1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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.
 18  *
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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 class ObjArrayKlass;
 33 
 34 // ArrayKlass is the abstract baseclass for all array classes
 35 
 36 class ArrayKlass: public Klass {
 37   friend class VMStructs;
 38 
 39  public:
 40   enum ArrayProperties : uint32_t {
 41     DEFAULT         = 0,
 42     NULL_RESTRICTED = 1 << 0,
 43     NON_ATOMIC      = 1 << 1,
 44     // FINAL           = 1 << 2,
 45     // VOLATILE        = 1 << 3
 46     INVALID         = 1 << 4,
 47     DUMMY           = 1 << 5      // Just to transition the code, to be removed ASAP
 48   };
 49 
 50   static bool is_null_restricted(ArrayProperties props) { return (props & NULL_RESTRICTED) != 0; }
 51   static bool is_non_atomic(ArrayProperties props) { return (props & NON_ATOMIC) != 0; }
 52 
 53  private:
 54   // If you add a new field that points to any metaspace object, you
 55   // must add this field to ArrayKlass::metaspace_pointers_do().
 56   int      _dimension;         // This is n'th-dimensional array.
 57   ArrayProperties _properties;
 58   ObjArrayKlass* volatile _higher_dimension;  // Refers the (n+1)'th-dimensional array (if present).
 59   ArrayKlass* volatile    _lower_dimension;   // Refers the (n-1)'th-dimensional array (if present).
 60 
 61  protected:
 62   // Constructors
 63   // The constructor with the Symbol argument does the real array
 64   // initialization, the other is a dummy
 65   ArrayKlass(Symbol* name, KlassKind kind, ArrayProperties props, markWord prototype_header = markWord::prototype());
 66   ArrayKlass();
 67 
 68   // Create array_name for element klass
 69   static Symbol* create_element_klass_array_name(Klass* element_klass, TRAPS);
 70 
 71   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
 72 
 73  public:
 74 
 75   // Testing operation
 76   DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
 77 
 78   // Returns the ObjArrayKlass for n'th dimension.
 79   ArrayKlass* array_klass(int n, TRAPS);
 80   ArrayKlass* array_klass_or_null(int n);
 81 
 82   // Returns the array class with this class as element type.
 83   ArrayKlass* array_klass(TRAPS);
 84   ArrayKlass* array_klass_or_null();
 85 
 86   // Instance variables
 87   int dimension() const                 { return _dimension;      }
 88   void set_dimension(int dimension)     { _dimension = dimension; }
 89 
 90   ArrayProperties properties() const { return _properties; }
 91   void set_properties(ArrayProperties props) { _properties = props; }
 92   static ByteSize properties_offset() { return byte_offset_of(ArrayKlass, _properties); }
 93 
 94   ObjArrayKlass* higher_dimension() const     { return _higher_dimension; }
 95   inline ObjArrayKlass* higher_dimension_acquire() const; // load with acquire semantics
 96   void set_higher_dimension(ObjArrayKlass* k) { _higher_dimension = k; }
 97   inline void release_set_higher_dimension(ObjArrayKlass* k); // store with release semantics
 98 
 99   ArrayKlass* lower_dimension() const      { return _lower_dimension; }
100   void set_lower_dimension(ArrayKlass* k)  { _lower_dimension = k; }
101 
102   // offset of first element, including any padding for the sake of alignment
103   int  array_header_in_bytes() const    { return layout_helper_header_size(layout_helper()); }
104   int  log2_element_size() const        { return layout_helper_log2_element_size(layout_helper()); }
105   // type of elements (T_OBJECT for both oop arrays and array-arrays)
106   BasicType element_type() const        { return layout_helper_element_type(layout_helper()); }
107 
108   virtual InstanceKlass* java_super() const;
109 
110   // Allocation
111   // Sizes points to the first dimension of the array, subsequent dimensions
112   // are always in higher memory.  The callers of these set that up.
113   virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
114   objArrayOop allocate_arrayArray(int n, int length, TRAPS);
115 
116   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
117   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
118 
119   // Lookup operations
120   Method* uncached_lookup_method(const Symbol* name,
121                                  const Symbol* signature,
122                                  OverpassLookupMode overpass_mode,
123                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
124 
125   static ArrayKlass* cast(Klass* k) {
126     return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
127   }
128 
129   static const ArrayKlass* cast(const Klass* k) {
130     assert(k->is_array_klass(), "cast to ArrayKlass");
131     return static_cast<const ArrayKlass*>(k);
132   }
133 
134   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
135                                                   Array<InstanceKlass*>* transitive_interfaces);
136 
137   oop component_mirror() const;
138 
139   // Sizing
140   static int static_size(int header_size);
141 
142   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
143 
144   // Return a handle.
145   static void     complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
146 
147   // JVMTI support
148   jint jvmti_class_status() const;
149 
150 #if INCLUDE_CDS
151   // CDS support - remove and restore oops from metadata. Oops are not shared.
152   virtual void remove_unshareable_info();
153   virtual void remove_java_mirror();
154   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
155   void cds_print_value_on(outputStream* st) const;
156 #endif
157 
158   void log_array_class_load(Klass* k);
159   // Printing
160   void print_on(outputStream* st) const;
161   void print_value_on(outputStream* st) const;
162 
163   void oop_print_on(oop obj, outputStream* st);
164 
165   // Verification
166   void verify_on(outputStream* st);
167 
168   void oop_verify_on(oop obj, outputStream* st);
169 };
170 
171 class ArrayDescription : public StackObj {
172   public:
173    Klass::KlassKind _kind;
174    ArrayKlass::ArrayProperties _properties;
175    LayoutKind _layout_kind;
176    ArrayDescription(Klass::KlassKind k, ArrayKlass::ArrayProperties p, LayoutKind lk) { _kind = k; _properties = p; _layout_kind = lk; }
177  };
178 
179 #endif // SHARE_OOPS_ARRAYKLASS_HPP