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.
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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
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:
56 InstanceRefKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
57 // Type testing
58 bool oop_is_instanceRef() const { return true; }
59
60 // Casting from Klass*
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
73 private:
74 template<class OopClosureType, class OopType, bool is_extended>
75 void do_metadata_if_applicable(oop obj, OopClosureType *cl);
76
77 public:
78 template<class OopClosureType>
79 int oop_iterate_and_dispatch(oop obj, OopClosureType *cl);
80
81 int get_linear_oop_intervals(oop obj, OopInterval* &start, int &size) { return -_instance_ref_klass; }
82
83 int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) {
84 return oop_oop_iterate_v(obj, blk);
85 }
86 int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) {
87 return oop_oop_iterate_v_m(obj, blk, mr);
88 }
89
90 #define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
91 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
92 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr);
93
94 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
95 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
96
97 #if INCLUDE_ALL_GCS
98 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
99 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
100
101 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
102 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
103 #endif // INCLUDE_ALL_GCS
104
105 static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
106 static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
107 static bool owns_pending_list_lock(JavaThread* thread);
108
109 // Update non-static oop maps so 'referent', 'nextPending' and
110 // 'discovered' will look like non-oops
111 static void update_nonstatic_oop_maps(Klass* k);
112
113 public:
114 // Verification
115 void oop_verify_on(oop obj, outputStream* st);
116 };
117
118 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP