1 /*
   2  * Copyright (c) 1997, 2016, 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
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_ARRAYKLASS_HPP
  26 #define SHARE_VM_OOPS_ARRAYKLASS_HPP
  27 
  28 #include "memory/universe.hpp"
  29 #include "oops/klass.hpp"
  30 
  31 class fieldDescriptor;
  32 class klassVtable;
  33 
  34 // ArrayKlass is the abstract baseclass for all array classes
  35 
  36 class ArrayKlass: public Klass {
  37   friend class VMStructs;
  38  private:
  39   int      _dimension;         // This is n'th-dimensional array.
  40   Klass* volatile _higher_dimension;  // Refers the (n+1)'th-dimensional array (if present).
  41   Klass* volatile _lower_dimension;   // Refers the (n-1)'th-dimensional array (if present).
  42 
  43  protected:
  44   // Constructors
  45   // The constructor with the Symbol argument does the real array
  46   // initialization, the other is a dummy
  47   ArrayKlass(Symbol* name);
  48   ArrayKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
  49 
  50  public:
  51   // Testing operation
  52   DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
  53 
  54   // Instance variables
  55   int dimension() const                 { return _dimension;      }
  56   void set_dimension(int dimension)     { _dimension = dimension; }
  57 
  58   Klass* higher_dimension() const     { return _higher_dimension; }
  59   void set_higher_dimension(Klass* k) { _higher_dimension = k; }
  60   Klass** adr_higher_dimension()      { return (Klass**)&this->_higher_dimension;}
  61 
  62   Klass* lower_dimension() const      { return _lower_dimension; }
  63   void set_lower_dimension(Klass* k)  { _lower_dimension = k; }
  64   Klass** adr_lower_dimension()       { return (Klass**)&this->_lower_dimension;}
  65 
  66   // offset of first element, including any padding for the sake of alignment
  67   int  array_header_in_bytes() const    { return layout_helper_header_size(layout_helper()); }
  68   int  log2_element_size() const        { return layout_helper_log2_element_size(layout_helper()); }
  69   // type of elements (T_OBJECT for both oop arrays and array-arrays)
  70   BasicType element_type() const        { return layout_helper_element_type(layout_helper()); }
  71 
  72   virtual Klass* java_super() const;//{ return SystemDictionary::Object_klass(); }
  73 
  74   // Allocation
  75   // Sizes points to the first dimension of the array, subsequent dimensions
  76   // are always in higher memory.  The callers of these set that up.
  77   virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
  78   objArrayOop allocate_arrayArray(int n, int length, TRAPS);
  79 
  80   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
  81   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
  82 
  83   // Lookup operations
  84   Method* uncached_lookup_method(const Symbol* name,
  85                                  const Symbol* signature,
  86                                  OverpassLookupMode overpass_mode) const;
  87 
  88   static ArrayKlass* cast(Klass* k) {
  89     return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
  90   }
  91 
  92   static const ArrayKlass* cast(const Klass* k) {
  93     assert(k->is_array_klass(), "cast to ArrayKlass");
  94     return static_cast<const ArrayKlass*>(k);
  95   }
  96 
  97   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
  98   bool compute_is_subtype_of(Klass* k);
  99 
 100   // Sizing
 101   static int header_size()                 { return sizeof(ArrayKlass)/HeapWordSize; }
 102   static int static_size(int header_size);
 103 
 104 #if INCLUDE_SERVICES
 105   virtual void collect_statistics(KlassSizeStats *sz) const {
 106     Klass::collect_statistics(sz);
 107     // Do nothing for now, but remember to modify if you add new
 108     // stuff to ArrayKlass.
 109   }
 110 #endif
 111 
 112   // Java vtable
 113   klassVtable* vtable() const;             // return new klassVtable
 114  protected:
 115   inline intptr_t* start_of_vtable() const;
 116 
 117  public:
 118   // Iterators
 119   void array_klasses_do(void f(Klass* k));
 120   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
 121 
 122   // Return a handle.
 123   static void     complete_create_array_klass(ArrayKlass* k, KlassHandle super_klass, TRAPS);
 124 
 125 
 126   // jvm support
 127   jint compute_modifier_flags(TRAPS) const;
 128 
 129   // JVMTI support
 130   jint jvmti_class_status() const;
 131 
 132   // CDS support - remove and restore oops from metadata. Oops are not shared.
 133   virtual void remove_unshareable_info();
 134   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
 135 
 136   // Printing
 137   void print_on(outputStream* st) const;
 138   void print_value_on(outputStream* st) const;
 139 
 140   void oop_print_on(oop obj, outputStream* st);
 141 
 142   // Verification
 143   void verify_on(outputStream* st);
 144 
 145   void oop_verify_on(oop obj, outputStream* st);
 146 };
 147 
 148 // Array oop iteration macros for declarations.
 149 // Used to generate the declarations in the *ArrayKlass header files.
 150 
 151 #define OOP_OOP_ITERATE_DECL_RANGE(OopClosureType, nv_suffix)                                   \
 152   void oop_oop_iterate_range##nv_suffix(oop obj, OopClosureType* closure, int start, int end);
 153 
 154 #if INCLUDE_ALL_GCS
 155 // Named NO_BACKWARDS because the definition used by *ArrayKlass isn't reversed, see below.
 156 #define OOP_OOP_ITERATE_DECL_NO_BACKWARDS(OopClosureType, nv_suffix)            \
 157   void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
 158 #endif // INCLUDE_ALL_GCS
 159 
 160 
 161 // Array oop iteration macros for definitions.
 162 // Used to generate the definitions in the *ArrayKlass.inline.hpp files.
 163 
 164 #define OOP_OOP_ITERATE_DEFN_RANGE(KlassType, OopClosureType, nv_suffix)                                  \
 165                                                                                                           \
 166 void KlassType::oop_oop_iterate_range##nv_suffix(oop obj, OopClosureType* closure, int start, int end) {  \
 167   oop_oop_iterate_range<nvs_to_bool(nv_suffix)>(obj, closure, start, end);                                \
 168 }
 169 
 170 #if INCLUDE_ALL_GCS
 171 #define OOP_OOP_ITERATE_DEFN_NO_BACKWARDS(KlassType, OopClosureType, nv_suffix)           \
 172 void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) {  \
 173   /* No reverse implementation ATM. */                                                    \
 174   oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure);                                  \
 175 }
 176 #else
 177 #define OOP_OOP_ITERATE_DEFN_NO_BACKWARDS(KlassType, OopClosureType, nv_suffix)
 178 #endif
 179 
 180 #endif // SHARE_VM_OOPS_ARRAYKLASS_HPP