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