jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegion.cpp@18f526145aea (annotated)

src/share/vm/gc_implementation/g1/heapRegion.cpp@18f526145aea (annotated)

src/share/vm/gc_implementation/g1/heapRegion.cpp

Wed, 29 Jul 2009 16:00:35 -0700

author: trims
date: Wed, 29 Jul 2009 16:00:35 -0700
changeset 1301: 18f526145aea
parent 1280: df6caf649ff7
parent 1279: bd02caa94611
child 1377: 2c79770d1f6e
permissions: -rw-r--r--

Merge

 /*
  * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_heapRegion.cpp.incl"
 HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1,
                                  HeapRegion* hr, OopClosure* cl,
                                  CardTableModRefBS::PrecisionStyle precision,
                                  FilterKind fk) :
   ContiguousSpaceDCTOC(hr, cl, precision, NULL),
   _hr(hr), _fk(fk), _g1(g1)
 {}
 FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r,
                                                    OopClosure* oc) :
   _r_bottom(r->bottom()), _r_end(r->end()),
   _oc(oc), _out_of_region(0)
 {}
 class VerifyLiveClosure: public OopClosure {
 private:
   G1CollectedHeap* _g1h;
   CardTableModRefBS* _bs;
   oop _containing_obj;
   bool _failures;
   int _n_failures;
   bool _use_prev_marking;
 public:
   // use_prev_marking == true  -> use "prev" marking information,
   // use_prev_marking == false -> use "next" marking information
   VerifyLiveClosure(G1CollectedHeap* g1h, bool use_prev_marking) :
     _g1h(g1h), _bs(NULL), _containing_obj(NULL),
     _failures(false), _n_failures(0), _use_prev_marking(use_prev_marking)
   {
     BarrierSet* bs = _g1h->barrier_set();
     if (bs->is_a(BarrierSet::CardTableModRef))
       _bs = (CardTableModRefBS*)bs;
   }
   void set_containing_obj(oop obj) {
     _containing_obj = obj;
   }
   bool failures() { return _failures; }
   int n_failures() { return _n_failures; }
   virtual void do_oop(narrowOop* p) { do_oop_work(p); }
   virtual void do_oop(      oop* p) { do_oop_work(p); }
   template <class T> void do_oop_work(T* p) {
     assert(_containing_obj != NULL, "Precondition");
     assert(!_g1h->is_obj_dead_cond(_containing_obj, _use_prev_marking),
            "Precondition");
     T heap_oop = oopDesc::load_heap_oop(p);
     if (!oopDesc::is_null(heap_oop)) {
       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
       bool failed = false;
       if (!_g1h->is_in_closed_subset(obj) ||
           _g1h->is_obj_dead_cond(obj, _use_prev_marking)) {
         if (!_failures) {
           gclog_or_tty->print_cr("");
           gclog_or_tty->print_cr("----------");
         }
         if (!_g1h->is_in_closed_subset(obj)) {
           gclog_or_tty->print_cr("Field "PTR_FORMAT
                         " of live obj "PTR_FORMAT
                         " points to obj "PTR_FORMAT
                         " not in the heap.",
                         p, (void*) _containing_obj, (void*) obj);
         } else {
           gclog_or_tty->print_cr("Field "PTR_FORMAT
                         " of live obj "PTR_FORMAT
                         " points to dead obj "PTR_FORMAT".",
                         p, (void*) _containing_obj, (void*) obj);
         }
         gclog_or_tty->print_cr("Live obj:");
         _containing_obj->print_on(gclog_or_tty);
         gclog_or_tty->print_cr("Bad referent:");
         obj->print_on(gclog_or_tty);
         gclog_or_tty->print_cr("----------");
         _failures = true;
         failed = true;
         _n_failures++;
       }
       if (!_g1h->full_collection()) {
         HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
         HeapRegion* to   = _g1h->heap_region_containing(obj);
         if (from != NULL && to != NULL &&
             from != to &&
             !to->isHumongous()) {
           jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
           jbyte cv_field = *_bs->byte_for_const(p);
           const jbyte dirty = CardTableModRefBS::dirty_card_val();
           bool is_bad = !(from->is_young()
                           || to->rem_set()->contains_reference(p)
                           || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed
                               (_containing_obj->is_objArray() ?
                                   cv_field == dirty
                                : cv_obj == dirty || cv_field == dirty));
           if (is_bad) {
             if (!_failures) {
               gclog_or_tty->print_cr("");
               gclog_or_tty->print_cr("----------");
             }
             gclog_or_tty->print_cr("Missing rem set entry:");
             gclog_or_tty->print_cr("Field "PTR_FORMAT
                           " of obj "PTR_FORMAT
                           ", in region %d ["PTR_FORMAT
                           ", "PTR_FORMAT"),",
                           p, (void*) _containing_obj,
                           from->hrs_index(),
                           from->bottom(),
                           from->end());
             _containing_obj->print_on(gclog_or_tty);
             gclog_or_tty->print_cr("points to obj "PTR_FORMAT
                           " in region %d ["PTR_FORMAT
                           ", "PTR_FORMAT").",
                           (void*) obj, to->hrs_index(),
                           to->bottom(), to->end());
             obj->print_on(gclog_or_tty);
             gclog_or_tty->print_cr("Obj head CTE = %d, field CTE = %d.",
                           cv_obj, cv_field);
             gclog_or_tty->print_cr("----------");
             _failures = true;
             if (!failed) _n_failures++;
           }
         }
       }
     }
   }
 };
 template<class ClosureType>
 HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h,
                                HeapRegion* hr,
                                HeapWord* cur, HeapWord* top) {
   oop cur_oop = oop(cur);
   int oop_size = cur_oop->size();
   HeapWord* next_obj = cur + oop_size;
   while (next_obj < top) {
     // Keep filtering the remembered set.
     if (!g1h->is_obj_dead(cur_oop, hr)) {
       // Bottom lies entirely below top, so we can call the
       // non-memRegion version of oop_iterate below.
       cur_oop->oop_iterate(cl);
     }
     cur = next_obj;
     cur_oop = oop(cur);
     oop_size = cur_oop->size();
     next_obj = cur + oop_size;
   }
   return cur;
 }
 void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr,
                                               HeapWord* bottom,
                                               HeapWord* top,
                                               OopClosure* cl) {
   G1CollectedHeap* g1h = _g1;
   int oop_size;
   OopClosure* cl2 = cl;
   FilterIntoCSClosure intoCSFilt(this, g1h, cl);
   FilterOutOfRegionClosure outOfRegionFilt(_hr, cl);
   switch (_fk) {
   case IntoCSFilterKind:      cl2 = &intoCSFilt; break;
   case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break;
   }
   // Start filtering what we add to the remembered set. If the object is
   // not considered dead, either because it is marked (in the mark bitmap)
   // or it was allocated after marking finished, then we add it. Otherwise
   // we can safely ignore the object.
   if (!g1h->is_obj_dead(oop(bottom), _hr)) {
     oop_size = oop(bottom)->oop_iterate(cl2, mr);
   } else {
     oop_size = oop(bottom)->size();
   }
   bottom += oop_size;
   if (bottom < top) {
     // We replicate the loop below for several kinds of possible filters.
     switch (_fk) {
     case NoFilterKind:
       bottom = walk_mem_region_loop(cl, g1h, _hr, bottom, top);
       break;
     case IntoCSFilterKind: {
       FilterIntoCSClosure filt(this, g1h, cl);
       bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
       break;
     }
     case OutOfRegionFilterKind: {
       FilterOutOfRegionClosure filt(_hr, cl);
       bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
       break;
     }
     default:
       ShouldNotReachHere();
     }
     // Last object. Need to do dead-obj filtering here too.
     if (!g1h->is_obj_dead(oop(bottom), _hr)) {
       oop(bottom)->oop_iterate(cl2, mr);
     }
   }
 }
 void HeapRegion::reset_after_compaction() {
   G1OffsetTableContigSpace::reset_after_compaction();
   // After a compaction the mark bitmap is invalid, so we must
   // treat all objects as being inside the unmarked area.
   zero_marked_bytes();
   init_top_at_mark_start();
 }
 DirtyCardToOopClosure*
 HeapRegion::new_dcto_closure(OopClosure* cl,
                              CardTableModRefBS::PrecisionStyle precision,
                              HeapRegionDCTOC::FilterKind fk) {
   return new HeapRegionDCTOC(G1CollectedHeap::heap(),
                              this, cl, precision, fk);
 }
 void HeapRegion::hr_clear(bool par, bool clear_space) {
   _humongous_type = NotHumongous;
   _humongous_start_region = NULL;
   _in_collection_set = false;
   _is_gc_alloc_region = false;
   // Age stuff (if parallel, this will be done separately, since it needs
   // to be sequential).
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   set_young_index_in_cset(-1);
   uninstall_surv_rate_group();
   set_young_type(NotYoung);
   // In case it had been the start of a humongous sequence, reset its end.
   set_end(_orig_end);
   if (!par) {
     // If this is parallel, this will be done later.
     HeapRegionRemSet* hrrs = rem_set();
     if (hrrs != NULL) hrrs->clear();
     _claimed = InitialClaimValue;
   }
   zero_marked_bytes();
   set_sort_index(-1);
   _offsets.resize(HeapRegion::GrainWords);
   init_top_at_mark_start();
   if (clear_space) clear(SpaceDecorator::Mangle);
 }
 // <PREDICTION>
 void HeapRegion::calc_gc_efficiency() {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   _gc_efficiency = (double) garbage_bytes() /
                             g1h->predict_region_elapsed_time_ms(this, false);
 }
 // </PREDICTION>
 void HeapRegion::set_startsHumongous() {
   _humongous_type = StartsHumongous;
   _humongous_start_region = this;
   assert(end() == _orig_end, "Should be normal before alloc.");
 }
 bool HeapRegion::claimHeapRegion(jint claimValue) {
   jint current = _claimed;
   if (current != claimValue) {
     jint res = Atomic::cmpxchg(claimValue, &_claimed, current);
     if (res == current) {
       return true;
     }
   }
   return false;
 }
 HeapWord* HeapRegion::next_block_start_careful(HeapWord* addr) {
   HeapWord* low = addr;
   HeapWord* high = end();
   while (low < high) {
     size_t diff = pointer_delta(high, low);
     // Must add one below to bias toward the high amount.  Otherwise, if
   // "high" were at the desired value, and "low" were one less, we
     // would not converge on "high".  This is not symmetric, because
     // we set "high" to a block start, which might be the right one,
     // which we don't do for "low".
     HeapWord* middle = low + (diff+1)/2;
     if (middle == high) return high;
     HeapWord* mid_bs = block_start_careful(middle);
     if (mid_bs < addr) {
       low = middle;
     } else {
       high = mid_bs;
     }
   }
   assert(low == high && low >= addr, "Didn't work.");
   return low;
 }
 void HeapRegion::set_next_on_unclean_list(HeapRegion* r) {
   assert(r == NULL || r->is_on_unclean_list(), "Malformed unclean list.");
   _next_in_special_set = r;
 }
 void HeapRegion::set_on_unclean_list(bool b) {
   _is_on_unclean_list = b;
 }
 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
   G1OffsetTableContigSpace::initialize(mr, false, mangle_space);
   hr_clear(false/*par*/, clear_space);
 }
 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
 #endif // _MSC_VER
 HeapRegion::
 HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
                      MemRegion mr, bool is_zeroed)
   : G1OffsetTableContigSpace(sharedOffsetArray, mr, is_zeroed),
     _next_fk(HeapRegionDCTOC::NoFilterKind),
     _hrs_index(-1),
     _humongous_type(NotHumongous), _humongous_start_region(NULL),
     _in_collection_set(false), _is_gc_alloc_region(false),
     _is_on_free_list(false), _is_on_unclean_list(false),
     _next_in_special_set(NULL), _orig_end(NULL),
     _claimed(InitialClaimValue), _evacuation_failed(false),
     _prev_marked_bytes(0), _next_marked_bytes(0), _sort_index(-1),
     _young_type(NotYoung), _next_young_region(NULL),
     _next_dirty_cards_region(NULL),
     _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
     _rem_set(NULL), _zfs(NotZeroFilled)
 {
   _orig_end = mr.end();
   // Note that initialize() will set the start of the unmarked area of the
   // region.
   this->initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
   set_top(bottom());
   set_saved_mark();
   _rem_set =  new HeapRegionRemSet(sharedOffsetArray, this);
   assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant.");
   // In case the region is allocated during a pause, note the top.
   // We haven't done any counting on a brand new region.
   _top_at_conc_mark_count = bottom();
 }
 class NextCompactionHeapRegionClosure: public HeapRegionClosure {
   const HeapRegion* _target;
   bool _target_seen;
   HeapRegion* _last;
   CompactibleSpace* _res;
 public:
   NextCompactionHeapRegionClosure(const HeapRegion* target) :
     _target(target), _target_seen(false), _res(NULL) {}
   bool doHeapRegion(HeapRegion* cur) {
     if (_target_seen) {
       if (!cur->isHumongous()) {
         _res = cur;
         return true;
       }
     } else if (cur == _target) {
       _target_seen = true;
     }
     return false;
   }
   CompactibleSpace* result() { return _res; }
 };
 CompactibleSpace* HeapRegion::next_compaction_space() const {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   // cast away const-ness
   HeapRegion* r = (HeapRegion*) this;
   NextCompactionHeapRegionClosure blk(r);
   g1h->heap_region_iterate_from(r, &blk);
   return blk.result();
 }
 void HeapRegion::set_continuesHumongous(HeapRegion* start) {
   // The order is important here.
   start->add_continuingHumongousRegion(this);
   _humongous_type = ContinuesHumongous;
   _humongous_start_region = start;
 }
 void HeapRegion::add_continuingHumongousRegion(HeapRegion* cont) {
   // Must join the blocks of the current H region seq with the block of the
   // added region.
   offsets()->join_blocks(bottom(), cont->bottom());
   arrayOop obj = (arrayOop)(bottom());
   obj->set_length((int) (obj->length() + cont->capacity()/jintSize));
   set_end(cont->end());
   set_top(cont->end());
 }
 void HeapRegion::save_marks() {
   set_saved_mark();
 }
 void HeapRegion::oops_in_mr_iterate(MemRegion mr, OopClosure* cl) {
   HeapWord* p = mr.start();
   HeapWord* e = mr.end();
   oop obj;
   while (p < e) {
     obj = oop(p);
     p += obj->oop_iterate(cl);
   }
   assert(p == e, "bad memregion: doesn't end on obj boundary");
 }
 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
 void HeapRegion::oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \
   ContiguousSpace::oop_since_save_marks_iterate##nv_suffix(cl);              \
 }
 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN)
 void HeapRegion::oop_before_save_marks_iterate(OopClosure* cl) {
   oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl);
 }
 #ifdef DEBUG
 HeapWord* HeapRegion::allocate(size_t size) {
   jint state = zero_fill_state();
   assert(!G1CollectedHeap::heap()->allocs_are_zero_filled() ||
          zero_fill_is_allocated(),
          "When ZF is on, only alloc in ZF'd regions");
   return G1OffsetTableContigSpace::allocate(size);
 }
 #endif
 void HeapRegion::set_zero_fill_state_work(ZeroFillState zfs) {
   assert(top() == bottom() || zfs == Allocated,
          "Region must be empty, or we must be setting it to allocated.");
   assert(ZF_mon->owned_by_self() ||
          Universe::heap()->is_gc_active(),
          "Must hold the lock or be a full GC to modify.");
   _zfs = zfs;
 }
 void HeapRegion::set_zero_fill_complete() {
   set_zero_fill_state_work(ZeroFilled);
   if (ZF_mon->owned_by_self()) {
     ZF_mon->notify_all();
   }
 }
 void HeapRegion::ensure_zero_filled() {
   MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
   ensure_zero_filled_locked();
 }
 void HeapRegion::ensure_zero_filled_locked() {
   assert(ZF_mon->owned_by_self(), "Precondition");
   bool should_ignore_zf = SafepointSynchronize::is_at_safepoint();
   assert(should_ignore_zf || Heap_lock->is_locked(),
          "Either we're in a GC or we're allocating a region.");
   switch (zero_fill_state()) {
   case HeapRegion::NotZeroFilled:
     set_zero_fill_in_progress(Thread::current());
     {
       ZF_mon->unlock();
       Copy::fill_to_words(bottom(), capacity()/HeapWordSize);
       ZF_mon->lock_without_safepoint_check();
     }
     // A trap.
     guarantee(zero_fill_state() == HeapRegion::ZeroFilling
               && zero_filler() == Thread::current(),
               "AHA!  Tell Dave D if you see this...");
     set_zero_fill_complete();
     // gclog_or_tty->print_cr("Did sync ZF.");
     ConcurrentZFThread::note_sync_zfs();
     break;
   case HeapRegion::ZeroFilling:
     if (should_ignore_zf) {
       // We can "break" the lock and take over the work.
       Copy::fill_to_words(bottom(), capacity()/HeapWordSize);
       set_zero_fill_complete();
       ConcurrentZFThread::note_sync_zfs();
       break;
     } else {
       ConcurrentZFThread::wait_for_ZF_completed(this);
     }
   case HeapRegion::ZeroFilled:
     // Nothing to do.
     break;
   case HeapRegion::Allocated:
     guarantee(false, "Should not call on allocated regions.");
   }
   assert(zero_fill_state() == HeapRegion::ZeroFilled, "Post");
 }
 HeapWord*
 HeapRegion::object_iterate_mem_careful(MemRegion mr,
                                                  ObjectClosure* cl) {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   // We used to use "block_start_careful" here.  But we're actually happy
   // to update the BOT while we do this...
   HeapWord* cur = block_start(mr.start());
   mr = mr.intersection(used_region());
   if (mr.is_empty()) return NULL;
   // Otherwise, find the obj that extends onto mr.start().
   assert(cur <= mr.start()
          && (oop(cur)->klass_or_null() == NULL ||
              cur + oop(cur)->size() > mr.start()),
          "postcondition of block_start");
   oop obj;
   while (cur < mr.end()) {
     obj = oop(cur);
     if (obj->klass_or_null() == NULL) {
       // Ran into an unparseable point.
       return cur;
     } else if (!g1h->is_obj_dead(obj)) {
       cl->do_object(obj);
     }
     if (cl->abort()) return cur;
     // The check above must occur before the operation below, since an
     // abort might invalidate the "size" operation.
     cur += obj->size();
   }
   return NULL;
 }
 HeapWord*
 HeapRegion::
 oops_on_card_seq_iterate_careful(MemRegion mr,
                                      FilterOutOfRegionClosure* cl) {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   // If we're within a stop-world GC, then we might look at a card in a
   // GC alloc region that extends onto a GC LAB, which may not be
   // parseable.  Stop such at the "saved_mark" of the region.
   if (G1CollectedHeap::heap()->is_gc_active()) {
     mr = mr.intersection(used_region_at_save_marks());
   } else {
     mr = mr.intersection(used_region());
   }
   if (mr.is_empty()) return NULL;
   // Otherwise, find the obj that extends onto mr.start().
   // We used to use "block_start_careful" here.  But we're actually happy
   // to update the BOT while we do this...
   HeapWord* cur = block_start(mr.start());
   assert(cur <= mr.start(), "Postcondition");
   while (cur <= mr.start()) {
     if (oop(cur)->klass_or_null() == NULL) {
       // Ran into an unparseable point.
       return cur;
     }
     // Otherwise...
     int sz = oop(cur)->size();
     if (cur + sz > mr.start()) break;
     // Otherwise, go on.
     cur = cur + sz;
   }
   oop obj;
   obj = oop(cur);
   // If we finish this loop...
   assert(cur <= mr.start()
          && obj->klass_or_null() != NULL
          && cur + obj->size() > mr.start(),
          "Loop postcondition");
   if (!g1h->is_obj_dead(obj)) {
     obj->oop_iterate(cl, mr);
   }
   HeapWord* next;
   while (cur < mr.end()) {
     obj = oop(cur);
     if (obj->klass_or_null() == NULL) {
       // Ran into an unparseable point.
       return cur;
     };
     // Otherwise:
     next = (cur + obj->size());
     if (!g1h->is_obj_dead(obj)) {
       if (next < mr.end()) {
         obj->oop_iterate(cl);
       } else {
         // this obj spans the boundary.  If it's an array, stop at the
         // boundary.
         if (obj->is_objArray()) {
           obj->oop_iterate(cl, mr);
         } else {
           obj->oop_iterate(cl);
         }
       }
     }
     cur = next;
   }
   return NULL;
 }
 void HeapRegion::print() const { print_on(gclog_or_tty); }
 void HeapRegion::print_on(outputStream* st) const {
   if (isHumongous()) {
     if (startsHumongous())
       st->print(" HS");
     else
       st->print(" HC");
   } else {
     st->print("   ");
   }
   if (in_collection_set())
     st->print(" CS");
   else if (is_gc_alloc_region())
     st->print(" A ");
   else
     st->print("   ");
   if (is_young())
     st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y "));
   else
     st->print("   ");
   if (is_empty())
     st->print(" F");
   else
     st->print("  ");
   st->print(" %d", _gc_time_stamp);
   G1OffsetTableContigSpace::print_on(st);
 }
 void HeapRegion::verify(bool allow_dirty) const {
   verify(allow_dirty, /* use_prev_marking */ true);
 }
 #define OBJ_SAMPLE_INTERVAL 0
 #define BLOCK_SAMPLE_INTERVAL 100
 // This really ought to be commoned up into OffsetTableContigSpace somehow.
 // We would need a mechanism to make that code skip dead objects.
 void HeapRegion::verify(bool allow_dirty, bool use_prev_marking) const {
   G1CollectedHeap* g1 = G1CollectedHeap::heap();
   HeapWord* p = bottom();
   HeapWord* prev_p = NULL;
   int objs = 0;
   int blocks = 0;
   VerifyLiveClosure vl_cl(g1, use_prev_marking);
   while (p < top()) {
     size_t size = oop(p)->size();
     if (blocks == BLOCK_SAMPLE_INTERVAL) {
       guarantee(p == block_start_const(p + (size/2)),
                 "check offset computation");
       blocks = 0;
     } else {
       blocks++;
     }
     if (objs == OBJ_SAMPLE_INTERVAL) {
       oop obj = oop(p);
       if (!g1->is_obj_dead_cond(obj, this, use_prev_marking)) {
         obj->verify();
         vl_cl.set_containing_obj(obj);
         obj->oop_iterate(&vl_cl);
         if (G1MaxVerifyFailures >= 0
             && vl_cl.n_failures() >= G1MaxVerifyFailures) break;
       }
       objs = 0;
     } else {
       objs++;
     }
     prev_p = p;
     p += size;
   }
   HeapWord* rend = end();
   HeapWord* rtop = top();
   if (rtop < rend) {
     guarantee(block_start_const(rtop + (rend - rtop) / 2) == rtop,
               "check offset computation");
   }
   if (vl_cl.failures()) {
     gclog_or_tty->print_cr("Heap:");
     G1CollectedHeap::heap()->print_on(gclog_or_tty, true /* extended */);
     gclog_or_tty->print_cr("");
   }
   if (VerifyDuringGC &&
       G1VerifyConcMarkPrintReachable &&
       vl_cl.failures()) {
     g1->concurrent_mark()->print_prev_bitmap_reachable();
   }
   guarantee(!vl_cl.failures(), "region verification failed");
   guarantee(p == top(), "end of last object must match end of space");
 }
 // G1OffsetTableContigSpace code; copied from space.cpp.  Hope this can go
 // away eventually.
 void G1OffsetTableContigSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
   // false ==> we'll do the clearing if there's clearing to be done.
   ContiguousSpace::initialize(mr, false, mangle_space);
   _offsets.zero_bottom_entry();
   _offsets.initialize_threshold();
   if (clear_space) clear(mangle_space);
 }
 void G1OffsetTableContigSpace::clear(bool mangle_space) {
   ContiguousSpace::clear(mangle_space);
   _offsets.zero_bottom_entry();
   _offsets.initialize_threshold();
 }
 void G1OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
   Space::set_bottom(new_bottom);
   _offsets.set_bottom(new_bottom);
 }
 void G1OffsetTableContigSpace::set_end(HeapWord* new_end) {
   Space::set_end(new_end);
   _offsets.resize(new_end - bottom());
 }
 void G1OffsetTableContigSpace::print() const {
   print_short();
   gclog_or_tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
                 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
                 bottom(), top(), _offsets.threshold(), end());
 }
 HeapWord* G1OffsetTableContigSpace::initialize_threshold() {
   return _offsets.initialize_threshold();
 }
 HeapWord* G1OffsetTableContigSpace::cross_threshold(HeapWord* start,
                                                     HeapWord* end) {
   _offsets.alloc_block(start, end);
   return _offsets.threshold();
 }
 HeapWord* G1OffsetTableContigSpace::saved_mark_word() const {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   assert( _gc_time_stamp <= g1h->get_gc_time_stamp(), "invariant" );
   if (_gc_time_stamp < g1h->get_gc_time_stamp())
     return top();
   else
     return ContiguousSpace::saved_mark_word();
 }
 void G1OffsetTableContigSpace::set_saved_mark() {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp();
   if (_gc_time_stamp < curr_gc_time_stamp) {
     // The order of these is important, as another thread might be
     // about to start scanning this region. If it does so after
     // set_saved_mark and before _gc_time_stamp = ..., then the latter
     // will be false, and it will pick up top() as the high water mark
     // of region. If it does so after _gc_time_stamp = ..., then it
     // will pick up the right saved_mark_word() as the high water mark
     // of the region. Either way, the behaviour will be correct.
     ContiguousSpace::set_saved_mark();
     OrderAccess::storestore();
     _gc_time_stamp = curr_gc_time_stamp;
     // The following fence is to force a flush of the writes above, but
     // is strictly not needed because when an allocating worker thread
     // calls set_saved_mark() it does so under the ParGCRareEvent_lock;
     // when the lock is released, the write will be flushed.
     // OrderAccess::fence();
   }
 }
 G1OffsetTableContigSpace::
 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
                          MemRegion mr, bool is_zeroed) :
   _offsets(sharedOffsetArray, mr),
   _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true),
   _gc_time_stamp(0)
 {
   _offsets.set_space(this);
   initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
 }
 size_t RegionList::length() {
   size_t len = 0;
   HeapRegion* cur = hd();
   DEBUG_ONLY(HeapRegion* last = NULL);
   while (cur != NULL) {
     len++;
     DEBUG_ONLY(last = cur);
     cur = get_next(cur);
   }
   assert(last == tl(), "Invariant");
   return len;
 }
 void RegionList::insert_before_head(HeapRegion* r) {
   assert(well_formed(), "Inv");
   set_next(r, hd());
   _hd = r;
   _sz++;
   if (tl() == NULL) _tl = r;
   assert(well_formed(), "Inv");
 }
 void RegionList::prepend_list(RegionList* new_list) {
   assert(well_formed(), "Precondition");
   assert(new_list->well_formed(), "Precondition");
   HeapRegion* new_tl = new_list->tl();
   if (new_tl != NULL) {
     set_next(new_tl, hd());
     _hd = new_list->hd();
     _sz += new_list->sz();
     if (tl() == NULL) _tl = new_list->tl();
   } else {
     assert(new_list->hd() == NULL && new_list->sz() == 0, "Inv");
   }
   assert(well_formed(), "Inv");
 }
 void RegionList::delete_after(HeapRegion* r) {
   assert(well_formed(), "Precondition");
   HeapRegion* next = get_next(r);
   assert(r != NULL, "Precondition");
   HeapRegion* next_tl = get_next(next);
   set_next(r, next_tl);
   dec_sz();
   if (next == tl()) {
     assert(next_tl == NULL, "Inv");
     _tl = r;
   }
   assert(well_formed(), "Inv");
 }
 HeapRegion* RegionList::pop() {
   assert(well_formed(), "Inv");
   HeapRegion* res = hd();
   if (res != NULL) {
     _hd = get_next(res);
     _sz--;
     set_next(res, NULL);
     if (sz() == 0) _tl = NULL;
   }
   assert(well_formed(), "Inv");
   return res;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/heapRegion.cpp@18f526145aea (annotated)

src/share/vm/gc_implementation/g1/heapRegion.cpp