Sat, 01 Sep 2012 13:25:18 -0400
6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
1 /*
2 * Copyright (c) 2011, 2012, 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 */
25 #ifndef SHARE_VM_OOPS_FIELDINFO_HPP
26 #define SHARE_VM_OOPS_FIELDINFO_HPP
28 #include "oops/constantPool.hpp"
29 #include "oops/typeArrayOop.hpp"
30 #include "classfile/vmSymbols.hpp"
32 // This class represents the field information contained in the fields
33 // array of an InstanceKlass. Currently it's laid on top an array of
34 // Java shorts but in the future it could simply be used as a real
35 // array type. FieldInfo generally shouldn't be used directly.
36 // Fields should be queried either through InstanceKlass or through
37 // the various FieldStreams.
38 class FieldInfo VALUE_OBJ_CLASS_SPEC {
39 friend class fieldDescriptor;
40 friend class JavaFieldStream;
41 friend class ClassFileParser;
43 public:
44 // fields
45 // Field info extracted from the class file and stored
46 // as an array of 7 shorts
47 enum FieldOffset {
48 access_flags_offset = 0,
49 name_index_offset = 1,
50 signature_index_offset = 2,
51 initval_index_offset = 3,
52 low_offset = 4,
53 high_offset = 5,
54 field_slots = 6
55 };
57 private:
58 u2 _shorts[field_slots];
60 void set_name_index(u2 val) { _shorts[name_index_offset] = val; }
61 void set_signature_index(u2 val) { _shorts[signature_index_offset] = val; }
62 void set_initval_index(u2 val) { _shorts[initval_index_offset] = val; }
64 u2 name_index() const { return _shorts[name_index_offset]; }
65 u2 signature_index() const { return _shorts[signature_index_offset]; }
66 u2 initval_index() const { return _shorts[initval_index_offset]; }
68 public:
69 static FieldInfo* from_field_array(Array<u2>* fields, int index) {
70 return ((FieldInfo*)fields->adr_at(index * field_slots));
71 }
72 static FieldInfo* from_field_array(u2* fields, int index) {
73 return ((FieldInfo*)(fields + index * field_slots));
74 }
76 void initialize(u2 access_flags,
77 u2 name_index,
78 u2 signature_index,
79 u2 initval_index,
80 u4 offset) {
81 _shorts[access_flags_offset] = access_flags;
82 _shorts[name_index_offset] = name_index;
83 _shorts[signature_index_offset] = signature_index;
84 _shorts[initval_index_offset] = initval_index;
85 set_offset(offset);
86 }
88 u2 access_flags() const { return _shorts[access_flags_offset]; }
89 u4 offset() const { return build_int_from_shorts(_shorts[low_offset], _shorts[high_offset]); }
91 Symbol* name(constantPoolHandle cp) const {
92 int index = name_index();
93 if (is_internal()) {
94 return lookup_symbol(index);
95 }
96 return cp->symbol_at(index);
97 }
99 Symbol* signature(constantPoolHandle cp) const {
100 int index = signature_index();
101 if (is_internal()) {
102 return lookup_symbol(index);
103 }
104 return cp->symbol_at(index);
105 }
107 void set_access_flags(u2 val) { _shorts[access_flags_offset] = val; }
108 void set_offset(u4 val) {
109 _shorts[low_offset] = extract_low_short_from_int(val);
110 _shorts[high_offset] = extract_high_short_from_int(val);
111 }
113 bool is_internal() const {
114 return (access_flags() & JVM_ACC_FIELD_INTERNAL) != 0;
115 }
117 Symbol* lookup_symbol(int symbol_index) const {
118 assert(is_internal(), "only internal fields");
119 return vmSymbols::symbol_at((vmSymbols::SID)symbol_index);
120 }
121 };
123 #endif // SHARE_VM_OOPS_FIELDINFO_HPP