1 /* 2 * Copyright (c) 2011, 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 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 "classfile/systemDictionary.hpp" 29 #include "memory/specialized_oop_closures.hpp" 30 #include "oops/instanceKlass.hpp" 31 #include "runtime/handles.hpp" 32 #include "utilities/macros.hpp" 33 34 // An InstanceMirrorKlass is a specialized InstanceKlass for 35 // java.lang.Class instances. These instances are special because 36 // they contain the static fields of the class in addition to the 37 // normal fields of Class. This means they are variable sized 38 // instances and need special logic for computing their size and for 39 // iteration of their oops. 40 41 42 class InstanceMirrorKlass: public InstanceKlass { 43 friend class VMStructs; 44 friend class InstanceKlass; 45 46 private: 47 static int _offset_of_static_fields; 48 49 // Constructor 50 InstanceMirrorKlass(int vtable_len, int itable_len, int static_field_size, int nonstatic_oop_map_size, ReferenceType rt, AccessFlags access_flags, bool is_anonymous) 51 : InstanceKlass(vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt, access_flags, is_anonymous) {} 52 53 public: 54 InstanceMirrorKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 55 // Type testing 56 bool oop_is_instanceMirror() const { return true; } 57 58 // Casting from Klass* 59 static InstanceMirrorKlass* cast(Klass* k) { 60 assert(k->oop_is_instanceMirror(), "cast to InstanceMirrorKlass"); 61 return (InstanceMirrorKlass*) k; 62 } 63 64 // Returns the size of the instance including the extra static fields. 65 virtual int oop_size(oop obj) const; 66 67 // Static field offset is an offset into the Heap, should be converted by 68 // based on UseCompressedOop for traversal 69 static HeapWord* start_of_static_fields(oop obj) { 70 return (HeapWord*)(cast_from_oop<intptr_t>(obj) + offset_of_static_fields()); 71 } 72 73 static void init_offset_of_static_fields() { 74 // Cache the offset of the static fields in the Class instance 75 assert(_offset_of_static_fields == 0, "once"); 76 _offset_of_static_fields = InstanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize; 77 } 78 79 static int offset_of_static_fields() { 80 return _offset_of_static_fields; 81 } 82 83 int compute_static_oop_field_count(oop obj); 84 85 // Given a Klass return the size of the instance 86 int instance_size(KlassHandle k); 87 88 // allocation 89 instanceOop allocate_instance(KlassHandle k, TRAPS); 90 91 // Garbage collection 92 int oop_adjust_pointers(oop obj); 93 void oop_follow_contents(oop obj); 94 95 // Parallel Scavenge and Parallel Old 96 PARALLEL_GC_DECLS 97 98 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) { 99 return oop_oop_iterate_v(obj, blk); 100 } 101 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) { 102 return oop_oop_iterate_v_m(obj, blk, mr); 103 } 104 105 #define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 106 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ 107 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); 108 109 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 110 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 111 112 #if INCLUDE_ALL_GCS 113 #define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 114 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); 115 116 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 117 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 118 #endif // INCLUDE_ALL_GCS 119 }; 120 121 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP