src/share/vm/gc_implementation/shared/markSweep.cpp

Sat, 01 Dec 2007 00:00:00 +0000

author
duke
date
Sat, 01 Dec 2007 00:00:00 +0000
changeset 435
a61af66fc99e
child 548
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duke@435 1 /*
duke@435 2 * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 #include "incls/_precompiled.incl"
duke@435 26 #include "incls/_markSweep.cpp.incl"
duke@435 27
duke@435 28 GrowableArray<oop>* MarkSweep::_marking_stack = NULL;
duke@435 29 GrowableArray<Klass*>* MarkSweep::_revisit_klass_stack = NULL;
duke@435 30
duke@435 31 GrowableArray<oop>* MarkSweep::_preserved_oop_stack = NULL;
duke@435 32 GrowableArray<markOop>* MarkSweep::_preserved_mark_stack= NULL;
duke@435 33 size_t MarkSweep::_preserved_count = 0;
duke@435 34 size_t MarkSweep::_preserved_count_max = 0;
duke@435 35 PreservedMark* MarkSweep::_preserved_marks = NULL;
duke@435 36 ReferenceProcessor* MarkSweep::_ref_processor = NULL;
duke@435 37
duke@435 38 #ifdef VALIDATE_MARK_SWEEP
duke@435 39 GrowableArray<oop*>* MarkSweep::_root_refs_stack = NULL;
duke@435 40 GrowableArray<oop> * MarkSweep::_live_oops = NULL;
duke@435 41 GrowableArray<oop> * MarkSweep::_live_oops_moved_to = NULL;
duke@435 42 GrowableArray<size_t>* MarkSweep::_live_oops_size = NULL;
duke@435 43 size_t MarkSweep::_live_oops_index = 0;
duke@435 44 size_t MarkSweep::_live_oops_index_at_perm = 0;
duke@435 45 GrowableArray<oop*>* MarkSweep::_other_refs_stack = NULL;
duke@435 46 GrowableArray<oop*>* MarkSweep::_adjusted_pointers = NULL;
duke@435 47 bool MarkSweep::_pointer_tracking = false;
duke@435 48 bool MarkSweep::_root_tracking = true;
duke@435 49
duke@435 50 GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops = NULL;
duke@435 51 GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops_moved_to = NULL;
duke@435 52 GrowableArray<size_t> * MarkSweep::_cur_gc_live_oops_size = NULL;
duke@435 53 GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops = NULL;
duke@435 54 GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops_moved_to = NULL;
duke@435 55 GrowableArray<size_t> * MarkSweep::_last_gc_live_oops_size = NULL;
duke@435 56 #endif
duke@435 57
duke@435 58 void MarkSweep::revisit_weak_klass_link(Klass* k) {
duke@435 59 _revisit_klass_stack->push(k);
duke@435 60 }
duke@435 61
duke@435 62
duke@435 63 void MarkSweep::follow_weak_klass_links() {
duke@435 64 // All klasses on the revisit stack are marked at this point.
duke@435 65 // Update and follow all subklass, sibling and implementor links.
duke@435 66 for (int i = 0; i < _revisit_klass_stack->length(); i++) {
duke@435 67 _revisit_klass_stack->at(i)->follow_weak_klass_links(&is_alive,&keep_alive);
duke@435 68 }
duke@435 69 follow_stack();
duke@435 70 }
duke@435 71
duke@435 72
duke@435 73 void MarkSweep::mark_and_follow(oop* p) {
duke@435 74 assert(Universe::heap()->is_in_reserved(p),
duke@435 75 "we should only be traversing objects here");
duke@435 76 oop m = *p;
duke@435 77 if (m != NULL && !m->mark()->is_marked()) {
duke@435 78 mark_object(m);
duke@435 79 m->follow_contents(); // Follow contents of the marked object
duke@435 80 }
duke@435 81 }
duke@435 82
duke@435 83 void MarkSweep::_mark_and_push(oop* p) {
duke@435 84 // Push marked object, contents will be followed later
duke@435 85 oop m = *p;
duke@435 86 mark_object(m);
duke@435 87 _marking_stack->push(m);
duke@435 88 }
duke@435 89
duke@435 90 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
duke@435 91
duke@435 92 void MarkSweep::follow_root(oop* p) {
duke@435 93 assert(!Universe::heap()->is_in_reserved(p),
