable _age_table;
38 // Size of object to pretenure in words; command line provides bytes
39 size_t _pretenure_size_threshold_words;
40
41 ageTable* age_table() { return &_age_table; }
42 // Initialize state to optimistically assume no promotion failure will
43 // happen.
44 void init_assuming_no_promotion_failure();
45 // True iff a promotion has failed in the current collection.
46 bool _promotion_failed;
47 bool promotion_failed() { return _promotion_failed; }
48
49 // Handling promotion failure. A young generation collection
50 // can fail if a live object cannot be copied out of its
51 // location in eden or from-space during the collection. If
52 // a collection fails, the young generation is left in a
53 // consistent state such that it can be collected by a
54 // full collection.
55 // Before the collection
56 // Objects are in eden or from-space
57 // All roots into the young generation point into eden or from-space.
58 //
59 // After a failed collection
60 // Objects may be in eden, from-space, or to-space
61 // An object A in eden or from-space may have a copy B
62 // in to-space. If B exists, all roots that once pointed
63 // to A must now point to B.
64 // All objects in the young generation are unmarked.
65 // Eden, from-space, and to-space will all be collected by
66 // the full collection.
67 void handle_promotion_failure(oop);
68
69 // In the absence of promotion failure, we wouldn't look at "from-space"
70 // objects after a young-gen collection. When promotion fails, however,
71 // the subsequent full collection will look at from-space objects:
72 // therefore we must remove their forwarding pointers.
73 void remove_forwarding_pointers();
74
75 // Preserve the mark of "obj", if necessary, in preparation for its mark
76 // word being overwritten with a self-forwarding-pointer.
77 void preserve_mark_if_necessary(oop obj, markOop m);
78
79 // When one is non-null, so is the other. Together, they each pair is
80 // an object with a preserved mark, and its mark value.
81 GrowableArray<oop>* _objs_with_preserved_marks;
82 GrowableArray<markOop>* _preserved_marks_of_objs;
83
84 // Returns true if the collection can be safely attempted.
85 // If this method returns false, a collection is not
86 // guaranteed to fail but the system may not be able
87 // to recover from the failure.
88 bool collection_attempt_is_safe();
89
90 // Promotion failure handling
91 OopClosure *_promo_failure_scan_stack_closure;
92 void set_promo_failure_scan_stack_closure(OopClosure *scan_stack_closure) {
93 _promo_failure_scan_stack_closure = scan_stack_closure;
94 }
95
96 GrowableArray<oop>* _promo_failure_scan_stack;
97 GrowableArray<oop>* promo_failure_scan_stack() const {
98 return _promo_failure_scan_stack;
99 }
100 void push_on_promo_failure_scan_stack(oop);
101 void drain_promo_failure_scan_stack(void);
102 bool _promo_failure_drain_in_progress;
103
104 // Performance Counters
105 GenerationCounters* _gen_counters;
106 CSpaceCounters* _eden_counters;
107 CSpaceCounters* _from_counters;
108 CSpaceCounters* _to_counters;
109
110 // sizing information
111 size_t _max_eden_size;
112 size_t _max_survivor_size;
113
114 // Allocation support
115 bool _should_allocate_from_space;
116 bool should_allocate_from_space() const {
117 return _should_allocate_from_space;
118 }
119 void clear_should_allocate_from_space() {
120 _should_allocate_from_space = false;
121 }
122 void set_should_allocate_from_space() {
123 _should_allocate_from_space = true;
124 }
125
126 protected:
127 // Spaces
128 EdenSpace* _eden_space;
129 ContiguousSpace* _from_space;
130 ContiguousSpace* _to_space;
131
132 enum SomeProtectedConstants {
133 // Generations are GenGrain-aligned and have size that are multiples of
134 // GenGrain.
135 MinFreeScratchWords = 100
136 };
137
138 // Return the size of a survivor space if this generation were of size
139 // gen_size.
140 size_t compute_survivor_size(size_t gen_size, size_t alignment) const {
141 size_t n = gen_size / (SurvivorRatio + 2);
142 return n > alignment ? align_size_down(n, alignment) : alignment;
143 }
144
145 public: // was "protected" but caused compile error on win32
146 class IsAliveClosure: public BoolObjectClosure {
147 Generation* _g;
148 public:
149 IsAliveClosure(Generation* g);
150 void do_object(oop p);
151 bool do_object_b(oop p);
152 };
153
154 class KeepAliveClosure: public OopClosure {
155 protected:
156 ScanWeakRefClosure* _cl;
157 CardTableRS* _rs;
158 public:
159 KeepAliveClosure(ScanWeakRefClosure* cl);
160 void do_oop(oop* p);
161 };
162
163 class FastKeepAliveClosure: public KeepAliveClosure {
164 protected:
165 HeapWord* _boundary;
166 public:
167 FastKeepAliveClosure(DefNewGeneration* g, ScanWeakRefClosure* cl);
168 void do_oop(oop* p);
169 };
170
171 class EvacuateFollowersClosure: public VoidClosure {
172 GenCollectedHeap* _gch;
173 int _level;
174 ScanClosure* _scan_cur_or_nonheap;
175 ScanClosure* _scan_older;
176 public:
177 EvacuateFollowersClosure(GenCollectedHeap* gch, int level,
178 ScanClosure* cur, ScanClosure* older);
179 void do_void();
180 };
181
182 class FastEvacuateFollowersClosure;
183 friend class FastEvacuateFollowersClosure;
184 class FastEvacuateFollowersClosure: public VoidClosure {
185 GenCollectedHeap* _gch;
186 int _level;
187 DefNewGeneration* _gen;
188 FastScanClosure* _scan_cur_or_nonheap;
189 FastScanClosure* _scan_older;
190 public:
191 FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level,
192 DefNewGeneration* gen,
193 FastScanClosure* cur,
194 FastScanClosure* older);
195 void do_void();
196 };
197
198 public:
199 DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
200 const char* policy="Copy");
201
202 virtual Generation::Name kind() { return Generation::DefNew; }
203
204 // Accessing spaces
205 EdenSpace* eden() const { return _eden_space; }
206 ContiguousSpace* from() const { return _from_space; }
207 ContiguousSpace* to() const { return _to_space; }
208
209 inline CompactibleSpace* first_compaction_space() const;
210
211 // Space enquiries
212 size_t capacity() const;
213 size_t used() const;
214 size_t free() const;
215 size_t max_capacity() const;
216 size_t capacity_before_gc() const;
217 size_t unsafe_max_alloc_nogc() const;
218 size_t contiguous_available() const;
219
220 size_t max_eden_size() const { return _max_eden_size; }
221 size_t max_survivor_size() const { return _max_survivor_size; }
222
223 bool supports_inline_contig_alloc() const { return true; }
224 HeapWord** top_addr() const;
225 HeapWord** end_addr() const;
226
227 // Thread-local allocation buffers
228 bool supports_tlab_allocation() const { return true; }
229 inline size_t tlab_capacity() const;
230 inline size_t unsafe_max_tlab_alloc() const;
231
232 // Grow the generation by the specified number of bytes.
233 // The size of bytes is assumed to be properly aligned.
234 // Return true if the expansion was successful.
235 bool expand(size_t bytes);
236
237 // DefNewGeneration cannot currently expand except at
238 // a GC.
239 virtual bool is_maximal_no_gc() const { return true; }
240
241 // Iteration
242 void object_iterate(ObjectClosure* blk);
243 void object_iterate_since_last_GC(ObjectClosure* cl);
244
245 void younger_refs_iterate(OopsInGenClosure* cl);
246
247 void space_iterate(SpaceClosure* blk, bool usedOnly = false);
248
249 // Allocation support
250 virtual bool should_allocate(size_t word_size, bool is_tlab) {
251 assert(UseTLAB || !is_tlab, "Should not allocate tlab");
252
253 size_t overflow_limit = (size_t)1 << (BitsPerSize_t - LogHeapWordSize);
254
255 const bool non_zero = word_size > 0;
256 const bool overflows = word_size >= overflow_limit;
257 const bool check_too_big = _pretenure_size_threshold_words > 0;
258 const bool not_too_big = word_size < _pretenure_size_threshold_words;
259 const bool size_ok = is_tlab || !check_too_big || not_too_big;
260
261 bool result = !overflows &&
262 non_zero &&
263 size_ok;
264
265 return result;
266 }
267
268 inline HeapWord* allocate(size_t word_size, bool is_tlab);
269 HeapWord* allocate_from_space(size_t word_size);
270
271 inline HeapWord* par_allocate(size_t word_size, bool is_tlab);
272
273 // Prologue & Epilogue
274 inline virtual void gc_prologue(bool full);
275 virtual void gc_epilogue(bool full);
276
277 // Doesn't require additional work during GC prologue and epilogue
278 virtual bool performs_in_place_marking() const { return false; }
279
280 // Accessing marks
281 void save_marks();
282 void reset_saved_marks();
283 bool no_allocs_since_save_marks();
284
285 // Need to declare the full complement of closures, whether we'll
286 // override them or not, or get message from the compiler:
287 // oop_since_save_marks_iterate_nv hides virtual function...
288 #define DefNew_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
289 void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
290
291 ALL_SINCE_SAVE_MARKS_CLOSURES(DefNew_SINCE_SAVE_MARKS_DECL)
292
293 #undef DefNew_SINCE_SAVE_MARKS_DECL
294
295 // For non-youngest collection, the DefNewGeneration can contribute
296 // "to-space".
297 void contribute_scratch(ScratchBlock*& list, Generation* requestor,
298 size_t max_alloc_words);
299
300 // GC support
301 virtual void compute_new_size();
302 virtual void collect(bool full,
303 bool clear_all_soft_refs,
304 size_t size,
305 bool is_tlab);
306 HeapWord* expand_and_allocate(size_t size,
307 bool is_tlab,
308 bool parallel = false);
309
310 oop copy_to_survivor_space(oop old, oop* from);
311 int tenuring_threshold() { return _tenuring_threshold; }
312
313 // Performance Counter support
314 void update_counters();
315
316 // Printing
317 virtual const char* name() const;
318 virtual const char* short_name() const { return "DefNew"; }
319
320 bool must_be_youngest() const { return true; }
321 bool must_be_oldest() const { return false; }
322
323 // PrintHeapAtGC support.
324 void print_on(outputStream* st) const;
325
326 void verify(bool allow_dirty);
327
328 protected:
329 void compute_space_boundaries(uintx minimum_eden_size);
330 // Scavenge support
331 void swap_spaces();
332 };