1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
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
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7 * published by the Free Software Foundation.
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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).
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
24
25 #ifndef SHARE_VM_OOPS_OOPSHIERARCHY_HPP
26 #define SHARE_VM_OOPS_OOPSHIERARCHY_HPP
27
28 #include "runtime/globals.hpp"
29 #include "utilities/globalDefinitions.hpp"
30
31 // OBJECT hierarchy
32 // This hierarchy is a representation hierarchy, i.e. if A is a superclass
33 // of B, A's representation is a prefix of B's representation.
34
35 typedef juint narrowOop; // Offset instead of address for an oop within a java object
36
37 // If compressed klass pointers then use narrowKlass.
38 typedef juint narrowKlass;
39
40 typedef void* OopOrNarrowOopStar;
41 typedef class markOopDesc* markOop;
42
43 #ifndef CHECK_UNHANDLED_OOPS
44
45 typedef class oopDesc* oop;
46 typedef class instanceOopDesc* instanceOop;
47 typedef class arrayOopDesc* arrayOop;
48 typedef class objArrayOopDesc* objArrayOop;
49 typedef class typeArrayOopDesc* typeArrayOop;
50
51 #else
52
53 // When CHECK_UNHANDLED_OOPS is defined, an "oop" is a class with a
54 // carefully chosen set of constructors and conversion operators to go
55 // to and from the underlying oopDesc pointer type.
56 //
57 // Because oop and its subclasses <type>Oop are class types, arbitrary
58 // conversions are not accepted by the compiler. Applying a cast to
59 // an oop will cause the best matched conversion operator to be
60 // invoked returning the underlying oopDesc* type if appropriate.
61 // No copy constructors, explicit user conversions or operators of
62 // numerical type should be defined within the oop class. Most C++
63 // compilers will issue a compile time error concerning the overloading
64 // ambiguity between operators of numerical and pointer types. If
65 // a conversion to or from an oop to a numerical type is needed,
66 // use the inline template methods, cast_*_oop, defined below.
67 //
68 // Converting NULL to oop to Handle implicit is no longer accepted by the
69 // compiler because there are too many steps in the conversion. Use Handle()
70 // instead, which generates less code anyway.
71
72 class Thread;
73 class PromotedObject;
74
75
76 class oop {
77 oopDesc* _o;
78
79 void register_oop();
80 void unregister_oop();
81
82 // friend class markOop;
83 public:
84 void set_obj(const void* p) {
85 raw_set_obj(p);
86 if (CheckUnhandledOops) register_oop();
87 }
88 void raw_set_obj(const void* p) { _o = (oopDesc*)p; }
89
90 oop() { set_obj(NULL); }
91 oop(const oop& o) { set_obj(o.obj()); }
92 oop(const volatile oop& o) { set_obj(o.obj()); }
93 oop(const void* p) { set_obj(p); }
94 ~oop() {
95 if (CheckUnhandledOops) unregister_oop();
96 }
97
98 oopDesc* obj() const volatile { return _o; }
99
100 // General access
101 oopDesc* operator->() const { return obj(); }
102 bool operator==(const oop o) const { return obj() == o.obj(); }
103 bool operator==(void *p) const { return obj() == p; }
104 bool operator!=(const volatile oop o) const { return obj() != o.obj(); }
105 bool operator!=(void *p) const { return obj() != p; }
106
107 bool operator<(oop o) const { return obj() < o.obj(); }
108 bool operator>(oop o) const { return obj() > o.obj(); }
109 bool operator<=(oop o) const { return obj() <= o.obj(); }
110 bool operator>=(oop o) const { return obj() >= o.obj(); }
111 bool operator!() const { return !obj(); }
112
113 // Assignment
114 oop& operator=(const oop& o) { _o = o.obj(); return *this; }
115 volatile oop& operator=(const oop& o) volatile { _o = o.obj(); return *this; }
116 volatile oop& operator=(const volatile oop& o) volatile { _o = o.obj(); return *this; }
117
118 // Explict user conversions
119 operator void* () const { return (void *)obj(); }
120 #ifndef SOLARIS
121 operator void* () const volatile { return (void *)obj(); }
122 #endif
123 operator HeapWord* () const { return (HeapWord*)obj(); }
124 operator oopDesc* () const volatile { return obj(); }
125 operator intptr_t* () const { return (intptr_t*)obj(); }
126 operator PromotedObject* () const { return (PromotedObject*)obj(); }
127 operator markOop () const volatile { return markOop(obj()); }
128 operator address () const { return (address)obj(); }
129
130 // from javaCalls.cpp
131 operator jobject () const { return (jobject)obj(); }
132 // from javaClasses.cpp
133 operator JavaThread* () const { return (JavaThread*)obj(); }
134
135 #ifndef _LP64
136 // from jvm.cpp
137 operator jlong* () const { return (jlong*)obj(); }
138 #endif
139
140 // from parNewGeneration and other things that want to get to the end of
141 // an oop for stuff (like ObjArrayKlass.cpp)
142 operator oop* () const { return (oop *)obj(); }
143 };
144
145 #define DEF_OOP(type) \
146 class type##OopDesc; \
147 class type##Oop : public oop { \
148 public: \
149 type##Oop() : oop() {} \
150 type##Oop(const oop& o) : oop(o) {} \
151 type##Oop(const volatile oop& o) : oop(o) {} \
152 type##Oop(const void* p) : oop(p) {} \
153 operator type##OopDesc* () const { return (type##OopDesc*)obj(); } \
154 type##OopDesc* operator->() const { \
155 return (type##OopDesc*)obj(); \
156 } \
157 type##Oop& operator=(const type##Oop& o) { \
158 oop::operator=(o); \
159 return *this; \
160 } \
161 volatile type##Oop& operator=(const type##Oop& o) volatile { \
162 (void)const_cast<oop&>(oop::operator=(o)); \
163 return *this; \
164 } \
165 volatile type##Oop& operator=(const volatile type##Oop& o) volatile {\
166 (void)const_cast<oop&>(oop::operator=(o)); \
167 return *this; \
168 } \
169 };
170
171 DEF_OOP(instance);
172 DEF_OOP(array);
173 DEF_OOP(objArray);
174 DEF_OOP(typeArray);
175
176 #endif // CHECK_UNHANDLED_OOPS
177
178 // For CHECK_UNHANDLED_OOPS, it is ambiguous C++ behavior to have the oop
179 // structure contain explicit user defined conversions of both numerical
180 // and pointer type. Define inline methods to provide the numerical conversions.
181 template <class T> inline oop cast_to_oop(T value) {
182 return (oop)(CHECK_UNHANDLED_OOPS_ONLY((void *))(value));
183 }
184 template <class T> inline T cast_from_oop(oop o) {
185 return (T)(CHECK_UNHANDLED_OOPS_ONLY((void*))o);
186 }
187
188 // The metadata hierarchy is separate from the oop hierarchy
189
190 // class MetaspaceObj
191 class ConstMethod;
192 class ConstantPoolCache;
193 class MethodData;
194 // class Metadata
195 class Method;
196 class ConstantPool;
197 // class CHeapObj
198 class CompiledICHolder;
199
200
201 // The klass hierarchy is separate from the oop hierarchy.
202
203 class Klass;
204 class InstanceKlass;
205 class InstanceMirrorKlass;
206 class InstanceClassLoaderKlass;
207 class InstanceRefKlass;
208 class ArrayKlass;
209 class ObjArrayKlass;
210 class TypeArrayKlass;
211
212 #endif // SHARE_VM_OOPS_OOPSHIERARCHY_HPP