1 /* 2 * Copyright (c) 1997, 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_INSTANCEREFKLASS_HPP 26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP 27 28 #include "oops/instanceKlass.hpp" 29 #include "utilities/macros.hpp" 30 31 // An InstanceRefKlass is a specialized InstanceKlass for Java 32 // classes that are subclasses of java/lang/ref/Reference. 33 // 34 // These classes are used to implement soft/weak/final/phantom 35 // references and finalization, and need special treatment by the 36 // garbage collector. 37 // 38 // During GC discovered reference objects are added (chained) to one 39 // of the four lists below, depending on the type of reference. 40 // The linked occurs through the next field in class java/lang/ref/Reference. 41 // 42 // Afterwards, the discovered references are processed in decreasing 43 // order of reachability. Reference objects eligible for notification 44 // are linked to the static pending_list in class java/lang/ref/Reference, 45 // and the pending list lock object in the same class is notified. 46 47 48 class InstanceRefKlass: public InstanceKlass { 49 friend class InstanceKlass; 50 51 // Constructor InstanceRefKlass(int vtable_len,int itable_len,int static_field_size,int nonstatic_oop_map_size,ReferenceType rt,AccessFlags access_flags,bool is_anonymous)52 InstanceRefKlass(int vtable_len, int itable_len, int static_field_size, int nonstatic_oop_map_size, ReferenceType rt, AccessFlags access_flags, bool is_anonymous) 53 : InstanceKlass(vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt, access_flags, is_anonymous) {} 54 55 public: InstanceRefKlass()56 InstanceRefKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 57 // Type testing oop_is_instanceRef() const58 bool oop_is_instanceRef() const { return true; } 59 60 // Casting from Klass* cast(Klass * k)61 static InstanceRefKlass* cast(Klass* k) { 62 assert(k->oop_is_instanceRef(), "cast to InstanceRefKlass"); 63 return (InstanceRefKlass*) k; 64 } 65 66 // Garbage collection 67 int oop_adjust_pointers(oop obj); 68 void oop_follow_contents(oop obj); 69 70 // Parallel Scavenge and Parallel Old 71 PARALLEL_GC_DECLS 72 oop_oop_iterate(oop obj,ExtendedOopClosure * blk)73 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) { 74 return oop_oop_iterate_v(obj, blk); 75 } oop_oop_iterate_m(oop obj,ExtendedOopClosure * blk,MemRegion mr)76 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) { 77 return oop_oop_iterate_v_m(obj, blk, mr); 78 } 79 80 #define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ 81 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ 82 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); 83 84 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL) 85 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL) 86 87 #if INCLUDE_ALL_GCS 88 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ 89 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); 90 91 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 92 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) 93 #endif // INCLUDE_ALL_GCS 94 95 static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock); 96 static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock); 97 static bool owns_pending_list_lock(JavaThread* thread); 98 99 // Update non-static oop maps so 'referent', 'nextPending' and 100 // 'discovered' will look like non-oops 101 static void update_nonstatic_oop_maps(Klass* k); 102 103 public: 104 // Verification 105 void oop_verify_on(oop obj, outputStream* st); 106 }; 107 108 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP 109