view src/share/vm/gc_implementation/parNew/parOopClosures.inline.hpp @ 3762:5c0a3c1858b1

7048782: CMS: assert(last_chunk_index_to_check<= last_chunk_index) failed: parCardTableModRefBS.cpp:359 Summary: The LNC array is sized before the start of a scavenge, while the heap may expand during a scavenge. With CMS, the last block of an arbitrary suffice of the LNC array may expand due to coalition with the expansion delta. We now take care not to attempt access past the end of the LNC array. LNC array code will be cleaned up and suitably encapsulated as part of the forthcoming performance RFE 7043675. Reviewed-by: brutisso
author ysr
date Thu, 02 Jun 2011 10:23:36 -0700
parents fc2b798ab316
children da91efe96a93
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/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_GC_IMPLEMENTATION_PARNEW_PAROOPCLOSURES_INLINE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_PARNEW_PAROOPCLOSURES_INLINE_HPP

#include "gc_implementation/parNew/parNewGeneration.hpp"
#include "gc_implementation/parNew/parOopClosures.hpp"
#include "memory/cardTableRS.hpp"

template <class T> inline void ParScanWeakRefClosure::do_oop_work(T* p) {
  assert (!oopDesc::is_null(*p), "null weak reference?");
  oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  // weak references are sometimes scanned twice; must check
  // that to-space doesn't already contain this object
  if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
    // we need to ensure that it is copied (see comment in
    // ParScanClosure::do_oop_work).
    klassOop objK = obj->klass();
    markOop m = obj->mark();
    oop new_obj;
    if (m->is_marked()) { // Contains forwarding pointer.
      new_obj = ParNewGeneration::real_forwardee(obj);
    } else {
      size_t obj_sz = obj->size_given_klass(objK->klass_part());
      new_obj = ((ParNewGeneration*)_g)->copy_to_survivor_space(_par_scan_state,
                                                                obj, obj_sz, m);
    }
    oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  }
}

inline void ParScanWeakRefClosure::do_oop_nv(oop* p)       { ParScanWeakRefClosure::do_oop_work(p); }
inline void ParScanWeakRefClosure::do_oop_nv(narrowOop* p) { ParScanWeakRefClosure::do_oop_work(p); }

template <class T> inline void ParScanClosure::par_do_barrier(T* p) {
  assert(generation()->is_in_reserved(p), "expected ref in generation");
  assert(!oopDesc::is_null(*p), "expected non-null object");
  oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  // If p points to a younger generation, mark the card.
  if ((HeapWord*)obj < gen_boundary()) {
    rs()->write_ref_field_gc_par(p, obj);
  }
}

template <class T>
inline void ParScanClosure::do_oop_work(T* p,
                                        bool gc_barrier,
                                        bool root_scan) {
  assert((!Universe::heap()->is_in_reserved(p) ||
          generation()->is_in_reserved(p))
         && (generation()->level() == 0 || gc_barrier),
         "The gen must be right, and we must be doing the barrier "
         "in older generations.");
  T heap_oop = oopDesc::load_heap_oop(p);
  if (!oopDesc::is_null(heap_oop)) {
    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
    if ((HeapWord*)obj < _boundary) {
#ifndef PRODUCT
      if (_g->to()->is_in_reserved(obj)) {
        tty->print_cr("Scanning field (" PTR_FORMAT ") twice?", p);
        GenCollectedHeap* gch =  (GenCollectedHeap*)Universe::heap();
        Space* sp = gch->space_containing(p);
        oop obj = oop(sp->block_start(p));
        assert((HeapWord*)obj < (HeapWord*)p, "Error");
        tty->print_cr("Object: " PTR_FORMAT, obj);
        tty->print_cr("-------");
        obj->print();
        tty->print_cr("-----");
        tty->print_cr("Heap:");
        tty->print_cr("-----");
        gch->print();
        ShouldNotReachHere();
      }
#endif
      // OK, we need to ensure that it is copied.
      // We read the klass and mark in this order, so that we can reliably
      // get the size of the object: if the mark we read is not a
      // forwarding pointer, then the klass is valid: the klass is only
      // overwritten with an overflow next pointer after the object is
      // forwarded.
      klassOop objK = obj->klass();
      markOop m = obj->mark();
      oop new_obj;
      if (m->is_marked()) { // Contains forwarding pointer.
        new_obj = ParNewGeneration::real_forwardee(obj);
        oopDesc::encode_store_heap_oop_not_null(p, new_obj);
      } else {
        size_t obj_sz = obj->size_given_klass(objK->klass_part());
        new_obj = _g->copy_to_survivor_space(_par_scan_state, obj, obj_sz, m);
        oopDesc::encode_store_heap_oop_not_null(p, new_obj);
        if (root_scan) {
          // This may have pushed an object.  If we have a root
          // category with a lot of roots, can't let the queue get too
          // full:
          (void)_par_scan_state->trim_queues(10 * ParallelGCThreads);
        }
      }
      if (gc_barrier) {
        // Now call parent closure
        par_do_barrier(p);
      }
    }
  }
}

inline void ParScanWithBarrierClosure::do_oop_nv(oop* p)       { ParScanClosure::do_oop_work(p, true, false); }
inline void ParScanWithBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, true, false); }

inline void ParScanWithoutBarrierClosure::do_oop_nv(oop* p)       { ParScanClosure::do_oop_work(p, false, false); }
inline void ParScanWithoutBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, false, false); }

#endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PAROOPCLOSURES_INLINE_HPP