Exemplo n.º 1
0
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);
    const InCSetState state = _g1->in_cset_state(obj);
    if (state.is_in_cset()) {
      // 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 {
      if (state.is_humongous()) {
        _g1->set_humongous_is_live(obj);
      }
      _par_scan_state->update_rs(_from, p, _worker_id);
    }
  }
}
Exemplo n.º 2
0
 uint max_regions(InCSetState dest) const {
   switch (dest.value()) {
     case InCSetState::Young:
       return _max_survivor_regions;
     case InCSetState::Old:
       return REGIONS_UNLIMITED;
     default:
       assert(false, "Unknown dest state: " CSETSTATE_FORMAT, dest.value());
       break;
   }
   // keep some compilers happy
   return 0;
 }
Exemplo n.º 3
0
void G1ParScanThreadState::report_promotion_event(InCSetState const dest_state,
        oop const old, size_t word_sz, uint age,
        HeapWord * const obj_ptr,
        const AllocationContext_t context) const {
    G1PLAB* alloc_buf = _plab_allocator->alloc_buffer(dest_state, context);
    if (alloc_buf->contains(obj_ptr)) {
        _g1h->_gc_tracer_stw->report_promotion_in_new_plab_event(old->klass(), word_sz, age,
                dest_state.value() == InCSetState::Old,
                alloc_buf->word_sz());
    } else {
        _g1h->_gc_tracer_stw->report_promotion_outside_plab_event(old->klass(), word_sz, age,
                dest_state.value() == InCSetState::Old);
    }
}
Exemplo n.º 4
0
void G1ParCopyClosure<barrier, do_mark_object, use_ext>::do_oop_work(T* p) {
  T heap_oop = oopDesc::load_heap_oop(p);

  if (oopDesc::is_null(heap_oop)) {
    return;
  }

  oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);

  assert(_worker_id == _par_scan_state->worker_id(), "sanity");

  const InCSetState state = _g1->in_cset_state(obj);
  if (state.is_in_cset()) {
    oop forwardee;
    markOop m = obj->mark();
    if (m->is_marked()) {
      forwardee = (oop) m->decode_pointer();
    } else {
      forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
    }
    assert(forwardee != NULL, "forwardee should not be NULL");
    oopDesc::encode_store_heap_oop(p, forwardee);
    if (do_mark_object != G1MarkNone && forwardee != obj) {
      // If the object is self-forwarded we don't need to explicitly
      // mark it, the evacuation failure protocol will do so.
      mark_forwarded_object(obj, forwardee);
    }

    if (barrier == G1BarrierKlass) {
      do_klass_barrier(p, forwardee);
    }
  } else {
    if (state.is_humongous()) {
      _g1->set_humongous_is_live(obj);
    }

    if (use_ext && state.is_ext()) {
      _par_scan_state->do_oop_ext(p);
    }
    // The object is not in collection set. If we're a root scanning
    // closure during an initial mark pause then attempt to mark the object.
    if (do_mark_object == G1MarkFromRoot) {
      mark_object(obj);
    }
  }
}
InCSetState G1ParScanThreadState::next_state(InCSetState const state, markOop const m, uint& age) {
  if (state.is_young()) {
    age = !m->has_displaced_mark_helper() ? m->age()
                                          : m->displaced_mark_helper()->age();
    if (age < _tenuring_threshold) {
      return state;
    }
  }
  return dest(state);
}
Exemplo n.º 6
0
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);
    const InCSetState state = _g1->in_cset_state(obj);
    if (state.is_in_cset_or_humongous()) {
      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);
    } else if (state.is_ext()) {
      _par_scan_state->do_oop_ext(p);
    } else {
      assert(!_g1->obj_in_cs(obj), "checking");
    }
  }
}
oop G1ParScanThreadState::copy_to_survivor_space(InCSetState const state,
                                                 oop const old,
                                                 markOop const old_mark) {
  const size_t word_sz = old->size();
  HeapRegion* const from_region = _g1h->heap_region_containing_raw(old);
  // +1 to make the -1 indexes valid...
  const int young_index = from_region->young_index_in_cset()+1;
  assert( (from_region->is_young() && young_index >  0) ||
         (!from_region->is_young() && young_index == 0), "invariant" );
  const AllocationContext_t context = from_region->allocation_context();

  uint age = 0;
  InCSetState dest_state = next_state(state, old_mark, age);
  HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_state, word_sz, context);

  // PLAB allocations should succeed most of the time, so we'll
  // normally check against NULL once and that's it.
  if (obj_ptr == NULL) {
    obj_ptr = _plab_allocator->allocate_direct_or_new_plab(dest_state, word_sz, context);
    if (obj_ptr == NULL) {
      obj_ptr = allocate_in_next_plab(state, &dest_state, word_sz, context);
      if (obj_ptr == NULL) {
        // This will either forward-to-self, or detect that someone else has
        // installed a forwarding pointer.
        return handle_evacuation_failure_par(old, old_mark);
      }
    }
  }

  assert(obj_ptr != NULL, "when we get here, allocation should have succeeded");
  assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap");

#ifndef PRODUCT
  // Should this evacuation fail?
  if (_g1h->evacuation_should_fail()) {
    // Doing this after all the allocation attempts also tests the
    // undo_allocation() method too.
    _plab_allocator->undo_allocation(dest_state, obj_ptr, word_sz, context);
    return handle_evacuation_failure_par(old, old_mark);
  }
#endif // !PRODUCT

  // We're going to allocate linearly, so might as well prefetch ahead.
  Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);

  const oop obj = oop(obj_ptr);
  const oop forward_ptr = old->forward_to_atomic(obj);
  if (forward_ptr == NULL) {
    Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);

    if (dest_state.is_young()) {
      if (age < markOopDesc::max_age) {
        age++;
      }
      if (old_mark->has_displaced_mark_helper()) {
        // In this case, we have to install the mark word first,
        // otherwise obj looks to be forwarded (the old mark word,
        // which contains the forward pointer, was copied)
        obj->set_mark(old_mark);
        markOop new_mark = old_mark->displaced_mark_helper()->set_age(age);
        old_mark->set_displaced_mark_helper(new_mark);
      } else {
        obj->set_mark(old_mark->set_age(age));
      }
      age_table()->add(age, word_sz);
    } else {
      obj->set_mark(old_mark);
    }

    if (G1StringDedup::is_enabled()) {
      const bool is_from_young = state.is_young();
      const bool is_to_young = dest_state.is_young();
      assert(is_from_young == _g1h->heap_region_containing_raw(old)->is_young(),
             "sanity");
      assert(is_to_young == _g1h->heap_region_containing_raw(obj)->is_young(),
             "sanity");
      G1StringDedup::enqueue_from_evacuation(is_from_young,
                                             is_to_young,
                                             _worker_id,
                                             obj);
    }

    size_t* const surv_young_words = surviving_young_words();
    surv_young_words[young_index] += word_sz;

    if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
      // We keep track of the next start index in the length field of
      // the to-space object. The actual length can be found in the
      // length field of the from-space object.
      arrayOop(obj)->set_length(0);
      oop* old_p = set_partial_array_mask(old);
      push_on_queue(old_p);
    } else {
      HeapRegion* const to_region = _g1h->heap_region_containing_raw(obj_ptr);
      _scanner.set_region(to_region);
      obj->oop_iterate_backwards(&_scanner);
    }
    return obj;
  } else {
    _plab_allocator->undo_allocation(dest_state, obj_ptr, word_sz, context);
    return forward_ptr;
  }
}