duke@435: /*
duke@435:  * Copyright 1997-2005 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: #include "incls/_precompiled.incl"
duke@435: #include "incls/_markSweep.cpp.incl"
duke@435: 
duke@435: GrowableArray<oop>*     MarkSweep::_marking_stack       = NULL;
duke@435: GrowableArray<Klass*>*  MarkSweep::_revisit_klass_stack = NULL;
duke@435: 
duke@435: GrowableArray<oop>*     MarkSweep::_preserved_oop_stack = NULL;
duke@435: GrowableArray<markOop>* MarkSweep::_preserved_mark_stack= NULL;
duke@435: size_t                  MarkSweep::_preserved_count = 0;
duke@435: size_t                  MarkSweep::_preserved_count_max = 0;
duke@435: PreservedMark*          MarkSweep::_preserved_marks = NULL;
duke@435: ReferenceProcessor*     MarkSweep::_ref_processor   = NULL;
duke@435: 
duke@435: #ifdef VALIDATE_MARK_SWEEP
duke@435: GrowableArray<oop*>*    MarkSweep::_root_refs_stack = NULL;
duke@435: GrowableArray<oop> *    MarkSweep::_live_oops = NULL;
duke@435: GrowableArray<oop> *    MarkSweep::_live_oops_moved_to = NULL;
duke@435: GrowableArray<size_t>*  MarkSweep::_live_oops_size = NULL;
duke@435: size_t                  MarkSweep::_live_oops_index = 0;
duke@435: size_t                  MarkSweep::_live_oops_index_at_perm = 0;
duke@435: GrowableArray<oop*>*    MarkSweep::_other_refs_stack = NULL;
duke@435: GrowableArray<oop*>*    MarkSweep::_adjusted_pointers = NULL;
duke@435: bool                    MarkSweep::_pointer_tracking = false;
duke@435: bool                    MarkSweep::_root_tracking = true;
duke@435: 
duke@435: GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops = NULL;
duke@435: GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops_moved_to = NULL;
duke@435: GrowableArray<size_t>   * MarkSweep::_cur_gc_live_oops_size = NULL;
duke@435: GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops = NULL;
duke@435: GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops_moved_to = NULL;
duke@435: GrowableArray<size_t>   * MarkSweep::_last_gc_live_oops_size = NULL;
duke@435: #endif
duke@435: 
duke@435: void MarkSweep::revisit_weak_klass_link(Klass* k) {
duke@435:   _revisit_klass_stack->push(k);
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::follow_weak_klass_links() {
duke@435:   // All klasses on the revisit stack are marked at this point.
duke@435:   // Update and follow all subklass, sibling and implementor links.
duke@435:   for (int i = 0; i < _revisit_klass_stack->length(); i++) {
duke@435:     _revisit_klass_stack->at(i)->follow_weak_klass_links(&is_alive,&keep_alive);
duke@435:   }
duke@435:   follow_stack();
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::mark_and_follow(oop* p) {
duke@435:   assert(Universe::heap()->is_in_reserved(p),
duke@435:          "we should only be traversing objects here");
duke@435:   oop m = *p;
duke@435:   if (m != NULL && !m->mark()->is_marked()) {
duke@435:     mark_object(m);
duke@435:     m->follow_contents();  // Follow contents of the marked object
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MarkSweep::_mark_and_push(oop* p) {
duke@435:   // Push marked object, contents will be followed later
duke@435:   oop m = *p;
duke@435:   mark_object(m);
duke@435:   _marking_stack->push(m);
duke@435: }
duke@435: 
duke@435: MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
duke@435: 
duke@435: void MarkSweep::follow_root(oop* p) {
duke@435:   assert(!Universe::heap()->is_in_reserved(p),
duke@435:          "roots shouldn't be things within the heap");
duke@435: #ifdef VALIDATE_MARK_SWEEP
duke@435:   if (ValidateMarkSweep) {
duke@435:     guarantee(!_root_refs_stack->contains(p), "should only be in here once");
duke@435:     _root_refs_stack->push(p);
duke@435:   }
duke@435: #endif
duke@435:   oop m = *p;
duke@435:   if (m != NULL && !m->mark()->is_marked()) {
duke@435:     mark_object(m);
duke@435:     m->follow_contents();  // Follow contents of the marked object
duke@435:   }
duke@435:   follow_stack();
duke@435: }
duke@435: 
duke@435: MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
duke@435: 
duke@435: void MarkSweep::follow_stack() {
duke@435:   while (!_marking_stack->is_empty()) {
duke@435:     oop obj = _marking_stack->pop();
duke@435:     assert (obj->is_gc_marked(), "p must be marked");
duke@435:     obj->follow_contents();
duke@435:   }
duke@435: }
duke@435: 
duke@435: MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
duke@435: 
duke@435: 
duke@435: // We preserve the mark which should be replaced at the end and the location that it
duke@435: // will go.  Note that the object that this markOop belongs to isn't currently at that
duke@435: // address but it will be after phase4
duke@435: void MarkSweep::preserve_mark(oop obj, markOop mark) {
duke@435:   // we try to store preserved marks in the to space of the new generation since this
duke@435:   // is storage which should be available.  Most of the time this should be sufficient
duke@435:   // space for the marks we need to preserve but if it isn't we fall back in using
duke@435:   // GrowableArrays to keep track of the overflow.
duke@435:   if (_preserved_count < _preserved_count_max) {
duke@435:     _preserved_marks[_preserved_count++].init(obj, mark);
duke@435:   } else {
duke@435:     if (_preserved_mark_stack == NULL) {
duke@435:       _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
duke@435:       _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
duke@435:     }
duke@435:     _preserved_mark_stack->push(mark);
duke@435:     _preserved_oop_stack->push(obj);
duke@435:   }
duke@435: }
duke@435: 
duke@435: MarkSweep::AdjustPointerClosure MarkSweep::adjust_root_pointer_closure(true);
duke@435: MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure(false);
duke@435: 
duke@435: void MarkSweep::adjust_marks() {
duke@435:   assert(_preserved_oop_stack == NULL ||
duke@435:          _preserved_oop_stack->length() == _preserved_mark_stack->length(),
duke@435:          "inconsistent preserved oop stacks");
duke@435: 
duke@435:   // adjust the oops we saved earlier
duke@435:   for (size_t i = 0; i < _preserved_count; i++) {
duke@435:     _preserved_marks[i].adjust_pointer();
duke@435:   }
duke@435: 
duke@435:   // deal with the overflow stack
duke@435:   if (_preserved_oop_stack) {
duke@435:     for (int i = 0; i < _preserved_oop_stack->length(); i++) {
duke@435:       oop* p = _preserved_oop_stack->adr_at(i);
duke@435:       adjust_pointer(p);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MarkSweep::restore_marks() {
duke@435:   assert(_preserved_oop_stack == NULL ||
duke@435:          _preserved_oop_stack->length() == _preserved_mark_stack->length(),
duke@435:          "inconsistent preserved oop stacks");
duke@435:   if (PrintGC && Verbose) {
duke@435:     gclog_or_tty->print_cr("Restoring %d marks", _preserved_count +
duke@435:                   (_preserved_oop_stack ? _preserved_oop_stack->length() : 0));
duke@435:   }
duke@435: 
duke@435:   // restore the marks we saved earlier
duke@435:   for (size_t i = 0; i < _preserved_count; i++) {
duke@435:     _preserved_marks[i].restore();
duke@435:   }
duke@435: 
duke@435:   // deal with the overflow
duke@435:   if (_preserved_oop_stack) {
duke@435:     for (int i = 0; i < _preserved_oop_stack->length(); i++) {
duke@435:       oop obj       = _preserved_oop_stack->at(i);
duke@435:       markOop mark  = _preserved_mark_stack->at(i);
duke@435:       obj->set_mark(mark);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: #ifdef VALIDATE_MARK_SWEEP
duke@435: 
duke@435: void MarkSweep::track_adjusted_pointer(oop* p, oop newobj, bool isroot) {
duke@435:   if (!ValidateMarkSweep)
duke@435:     return;
duke@435: 
duke@435:   if (!isroot) {
duke@435:     if (_pointer_tracking) {
duke@435:       guarantee(_adjusted_pointers->contains(p), "should have seen this pointer");
duke@435:       _adjusted_pointers->remove(p);
duke@435:     }
duke@435:   } else {
duke@435:     ptrdiff_t index = _root_refs_stack->find(p);
duke@435:     if (index != -1) {
duke@435:       int l = _root_refs_stack->length();
duke@435:       if (l > 0 && l - 1 != index) {
duke@435:         oop* last = _root_refs_stack->pop();
duke@435:         assert(last != p, "should be different");
duke@435:         _root_refs_stack->at_put(index, last);
duke@435:       } else {
duke@435:         _root_refs_stack->remove(p);
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::check_adjust_pointer(oop* p) {
duke@435:   _adjusted_pointers->push(p);
duke@435: }
duke@435: 
duke@435: 
duke@435: class AdjusterTracker: public OopClosure {
duke@435:  public:
duke@435:   AdjusterTracker() {};
duke@435:   void do_oop(oop* o)   { MarkSweep::check_adjust_pointer(o); }
duke@435: };
duke@435: 
duke@435: 
duke@435: void MarkSweep::track_interior_pointers(oop obj) {
duke@435:   if (ValidateMarkSweep) {
duke@435:     _adjusted_pointers->clear();
duke@435:     _pointer_tracking = true;
duke@435: 
duke@435:     AdjusterTracker checker;
duke@435:     obj->oop_iterate(&checker);
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::check_interior_pointers() {
duke@435:   if (ValidateMarkSweep) {
duke@435:     _pointer_tracking = false;
duke@435:     guarantee(_adjusted_pointers->length() == 0, "should have processed the same pointers");
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::reset_live_oop_tracking(bool at_perm) {
duke@435:   if (ValidateMarkSweep) {
duke@435:     guarantee((size_t)_live_oops->length() == _live_oops_index, "should be at end of live oops");
duke@435:     _live_oops_index = at_perm ? _live_oops_index_at_perm : 0;
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::register_live_oop(oop p, size_t size) {
duke@435:   if (ValidateMarkSweep) {
duke@435:     _live_oops->push(p);
duke@435:     _live_oops_size->push(size);
duke@435:     _live_oops_index++;
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MarkSweep::validate_live_oop(oop p, size_t size) {
duke@435:   if (ValidateMarkSweep) {
duke@435:     oop obj = _live_oops->at((int)_live_oops_index);
duke@435:     guarantee(obj == p, "should be the same object");
duke@435:     guarantee(_live_oops_size->at((int)_live_oops_index) == size, "should be the same size");
duke@435:     _live_oops_index++;
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MarkSweep::live_oop_moved_to(HeapWord* q, size_t size,
duke@435:                                   HeapWord* compaction_top) {
duke@435:   assert(oop(q)->forwardee() == NULL || oop(q)->forwardee() == oop(compaction_top),
duke@435:          "should be moved to forwarded location");
duke@435:   if (ValidateMarkSweep) {
duke@435:     MarkSweep::validate_live_oop(oop(q), size);
duke@435:     _live_oops_moved_to->push(oop(compaction_top));
duke@435:   }
duke@435:   if (RecordMarkSweepCompaction) {
duke@435:     _cur_gc_live_oops->push(q);
duke@435:     _cur_gc_live_oops_moved_to->push(compaction_top);
duke@435:     _cur_gc_live_oops_size->push(size);
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::compaction_complete() {
duke@435:   if (RecordMarkSweepCompaction) {
duke@435:     GrowableArray<HeapWord*>* _tmp_live_oops          = _cur_gc_live_oops;
duke@435:     GrowableArray<HeapWord*>* _tmp_live_oops_moved_to = _cur_gc_live_oops_moved_to;
duke@435:     GrowableArray<size_t>   * _tmp_live_oops_size     = _cur_gc_live_oops_size;
duke@435: 
duke@435:     _cur_gc_live_oops           = _last_gc_live_oops;
duke@435:     _cur_gc_live_oops_moved_to  = _last_gc_live_oops_moved_to;
duke@435:     _cur_gc_live_oops_size      = _last_gc_live_oops_size;
duke@435:     _last_gc_live_oops          = _tmp_live_oops;
duke@435:     _last_gc_live_oops_moved_to = _tmp_live_oops_moved_to;
duke@435:     _last_gc_live_oops_size     = _tmp_live_oops_size;
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void MarkSweep::print_new_location_of_heap_address(HeapWord* q) {
duke@435:   if (!RecordMarkSweepCompaction) {
duke@435:     tty->print_cr("Requires RecordMarkSweepCompaction to be enabled");
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   if (_last_gc_live_oops == NULL) {
duke@435:     tty->print_cr("No compaction information gathered yet");
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   for (int i = 0; i < _last_gc_live_oops->length(); i++) {
duke@435:     HeapWord* old_oop = _last_gc_live_oops->at(i);
duke@435:     size_t    sz      = _last_gc_live_oops_size->at(i);
duke@435:     if (old_oop <= q && q < (old_oop + sz)) {
duke@435:       HeapWord* new_oop = _last_gc_live_oops_moved_to->at(i);
duke@435:       size_t offset = (q - old_oop);
duke@435:       tty->print_cr("Address " PTR_FORMAT, q);
duke@435:       tty->print_cr(" Was in oop " PTR_FORMAT ", size %d, at offset %d", old_oop, sz, offset);
duke@435:       tty->print_cr(" Now in oop " PTR_FORMAT ", actual address " PTR_FORMAT, new_oop, new_oop + offset);
duke@435:       return;
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   tty->print_cr("Address " PTR_FORMAT " not found in live oop information from last GC", q);
duke@435: }
duke@435: #endif //VALIDATE_MARK_SWEEP
duke@435: 
duke@435: MarkSweep::IsAliveClosure MarkSweep::is_alive;
duke@435: 
duke@435: void MarkSweep::KeepAliveClosure::do_oop(oop* p) {
duke@435: #ifdef VALIDATE_MARK_SWEEP
duke@435:   if (ValidateMarkSweep) {
duke@435:     if (!Universe::heap()->is_in_reserved(p)) {
duke@435:       _root_refs_stack->push(p);
duke@435:     } else {
duke@435:       _other_refs_stack->push(p);
duke@435:     }
duke@435:   }
duke@435: #endif
duke@435:   mark_and_push(p);
duke@435: }
duke@435: 
duke@435: MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
duke@435: 
duke@435: void marksweep_init() { /* empty */ }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: 
duke@435: void MarkSweep::trace(const char* msg) {
duke@435:   if (TraceMarkSweep)
duke@435:     gclog_or_tty->print("%s", msg);
duke@435: }
duke@435: 
duke@435: #endif