view src/share/vm/memory/genOopClosures.inline.hpp @ 20304:a22acf6d7598

8048112: G1 Full GC needs to support the case when the very first region is not available Summary: Refactor preparation for compaction during Full GC so that it lazily initializes the first compaction point. This also avoids problems later when the first region may not be committed. Also reviewed by K. Barrett. Reviewed-by: brutisso
author tschatzl
date Mon, 21 Jul 2014 10:00:31 +0200
parents da91efe96a93
children 284953caf7aa
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/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
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 * 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.
 *
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#ifndef SHARE_VM_MEMORY_GENOOPCLOSURES_INLINE_HPP
#define SHARE_VM_MEMORY_GENOOPCLOSURES_INLINE_HPP

#include "memory/cardTableRS.hpp"
#include "memory/defNewGeneration.hpp"
#include "memory/genCollectedHeap.hpp"
#include "memory/genOopClosures.hpp"
#include "memory/genRemSet.hpp"
#include "memory/generation.hpp"
#include "memory/sharedHeap.hpp"
#include "memory/space.hpp"

inline OopsInGenClosure::OopsInGenClosure(Generation* gen) :
  ExtendedOopClosure(gen->ref_processor()), _orig_gen(gen), _rs(NULL) {
  set_generation(gen);
}

inline void OopsInGenClosure::set_generation(Generation* gen) {
  _gen = gen;
  _gen_boundary = _gen->reserved().start();
  // Barrier set for the heap, must be set after heap is initialized
  if (_rs == NULL) {
    GenRemSet* rs = SharedHeap::heap()->rem_set();
    assert(rs->rs_kind() == GenRemSet::CardTable, "Wrong rem set kind");
    _rs = (CardTableRS*)rs;
  }
}

template <class T> inline void OopsInGenClosure::do_barrier(T* p) {
  assert(generation()->is_in_reserved(p), "expected ref in generation");
  T heap_oop = oopDesc::load_heap_oop(p);
  assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
  oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  // If p points to a younger generation, mark the card.
  if ((HeapWord*)obj < _gen_boundary) {
    _rs->inline_write_ref_field_gc(p, obj);
  }
}

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

inline void OopsInKlassOrGenClosure::do_klass_barrier() {
  assert(_scanned_klass != NULL, "Must be");
  _scanned_klass->record_modified_oops();
}

// NOTE! Any changes made here should also be made
// in FastScanClosure::do_oop_work()
template <class T> inline void ScanClosure::do_oop_work(T* p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  // Should we copy the obj?
  if (!oopDesc::is_null(heap_oop)) {
    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
    if ((HeapWord*)obj < _boundary) {
      assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
      oop new_obj = obj->is_forwarded() ? obj->forwardee()
                                        : _g->copy_to_survivor_space(obj);
      oopDesc::encode_store_heap_oop_not_null(p, new_obj);
    }

    if (is_scanning_a_klass()) {
      do_klass_barrier();
    } else if (_gc_barrier) {
      // Now call parent closure
      do_barrier(p);
    }
  }
}

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

// NOTE! Any changes made here should also be made
// in ScanClosure::do_oop_work()
template <class T> inline void FastScanClosure::do_oop_work(T* p) {
  T heap_oop = oopDesc::load_heap_oop(p);
  // Should we copy the obj?
  if (!oopDesc::is_null(heap_oop)) {
    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
    if ((HeapWord*)obj < _boundary) {
      assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
      oop new_obj = obj->is_forwarded() ? obj->forwardee()
                                        : _g->copy_to_survivor_space(obj);
      oopDesc::encode_store_heap_oop_not_null(p, new_obj);
      if (is_scanning_a_klass()) {
        do_klass_barrier();
      } else if (_gc_barrier) {
        // Now call parent closure
        do_barrier(p);
      }
    }
  }
}

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

// Note similarity to ScanClosure; the difference is that
// the barrier set is taken care of outside this closure.
template <class T> inline void ScanWeakRefClosure::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)) {
    oop new_obj = obj->is_forwarded() ? obj->forwardee()
                                      : _g->copy_to_survivor_space(obj);
    oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  }
}

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

#endif // SHARE_VM_MEMORY_GENOOPCLOSURES_INLINE_HPP