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 private: 40 static int _offset_of_static_fields; 41 42 public: 43 // Type testing 44 bool oop_is_instanceMirror() const { return true; } 45 46 // Casting from klassOop 47 static instanceMirrorKlass* cast(klassOop k) { 48 assert(k->klass_part()->oop_is_instanceMirror(), "cast to instanceMirrorKlass"); 49 return (instanceMirrorKlass*) k->klass_part(); 50 } 51 52 // Returns the size of the instance including the extra static fields. 53 virtual int oop_size(oop obj) const; 54 55 // Static field offset is an offset into the Heap, should be converted by 56 // based on UseCompressedOop for traversal 57 static HeapWord* start_of_static_fields(oop obj) { 58 return (HeapWord*)((intptr_t)obj + offset_of_static_fields()); 59 } 60 61 static void init_offset_of_static_fields() { 62 // Cache the offset of the static fields in the Class instance 63 assert(_offset_of_static_fields == 0, "once"); 64 _offset_of_static_fields = instanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize; 65 } 66 67 static int offset_of_static_fields() { 68 return _offset_of_static_fields; 69 } 70 71 int compute_static_oop_field_count(oop obj); 72 73 // Given a Klass return the size of the instance 74 int instance_size(KlassHandle k); 75 76 // allocation 77 DEFINE_ALLOCATE_PERMANENT(instanceMirrorKlass); 78 instanceOop allocate_instance(KlassHandle k, TRAPS); 79 80 // Garbage collection 81 int oop_adjust_pointers(oop obj); 82 void oop_follow_contents(oop obj); 83 84 // Parallel Scavenge and Parallel Old 85 PARALLEL_GC_DECLS 86 87 int oop_oop_iterate(oop obj, OopClosure* blk) { 88 return oop_oop_iterate_v(obj, blk); 89 } 90 int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) { 91 return oop_oop_iterate_v_m(obj, blk, mr); 92 } 93 94 #define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 95 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ 96 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); 97 98 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 99 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 100 101 #ifndef SERIALGC 102 #define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 103 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); 104 105 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 106 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 107 #endif // !SERIALGC 108 }; 109 110 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP