view src/share/vm/oops/klass.inline.hpp @ 9618:4535697211eb

8139203: Consistent naming for klass type predicates 8138923: Remove oop coupling with InstanceKlass subclasses Summary: Renamed oop_is_instance and friends, removed the functions in oop that dug down into InstanceKlass. Reviewed-by: jrose, lfoltan, stefank
author coleenp
date Wed, 28 Oct 2015 09:47:23 -0400
parents dc9930a04ab0
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 * published by the Free Software Foundation.
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 * 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
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#include "memory/universe.hpp"
#include "oops/klass.hpp"
#include "oops/markOop.hpp"

inline void Klass::set_prototype_header(markOop header) {
  assert(!header->has_bias_pattern() || is_instance_klass(), "biased locking currently only supported for Java instances");
  _prototype_header = header;

inline bool Klass::is_null(Klass* obj)  { return obj == NULL; }
inline bool Klass::is_null(narrowKlass obj) { return obj == 0; }

// Encoding and decoding for klass field.

inline bool check_klass_alignment(Klass* obj) {
  return (intptr_t)obj % KlassAlignmentInBytes == 0;

inline narrowKlass Klass::encode_klass_not_null(Klass* v) {
  assert(!is_null(v), "klass value can never be zero");
  assert(check_klass_alignment(v), "Address not aligned");
  int    shift = Universe::narrow_klass_shift();
  uint64_t pd = (uint64_t)(pointer_delta((void*)v, Universe::narrow_klass_base(), 1));
  assert(KlassEncodingMetaspaceMax > pd, "change encoding max if new encoding");
  uint64_t result = pd >> shift;
  assert((result & CONST64(0xffffffff00000000)) == 0, "narrow klass pointer overflow");
  assert(decode_klass(result) == v, "reversibility");
  return (narrowKlass)result;

inline narrowKlass Klass::encode_klass(Klass* v) {
  return is_null(v) ? (narrowKlass)0 : encode_klass_not_null(v);

inline Klass* Klass::decode_klass_not_null(narrowKlass v) {
  assert(!is_null(v), "narrow klass value can never be zero");
  int    shift = Universe::narrow_klass_shift();
  Klass* result = (Klass*)(void*)((uintptr_t)Universe::narrow_klass_base() + ((uintptr_t)v << shift));
  assert(check_klass_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result));
  return result;

inline Klass* Klass::decode_klass(narrowKlass v) {
  return is_null(v) ? (Klass*)NULL : decode_klass_not_null(v);