duke@435 94 "roots shouldn't be things within the heap");
duke@435 95 #ifdef VALIDATE_MARK_SWEEP
duke@435 96 if (ValidateMarkSweep) {
duke@435 97 guarantee(!_root_refs_stack->contains(p), "should only be in here once");
duke@435 98 _root_refs_stack->push(p);
duke@435 99 }
duke@435 100 #endif
duke@435 101 oop m = *p;
duke@435 102 if (m != NULL && !m->mark()->is_marked()) {
duke@435 103 mark_object(m);
duke@435 104 m->follow_contents(); // Follow contents of the marked object
duke@435 105 }
duke@435 106 follow_stack();
duke@435 107 }
duke@435 108
duke@435 109 MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
duke@435 110
duke@435 111 void MarkSweep::follow_stack() {
duke@435 112 while (!_marking_stack->is_empty()) {
duke@435 113 oop obj = _marking_stack->pop();
duke@435 114 assert (obj->is_gc_marked(), "p must be marked");
duke@435 115 obj->follow_contents();
duke@435 116 }
duke@435 117 }
duke@435 118
duke@435 119 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
duke@435 120
duke@435 121
duke@435 122 // We preserve the mark which should be replaced at the end and the location that it
duke@435 123 // will go. Note that the object that this markOop belongs to isn't currently at that
duke@435 124 // address but it will be after phase4
duke@435 125 void MarkSweep::preserve_mark(oop obj, markOop mark) {
duke@435 126 // we try to store preserved marks in the to space of the new generation since this
duke@435 127 // is storage which should be available. Most of the time this should be sufficient
duke@435 128 // space for the marks we need to preserve but if it isn't we fall back in using
duke@435 129 // GrowableArrays to keep track of the overflow.
duke@435 130 if (_preserved_count < _preserved_count_max) {
duke@435 131 _preserved_marks[_preserved_count++].init(obj, mark);
duke@435 132 } else {
duke@435 133 if (_preserved_mark_stack == NULL) {
duke@435 134 _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
duke@435 135 _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
duke@435 136 }
duke@435 137 _preserved_mark_stack->push(mark);
duke@435 138 _preserved_oop_stack->push(obj);
duke@435 139 }
duke@435 140 }
duke@435 141
duke@435 142 MarkSweep::AdjustPointerClosure MarkSweep::adjust_root_pointer_closure(true);
duke@435 143 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure(false);
duke@435 144
duke@435 145 void MarkSweep::adjust_marks() {
duke@435 146 assert(_preserved_oop_stack == NULL ||
duke@435 147 _preserved_oop_stack->length() == _preserved_mark_stack->length(),
duke@435 148 "inconsistent preserved oop stacks");
duke@435 149
duke@435 150 // adjust the oops we saved earlier
duke@435 151 for (size_t i = 0; i < _preserved_count; i++) {
duke@435 152 _preserved_marks[i].adjust_pointer();
duke@435 153 }
duke@435 154
duke@435 155 // deal with the overflow stack
duke@435 156 if (_preserved_oop_stack) {
duke@435 157 for (int i = 0; i < _preserved_oop_stack->length(); i++) {
duke@435 158 oop* p = _preserved_oop_stack->adr_at(i);
duke@435 159 adjust_pointer(p);
duke@435 160 }
duke@435 161 }
duke@435 162 }
duke@435 163
duke@435 164 void MarkSweep::restore_marks() {
duke@435 165 assert(_preserved_oop_stack == NULL ||
duke@435 166 _preserved_oop_stack->length() == _preserved_mark_stack->length(),
duke@435 167 "inconsistent preserved oop stacks");
duke@435 168 if (PrintGC && Verbose) {
duke@435 169 gclog_or_tty->print_cr("Restoring %d marks", _preserved_count +
duke@435 170 (_preserved_oop_stack ? _preserved_oop_stack->length() : 0));
duke@435 171 }
duke@435 172
duke@435 173 // restore the marks we saved earlier
duke@435 174 for (size_t i = 0; i < _preserved_count; i++) {
duke@435 175 _preserved_marks[i].restore();
duke@435 176 }
duke@435 177
duke@435 178 // deal with the overflow
duke@435 179 if (_preserved_oop_stack) {
duke@435 180 for (int i = 0; i < _preserved_oop_stack->length(); i++) {
duke@435 181 oop obj = _preserved_oop_stack->at(i);
duke@435 182 markOop mark = _preserved_mark_stack->at(i);
duke@435 183 obj->set_mark(mark);
duke@435 184 }
duke@435 185 }
duke@435 186 }
duke@435 187
duke@435 188 #ifdef VALIDATE_MARK_SWEEP
duke@435 189
duke@435 190 void MarkSweep::track_adjusted_pointer(oop* p, oop newobj, bool isroot) {
duke@435 191 if (!ValidateMarkSweep)
duke@435 192 return;
duke@435 193
duke@435 194 if (!isroot) {
duke@435 195 if (_pointer_tracking) {
duke@435 196 guarantee(_adjusted_pointers->contains(p), "should have seen this pointer");
duke@435 197 _adjusted_pointers->remove(p);
duke@435 198 }
duke@435 199 } else {
duke@435 200 ptrdiff_t index = _root_refs_stack->find(p);
duke@435 201 if (index != -1) {
duke@435 202 int l = _root_refs_stack->length();
duke@435 203 if (l > 0 && l - 1 != index) {
duke@435 204 oop* last = _root_refs_stack->pop();
duke@435 205 assert(last != p, "should be different");
duke@435 206 _root_refs_stack->at_put(index, last);
duke@435 207 } else {
duke@435 208 _root_refs_stack->remove(p);
duke@435 209 }
duke@435 210 }
duke@435 211 }
duke@435 212 }
duke@435 213
duke@435 214
duke@435 215 void MarkSweep::check_adjust_pointer(oop* p) {
duke@435 216 _adjusted_pointers->push(p);
duke@435 217 }
duke@435 218
duke@435 219
duke@435 220 class AdjusterTracker: public OopClosure {
duke@435 221 public:
duke@435 222 AdjusterTracker() {};
duke@435 223 void do_oop(oop* o) { MarkSweep::check_adjust_pointer(o); }
duke@435 224 };
duke@435 225
duke@435 226
duke@435 227 void MarkSweep::track_interior_pointers(oop obj) {
duke@435 228 if (ValidateMarkSweep) {
duke@435 229 _adjusted_pointers->clear();
duke@435 230 _pointer_tracking = true;
duke@435 231
duke@435 232 AdjusterTracker checker;
duke@435 233 obj->oop_iterate(&checker);
duke@435 234 }
duke@435 235 }
duke@435 236
duke@435 237
duke@435 238 void MarkSweep::check_interior_pointers() {
duke@435 239 if (ValidateMarkSweep) {
duke@435 240 _pointer_tracking = false;
duke@435 241 guarantee(_adjusted_pointers->length() == 0, "should have processed the same pointers");
duke@435 242 }
duke@435 243 }
duke@435 244
duke@435 245
duke@435 246 void MarkSweep::reset_live_oop_tracking(bool at_perm) {
duke@435 247 if (ValidateMarkSweep) {
duke@435 248 guarantee((size_t)_live_oops->length() == _live_oops_index, "should be at end of live oops");
duke@435 249 _live_oops_index = at_perm ? _live_oops_index_at_perm : 0;
duke@435 250 }
duke@435 251 }
duke@435 252
duke@435 253
duke@435 254 void MarkSweep::register_live_oop(oop p, size_t size) {
duke@435 255 if (ValidateMarkSweep) {
duke@435 256 _live_oops->push(p);
duke@435 257 _live_oops_size->push(size);
duke@435 258 _live_oops_index++;
duke@435 259 }
duke@435 260 }
duke@435 261
duke@435 262 void MarkSweep::validate_live_oop(oop p, size_t size) {
duke@435 263 if (ValidateMarkSweep) {
duke@435 264 oop obj = _live_oops->at((int)_live_oops_index);
duke@435 265 guarantee(obj == p, "should be the same object");
duke@435 266 guarantee(_live_oops_size->at((int)_live_oops_index) == size, "should be the same size");
duke@435 267 _live_oops_index++;
duke@435 268 }
duke@435 269 }
duke@435 270
duke@435 271 void MarkSweep::live_oop_moved_to(HeapWord* q, size_t size,
duke@435 272 HeapWord* compaction_top) {
duke@435 273 assert(oop(q)->forwardee() == NULL || oop(q)->forwardee() == oop(compaction_top),
duke@435 274 "should be moved to forwarded location");
duke@435 275 if (ValidateMarkSweep) {
duke@435 276 MarkSweep::validate_live_oop(oop(q), size);
duke@435 277 _live_oops_moved_to->push(oop(compaction_top));
duke@435 278 }
duke@435 279 if (RecordMarkSweepCompaction) {
duke@435 280 _cur_gc_live_oops->push(q);
duke@435 281 _cur_gc_live_oops_moved_to->push(compaction_top);
duke@435 282 _cur_gc_live_oops_size->push(size);
duke@435 283 }
duke@435 284 }
duke@435 285
duke@435 286
duke@435 287 void MarkSweep::compaction_complete() {
duke@435 288 if (RecordMarkSweepCompaction) {
duke@435 289 GrowableArray<HeapWord*>* _tmp_live_oops = _cur_gc_live_oops;
duke@435 290 GrowableArray<HeapWord*>* _tmp_live_oops_moved_to = _cur_gc_live_oops_moved_to;
duke@435 291 GrowableArray<size_t> * _tmp_live_oops_size = _cur_gc_live_oops_size;
duke@435 292
duke@435 293 _cur_gc_live_oops = _last_gc_live_oops;
duke@435 294 _cur_gc_live_oops_moved_to = _last_gc_live_oops_moved_to;
duke@435 295 _cur_gc_live_oops_size = _last_gc_live_oops_size;
duke@435 296 _last_gc_live_oops = _tmp_live_oops;
duke@435 297 _last_gc_live_oops_moved_to = _tmp_live_oops_moved_to;
duke@435 298 _last_gc_live_oops_size = _tmp_live_oops_size;
duke@435 299 }
duke@435 300 }
duke@435 301
duke@435 302
duke@435 303 void MarkSweep::print_new_location_of_heap_address(HeapWord* q) {
duke@435 304 if (!RecordMarkSweepCompaction) {
duke@435 305 tty->print_cr("Requires RecordMarkSweepCompaction to be enabled");
duke@435 306 return;
duke@435 307 }
duke@435 308
duke@435 309 if (_last_gc_live_oops == NULL) {
duke@435 310 tty->print_cr("No compaction information gathered yet");
duke@435 311 return;
duke@435 312 }
duke@435 313
duke@435 314 for (int i = 0; i < _last_gc_live_oops->length(); i++) {
duke@435 315 HeapWord* old_oop = _last_gc_live_oops->at(i);
duke@435 316 size_t sz = _last_gc_live_oops_size->at(i);
duke@435 317 if (old_oop <= q && q < (old_oop + sz)) {
duke@435 318 HeapWord* new_oop = _last_gc_live_oops_moved_to->at(i);
duke@435 319 size_t offset = (q - old_oop);
duke@435 320 tty->print_cr("Address " PTR_FORMAT, q);
duke@435 321 tty->print_cr(" Was in oop " PTR_FORMAT ", size %d, at offset %d", old_oop, sz, offset);
duke@435 322 tty->print_cr(" Now in oop " PTR_FORMAT ", actual address " PTR_FORMAT, new_oop, new_oop + offset);
duke@435 323 return;
duke@435 324 }
duke@435 325 }
duke@435 326
duke@435 327 tty->print_cr("Address " PTR_FORMAT " not found in live oop information from last GC", q);
duke@435 328 }
duke@435 329 #endif //VALIDATE_MARK_SWEEP
duke@435 330
duke@435 331 MarkSweep::IsAliveClosure MarkSweep::is_alive;
duke@435 332
duke@435 333 void MarkSweep::KeepAliveClosure::do_oop(oop* p) {
duke@435 334 #ifdef VALIDATE_MARK_SWEEP
duke@435 335 if (ValidateMarkSweep) {
duke@435 336 if (!Universe::heap()->is_in_reserved(p)) {
duke@435 337 _root_refs_stack->push(p);
duke@435 338 } else {
duke@435 339 _other_refs_stack->push(p);
duke@435 340 }
duke@435 341 }
duke@435 342 #endif
duke@435 343 mark_and_push(p);
duke@435 344 }
duke@435 345
duke@435 346 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
duke@435 347
duke@435 348 void marksweep_init() { /* empty */ }
duke@435 349
duke@435 350 #ifndef PRODUCT
duke@435 351
duke@435 352 void MarkSweep::trace(const char* msg) {
duke@435 353 if (TraceMarkSweep)
duke@435 354 gclog_or_tty->print("%s", msg);
duke@435 355 }
duke@435 356
duke@435 357 #endif

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