1 /* 2 * Copyright (c) 1997, 2016, 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_INSTANCEREFKLASS_HPP 26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP 27 28 #include "gc/shared/specialized_oop_closures.hpp" 29 #include "oops/instanceKlass.hpp" 30 #include "utilities/macros.hpp" 31 32 class ClassFileParser; 33 34 // An InstanceRefKlass is a specialized InstanceKlass for Java 35 // classes that are subclasses of java/lang/ref/Reference. 36 // 37 // These classes are used to implement soft/weak/final/phantom 38 // references and finalization, and need special treatment by the 39 // garbage collector. 40 // 41 // During GC discovered reference objects are added (chained) to one 42 // of the four lists below, depending on the type of reference. 43 // The linked occurs through the next field in class java/lang/ref/Reference. 44 // 45 // Afterwards, the discovered references are processed in decreasing 46 // order of reachability. Reference objects eligible for notification 47 // are linked to the static pending_list in class java/lang/ref/Reference, 48 // and the pending list lock object in the same class is notified. 49 50 51 class InstanceRefKlass: public InstanceKlass { 52 friend class InstanceKlass; 53 private: 54 InstanceRefKlass(const ClassFileParser& parser) : InstanceKlass(parser, InstanceKlass::_misc_kind_reference) {} 55 56 public: 57 InstanceRefKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 58 59 // GC specific object visitors 60 // 61 // Mark Sweep 62 int oop_ms_adjust_pointers(oop obj); 63 #if INCLUDE_ALL_GCS 64 // Parallel Scavenge 65 void oop_ps_push_contents( oop obj, PSPromotionManager* pm); 66 // Parallel Compact 67 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm); 68 void oop_pc_update_pointers(oop obj, ParCompactionManager* cm); 69 #endif 70 71 // Oop fields (and metadata) iterators 72 // [nv = true] Use non-virtual calls to do_oop_nv. 73 // [nv = false] Use virtual calls to do_oop. 74 // 75 // The InstanceRefKlass iterators also support reference processing. 76 77 78 // Forward iteration 79 private: 80 // Iterate over all oop fields and metadata. 81 template <bool nv, class OopClosureType> 82 inline void oop_oop_iterate(oop obj, OopClosureType* closure); 83 84 // Reverse iteration 85 #if INCLUDE_ALL_GCS 86 // Iterate over all oop fields and metadata. 87 template <bool nv, class OopClosureType> 88 inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure); 89 #endif // INCLUDE_ALL_GCS 90 91 // Bounded range iteration 92 // Iterate over all oop fields and metadata. 93 template <bool nv, class OopClosureType> 94 inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr); 95 96 // Reference processing part of the iterators. 97 98 // Specialized for [T = oop] or [T = narrowOop]. 99 template <bool nv, typename T, class OopClosureType, class Contains> 100 inline void oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains); 101 102 // Only perform reference processing if the referent object is within mr. 103 template <bool nv, class OopClosureType> 104 inline void oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr); 105 106 // Reference processing 107 template <bool nv, class OopClosureType> 108 inline void oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure); 109 110 111 public: 112 113 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL) 114 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL) 115 116 #if INCLUDE_ALL_GCS 117 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS) 118 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS) 119 #endif // INCLUDE_ALL_GCS 120 121 static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock); 122 static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock); 123 static bool owns_pending_list_lock(JavaThread* thread); 124 125 // Update non-static oop maps so 'referent', 'nextPending' and 126 // 'discovered' will look like non-oops 127 static void update_nonstatic_oop_maps(Klass* k); 128 129 public: 130 // Verification 131 void oop_verify_on(oop obj, outputStream* st); 132 }; 133 134 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP