1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
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  24 
  25 #ifndef SHARE_OOPS_ARRAYKLASS_HPP
  26 #define SHARE_OOPS_ARRAYKLASS_HPP
  27 
  28 #include "oops/klass.hpp"
  29 
  30 class fieldDescriptor;
  31 class klassVtable;
  32 
  33 // ArrayKlass is the abstract baseclass for all array classes
  34 
  35 class ArrayKlass: public Klass {
  36   friend class VMStructs;
  37  private:
  38   // If you add a new field that points to any metaspace object, you
  39   // must add this field to ArrayKlass::metaspace_pointers_do().
  40   int      _dimension;         // This is n'th-dimensional array.
  41   Klass* volatile _higher_dimension;  // Refers the (n+1)'th-dimensional array (if present).
  42   Klass* volatile _lower_dimension;   // Refers the (n-1)'th-dimensional array (if present).
  43 
  44  protected:
  45   // Constructors
  46   // The constructor with the Symbol argument does the real array
  47   // initialization, the other is a dummy
  48   ArrayKlass(Symbol* name, KlassID id);
  49   ArrayKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
  50 
  51  public:
  52   // Testing operation
  53   DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
  54 
  55   // Instance variables
  56   int dimension() const                 { return _dimension;      }
  57   void set_dimension(int dimension)     { _dimension = dimension; }
  58 
  59   Klass* higher_dimension() const     { return _higher_dimension; }
  60   inline Klass* higher_dimension_acquire() const; // load with acquire semantics
  61   void set_higher_dimension(Klass* k) { _higher_dimension = k; }
  62   inline void release_set_higher_dimension(Klass* k); // store with release semantics
  63 
  64   Klass* lower_dimension() const      { return _lower_dimension; }
  65   void set_lower_dimension(Klass* k)  { _lower_dimension = k; }
  66 
  67   // offset of first element, including any padding for the sake of alignment
  68   int  array_header_in_bytes() const    { return layout_helper_header_size(layout_helper()); }
  69   int  log2_element_size() const        { return layout_helper_log2_element_size(layout_helper()); }
  70   // type of elements (T_OBJECT for both oop arrays and array-arrays)
  71   BasicType element_type() const        { return layout_helper_element_type(layout_helper()); }
  72 
  73   virtual InstanceKlass* java_super() const;//{ return SystemDictionary::Object_klass(); }
  74 
  75   // Allocation
  76   // Sizes points to the first dimension of the array, subsequent dimensions
  77   // are always in higher memory.  The callers of these set that up.
  78   virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
  79   objArrayOop allocate_arrayArray(int n, int length, TRAPS);
  80 
  81   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
  82   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
  83 
  84   // Lookup operations
  85   Method* uncached_lookup_method(const Symbol* name,
  86                                  const Symbol* signature,
  87                                  OverpassLookupMode overpass_mode,
  88                                  PrivateLookupMode private_mode = find_private) const;
  89 
  90   static ArrayKlass* cast(Klass* k) {
  91     return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
  92   }
  93 
  94   static const ArrayKlass* cast(const Klass* k) {
  95     assert(k->is_array_klass(), "cast to ArrayKlass");
  96     return static_cast<const ArrayKlass*>(k);
  97   }
  98 
  99   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 100                                                   Array<InstanceKlass*>* transitive_interfaces);
 101 
 102   // Sizing
 103   static int static_size(int header_size);
 104 
 105   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 106 
 107 #if INCLUDE_SERVICES
 108   virtual void collect_statistics(KlassSizeStats *sz) const {
 109     Klass::collect_statistics(sz);
 110     // Do nothing for now, but remember to modify if you add new
 111     // stuff to ArrayKlass.
 112   }
 113 #endif
 114 
 115   // Iterators
 116   void array_klasses_do(void f(Klass* k));
 117   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
 118 
 119   // Return a handle.
 120   static void     complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
 121 
 122 
 123   // jvm support
 124   jint compute_modifier_flags(TRAPS) const;
 125 
 126   // JVMTI support
 127   jint jvmti_class_status() const;
 128 
 129   // CDS support - remove and restore oops from metadata. Oops are not shared.
 130   virtual void remove_unshareable_info();
 131   virtual void remove_java_mirror();
 132   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
 133 
 134   // Printing
 135   void print_on(outputStream* st) const;
 136   void print_value_on(outputStream* st) const;
 137 
 138   void oop_print_on(oop obj, outputStream* st);
 139 
 140   // Verification
 141   void verify_on(outputStream* st);
 142 
 143   void oop_verify_on(oop obj, outputStream* st);
 144 };
 145 
 146 #endif // SHARE_OOPS_ARRAYKLASS_HPP