1 /*
2 * Copyright (c) 2019, 2021, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26
27 #include "precompiled.hpp"
28
29
30 #include "classfile/classLoaderDataGraph.hpp"
31 #include "code/codeCache.hpp"
32 #include "gc/shenandoah/shenandoahAsserts.hpp"
33 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
34 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
35 #include "gc/shenandoah/shenandoahRootVerifier.hpp"
36 #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp"
37 #include "gc/shenandoah/shenandoahStringDedup.hpp"
38 #include "gc/shenandoah/shenandoahUtils.hpp"
39 #include "gc/shared/oopStorage.inline.hpp"
40 #include "gc/shared/oopStorageSet.hpp"
41 #include "runtime/javaThread.hpp"
42 #include "runtime/jniHandles.hpp"
43 #include "runtime/threads.hpp"
44 #include "utilities/debug.hpp"
45 #include "utilities/enumIterator.hpp"
46
47 ShenandoahGCStateResetter::ShenandoahGCStateResetter() :
48 _heap(ShenandoahHeap::heap()),
49 _gc_state(_heap->gc_state()) {
50 _heap->_gc_state.clear();
51 }
52
53 ShenandoahGCStateResetter::~ShenandoahGCStateResetter() {
54 _heap->_gc_state.set(_gc_state);
55 assert(_heap->gc_state() == _gc_state, "Should be restored");
56 }
57
58 void ShenandoahRootVerifier::roots_do(OopIterateClosure* oops) {
59 ShenandoahGCStateResetter resetter;
60 shenandoah_assert_safepoint();
61
62 CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
63 CodeCache::blobs_do(&blobs);
64
65 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
66 ClassLoaderDataGraph::cld_do(&clds);
67
68 for (auto id : EnumRange<OopStorageSet::StrongId>()) {
69 OopStorageSet::storage(id)->oops_do(oops);
70 }
71
72 ShenandoahHeap* heap = ShenandoahHeap::heap();
73 if (heap->mode()->is_generational() && heap->is_gc_generation_young()) {
74 shenandoah_assert_safepoint();
75 heap->card_scan()->roots_do(oops);
76 }
77
78 // Do thread roots the last. This allows verification code to find
79 // any broken objects from those special roots first, not the accidental
80 // dangling reference from the thread root.
81 Threads::possibly_parallel_oops_do(true, oops, nullptr);
82 }
83
84 void ShenandoahRootVerifier::strong_roots_do(OopIterateClosure* oops) {
85 ShenandoahGCStateResetter resetter;
86 shenandoah_assert_safepoint();
87
88 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
89 ClassLoaderDataGraph::always_strong_cld_do(&clds);
90
91 for (auto id : EnumRange<OopStorageSet::StrongId>()) {
92 OopStorageSet::storage(id)->oops_do(oops);
93 }
94
95 ShenandoahHeap* heap = ShenandoahHeap::heap();
96 if (heap->mode()->is_generational() && heap->is_gc_generation_young()) {
97 heap->card_scan()->roots_do(oops);
98 }
99
100 // Do thread roots the last. This allows verification code to find
101 // any broken objects from those special roots first, not the accidental
102 // dangling reference from the thread root.
103 CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
104 Threads::possibly_parallel_oops_do(true, oops, &blobs);
105 }