src/share/vm/gc_implementation/g1/g1OopClosures.inline.hpp

/*
 * Copyright (c) 2001, 2014, 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
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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/g1ParScanThreadState.inline.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/heapRegionRemSet.hpp"
#include "memory/iterator.inline.hpp"
#include "runtime/prefetch.inline.hpp"

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

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->is_in_cset_or_humongous(oopDesc::decode_heap_oop_not_null(heap_oop))) {
    _oc->do_oop(p);
  }
}

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);
    }
  }
}

// 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);
    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);
    }
  }
}

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->is_in_cset_or_humongous(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);
    } else {
      assert(!_g1->obj_in_cs(obj), "checking");
    }
  }
}

template <class T>
inline void G1CMOopClosure::do_oop_nv(T* p) {
  oop obj = oopDesc::load_decode_heap_oop(p);
  if (_cm->verbose_high()) {
    gclog_or_tty->print_cr("[%u] we're looking at location "
                           "*"PTR_FORMAT" = "PTR_FORMAT,
                           _task->worker_id(), p2i(p), p2i((void*) obj));
  }
  _task->deal_with_reference(obj);
}

template <class T>
inline void G1RootRegionScanClosure::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);
    HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
    _cm->grayRoot(obj, obj->size(), _worker_id, hr);
  }
}

template <class T>
inline void G1Mux2Closure::do_oop_nv(T* p) {
  // Apply first closure; then apply the second.
  _c1->do_oop(p);
  _c2->do_oop(p);
}

template <class T>
inline void G1TriggerClosure::do_oop_nv(T* p) {
  // Record that this closure was actually applied (triggered).
  _triggered = true;
}

template <class T>
inline void G1InvokeIfNotTriggeredClosure::do_oop_nv(T* p) {
  if (!_trigger_cl->triggered()) {
    _oop_cl->do_oop(p);
  }
}

template <class T>
inline void G1UpdateRSOrPushRefOopClosure::do_oop_nv(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");

  // Do the safe subset of is_oop
#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 (_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.
    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);
  }
}

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP