1 /* 2 * Copyright (c) 2011, 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_VM_OOPS_INSTANCEMIRRORKLASS_HPP 26 #define SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP 27 28 #include "oops/instanceKlass.hpp" 29 30 // An instanceMirrorKlass is a specialized instanceKlass for 31 // java.lang.Class instances. These instances are special because 32 // they contain the static fields of the class in addition to the 33 // normal fields of Class. This means they are variable sized 34 // instances and need special logic for computing their size and for 35 // iteration of their oops. 36 37 38 class instanceMirrorKlass: public instanceKlass { 39 friend class VMStructs; 40 41 private: 42 static int _offset_of_static_fields; 43 44 public: 45 // Type testing 46 bool oop_is_instanceMirror() const { return true; } 47 48 // Casting from klassOop 49 static instanceMirrorKlass* cast(klassOop k) { 50 assert(k->klass_part()->oop_is_instanceMirror(), "cast to instanceMirrorKlass"); 51 return (instanceMirrorKlass*) k->klass_part(); 52 } 53 54 // Returns the size of the instance including the extra static fields. 55 virtual int oop_size(oop obj) const; 56 57 // Static field offset is an offset into the Heap, should be converted by 58 // based on UseCompressedOop for traversal 59 static HeapWord* start_of_static_fields(oop obj) { 60 return (HeapWord*)((intptr_t)obj + offset_of_static_fields()); 61 } 62 63 static void init_offset_of_static_fields() { 64 // Cache the offset of the static fields in the Class instance 65 assert(_offset_of_static_fields == 0, "once"); 66 _offset_of_static_fields = instanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize; 67 } 68 69 static int offset_of_static_fields() { 70 return _offset_of_static_fields; 71 } 72 73 int compute_static_oop_field_count(oop obj); 74 75 // Given a Klass return the size of the instance 76 int instance_size(KlassHandle k); 77 78 // allocation 79 DEFINE_ALLOCATE_PERMANENT(instanceMirrorKlass); 80 instanceOop allocate_instance(KlassHandle k, TRAPS); 81 82 // Garbage collection 83 int oop_adjust_pointers(oop obj); 84 void oop_follow_contents(oop obj); 85 86 // Parallel Scavenge and Parallel Old 87 PARALLEL_GC_DECLS 88 89 int oop_oop_iterate(oop obj, OopClosure* blk) { 90 return oop_oop_iterate_v(obj, blk); 91 } 92 int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) { 93 return oop_oop_iterate_v_m(obj, blk, mr); 94 } 95 96 #define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 97 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ 98 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); 99 100 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 101 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 102 103 #ifndef SERIALGC 104 #define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 105 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); 106 107 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 108 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 109 #endif // !SERIALGC 110 }; 111 112 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP