1 /* 2 * Copyright (c) 2011, 2015, 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 "gc/shared/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 // GC specific object visitors 92 // 93 // Mark Sweep 94 void oop_ms_follow_contents(oop obj); 95 int oop_ms_adjust_pointers(oop obj); 96 #if INCLUDE_ALL_GCS 97 // Parallel Scavenge 98 void oop_ps_push_contents( oop obj, PSPromotionManager* pm); 99 // Parallel Compact 100 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm); 101 void oop_pc_update_pointers(oop obj); 102 #endif 103 104 // Oop fields (and metadata) iterators 105 // [nv = true] Use non-virtual calls to do_oop_nv. 106 // [nv = false] Use virtual calls to do_oop. 107 // 108 // The InstanceMirrorKlass iterators also visit the hidden Klass pointer. 109 110 public: 111 // Iterate over the static fields. 112 template <bool nv, class OopClosureType> 113 inline void oop_oop_iterate_statics(oop obj, OopClosureType* closure); 114 115 private: 116 // Iterate over the static fields. 117 // Specialized for [T = oop] or [T = narrowOop]. 118 template <bool nv, typename T, class OopClosureType> 119 inline void oop_oop_iterate_statics_specialized(oop obj, OopClosureType* closure); 120 121 // Forward iteration 122 // Iterate over the oop fields and metadata. 123 template <bool nv, class OopClosureType> 124 inline int oop_oop_iterate(oop obj, OopClosureType* closure); 125 126 127 // Reverse iteration 128 #if INCLUDE_ALL_GCS 129 // Iterate over the oop fields and metadata. 130 template <bool nv, class OopClosureType> 131 inline int oop_oop_iterate_reverse(oop obj, OopClosureType* closure); 132 #endif 133 134 135 // Bounded range iteration 136 // Iterate over the oop fields and metadata. 137 template <bool nv, class OopClosureType> 138 inline int oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr); 139 140 // Iterate over the static fields. 141 template <bool nv, class OopClosureType> 142 inline void oop_oop_iterate_statics_bounded(oop obj, OopClosureType* closure, MemRegion mr); 143 144 // Iterate over the static fields. 145 // Specialized for [T = oop] or [T = narrowOop]. 146 template <bool nv, typename T, class OopClosureType> 147 inline void oop_oop_iterate_statics_specialized_bounded(oop obj, OopClosureType* closure, MemRegion mr); 148 149 150 public: 151 152 #define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 153 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ 154 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); 155 156 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 157 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL) 158 159 #if INCLUDE_ALL_GCS 160 #define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 161 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); 162 163 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 164 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 165 #endif // INCLUDE_ALL_GCS 166 }; 167 168 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP