hotspot/src/share/vm/gc_implementation/g1/g1OopClosures.inline.hpp
author johnc
Fri, 02 Dec 2011 12:39:23 -0800
changeset 11202 6be05533238b
parent 9994 efb74fdbd46e
child 11584 e1df4d08a1f4
permissions -rw-r--r--
7114095: G1: assert(obj == oopDesc::load_decode_heap_oop(p)) failed: p should still be pointing to obj Summary: As a result of the changes for 4965777, the G1 reference field scanning closure could be applied to the discovered field of a reference object twice. The failing assert is too strong if the result of the first application of the closure is stolen, and the referenced object, evacuated by another worker thread. Reviewed-by: ysr, tonyp

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP

#include "gc_implementation/g1/concurrentMark.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1OopClosures.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"

/*
 * This really ought to be an inline function, but apparently the C++
 * compiler sometimes sees fit to ignore inline declarations.  Sigh.
 */

// This must a ifdef'ed because the counting it controls is in a
// perf-critical inner loop.
#define FILTERINTOCSCLOSURE_DOHISTOGRAMCOUNT 0

template <class T> inline void FilterIntoCSClosure::do_oop_nv(T* p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  if (!oopDesc::is_null(heap_oop) &&
      _g1->obj_in_cs(oopDesc::decode_heap_oop_not_null(heap_oop))) {
    _oc->do_oop(p);
#if FILTERINTOCSCLOSURE_DOHISTOGRAMCOUNT
    if (_dcto_cl != NULL)
      _dcto_cl->incr_count();
#endif
  }
}

#define FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT 0

template <class T> inline void FilterOutOfRegionClosure::do_oop_nv(T* p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  if (!oopDesc::is_null(heap_oop)) {
    HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop);
    if (obj_hw < _r_bottom || obj_hw >= _r_end) {
      _oc->do_oop(p);
#if FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT
      _out_of_region++;
#endif
    }
  }
}

// This closure is applied to the fields of the objects that have just been copied.
template <class T> inline void G1ParScanClosure::do_oop_nv(T* p) {
  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 (_g1->in_cset_fast_test(obj)) {
      // We're not going to even bother checking whether the object is
      // already forwarded or not, as this usually causes an immediate
      // stall. We'll try to prefetch the object (for write, given that
      // we might need to install the forwarding reference) and we'll
      // get back to it when pop it from the queue
      Prefetch::write(obj->mark_addr(), 0);
      Prefetch::read(obj->mark_addr(), (HeapWordSize*2));

      // slightly paranoid test; I'm trying to catch potential
      // problems before we go into push_on_queue to know where the
      // problem is coming from
      assert((obj == oopDesc::load_decode_heap_oop(p)) ||
             (obj->is_forwarded() &&
                 obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
             "p should still be pointing to obj or to its forwardee");

      _par_scan_state->push_on_queue(p);
    } else {
      _par_scan_state->update_rs(_from, p, _par_scan_state->queue_num());
    }
  }
}

template <class T> inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
  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 (_g1->in_cset_fast_test(obj)) {
      Prefetch::write(obj->mark_addr(), 0);
      Prefetch::read(obj->mark_addr(), (HeapWordSize*2));

      // Place on the references queue
      _par_scan_state->push_on_queue(p);
    }
  }
}

template <class T> inline void G1CMOopClosure::do_oop_nv(T* p) {
  assert(_g1h->is_in_g1_reserved((HeapWord*) p), "invariant");
  assert(!_g1h->is_on_master_free_list(
                    _g1h->heap_region_containing((HeapWord*) p)), "invariant");

  oop obj = oopDesc::load_decode_heap_oop(p);
  if (_cm->verbose_high()) {
    gclog_or_tty->print_cr("[%d] we're looking at location "
                           "*"PTR_FORMAT" = "PTR_FORMAT,
                           _task->task_id(), p, (void*) obj);
  }
  _task->deal_with_reference(obj);
}

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP