1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   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.
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   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  *
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  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   Klass* _element_klass;            // The klass of the elements of this array type
  46                                     // The element type must be registered for both object arrays
  47                                     // (incl. object arrays with value type elements) and value type
  48                                     // arrays containing flattened value types. However, the element
  49                                     // type must not be registered for arrays of primitive types.
  50                                     // TODO: Update the class hierarchy so that element klass appears
  51                                     // only in array that contain non-primitive types.
  52   // Constructors
  53   // The constructor with the Symbol argument does the real array
  54   // initialization, the other is a dummy
  55   ArrayKlass(Symbol* name, KlassID id);
  56   ArrayKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
  57 
  58   // Create array_name for element klass, creates a permanent symbol, returns result
  59   static Symbol* create_element_klass_array_name(bool is_qtype, Klass* element_klass, TRAPS);
  60 
  61  public:
  62   // Instance variables
  63   virtual Klass* element_klass() const      { return _element_klass; }
  64   virtual void set_element_klass(Klass* k)  { _element_klass = k; }
  65 
  66   // Compiler/Interpreter offset
  67   static ByteSize element_klass_offset() { return in_ByteSize(offset_of(ArrayKlass, _element_klass)); }
  68 
  69   // Presented with an ArrayKlass, which storage_properties should be encoded into arrayOop
  70   virtual ArrayStorageProperties storage_properties() { return ArrayStorageProperties::empty; }
  71 
  72   // Testing operation
  73   DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
  74 
  75   // Instance variables
  76   int dimension() const                 { return _dimension;      }
  77   void set_dimension(int dimension)     { _dimension = dimension; }
  78 
  79   Klass* higher_dimension() const     { return _higher_dimension; }
  80   inline Klass* higher_dimension_acquire() const; // load with acquire semantics
  81   void set_higher_dimension(Klass* k) { _higher_dimension = k; }
  82   inline void release_set_higher_dimension(Klass* k); // store with release semantics
  83 
  84   Klass* lower_dimension() const      { return _lower_dimension; }
  85   void set_lower_dimension(Klass* k)  { _lower_dimension = k; }
  86 
  87   // offset of first element, including any padding for the sake of alignment
  88   int  array_header_in_bytes() const    { return layout_helper_header_size(layout_helper()); }
  89   int  log2_element_size() const        { return layout_helper_log2_element_size(layout_helper()); }
  90   // type of elements (T_OBJECT for both oop arrays and array-arrays)
  91   BasicType element_type() const        { return layout_helper_element_type(layout_helper()); }
  92 
  93   virtual InstanceKlass* java_super() const;//{ return SystemDictionary::Object_klass(); }
  94 
  95   // Allocation
  96   // Sizes points to the first dimension of the array, subsequent dimensions
  97   // are always in higher memory.  The callers of these set that up.
  98   virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
  99   objArrayOop allocate_arrayArray(int n, int length, TRAPS);
 100 
 101   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 102   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 103 
 104   // Lookup operations
 105   Method* uncached_lookup_method(const Symbol* name,
 106                                  const Symbol* signature,
 107                                  OverpassLookupMode overpass_mode,
 108                                  PrivateLookupMode private_mode = find_private) const;
 109 
 110   static ArrayKlass* cast(Klass* k) {
 111     return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
 112   }
 113 
 114   static const ArrayKlass* cast(const Klass* k) {
 115     assert(k->is_array_klass(), "cast to ArrayKlass");
 116     return static_cast<const ArrayKlass*>(k);
 117   }
 118 
 119   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 120                                                   Array<InstanceKlass*>* transitive_interfaces);
 121 
 122   oop component_mirror() const;
 123 
 124   // Sizing
 125   static int static_size(int header_size);
 126 
 127   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 128 
 129 #if INCLUDE_SERVICES
 130   virtual void collect_statistics(KlassSizeStats *sz) const {
 131     Klass::collect_statistics(sz);
 132     // Do nothing for now, but remember to modify if you add new
 133     // stuff to ArrayKlass.
 134   }
 135 #endif
 136 
 137   // Iterators
 138   void array_klasses_do(void f(Klass* k));
 139 
 140   // Return a handle.
 141   static void     complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
 142 
 143 
 144   // jvm support
 145   jint compute_modifier_flags(TRAPS) const;
 146 
 147   // JVMTI support
 148   jint jvmti_class_status() const;
 149 
 150   // CDS support - remove and restore oops from metadata. Oops are not shared.
 151   virtual void remove_unshareable_info();
 152   virtual void remove_java_mirror();
 153   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
 154 
 155   // Printing
 156   void print_on(outputStream* st) const;
 157   void print_value_on(outputStream* st) const;
 158 
 159   void oop_print_on(oop obj, outputStream* st);
 160 
 161   // Verification
 162   void verify_on(outputStream* st);
 163 
 164   void oop_verify_on(oop obj, outputStream* st);
 165 };
 166 
 167 #endif // SHARE_OOPS_ARRAYKLASS_HPP