1 /*
  2  * Copyright (c) 1997, 2021, 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_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;
 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 = PrivateLookupMode::find) 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   // Iterators
108   void array_klasses_do(void f(Klass* k));
109   void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
110 
111   // Return a handle.
112   static void     complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
113 
114 
115   // jvm support
116   jint compute_modifier_flags() const;
117 
118   // JVMTI support
119   jint jvmti_class_status() const;
120 
121   // CDS support - remove and restore oops from metadata. Oops are not shared.
122   virtual void remove_unshareable_info();
123   virtual void remove_java_mirror();
124   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
125 
126   // Printing
127   void print_on(outputStream* st) const;
128   void print_value_on(outputStream* st) const;
129 
130   void oop_print_on(oop obj, outputStream* st);
131 
132   // Verification
133   void verify_on(outputStream* st);
134 
135   void oop_verify_on(oop obj, outputStream* st);
136 };
137 
138 #endif // SHARE_OOPS_ARRAYKLASS_HPP