Mercurial > hg > graal-jvmci-8
comparison src/share/vm/memory/compactingPermGenGen.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 2c106685d6d0 |
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1 /* | |
2 * Copyright 2003-2006 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 #include "incls/_precompiled.incl" | |
26 #include "incls/_compactingPermGenGen.cpp.incl" | |
27 | |
28 | |
29 // Recursively adjust all pointers in an object and all objects by | |
30 // referenced it. Clear marks on objects in order to prevent visiting | |
31 // any object twice. | |
32 | |
33 class RecursiveAdjustSharedObjectClosure : public OopClosure { | |
34 public: | |
35 void do_oop(oop* o) { | |
36 oop obj = *o; | |
37 if (obj->is_shared_readwrite()) { | |
38 if (obj->mark()->is_marked()) { | |
39 obj->init_mark(); // Don't revisit this object. | |
40 obj->oop_iterate(this); // Recurse - adjust objects referenced. | |
41 obj->adjust_pointers(); // Adjust this object's references. | |
42 | |
43 // Special case: if a class has a read-only constant pool, | |
44 // then the read-write objects referenced by the pool must | |
45 // have their marks reset. | |
46 | |
47 if (obj->klass() == Universe::instanceKlassKlassObj()) { | |
48 instanceKlass* ik = instanceKlass::cast((klassOop)obj); | |
49 constantPoolOop cp = ik->constants(); | |
50 if (cp->is_shared_readonly()) { | |
51 cp->oop_iterate(this); | |
52 } | |
53 } | |
54 } | |
55 } | |
56 }; | |
57 }; | |
58 | |
59 | |
60 // We need to go through all placeholders in the system dictionary and | |
61 // try to resolve them into shared classes. Other threads might be in | |
62 // the process of loading a shared class and have strong roots on | |
63 // their stack to the class without having added the class to the | |
64 // dictionary yet. This means the class will be marked during phase 1 | |
65 // but will not be unmarked during the application of the | |
66 // RecursiveAdjustSharedObjectClosure to the SystemDictionary. Note | |
67 // that we must not call find_shared_class with non-read-only symbols | |
68 // as doing so can cause hash codes to be computed, destroying | |
69 // forwarding pointers. | |
70 class TraversePlaceholdersClosure : public OopClosure { | |
71 public: | |
72 void do_oop(oop* o) { | |
73 oop obj = *o; | |
74 if (obj->klass() == Universe::symbolKlassObj() && | |
75 obj->is_shared_readonly()) { | |
76 symbolHandle sym((symbolOop) obj); | |
77 oop k = SystemDictionary::find_shared_class(sym); | |
78 if (k != NULL) { | |
79 RecursiveAdjustSharedObjectClosure clo; | |
80 clo.do_oop(&k); | |
81 } | |
82 } | |
83 } | |
84 }; | |
85 | |
86 | |
87 void CompactingPermGenGen::initialize_performance_counters() { | |
88 | |
89 const char* gen_name = "perm"; | |
90 | |
91 // Generation Counters - generation 2, 1 subspace | |
92 _gen_counters = new GenerationCounters(gen_name, 2, 1, &_virtual_space); | |
93 | |
94 _space_counters = new CSpaceCounters(gen_name, 0, | |
95 _virtual_space.reserved_size(), | |
96 _the_space, _gen_counters); | |
97 } | |
98 | |
99 void CompactingPermGenGen::update_counters() { | |
100 if (UsePerfData) { | |
101 _space_counters->update_all(); | |
102 _gen_counters->update_all(); | |
103 } | |
104 } | |
105 | |
106 | |
107 CompactingPermGenGen::CompactingPermGenGen(ReservedSpace rs, | |
108 ReservedSpace shared_rs, | |
109 size_t initial_byte_size, | |
110 int level, GenRemSet* remset, | |
111 ContiguousSpace* space, | |
112 PermanentGenerationSpec* spec_) : | |
113 OneContigSpaceCardGeneration(rs, initial_byte_size, MinPermHeapExpansion, | |
114 level, remset, space) { | |
115 | |
116 set_spec(spec_); | |
117 if (!UseSharedSpaces && !DumpSharedSpaces) { | |
118 spec()->disable_sharing(); | |
119 } | |
120 | |
121 // Break virtual space into address ranges for all spaces. | |
122 | |
123 if (spec()->enable_shared_spaces()) { | |
124 shared_end = (HeapWord*)(shared_rs.base() + shared_rs.size()); | |
125 misccode_end = shared_end; | |
126 misccode_bottom = misccode_end - heap_word_size(spec()->misc_code_size()); | |
127 miscdata_end = misccode_bottom; | |
128 miscdata_bottom = miscdata_end - heap_word_size(spec()->misc_data_size()); | |
129 readwrite_end = miscdata_bottom; | |
130 readwrite_bottom = | |
131 readwrite_end - heap_word_size(spec()->read_write_size()); | |
132 readonly_end = readwrite_bottom; | |
133 readonly_bottom = | |
134 readonly_end - heap_word_size(spec()->read_only_size()); | |
135 shared_bottom = readonly_bottom; | |
136 unshared_end = shared_bottom; | |
137 assert((char*)shared_bottom == shared_rs.base(), "shared space mismatch"); | |
138 } else { | |
139 shared_end = (HeapWord*)(rs.base() + rs.size()); | |
140 misccode_end = shared_end; | |
141 misccode_bottom = shared_end; | |
142 miscdata_end = shared_end; | |
143 miscdata_bottom = shared_end; | |
144 readwrite_end = shared_end; | |
145 readwrite_bottom = shared_end; | |
146 readonly_end = shared_end; | |
147 readonly_bottom = shared_end; | |
148 shared_bottom = shared_end; | |
149 unshared_end = shared_bottom; | |
150 } | |
151 unshared_bottom = (HeapWord*) rs.base(); | |
152 | |
153 // Verify shared and unshared spaces adjacent. | |
154 assert((char*)shared_bottom == rs.base()+rs.size(), "shared space mismatch"); | |
155 assert(unshared_end > unshared_bottom, "shared space mismatch"); | |
156 | |
157 // Split reserved memory into pieces. | |
158 | |
159 ReservedSpace ro_rs = shared_rs.first_part(spec()->read_only_size(), | |
160 UseSharedSpaces); | |
161 ReservedSpace tmp_rs1 = shared_rs.last_part(spec()->read_only_size()); | |
162 ReservedSpace rw_rs = tmp_rs1.first_part(spec()->read_write_size(), | |
163 UseSharedSpaces); | |
164 ReservedSpace tmp_rs2 = tmp_rs1.last_part(spec()->read_write_size()); | |
165 ReservedSpace md_rs = tmp_rs2.first_part(spec()->misc_data_size(), | |
166 UseSharedSpaces); | |
167 ReservedSpace mc_rs = tmp_rs2.last_part(spec()->misc_data_size()); | |
168 | |
169 _shared_space_size = spec()->read_only_size() | |
170 + spec()->read_write_size() | |
171 + spec()->misc_data_size() | |
172 + spec()->misc_code_size(); | |
173 | |
174 // Allocate the unshared (default) space. | |
175 _the_space = new ContigPermSpace(_bts, | |
176 MemRegion(unshared_bottom, heap_word_size(initial_byte_size))); | |
177 if (_the_space == NULL) | |
178 vm_exit_during_initialization("Could not allocate an unshared" | |
179 " CompactingPermGen Space"); | |
180 | |
181 // Allocate shared spaces | |
182 if (spec()->enable_shared_spaces()) { | |
183 | |
184 // If mapping a shared file, the space is not committed, don't | |
185 // mangle. | |
186 NOT_PRODUCT(bool old_ZapUnusedHeapArea = ZapUnusedHeapArea;) | |
187 NOT_PRODUCT(if (UseSharedSpaces) ZapUnusedHeapArea = false;) | |
188 | |
189 // Commit the memory behind the shared spaces if dumping (not | |
190 // mapping). | |
191 if (DumpSharedSpaces) { | |
192 _ro_vs.initialize(ro_rs, spec()->read_only_size()); | |
193 _rw_vs.initialize(rw_rs, spec()->read_write_size()); | |
194 _md_vs.initialize(md_rs, spec()->misc_data_size()); | |
195 _mc_vs.initialize(mc_rs, spec()->misc_code_size()); | |
196 } | |
197 | |
198 // Allocate the shared spaces. | |
199 _ro_bts = new BlockOffsetSharedArray( | |
200 MemRegion(readonly_bottom, | |
201 heap_word_size(spec()->read_only_size())), | |
202 heap_word_size(spec()->read_only_size())); | |
203 _ro_space = new OffsetTableContigSpace(_ro_bts, | |
204 MemRegion(readonly_bottom, readonly_end)); | |
205 _rw_bts = new BlockOffsetSharedArray( | |
206 MemRegion(readwrite_bottom, | |
207 heap_word_size(spec()->read_write_size())), | |
208 heap_word_size(spec()->read_write_size())); | |
209 _rw_space = new OffsetTableContigSpace(_rw_bts, | |
210 MemRegion(readwrite_bottom, readwrite_end)); | |
211 | |
212 // Restore mangling flag. | |
213 NOT_PRODUCT(ZapUnusedHeapArea = old_ZapUnusedHeapArea;) | |
214 | |
215 if (_ro_space == NULL || _rw_space == NULL) | |
216 vm_exit_during_initialization("Could not allocate a shared space"); | |
217 | |
218 // Cover both shared spaces entirely with cards. | |
219 _rs->resize_covered_region(MemRegion(readonly_bottom, readwrite_end)); | |
220 | |
221 if (UseSharedSpaces) { | |
222 | |
223 // Map in the regions in the shared file. | |
224 FileMapInfo* mapinfo = FileMapInfo::current_info(); | |
225 size_t image_alignment = mapinfo->alignment(); | |
226 CollectedHeap* ch = Universe::heap(); | |
227 if ((!mapinfo->map_space(ro, ro_rs, _ro_space)) || | |
228 (!mapinfo->map_space(rw, rw_rs, _rw_space)) || | |
229 (!mapinfo->map_space(md, md_rs, NULL)) || | |
230 (!mapinfo->map_space(mc, mc_rs, NULL)) || | |
231 // check the alignment constraints | |
232 (ch == NULL || ch->kind() != CollectedHeap::GenCollectedHeap || | |
233 image_alignment != | |
234 ((GenCollectedHeap*)ch)->gen_policy()->max_alignment())) { | |
235 // Base addresses didn't match; skip sharing, but continue | |
236 shared_rs.release(); | |
237 spec()->disable_sharing(); | |
238 // If -Xshare:on is specified, print out the error message and exit VM, | |
239 // otherwise, set UseSharedSpaces to false and continue. | |
240 if (RequireSharedSpaces) { | |
241 vm_exit_during_initialization("Unable to use shared archive.", NULL); | |
242 } else { | |
243 FLAG_SET_DEFAULT(UseSharedSpaces, false); | |
244 } | |
245 | |
246 // Note: freeing the block offset array objects does not | |
247 // currently free up the underlying storage. | |
248 delete _ro_bts; | |
249 _ro_bts = NULL; | |
250 delete _ro_space; | |
251 _ro_space = NULL; | |
252 delete _rw_bts; | |
253 _rw_bts = NULL; | |
254 delete _rw_space; | |
255 _rw_space = NULL; | |
256 shared_end = (HeapWord*)(rs.base() + rs.size()); | |
257 _rs->resize_covered_region(MemRegion(shared_bottom, shared_bottom)); | |
258 } | |
259 } | |
260 | |
261 // Reserved region includes shared spaces for oop.is_in_reserved(). | |
262 _reserved.set_end(shared_end); | |
263 | |
264 } else { | |
265 _ro_space = NULL; | |
266 _rw_space = NULL; | |
267 } | |
268 } | |
269 | |
270 | |
271 // Do a complete scan of the shared read write space to catch all | |
272 // objects which contain references to any younger generation. Forward | |
