Exemplo n.º 1
0
template <class T> inline void HRInto_G1RemSet::par_write_ref_nv(HeapRegion* from, T* p, int tid) {
  oop obj = oopDesc::load_decode_heap_oop(p);
#ifdef ASSERT
  // can't do because of races
  // assert(obj == NULL || obj->is_oop(), "expected an oop");

  // Do the safe subset of is_oop
  if (obj != NULL) {
#ifdef CHECK_UNHANDLED_OOPS
    oopDesc* o = obj.obj();
#else
    oopDesc* o = obj;
#endif // CHECK_UNHANDLED_OOPS
    assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
    assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
  }
#endif // ASSERT

  assert(from == NULL || from->is_in_reserved(p), "p is not in from");

  HeapRegion* to = _g1->heap_region_containing(obj);
  // The test below could be optimized by applying a bit op to to and from.
  if (to != NULL && from != NULL && from != to) {
    // The _traversal_in_progress flag is true during the collection pause,
    // false during the evacuation failure handling. This should avoid a
    // potential loop if we were to add the card containing 'p' to the DCQS
    // that's used to regenerate the remembered sets for the collection set,
    // in the event of an evacuation failure, here. The UpdateRSImmediate
    // closure will eventally call this routine.
    if (_traversal_in_progress &&
        to->in_collection_set() && !self_forwarded(obj)) {

      assert(_cset_rs_update_cl[tid] != NULL, "should have been set already");
      _cset_rs_update_cl[tid]->do_oop(p);

      // Deferred updates to the CSet are either discarded (in the normal case),
      // or processed (if an evacuation failure occurs) at the end
      // of the collection.
      // See HRInto_G1RemSet::cleanup_after_oops_into_collection_set_do().
    } else {
#if G1_REM_SET_LOGGING
      gclog_or_tty->print_cr("Adding " PTR_FORMAT " (" PTR_FORMAT ") to RS"
                             " for region [" PTR_FORMAT ", " PTR_FORMAT ")",
                             p, obj,
                             to->bottom(), to->end());
#endif
      assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
      to->rem_set()->add_reference(p, tid);
    }
  }
}
Exemplo n.º 2
0
template <class T> inline void HRInto_G1RemSet::par_write_ref_nv(HeapRegion* from, T* p, int tid) {
  oop obj = oopDesc::load_decode_heap_oop(p);
#ifdef ASSERT
  // can't do because of races
  // assert(obj == NULL || obj->is_oop(), "expected an oop");

  // Do the safe subset of is_oop
  if (obj != NULL) {
#ifdef CHECK_UNHANDLED_OOPS
    oopDesc* o = obj.obj();
#else
    oopDesc* o = obj;
#endif // CHECK_UNHANDLED_OOPS
    assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
    assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
  }
#endif // ASSERT
  assert(from == NULL || from->is_in_reserved(p),
         "p is not in from");
  HeapRegion* to = _g1->heap_region_containing(obj);
  // The test below could be optimized by applying a bit op to to and from.
  if (to != NULL && from != NULL && from != to) {
    // There is a tricky infinite loop if we keep pushing
    // self forwarding pointers onto our _new_refs list.
    // The _par_traversal_in_progress flag is true during the collection pause,
    // false during the evacuation failure handing.
    if (_par_traversal_in_progress &&
        to->in_collection_set() && !self_forwarded(obj)) {
      _new_refs[tid]->push((void*)p);
      // Deferred updates to the Cset are either discarded (in the normal case),
      // or processed (if an evacuation failure occurs) at the end
      // of the collection.
      // See HRInto_G1RemSet::cleanup_after_oops_into_collection_set_do().
    } else {
#if G1_REM_SET_LOGGING
      gclog_or_tty->print_cr("Adding " PTR_FORMAT " (" PTR_FORMAT ") to RS"
                             " for region [" PTR_FORMAT ", " PTR_FORMAT ")",
                             p, obj,
                             to->bottom(), to->end());
#endif
      assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
      to->rem_set()->add_reference(p, tid);
    }
  }
}
inline void G1UpdateRSOrPushRefOopClosure::do_oop_nv(T* p) {
  oop obj = oopDesc::load_decode_heap_oop(p);
#ifdef ASSERT
  // can't do because of races
  // assert(obj == NULL || obj->is_oop(), "expected an oop");

  // Do the safe subset of is_oop
  if (obj != NULL) {
#ifdef CHECK_UNHANDLED_OOPS
    oopDesc* o = obj.obj();
#else
    oopDesc* o = obj;
#endif // CHECK_UNHANDLED_OOPS
    assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
    assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
  }
#endif // ASSERT

  assert(_from != NULL, "from region must be non-NULL");
  assert(_from->is_in_reserved(p), "p is not in from");

  HeapRegion* to = _g1->heap_region_containing(obj);
  if (to != NULL && _from != to) {
    // The _record_refs_into_cset flag is true during the RSet
    // updating part of an evacuation pause. It is false at all
    // other times:
    //  * rebuilding the rembered sets after a full GC
    //  * during concurrent refinement.
    //  * updating the remembered sets of regions in the collection
    //    set in the event of an evacuation failure (when deferred
    //    updates are enabled).

    if (_record_refs_into_cset && to->in_collection_set()) {
      // We are recording references that point into the collection
      // set and this particular reference does exactly that...
      // If the referenced object has already been forwarded
      // to itself, we are handling an evacuation failure and
      // we have already visited/tried to copy this object
      // there is no need to retry.
      if (!self_forwarded(obj)) {
        assert(_push_ref_cl != NULL, "should not be null");
        // Push the reference in the refs queue of the G1ParScanThreadState
        // instance for this worker thread.
        _push_ref_cl->do_oop(p);
      }

      // Deferred updates to the CSet are either discarded (in the normal case),
      // or processed (if an evacuation failure occurs) at the end
      // of the collection.
      // See G1RemSet::cleanup_after_oops_into_collection_set_do().
      return;
    }

    // We either don't care about pushing references that point into the
    // collection set (i.e. we're not during an evacuation pause) _or_
    // the reference doesn't point into the collection set. Either way
    // we add the reference directly to the RSet of the region containing
    // the referenced object.
    assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
    to->rem_set()->add_reference(p, _worker_i);
  }
}
Exemplo n.º 4
0
inline void G1UpdateRSOrPushRefOopClosure::do_oop_work(T* p) {
  oop obj = oopDesc::load_decode_heap_oop(p);
  if (obj == NULL) {
    return;
  }

#ifdef ASSERT
  // can't do because of races
  // assert(obj == NULL || obj->is_oop(), "expected an oop");
  assert(check_obj_alignment(obj), "not oop aligned");
  assert(_g1->is_in_reserved(obj), "must be in heap");
#endif // ASSERT

  assert(_from != NULL, "from region must be non-NULL");
  assert(_from->is_in_reserved(p) ||
         (_from->is_humongous() &&
          _g1->heap_region_containing(p)->is_humongous() &&
          _from->humongous_start_region() == _g1->heap_region_containing(p)->humongous_start_region()),
         "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
         p2i(p), _from->hrm_index(), _from->humongous_start_region()->hrm_index());

  HeapRegion* to = _g1->heap_region_containing(obj);
  if (_from == to) {
    // Normally this closure should only be called with cross-region references.
    // But since Java threads are manipulating the references concurrently and we
    // reload the values things may have changed.
    // Also this check lets slip through references from a humongous continues region
    // to its humongous start region, as they are in different regions, and adds a
    // remembered set entry. This is benign (apart from memory usage), as we never
    // try to either evacuate or eager reclaim these kind of regions.
    return;
  }

  // The _record_refs_into_cset flag is true during the RSet
  // updating part of an evacuation pause. It is false at all
  // other times:
  //  * rebuilding the remembered sets after a full GC
  //  * during concurrent refinement.
  //  * updating the remembered sets of regions in the collection
  //    set in the event of an evacuation failure (when deferred
  //    updates are enabled).

  if (_record_refs_into_cset && to->in_collection_set()) {
    // We are recording references that point into the collection
    // set and this particular reference does exactly that...
    // If the referenced object has already been forwarded
    // to itself, we are handling an evacuation failure and
    // we have already visited/tried to copy this object
    // there is no need to retry.
    if (!self_forwarded(obj)) {
      assert(_push_ref_cl != NULL, "should not be null");
      // Push the reference in the refs queue of the G1ParScanThreadState
      // instance for this worker thread.
      _push_ref_cl->do_oop(p);
    }

    // Deferred updates to the CSet are either discarded (in the normal case),
    // or processed (if an evacuation failure occurs) at the end
    // of the collection.
    // See G1RemSet::cleanup_after_oops_into_collection_set_do().
  } else {
    // We either don't care about pushing references that point into the
    // collection set (i.e. we're not during an evacuation pause) _or_
    // the reference doesn't point into the collection set. Either way
    // we add the reference directly to the RSet of the region containing
    // the referenced object.
    assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
    to->rem_set()->add_reference(p, _worker_i);
  }
}