view src/share/vm/oops/arrayKlass.hpp @ 9126:bc26f978b0ce

HotSpotResolvedObjectType: implement hasFinalizeSubclass() correctly don't use the (wrong) cached value, but ask the runtime on each request. Fixes regression on xml.* benchmarks @ specjvm2008. The problem was: After the constructor of Object was deoptimized due to an assumption violation, it was recompiled again after some time. However, on recompilation, the value of hasFinalizeSubclass for the class was not updated and it was compiled again with a, now wrong, assumption, which then triggers deoptimization again. This was repeated until it hit the recompilation limit (defined by PerMethodRecompilationCutoff), and therefore only executed by the interpreter from now on, causing the performance regression.
author Bernhard Urban <bernhard.urban@jku.at>
date Mon, 15 Apr 2013 19:54:58 +0200
parents 16fb9f942703
children e0c9a1d29eb4
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/*
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 * 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.
 *
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#ifndef SHARE_VM_OOPS_ARRAYKLASS_HPP
#define SHARE_VM_OOPS_ARRAYKLASS_HPP

#include "memory/universe.hpp"
#include "oops/klass.hpp"

class klassVtable;

// ArrayKlass is the abstract baseclass for all array classes

class ArrayKlass: public Klass {
  friend class VMStructs;
 private:
  int      _dimension;         // This is n'th-dimensional array.
  Klass* volatile _higher_dimension;  // Refers the (n+1)'th-dimensional array (if present).
  Klass* volatile _lower_dimension;   // Refers the (n-1)'th-dimensional array (if present).
  int      _vtable_len;        // size of vtable for this klass
  juint    _alloc_size;        // allocation profiling support
  oop      _component_mirror;  // component type, as a java/lang/Class

 protected:
  // Constructors
  // The constructor with the Symbol argument does the real array
  // initialization, the other is a dummy
  ArrayKlass(Symbol* name);
  ArrayKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }

 public:
  // Testing operation
  bool oop_is_array_slow() const { return true; }

  // Instance variables
  int dimension() const                 { return _dimension;      }
  void set_dimension(int dimension)     { _dimension = dimension; }

  Klass* higher_dimension() const     { return _higher_dimension; }
  void set_higher_dimension(Klass* k) { _higher_dimension = k; }
  Klass** adr_higher_dimension()      { return (Klass**)&this->_higher_dimension;}

  Klass* lower_dimension() const      { return _lower_dimension; }
  void set_lower_dimension(Klass* k)  { _lower_dimension = k; }
  Klass** adr_lower_dimension()       { return (Klass**)&this->_lower_dimension;}

  // Allocation profiling support
  juint alloc_size() const              { return _alloc_size; }
  void set_alloc_size(juint n)          { _alloc_size = n; }

  // offset of first element, including any padding for the sake of alignment
  int  array_header_in_bytes() const    { return layout_helper_header_size(layout_helper()); }
  int  log2_element_size() const        { return layout_helper_log2_element_size(layout_helper()); }
  // type of elements (T_OBJECT for both oop arrays and array-arrays)
  BasicType element_type() const        { return layout_helper_element_type(layout_helper()); }

  oop  component_mirror() const         { return _component_mirror; }
  void set_component_mirror(oop m)      { klass_oop_store(&_component_mirror, m); }
  oop* adr_component_mirror()           { return (oop*)&this->_component_mirror;}

  // Compiler/Interpreter offset
  static ByteSize component_mirror_offset() { return in_ByteSize(offset_of(ArrayKlass, _component_mirror)); }

  virtual Klass* java_super() const;//{ return SystemDictionary::Object_klass(); }

  // Allocation
  // Sizes points to the first dimension of the array, subsequent dimensions
  // are always in higher memory.  The callers of these set that up.
  virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
  objArrayOop allocate_arrayArray(int n, int length, TRAPS);

  // Lookup operations
  Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;

  // Casting from Klass*
  static ArrayKlass* cast(Klass* k) {
    assert(k->oop_is_array(), "cast to ArrayKlass");
    return (ArrayKlass*) k;
  }

  GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
  bool compute_is_subtype_of(Klass* k);

  // Sizing
  static int header_size()                 { return sizeof(ArrayKlass)/HeapWordSize; }
  static int static_size(int header_size);

#if INCLUDE_SERVICES
  virtual void collect_statistics(KlassSizeStats *sz) const {
    Klass::collect_statistics(sz);
    // Do nothing for now, but remember to modify if you add new
    // stuff to ArrayKlass.
  }
#endif

  // Java vtable
  klassVtable* vtable() const;             // return new klassVtable
  int  vtable_length() const               { return _vtable_len; }
  static int base_vtable_length()          { return Universe::base_vtable_size(); }
  void set_vtable_length(int len)          { assert(len == base_vtable_length(), "bad length"); _vtable_len = len; }
 protected:
  inline intptr_t* start_of_vtable() const;

 public:
  // Iterators
  void array_klasses_do(void f(Klass* k));
  void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
  void with_array_klasses_do(void f(Klass* k));

  // GC support
  virtual void oops_do(OopClosure* cl);

  // Return a handle.
  static void     complete_create_array_klass(ArrayKlass* k, KlassHandle super_klass, TRAPS);


  // jvm support
  jint compute_modifier_flags(TRAPS) const;

  // JVMTI support
  jint jvmti_class_status() const;

  // CDS support - remove and restore oops from metadata. Oops are not shared.
  virtual void remove_unshareable_info();
  virtual void restore_unshareable_info(TRAPS);

  // Printing
  void print_on(outputStream* st) const;
  void print_value_on(outputStream* st) const;

  void oop_print_on(oop obj, outputStream* st);

  // Verification
  void verify_on(outputStream* st);

  void oop_verify_on(oop obj, outputStream* st);
};

#endif // SHARE_VM_OOPS_ARRAYKLASS_HPP