jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegion.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/heapRegion.cpp@15c5903cf9e1 (annotated)

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

Mon, 03 Aug 2009 12:59:30 -0700

author: johnc
date: Mon, 03 Aug 2009 12:59:30 -0700
changeset 1324: 15c5903cf9e1
parent 1301: 18f526145aea
child 1377: 2c79770d1f6e
permissions: -rw-r--r--

6865703: G1: Parallelize hot card cache cleanup
Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads.
Reviewed-by: jmasa, tonyp

 /*
  * 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@15c5903cf9e1 (annotated)

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