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 "oops/instanceKlass.hpp" 30 #include "runtime/handles.hpp" 31 #include "utilities/macros.hpp" 32 #include "utilities/templateIdioms.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 75 static int offset_of_static_fields() { 76 return _offset_of_static_fields; 77 } 78 79 int compute_static_oop_field_count(oop obj); 80 81 // Given a Klass return the size of the instance 82 int instance_size(KlassHandle k); 83 84 // allocation 85 instanceOop allocate_instance(KlassHandle k, TRAPS); 86 87 // Garbage collection 88 int oop_adjust_pointers(oop obj); 89 void oop_follow_contents(oop obj); 90 91 private: 92 // Some dispatch functions for auto dispatching 93 template<class OopType, class OopClosureType> 94 void oop_iterate_and_dispatch_helper(oop obj, OopClosureType *closure); 95 96 // Make sure metadata only gets dispatched for ExtendedOopClosure using SFINAE 97 template <class OopClosureType> 98 typename enable_if<is_kind_of<ExtendedOopClosure, OopClosureType>::value, void>::type 99 do_metadata_if_applicable(oop obj, OopClosureType *cl); 100 101 template <class OopClosureType> 102 typename enable_if<!is_kind_of<ExtendedOopClosure, OopClosureType>::value, void>::type 103 do_metadata_if_applicable(oop obj, OopClosureType *cl) {} 104 105 public: 106 template<class OopClosureType> 107 int oop_iterate_and_dispatch(oop obj, OopClosureType *cl); 108 109 int get_linear_oop_intervals(oop obj, OopInterval* &start, int &size) { return _instance_mirror_klass; } 110 111 // Parallel Scavenge and Parallel Old 112 PARALLEL_GC_DECLS 113 114 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) { 115 return oop_oop_iterate_v(obj, blk); 116 } 117 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) { 118 return oop_oop_iterate_v_m(obj, blk, mr); 119 } 120 121 #define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 122 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ 123 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); 124 125 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 126 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 127 128 #if INCLUDE_ALL_GCS 129 #define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 130 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); 131 132 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 133 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 134 #endif // INCLUDE_ALL_GCS 135 }; 136 137 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP