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

Sun, 13 Apr 2008 17:43:42 -0400

author
coleenp
date
Sun, 13 Apr 2008 17:43:42 -0400
changeset 548
ba764ed4b6f2
parent 435
a61af66fc99e
child 631
d1605aabd0a1
permissions
-rw-r--r--

6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold

     1 /*
     2  * Copyright 1997-2005 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  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_markSweep.cpp.incl"
    28 GrowableArray<oop>*     MarkSweep::_marking_stack       = NULL;
    29 GrowableArray<Klass*>*  MarkSweep::_revisit_klass_stack = NULL;
    31 GrowableArray<oop>*     MarkSweep::_preserved_oop_stack = NULL;
    32 GrowableArray<markOop>* MarkSweep::_preserved_mark_stack= NULL;
    33 size_t                  MarkSweep::_preserved_count = 0;
    34 size_t                  MarkSweep::_preserved_count_max = 0;
    35 PreservedMark*          MarkSweep::_preserved_marks = NULL;
    36 ReferenceProcessor*     MarkSweep::_ref_processor   = NULL;
    38 #ifdef VALIDATE_MARK_SWEEP
    39 GrowableArray<void*>*   MarkSweep::_root_refs_stack = NULL;
    40 GrowableArray<oop> *    MarkSweep::_live_oops = NULL;
    41 GrowableArray<oop> *    MarkSweep::_live_oops_moved_to = NULL;
    42 GrowableArray<size_t>*  MarkSweep::_live_oops_size = NULL;
    43 size_t                  MarkSweep::_live_oops_index = 0;
    44 size_t                  MarkSweep::_live_oops_index_at_perm = 0;
    45 GrowableArray<void*>*   MarkSweep::_other_refs_stack = NULL;
    46 GrowableArray<void*>*   MarkSweep::_adjusted_pointers = NULL;
    47 bool                         MarkSweep::_pointer_tracking = false;
    48 bool                         MarkSweep::_root_tracking = true;
    50 GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops = NULL;
    51 GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops_moved_to = NULL;
    52 GrowableArray<size_t>   * MarkSweep::_cur_gc_live_oops_size = NULL;
    53 GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops = NULL;
    54 GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops_moved_to = NULL;
    55 GrowableArray<size_t>   * MarkSweep::_last_gc_live_oops_size = NULL;
    56 #endif
    58 void MarkSweep::revisit_weak_klass_link(Klass* k) {
    59   _revisit_klass_stack->push(k);
    60 }
    62 void MarkSweep::follow_weak_klass_links() {
    63   // All klasses on the revisit stack are marked at this point.
    64   // Update and follow all subklass, sibling and implementor links.
    65   for (int i = 0; i < _revisit_klass_stack->length(); i++) {
    66     _revisit_klass_stack->at(i)->follow_weak_klass_links(&is_alive,&keep_alive);
    67   }
    68   follow_stack();
    69 }
    71 MarkSweep::FollowRootClosure  MarkSweep::follow_root_closure;
    73 void MarkSweep::FollowRootClosure::do_oop(oop* p)       { follow_root(p); }
    74 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
    76 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
    78 void MarkSweep::MarkAndPushClosure::do_oop(oop* p)       { mark_and_push(p); }
    79 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
    81 void MarkSweep::follow_stack() {
    82   while (!_marking_stack->is_empty()) {
    83     oop obj = _marking_stack->pop();
    84     assert (obj->is_gc_marked(), "p must be marked");
    85     obj->follow_contents();
    86   }
    87 }
    89 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
    91 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
    93 // We preserve the mark which should be replaced at the end and the location that it
    94 // will go.  Note that the object that this markOop belongs to isn't currently at that
    95 // address but it will be after phase4
    96 void MarkSweep::preserve_mark(oop obj, markOop mark) {
    97   // we try to store preserved marks in the to space of the new generation since this
    98   // is storage which should be available.  Most of the time this should be sufficient
    99   // space for the marks we need to preserve but if it isn't we fall back in using
   100   // GrowableArrays to keep track of the overflow.
