1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24
25#ifndef SHARE_VM_OOPS_OOPSHIERARCHY_HPP
26#define SHARE_VM_OOPS_OOPSHIERARCHY_HPP
27
28#include "metaprogramming/integralConstant.hpp"
29#include "metaprogramming/primitiveConversions.hpp"
30#include "runtime/globals.hpp"
31#include "utilities/globalDefinitions.hpp"
32
33// OBJECT hierarchy
34// This hierarchy is a representation hierarchy, i.e. if A is a superclass
35// of B, A's representation is a prefix of B's representation.
36
37typedef juint narrowOop; // Offset instead of address for an oop within a java object
38
39// If compressed klass pointers then use narrowKlass.
40typedef juint  narrowKlass;
41
42typedef void* OopOrNarrowOopStar;
43typedef class   markOopDesc*                markOop;
44
45#ifndef CHECK_UNHANDLED_OOPS
46
47typedef class oopDesc*                            oop;
48typedef class   instanceOopDesc*            instanceOop;
49typedef class   arrayOopDesc*                    arrayOop;
50typedef class     objArrayOopDesc*            objArrayOop;
51typedef class     typeArrayOopDesc*            typeArrayOop;
52
53#else
54
55// When CHECK_UNHANDLED_OOPS is defined, an "oop" is a class with a
56// carefully chosen set of constructors and conversion operators to go
57// to and from the underlying oopDesc pointer type.
58//
59// Because oop and its subclasses <type>Oop are class types, arbitrary
60// conversions are not accepted by the compiler.  Applying a cast to
61// an oop will cause the best matched conversion operator to be
62// invoked returning the underlying oopDesc* type if appropriate.
63// No copy constructors, explicit user conversions or operators of
64// numerical type should be defined within the oop class. Most C++
65// compilers will issue a compile time error concerning the overloading
66// ambiguity between operators of numerical and pointer types. If
67// a conversion to or from an oop to a numerical type is needed,
68// use the inline template methods, cast_*_oop, defined below.
69//
70// Converting NULL to oop to Handle implicit is no longer accepted by the
71// compiler because there are too many steps in the conversion.  Use Handle()
72// instead, which generates less code anyway.
73
74class Thread;
75class PromotedObject;
76
77
78class oop {
79  oopDesc* _o;
80
81  void register_oop();
82  void unregister_oop();
83
84  // friend class markOop;
85public:
86  void set_obj(const void* p)         {
87    raw_set_obj(p);
88    if (CheckUnhandledOops) register_oop();
89  }
90  void raw_set_obj(const void* p)     { _o = (oopDesc*)p; }
91
92  oop()                               { set_obj(NULL); }
93  oop(const oop& o)                   { set_obj(o.obj()); }
94  oop(const volatile oop& o)          { set_obj(o.obj()); }
95  oop(const void* p)                  { set_obj(p); }
96  ~oop()                              {
97    if (CheckUnhandledOops) unregister_oop();
98  }
99
100  oopDesc* obj()  const volatile      { return _o; }
101
102  // General access
103  oopDesc*  operator->() const        { return obj(); }
104  bool operator==(const oop o) const  { return obj() == o.obj(); }
105  bool operator==(void *p) const      { return obj() == p; }
106  bool operator!=(const volatile oop o) const  { return obj() != o.obj(); }
107  bool operator!=(void *p) const      { return obj() != p; }
108
109  bool operator<(oop o) const         { return obj() < o.obj(); }
110  bool operator>(oop o) const         { return obj() > o.obj(); }
111  bool operator<=(oop o) const        { return obj() <= o.obj(); }
112  bool operator>=(oop o) const        { return obj() >= o.obj(); }
113  bool operator!() const              { return !obj(); }
114
115  // Assignment
116  oop& operator=(const oop& o)                            { _o = o.obj(); return *this; }
117  volatile oop& operator=(const oop& o) volatile          { _o = o.obj(); return *this; }
118  volatile oop& operator=(const volatile oop& o) volatile { _o = o.obj(); return *this; }
119
120  // Explict user conversions
121  operator void* () const             { return (void *)obj(); }
122#ifndef SOLARIS
123  operator void* () const volatile    { return (void *)obj(); }
124#endif
125  operator HeapWord* () const         { return (HeapWord*)obj(); }
126  operator oopDesc* () const volatile { return obj(); }
127  operator intptr_t* () const         { return (intptr_t*)obj(); }
128  operator PromotedObject* () const   { return (PromotedObject*)obj(); }
129  operator markOop () const volatile  { return markOop(obj()); }
130  operator address   () const         { return (address)obj(); }
131
132  // from javaCalls.cpp
133  operator jobject () const           { return (jobject)obj(); }
134  // from javaClasses.cpp
135  operator JavaThread* () const       { return (JavaThread*)obj(); }
136
137#ifndef _LP64
138  // from jvm.cpp
139  operator jlong* () const            { return (jlong*)obj(); }
140#endif
141
142  // from parNewGeneration and other things that want to get to the end of
143  // an oop for stuff (like ObjArrayKlass.cpp)
144  operator oop* () const              { return (oop *)obj(); }
145};
146
147template<>
148struct PrimitiveConversions::Translate<oop> : public TrueType {
149  typedef oop Value;
150  typedef oopDesc* Decayed;
151
152  static Decayed decay(Value x) { return x.obj(); }
153  static Value recover(Decayed x) { return oop(x); }
154};
155
156#define DEF_OOP(type)                                                      \
157   class type##OopDesc;                                                    \
158   class type##Oop : public oop {                                          \
159     public:                                                               \
160       type##Oop() : oop() {}                                              \
161       type##Oop(const oop& o) : oop(o) {}                                 \
162       type##Oop(const volatile oop& o) : oop(o) {}                        \
163       type##Oop(const void* p) : oop(p) {}                                \
164       operator type##OopDesc* () const { return (type##OopDesc*)obj(); }  \
165       type##OopDesc* operator->() const {                                 \
166            return (type##OopDesc*)obj();                                  \
167       }                                                                   \
168       type##Oop& operator=(const type##Oop& o) {                          \
169            oop::operator=(o);                                             \
170            return *this;                                                  \
171       }                                                                   \
172       volatile type##Oop& operator=(const type##Oop& o) volatile {        \
173            (void)const_cast<oop&>(oop::operator=(o));                     \
174            return *this;                                                  \
175       }                                                                   \
176       volatile type##Oop& operator=(const volatile type##Oop& o) volatile {\
177            (void)const_cast<oop&>(oop::operator=(o));                     \
178            return *this;                                                  \
179       }                                                                   \
180   };
181
182DEF_OOP(instance);
183DEF_OOP(array);
184DEF_OOP(objArray);
185DEF_OOP(typeArray);
186
187#endif // CHECK_UNHANDLED_OOPS
188
189// For CHECK_UNHANDLED_OOPS, it is ambiguous C++ behavior to have the oop
190// structure contain explicit user defined conversions of both numerical
191// and pointer type. Define inline methods to provide the numerical conversions.
192template <class T> inline oop cast_to_oop(T value) {
193  return (oop)(CHECK_UNHANDLED_OOPS_ONLY((void *))(value));
194}
195template <class T> inline T cast_from_oop(oop o) {
196  return (T)(CHECK_UNHANDLED_OOPS_ONLY((void*))o);
197}
198
199// The metadata hierarchy is separate from the oop hierarchy
200
201//      class MetaspaceObj
202class   ConstMethod;
203class   ConstantPoolCache;
204class   MethodData;
205//      class Metadata
206class   Method;
207class   ConstantPool;
208//      class CHeapObj
209class   CompiledICHolder;
210
211
212// The klass hierarchy is separate from the oop hierarchy.
213
214class Klass;
215class   InstanceKlass;
216class     InstanceMirrorKlass;
217class     InstanceClassLoaderKlass;
218class     InstanceRefKlass;
219class   ArrayKlass;
220class     ObjArrayKlass;
221class     TypeArrayKlass;
222
223#endif // SHARE_VM_OOPS_OOPSHIERARCHY_HPP
224