273 // the pointers. Avoid space_iterate, as actually visiting all the | |
274 // objects in the space will page in more objects than we need. | |
275 // Instead, use the system dictionary as strong roots into the read | |
276 // write space. | |
277 | |
278 void CompactingPermGenGen::pre_adjust_pointers() { | |
279 if (spec()->enable_shared_spaces()) { | |
280 RecursiveAdjustSharedObjectClosure blk; | |
281 Universe::oops_do(&blk); | |
282 StringTable::oops_do(&blk); | |
283 SystemDictionary::always_strong_classes_do(&blk); | |
284 TraversePlaceholdersClosure tpc; | |
285 SystemDictionary::placeholders_do(&tpc); | |
286 } | |
287 } | |
288 | |
289 | |
290 #ifdef ASSERT | |
291 class VerifyMarksClearedClosure : public ObjectClosure { | |
292 public: | |
293 void do_object(oop obj) { | |
294 assert(SharedSkipVerify || !obj->mark()->is_marked(), | |
295 "Shared oop still marked?"); | |
296 } | |
297 }; | |
298 #endif | |
299 | |
300 | |
301 void CompactingPermGenGen::post_compact() { | |
302 #ifdef ASSERT | |
303 if (!SharedSkipVerify && spec()->enable_shared_spaces()) { | |
304 VerifyMarksClearedClosure blk; | |
305 rw_space()->object_iterate(&blk); | |
306 } | |
307 #endif | |
308 } | |
309 | |
310 | |
311 void CompactingPermGenGen::space_iterate(SpaceClosure* blk, bool usedOnly) { | |
312 OneContigSpaceCardGeneration::space_iterate(blk, usedOnly); | |
313 if (spec()->enable_shared_spaces()) { | |
314 #ifdef PRODUCT | |
315 // Making the rw_space walkable will page in the entire space, and | |
316 // is to be avoided. However, this is required for Verify options. | |
317 ShouldNotReachHere(); | |
318 #endif | |
319 | |
320 blk->do_space(ro_space()); | |
321 blk->do_space(rw_space()); | |
322 } | |
323 } | |
324 | |
325 | |
326 void CompactingPermGenGen::print_on(outputStream* st) const { | |
327 OneContigSpaceCardGeneration::print_on(st); | |
328 if (spec()->enable_shared_spaces()) { | |
329 st->print(" ro"); | |
330 ro_space()->print_on(st); | |
331 st->print(" rw"); | |
332 rw_space()->print_on(st); | |
333 } else { | |
334 st->print_cr("No shared spaces configured."); | |
335 } | |
336 } | |
337 | |
338 | |
339 // References from the perm gen to the younger generation objects may | |
340 // occur in static fields in Java classes or in constant pool references | |
341 // to String objects. | |
342 | |
343 void CompactingPermGenGen::younger_refs_iterate(OopsInGenClosure* blk) { | |
344 OneContigSpaceCardGeneration::younger_refs_iterate(blk); | |
345 if (spec()->enable_shared_spaces()) { | |
346 blk->set_generation(this); | |
347 // ro_space has no younger gen refs. | |
348 _rs->younger_refs_in_space_iterate(rw_space(), blk); | |
349 blk->reset_generation(); | |
350 } | |
351 } | |
352 | |
353 | |
354 // Shared spaces are addressed in pre_adjust_pointers. | |
355 void CompactingPermGenGen::adjust_pointers() { | |
356 the_space()->adjust_pointers(); | |
357 } | |
358 | |
359 | |
360 void CompactingPermGenGen::compact() { | |
361 the_space()->compact(); | |
362 } | |
363 | |
364 | |
365 size_t CompactingPermGenGen::contiguous_available() const { | |
366 // Don't include shared spaces. | |
367 return OneContigSpaceCardGeneration::contiguous_available() | |
368 - _shared_space_size; | |
369 } | |
370 | |
371 size_t CompactingPermGenGen::max_capacity() const { | |
372 // Don't include shared spaces. | |
373 assert(UseSharedSpaces || (_shared_space_size == 0), | |
374 "If not used, the size of shared spaces should be 0"); | |
375 return OneContigSpaceCardGeneration::max_capacity() | |
376 - _shared_space_size; | |
377 } | |
378 | |
379 | |
380 | |
381 bool CompactingPermGenGen::grow_by(size_t bytes) { | |
382 // Don't allow _virtual_size to expand into shared spaces. | |
383 size_t max_bytes = _virtual_space.uncommitted_size() - _shared_space_size; | |
384 if (bytes > _shared_space_size) { | |
385 bytes = _shared_space_size; | |
386 } | |
387 return OneContigSpaceCardGeneration::grow_by(bytes); | |
388 } | |
389 | |
390 | |
391 void CompactingPermGenGen::grow_to_reserved() { | |
392 // Don't allow _virtual_size to expand into shared spaces. | |
393 if (_virtual_space.uncommitted_size() > _shared_space_size) { | |
394 size_t remaining_bytes = | |
395 _virtual_space.uncommitted_size() - _shared_space_size; | |
396 bool success = OneContigSpaceCardGeneration::grow_by(remaining_bytes); | |
397 DEBUG_ONLY(if (!success) warning("grow to reserved failed");) | |
398 } | |
399 } | |
400 | |
401 | |
402 // No young generation references, clear this generation's main space's | |
403 // card table entries. Do NOT clear the card table entries for the | |
404 // read-only space (always clear) or the read-write space (valuable | |
405 // information). | |
406 | |
407 void CompactingPermGenGen::clear_remembered_set() { | |
408 _rs->clear(MemRegion(the_space()->bottom(), the_space()->end())); | |
409 } | |
410 | |
411 | |
412 // Objects in this generation's main space may have moved, invalidate | |
413 // that space's cards. Do NOT invalidate the card table entries for the | |
414 // read-only or read-write spaces, as those objects never move. | |
415 | |
416 void CompactingPermGenGen::invalidate_remembered_set() { | |
417 _rs->invalidate(used_region()); | |
418 } | |
419 | |
420 | |
421 void CompactingPermGenGen::verify(bool allow_dirty) { | |
422 the_space()->verify(allow_dirty); | |
423 if (!SharedSkipVerify && spec()->enable_shared_spaces()) { | |
424 ro_space()->verify(allow_dirty); | |
425 rw_space()->verify(allow_dirty); | |
426 } | |
427 } | |
428 | |
429 | |
430 HeapWord* CompactingPermGenGen::unshared_bottom; | |
431 HeapWord* CompactingPermGenGen::unshared_end; | |
432 HeapWord* CompactingPermGenGen::shared_bottom; | |
433 HeapWord* CompactingPermGenGen::shared_end; | |
434 HeapWord* CompactingPermGenGen::readonly_bottom; | |
435 HeapWord* CompactingPermGenGen::readonly_end; | |
436 HeapWord* CompactingPermGenGen::readwrite_bottom; | |
437 HeapWord* CompactingPermGenGen::readwrite_end; | |
438 HeapWord* CompactingPermGenGen::miscdata_bottom; | |
439 HeapWord* CompactingPermGenGen::miscdata_end; | |
440 HeapWord* CompactingPermGenGen::misccode_bottom; | |
441 HeapWord* CompactingPermGenGen::misccode_end; | |
442 | |
443 // JVM/TI RedefineClasses() support: | |
444 bool CompactingPermGenGen::remap_shared_readonly_as_readwrite() { | |
445 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); | |
446 | |
447 if (UseSharedSpaces) { | |
448 // remap the shared readonly space to shared readwrite, private | |
449 FileMapInfo* mapinfo = FileMapInfo::current_info(); | |
450 if (!mapinfo->remap_shared_readonly_as_readwrite()) { | |
451 return false; | |
452 } | |
453 } | |
454 return true; | |
455 } | |
456 | |
457 void** CompactingPermGenGen::_vtbl_list; |