1 /*
2 * Copyright (c) 2014, 2018, 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 "aot/aotLoader.hpp"
27 #include "classfile/classLoaderData.hpp"
28 #include "classfile/stringTable.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "gc/shared/strongRootsScope.hpp"
31 #include "jfr/leakprofiler/chains/edgeQueue.hpp"
32 #include "jfr/leakprofiler/chains/rootSetClosure.hpp"
33 #include "jfr/leakprofiler/utilities/saveRestore.hpp"
34 #include "jfr/leakprofiler/utilities/unifiedOop.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/access.inline.hpp"
37 #include "prims/jvmtiExport.hpp"
38 #include "runtime/jniHandles.inline.hpp"
39 #include "runtime/synchronizer.hpp"
40 #include "runtime/thread.hpp"
41 #include "services/management.hpp"
42 #include "utilities/align.hpp"
43
44 RootSetClosure::RootSetClosure(EdgeQueue* edge_queue) :
45 _edge_queue(edge_queue) {
46 }
47
48 void RootSetClosure::do_oop(oop* ref) {
49 assert(ref != NULL, "invariant");
50 // We discard unaligned root references because
51 // our reference tagging scheme will use
52 // the lowest bit in a represented reference
53 // to indicate the reference is narrow.
54 // It is mainly roots delivered via nmethods::do_oops()
55 // that come in unaligned. It should be ok to duck these
56 // since they are supposedly weak.
57 if (!is_aligned(ref, HeapWordSize)) {
58 return;
59 }
60
61 assert(is_aligned(ref, HeapWordSize), "invariant");
62 const oop pointee = *ref;
63 if (pointee != NULL) {
64 closure_impl(ref, pointee);
65 }
66 }
67
68 void RootSetClosure::do_oop(narrowOop* ref) {
69 assert(ref != NULL, "invariant");
70 assert(is_aligned(ref, sizeof(narrowOop)), "invariant");
71 const oop pointee = RawAccess<>::oop_load(ref);
72 if (pointee != NULL) {
73 closure_impl(UnifiedOop::encode(ref), pointee);
74 }
75 }
76
77 void RootSetClosure::closure_impl(const oop* reference, const oop pointee) {
78 if (!_edge_queue->is_full()) {
79 _edge_queue->add(NULL, reference);
80 }
81 }
82
83 void RootSetClosure::add_to_queue(EdgeQueue* edge_queue) {
84 RootSetClosure rs(edge_queue);
85 process_roots(&rs);
86 }
87
88 class RootSetClosureMarkScope : public MarkScope {
89 };
90
91 void RootSetClosure::process_roots(OopClosure* closure) {
92 SaveRestoreCLDClaimBits save_restore_cld_claim_bits;
93 RootSetClosureMarkScope mark_scope;
94
95 CLDToOopClosure cldt_closure(closure, ClassLoaderData::_claim_value_strong);
96 ClassLoaderDataGraph::always_strong_cld_do(&cldt_closure);
97 CodeBlobToOopClosure blobs(closure, false);
98 Threads::oops_do(closure, &blobs);
99 ObjectSynchronizer::oops_do(closure);
100 Universe::oops_do(closure);
101 JNIHandles::oops_do(closure);
102 JvmtiExport::oops_do(closure);
103 SystemDictionary::oops_do(closure);
104 Management::oops_do(closure);
105 StringTable::oops_do(closure);
106 AOTLoader::oops_do(closure);
107 }