rev 59083 : DRAFT 8236522: NonTearable marker interface for inline classes to enforce atomicity

   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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  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   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   // Are loads and stores to this concrete array type atomic?
  73   // Note that Object[] is naturally atomic, but its subtypes may not be.
  74   virtual bool element_access_is_atomic() { return true; }
  75 
  76   // Testing operation
  77   DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
  78 
  79   // Instance variables
  80   int dimension() const                 { return _dimension;      }
  81   void set_dimension(int dimension)     { _dimension = dimension; }
  82 
  83   Klass* higher_dimension() const     { return _higher_dimension; }
  84   inline Klass* higher_dimension_acquire() const; // load with acquire semantics
  85   void set_higher_dimension(Klass* k) { _higher_dimension = k; }
  86   inline void release_set_higher_dimension(Klass* k); // store with release semantics
  87 
  88   Klass* lower_dimension() const      { return _lower_dimension; }
  89   void set_lower_dimension(Klass* k)  { _lower_dimension = k; }
  90 
  91   // offset of first element, including any padding for the sake of alignment
  92   int  array_header_in_bytes() const    { return layout_helper_header_size(layout_helper()); }
  93   int  log2_element_size() const        { return layout_helper_log2_element_size(layout_helper()); }
  94   // type of elements (T_OBJECT for both oop arrays and array-arrays)
  95   BasicType element_type() const        { return layout_helper_element_type(layout_helper()); }
  96 
  97   virtual InstanceKlass* java_super() const;//{ return SystemDictionary::Object_klass(); }
  98 
  99   // Allocation
 100   // Sizes points to the first dimension of the array, subsequent dimensions
 101   // are always in higher memory.  The callers of these set that up.
 102   virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
 103   objArrayOop allocate_arrayArray(int n, int length, TRAPS);
 104 
 105   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 106   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 107 
 108   // Lookup operations
 109   Method* uncached_lookup_method(const Symbol* name,
 110                                  const Symbol* signature,
 111                                  OverpassLookupMode overpass_mode,
 112                                  PrivateLookupMode private_mode = find_private) const;
 113 
 114   static ArrayKlass* cast(Klass* k) {
 115     return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
 116   }
 117 
 118   static const ArrayKlass* cast(const Klass* k) {
 119     assert(k->is_array_klass(), "cast to ArrayKlass");
 120     return static_cast<const ArrayKlass*>(k);
 121   }
 122 
 123   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 124                                                   Array<InstanceKlass*>* transitive_interfaces);
 125 
 126   oop component_mirror() const;
 127 
 128   // Sizing
 129   static int static_size(int header_size);
 130 
 131   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 132 
 133   // Iterators
 134   void array_klasses_do(void f(Klass* k));
 135 
 136   // Return a handle.
 137   static void     complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
 138 
 139 
 140   // jvm support
 141   jint compute_modifier_flags(TRAPS) const;
 142 
 143   // JVMTI support
 144   jint jvmti_class_status() const;
 145 
 146   // CDS support - remove and restore oops from metadata. Oops are not shared.
 147   virtual void remove_unshareable_info();
 148   virtual void remove_java_mirror();
 149   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
 150 
 151   // Printing
 152   void print_on(outputStream* st) const;
 153   void print_value_on(outputStream* st) const;
 154 
 155   void oop_print_on(oop obj, outputStream* st);
 156 
 157   // Verification
 158   void verify_on(outputStream* st);
 159 
 160   void oop_verify_on(oop obj, outputStream* st);
 161 };
 162 
 163 #endif // SHARE_OOPS_ARRAYKLASS_HPP
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