   101   if (_preserved_count < _preserved_count_max) {
   102     _preserved_marks[_preserved_count++].init(obj, mark);
   103   } else {
   104     if (_preserved_mark_stack == NULL) {
   105       _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
   106       _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
   107     }
   108     _preserved_mark_stack->push(mark);
   109     _preserved_oop_stack->push(obj);
   110   }
   111 }
   113 MarkSweep::AdjustPointerClosure MarkSweep::adjust_root_pointer_closure(true);
   114 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure(false);
   116 void MarkSweep::AdjustPointerClosure::do_oop(oop* p)       { adjust_pointer(p, _is_root); }
   117 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p, _is_root); }
   119 void MarkSweep::adjust_marks() {
   120   assert(_preserved_oop_stack == NULL ||
   121          _preserved_oop_stack->length() == _preserved_mark_stack->length(),
   122          "inconsistent preserved oop stacks");
   124   // adjust the oops we saved earlier
   125   for (size_t i = 0; i < _preserved_count; i++) {
   126     _preserved_marks[i].adjust_pointer();
   127   }
   129   // deal with the overflow stack
   130   if (_preserved_oop_stack) {
   131     for (int i = 0; i < _preserved_oop_stack->length(); i++) {
   132       oop* p = _preserved_oop_stack->adr_at(i);
   133       adjust_pointer(p);
   134     }
   135   }
   136 }
   138 void MarkSweep::restore_marks() {
   139   assert(_preserved_oop_stack == NULL ||
   140          _preserved_oop_stack->length() == _preserved_mark_stack->length(),
   141          "inconsistent preserved oop stacks");
   142   if (PrintGC && Verbose) {
   143     gclog_or_tty->print_cr("Restoring %d marks", _preserved_count +
   144                   (_preserved_oop_stack ? _preserved_oop_stack->length() : 0));
   145   }
   147   // restore the marks we saved earlier
   148   for (size_t i = 0; i < _preserved_count; i++) {
   149     _preserved_marks[i].restore();
   150   }
   152   // deal with the overflow
   153   if (_preserved_oop_stack) {
   154     for (int i = 0; i < _preserved_oop_stack->length(); i++) {
   155       oop obj       = _preserved_oop_stack->at(i);
   156       markOop mark  = _preserved_mark_stack->at(i);
   157       obj->set_mark(mark);
   158     }
   159   }
   160 }
   162 #ifdef VALIDATE_MARK_SWEEP
   164 void MarkSweep::track_adjusted_pointer(void* p, bool isroot) {
   165   if (!ValidateMarkSweep)
   166     return;
   168   if (!isroot) {
   169     if (_pointer_tracking) {
   170       guarantee(_adjusted_pointers->contains(p), "should have seen this pointer");
   171       _adjusted_pointers->remove(p);
   172     }
   173   } else {
   174     ptrdiff_t index = _root_refs_stack->find(p);
   175     if (index != -1) {
   176       int l = _root_refs_stack->length();
   177       if (l > 0 && l - 1 != index) {
   178         void* last = _root_refs_stack->pop();
   179         assert(last != p, "should be different");
   180         _root_refs_stack->at_put(index, last);
   181       } else {
   182         _root_refs_stack->remove(p);
   183       }
   184     }
   185   }
   186 }
   188 void MarkSweep::check_adjust_pointer(void* p) {
   189   _adjusted_pointers->push(p);
   190 }
   192 class AdjusterTracker: public OopClosure {
   193  public:
   194   AdjusterTracker() {}
   195   void do_oop(oop* o)       { MarkSweep::check_adjust_pointer(o); }
   196   void do_oop(narrowOop* o) { MarkSweep::check_adjust_pointer(o); }
   197 };
   199 void MarkSweep::track_interior_pointers(oop obj) {
   200   if (ValidateMarkSweep) {
   201     _adjusted_pointers->clear();
   202     _pointer_tracking = true;
   204     AdjusterTracker checker;
   205     obj->oop_iterate(&checker);
   206   }
   207 }
   209 void MarkSweep::check_interior_pointers() {
   210   if (ValidateMarkSweep) {
   211     _pointer_tracking = false;
   212     guarantee(_adjusted_pointers->length() == 0, "should have processed the same pointers");
   213   }
   214 }
   216 void MarkSweep::reset_live_oop_tracking(bool at_perm) {
   217   if (ValidateMarkSweep) {
   218     guarantee((size_t)_live_oops->length() == _live_oops_index, "should be at end of live oops");
   219     _live_oops_index = at_perm ? _live_oops_index_at_perm : 0;
   220   }
   221 }
   223 void MarkSweep::register_live_oop(oop p, size_t size) {
   224   if (ValidateMarkSweep) {
   225     _live_oops->push(p);
   226     _live_oops_size->push(size);
   227     _live_oops_index++;
   228   }
   229 }
   231 void MarkSweep::validate_live_oop(oop p, size_t size) {
   232   if (ValidateMarkSweep) {
   233     oop obj = _live_oops->at((int)_live_oops_index);
   234     guarantee(obj == p, "should be the same object");
   235     guarantee(_live_oops_size->at((int)_live_oops_index) == size, "should be the same size");
   236     _live_oops_index++;
   237   }
   238 }
   240 void MarkSweep::live_oop_moved_to(HeapWord* q, size_t size,
   241                                   HeapWord* compaction_top) {
   242   assert(oop(q)->forwardee() == NULL || oop(q)->forwardee() == oop(compaction_top),
   243          "should be moved to forwarded location");
   244   if (ValidateMarkSweep) {
   245     MarkSweep::validate_live_oop(oop(q), size);
   246     _live_oops_moved_to->push(oop(compaction_top));
   247   }
   248   if (RecordMarkSweepCompaction) {
   249     _cur_gc_live_oops->push(q);
   250     _cur_gc_live_oops_moved_to->push(compaction_top);
   251     _cur_gc_live_oops_size->push(size);
   252   }
   253 }
   255 void MarkSweep::compaction_complete() {
   256   if (RecordMarkSweepCompaction) {
   257     GrowableArray<HeapWord*>* _tmp_live_oops          = _cur_gc_live_oops;
   258     GrowableArray<HeapWord*>* _tmp_live_oops_moved_to = _cur_gc_live_oops_moved_to;
   259     GrowableArray<size_t>   * _tmp_live_oops_size     = _cur_gc_live_oops_size;
   261     _cur_gc_live_oops           = _last_gc_live_oops;
   262     _cur_gc_live_oops_moved_to  = _last_gc_live_oops_moved_to;
   263     _cur_gc_live_oops_size      = _last_gc_live_oops_size;
   264     _last_gc_live_oops          = _tmp_live_oops;
   265     _last_gc_live_oops_moved_to = _tmp_live_oops_moved_to;
   266     _last_gc_live_oops_size     = _tmp_live_oops_size;
   267   }
   268 }
   270 void MarkSweep::print_new_location_of_heap_address(HeapWord* q) {
   271   if (!RecordMarkSweepCompaction) {
   272     tty->print_cr("Requires RecordMarkSweepCompaction to be enabled");
   273     return;
   274   }
   276   if (_last_gc_live_oops == NULL) {
   277     tty->print_cr("No compaction information gathered yet");
   278     return;
   279   }
   281   for (int i = 0; i < _last_gc_live_oops->length(); i++) {
   282     HeapWord* old_oop = _last_gc_live_oops->at(i);
   283     size_t    sz      = _last_gc_live_oops_size->at(i);
   284     if (old_oop <= q && q < (old_oop + sz)) {
   285       HeapWord* new_oop = _last_gc_live_oops_moved_to->at(i);
   286       size_t offset = (q - old_oop);
   287       tty->print_cr("Address " PTR_FORMAT, q);
   288       tty->print_cr(" Was in oop " PTR_FORMAT ", size " SIZE_FORMAT ", at offset " SIZE_FORMAT, old_oop, sz, offset);
   289       tty->print_cr(" Now in oop " PTR_FORMAT ", actual address " PTR_FORMAT, new_oop, new_oop + offset);
   290       return;
   291     }
   292   }
   294   tty->print_cr("Address " PTR_FORMAT " not found in live oop information from last GC", q);
   295 }
   296 #endif //VALIDATE_MARK_SWEEP
   298 MarkSweep::IsAliveClosure   MarkSweep::is_alive;
   300 void MarkSweep::IsAliveClosure::do_object(oop p)   { ShouldNotReachHere(); }
   301 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
   303 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
   305 void MarkSweep::KeepAliveClosure::do_oop(oop* p)       { MarkSweep::KeepAliveClosure::do_oop_work(p); }
   306 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
   308 void marksweep_init() { /* empty */ }
   310 #ifndef PRODUCT
   312 void MarkSweep::trace(const char* msg) {
   313   if (TraceMarkSweep)
   314     gclog_or_tty->print("%s", msg);
   315 }
   317 #endif

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