1/*
2 * Copyright (c) 2014, 2019, 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#include "precompiled.hpp"
26#include "classfile/javaClasses.hpp"
27#include "jfr/leakprofiler/chains/edge.hpp"
28#include "jfr/leakprofiler/chains/edgeStore.hpp"
29#include "jfr/leakprofiler/chains/edgeUtils.hpp"
30#include "jfr/leakprofiler/utilities/unifiedOop.hpp"
31#include "oops/fieldStreams.hpp"
32#include "oops/instanceKlass.hpp"
33#include "oops/objArrayOop.inline.hpp"
34#include "oops/oopsHierarchy.hpp"
35#include "runtime/handles.inline.hpp"
36
37bool EdgeUtils::is_leak_edge(const Edge& edge) {
38 return (const Edge*)edge.pointee()->mark() == &edge;
39}
40
41static int field_offset(const StoredEdge& edge) {
42 assert(!edge.is_root(), "invariant");
43 const oop ref_owner = edge.reference_owner();
44 assert(ref_owner != NULL, "invariant");
45 const oop* reference = UnifiedOop::decode(edge.reference());
46 assert(reference != NULL, "invariant");
47 assert(!UnifiedOop::is_narrow(reference), "invariant");
48 assert(!ref_owner->is_array(), "invariant");
49 assert(ref_owner->is_instance(), "invariant");
50 const int offset = (int)pointer_delta(reference, ref_owner, sizeof(char));
51 assert(offset < (ref_owner->size() * HeapWordSize), "invariant");
52 return offset;
53}
54
55static const InstanceKlass* field_type(const StoredEdge& edge) {
56 assert(!edge.is_root() || !EdgeUtils::is_array_element(edge), "invariant");
57 return (const InstanceKlass*)edge.reference_owner_klass();
58}
59
60const Symbol* EdgeUtils::field_name_symbol(const Edge& edge) {
61 assert(!edge.is_root(), "invariant");
62 assert(!is_array_element(edge), "invariant");
63 const int offset = field_offset(edge);
64 const InstanceKlass* ik = field_type(edge);
65 while (ik != NULL) {
66 JavaFieldStream jfs(ik);
67 while (!jfs.done()) {
68 if (offset == jfs.offset()) {
69 return jfs.name();
70 }
71 jfs.next();
72 }
73 ik = (InstanceKlass*)ik->super();
74 }
75 return NULL;
76}
77
78jshort EdgeUtils::field_modifiers(const Edge& edge) {
79 const int offset = field_offset(edge);
80 const InstanceKlass* ik = field_type(edge);
81
82 while (ik != NULL) {
83 JavaFieldStream jfs(ik);
84 while (!jfs.done()) {
85 if (offset == jfs.offset()) {
86 return jfs.access_flags().as_short();
87 }
88 jfs.next();
89 }
90 ik = (InstanceKlass*)ik->super();
91 }
92 return 0;
93}
94
95bool EdgeUtils::is_array_element(const Edge& edge) {
96 assert(!edge.is_root(), "invariant");
97 const oop ref_owner = edge.reference_owner();
98 assert(ref_owner != NULL, "invariant");
99 return ref_owner->is_objArray();
100}
101
102static int array_offset(const Edge& edge) {
103 assert(!edge.is_root(), "invariant");
104 const oop ref_owner = edge.reference_owner();
105 assert(ref_owner != NULL, "invariant");
106 const oop* reference = UnifiedOop::decode(edge.reference());
107 assert(reference != NULL, "invariant");
108 assert(!UnifiedOop::is_narrow(reference), "invariant");
109 assert(ref_owner->is_array(), "invariant");
110 const objArrayOop ref_owner_array = static_cast<const objArrayOop>(ref_owner);
111 const int offset = (int)pointer_delta(reference, ref_owner_array->base(), heapOopSize);
112 assert(offset >= 0 && offset < ref_owner_array->length(), "invariant");
113 return offset;
114}
115
116int EdgeUtils::array_index(const Edge& edge) {
117 return is_array_element(edge) ? array_offset(edge) : 0;
118}
119
120int EdgeUtils::array_size(const Edge& edge) {
121 if (is_array_element(edge)) {
122 const oop ref_owner = edge.reference_owner();
123 assert(ref_owner != NULL, "invariant");
124 assert(ref_owner->is_objArray(), "invariant");
125 return ((objArrayOop)(ref_owner))->length();
126 }
127 return 0;
128}
129
130const Edge* EdgeUtils::root(const Edge& edge) {
131 const Edge* current = &edge;
132 const Edge* parent = current->parent();
133 while (parent != NULL) {
134 current = parent;
135 parent = current->parent();
136 }
137 assert(current != NULL, "invariant");
138 return current;
139}
140
141const Edge* EdgeUtils::ancestor(const Edge& edge, size_t distance) {
142 const Edge* current = &edge;
143 const Edge* parent = current->parent();
144 size_t seek = 0;
145 while (parent != NULL && seek != distance) {
146 seek++;
147 current = parent;
148 parent = parent->parent();
149 }
150 return current;
151}
152