/*

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * 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.

 *

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#ifndef SHARE_OOPS_MARKWORD_INLINE_HPP

#define SHARE_OOPS_MARKWORD_INLINE_HPP

#include "oops/klass.hpp"

#include "oops/markWord.hpp"

#include "runtime/globals.hpp"

// Should this header be preserved during GC?

template <typename KlassProxy>

inline bool markWord::must_be_preserved(KlassProxy klass) const {

  if (UseBiasedLocking) {

    if (has_bias_pattern()) {

      // Will reset bias at end of collection

      // Mark words of biased and currently locked objects are preserved separately

      return false;

    }

    markWord prototype_header = prototype_for_klass(klass);

    if (prototype_header.has_bias_pattern()) {

      // Individual instance which has its bias revoked; must return

      // true for correctness

      return true;

    }

  }

  return (!is_unlocked() || !has_no_hash());

}

// Should this header be preserved in the case of a promotion failure during scavenge?

template <typename KlassProxy>

inline bool markWord::must_be_preserved_for_promotion_failure(KlassProxy klass) const {

  if (UseBiasedLocking) {

    // We don't explicitly save off the mark words of biased and

    // currently-locked objects during scavenges, so if during a

    // promotion failure we encounter either a biased mark word or a

    // klass which still has a biasable prototype header, we have to

    // preserve the mark word. This results in oversaving, but promotion

    // failures are rare, and this avoids adding more complex logic to

    // the scavengers to call new variants of

    // BiasedLocking::preserve_marks() / restore_marks() in the middle

    // of a scavenge when a promotion failure has first been detected.

    if (has_bias_pattern() || prototype_for_klass(klass).has_bias_pattern()) {

      return true;

    }

  }

  return (!is_unlocked() || !has_no_hash());

}

// Same as must_be_preserved_for_promotion_failure().

inline bool markWord::must_be_preserved_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const {

  return must_be_preserved_for_promotion_failure(klass_of_obj_containing_mark);

}

inline markWord markWord::prototype_for_klass(const Klass* klass) {

  markWord prototype_header = klass->prototype_header();

  assert(prototype_header == prototype() || prototype_header.has_bias_pattern(), "corrupt prototype header");

  return prototype_header;

}

#endif // SHARE_OOPS_MARKWORD_INLINE_HPP