1 /*
2 * Copyright (c) 1997, 2013, 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
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7 * published by the Free Software Foundation.
8 *
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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 #if INCLUDE_ALL_GCS
31 #include "gc_implementation/shenandoah/shenandoah_globals.hpp"
32 #endif
33
34 // OBJECT hierarchy
35 // This hierarchy is a representation hierarchy, i.e. if A is a superclass
36 // of B, A's representation is a prefix of B's representation.
37
38 typedef juint narrowOop; // Offset instead of address for an oop within a java object
39
40 // If compressed klass pointers then use narrowKlass.
41 typedef juint narrowKlass;
42
43 typedef void* OopOrNarrowOopStar;
44 typedef class markOopDesc* markOop;
45
46 #ifndef CHECK_UNHANDLED_OOPS
47
48 typedef class oopDesc* oop;
49 typedef class instanceOopDesc* instanceOop;
50 typedef class arrayOopDesc* arrayOop;
51 typedef class objArrayOopDesc* objArrayOop;
52 typedef class typeArrayOopDesc* typeArrayOop;
53
54 #else
55
56 // When CHECK_UNHANDLED_OOPS is defined, an "oop" is a class with a
57 // carefully chosen set of constructors and conversion operators to go
58 // to and from the underlying oopDesc pointer type.
59 //
60 // Because oop and its subclasses <type>Oop are class types, arbitrary
61 // conversions are not accepted by the compiler. Applying a cast to
62 // an oop will cause the best matched conversion operator to be
63 // invoked returning the underlying oopDesc* type if appropriate.
64 // No copy constructors, explicit user conversions or operators of
65 // numerical type should be defined within the oop class. Most C++
66 // compilers will issue a compile time error concerning the overloading
67 // ambiguity between operators of numerical and pointer types. If
68 // a conversion to or from an oop to a numerical type is needed,
69 // use the inline template methods, cast_*_oop, defined below.
70 //
71 // Converting NULL to oop to Handle implicit is no longer accepted by the
72 // compiler because there are too many steps in the conversion. Use Handle()
73 // instead, which generates less code anyway.
74
75 class Thread;
76 class PromotedObject;
77
78
79 class oop {
80 oopDesc* _o;
81
82 void register_oop();
83 void unregister_oop();
84
85 // friend class markOop;
86 public:
87 void set_obj(const void* p) {
88 raw_set_obj(p);
89 if (CheckUnhandledOops) register_oop();
90 }
91 void raw_set_obj(const void* p) { _o = (oopDesc*)p; }
92
93 oop() { set_obj(NULL); }
94 oop(const oop& o) { set_obj(o.obj()); }
95 oop(const volatile oop& o) { set_obj(o.obj()); }
96 oop(const void* p) { set_obj(p); }
97 ~oop() {
98 if (CheckUnhandledOops) unregister_oop();
99 }
100
101 oopDesc* obj() const volatile { return _o; }
102
103 // General access
104 oopDesc* operator->() const { return obj(); }
105 bool operator==(const oop o) const {
106 #if INCLUDE_ALL_GCS
107 if (VerifyStrictOopOperations) {
108 ShouldNotReachHere();
109 }
110 #endif
111 return obj() == o.obj();
112 }
113 bool operator==(void *p) const {
114 #if INCLUDE_ALL_GCS
115 if (p != NULL && VerifyStrictOopOperations) {
116 ShouldNotReachHere();
117 }
118 #endif
119 return obj() == p;
120 }
121 bool operator!=(const volatile oop o) const {
122 #if INCLUDE_ALL_GCS
123 if (VerifyStrictOopOperations) {
124 ShouldNotReachHere();
125 }
126 #endif
127 return obj() != o.obj();
128 }
129 bool operator!=(void *p) const {
130 #if INCLUDE_ALL_GCS
131 if (p != NULL && VerifyStrictOopOperations) {
132 ShouldNotReachHere();
133 }
134 #endif
135 return obj() != p;
136 }
137
138 bool operator<(oop o) const { return obj() < o.obj(); }
139 bool operator>(oop o) const { return obj() > o.obj(); }
140 bool operator<=(oop o) const { return obj() <= o.obj(); }
141 bool operator>=(oop o) const { return obj() >= o.obj(); }
142 bool operator!() const { return !obj(); }
143
144 // Assignment
145 oop& operator=(const oop& o) { _o = o.obj(); return *this; }
146 #ifndef SOLARIS
147 volatile oop& operator=(const oop& o) volatile { _o = o.obj(); return *this; }
148 #endif
149 volatile oop& operator=(const volatile oop& o) volatile { _o = o.obj(); return *this; }
150
151 // Explict user conversions
152 operator void* () const { return (void *)obj(); }
153 #ifndef SOLARIS
154 operator void* () const volatile { return (void *)obj(); }
155 #endif
156 operator HeapWord* () const { return (HeapWord*)obj(); }
157 operator oopDesc* () const { return obj(); }
158 operator intptr_t* () const { return (intptr_t*)obj(); }
159 operator PromotedObject* () const { return (PromotedObject*)obj(); }
160 operator markOop () const { return markOop(obj()); }
161
162 operator address () const { return (address)obj(); }
163
164 // from javaCalls.cpp
165 operator jobject () const { return (jobject)obj(); }
166 // from javaClasses.cpp
167 operator JavaThread* () const { return (JavaThread*)obj(); }
168
169 #ifndef _LP64
170 // from jvm.cpp
171 operator jlong* () const { return (jlong*)obj(); }
172 #endif
173
174 // from parNewGeneration and other things that want to get to the end of
175 // an oop for stuff (like ObjArrayKlass.cpp)
176 operator oop* () const { return (oop *)obj(); }
177 };
178
179 #define DEF_OOP(type) \
180 class type##OopDesc; \
181 class type##Oop : public oop { \
182 public: \
183 type##Oop() : oop() {} \
184 type##Oop(const oop& o) : oop(o) {} \
185 type##Oop(const volatile oop& o) : oop(o) {} \
186 type##Oop(const void* p) : oop(p) {} \
187 operator type##OopDesc* () const { return (type##OopDesc*)obj(); } \
188 type##OopDesc* operator->() const { \
189 return (type##OopDesc*)obj(); \
190 } \
191 type##Oop& operator=(const type##Oop& o) { \
192 oop::operator=(o); \
193 return *this; \
194 } \
195 NOT_SOLARIS( \
196 volatile type##Oop& operator=(const type##Oop& o) volatile { \
197 (void)const_cast<oop&>(oop::operator=(o)); \
198 return *this; \
199 }) \
200 volatile type##Oop& operator=(const volatile type##Oop& o) volatile {\
201 (void)const_cast<oop&>(oop::operator=(o)); \
202 return *this; \
203 } \
204 };
205
206 DEF_OOP(instance);
207 DEF_OOP(array);
208 DEF_OOP(objArray);
209 DEF_OOP(typeArray);
210
211 #endif // CHECK_UNHANDLED_OOPS
212
213 // For CHECK_UNHANDLED_OOPS, it is ambiguous C++ behavior to have the oop
214 // structure contain explicit user defined conversions of both numerical
215 // and pointer type. Define inline methods to provide the numerical conversions.
216 template <class T> inline oop cast_to_oop(T value) {
217 return (oop)(CHECK_UNHANDLED_OOPS_ONLY((void *))(value));
218 }
219 template <class T> inline T cast_from_oop(oop o) {
220 return (T)(CHECK_UNHANDLED_OOPS_ONLY((void*))o);
221 }
222
223 // The metadata hierarchy is separate from the oop hierarchy
224
225 // class MetaspaceObj
226 class ConstMethod;
227 class ConstantPoolCache;
228 class MethodData;
229 // class Metadata
230 class Method;
231 class ConstantPool;
232 // class CHeapObj
233 class CompiledICHolder;
234
235
236 // The klass hierarchy is separate from the oop hierarchy.
237
238 class Klass;
239 class InstanceKlass;
240 class InstanceMirrorKlass;
241 class InstanceClassLoaderKlass;
242 class InstanceRefKlass;
243 class ArrayKlass;
244 class ObjArrayKlass;
245 class TypeArrayKlass;
246
247 #endif // SHARE_VM_OOPS_OOPSHIERARCHY_HPP