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/shenandoahGeneration.hpp"
35 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
36 #include "gc/shenandoah/shenandoahRootVerifier.hpp"
37 #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp"
38 #include "gc/shenandoah/shenandoahStringDedup.hpp"
39 #include "gc/shenandoah/shenandoahUtils.hpp"
40 #include "gc/shared/oopStorage.inline.hpp"
41 #include "gc/shared/oopStorageSet.hpp"
42 #include "runtime/javaThread.hpp"
43 #include "runtime/jniHandles.hpp"
44 #include "runtime/threads.hpp"
45 #include "utilities/debug.hpp"
46 #include "utilities/enumIterator.hpp"
47
48 ShenandoahGCStateResetter::ShenandoahGCStateResetter() :
49 _heap(ShenandoahHeap::heap()),
50 _gc_state(_heap->gc_state()),
51 _gc_state_changed(_heap->_gc_state_changed) {
52 // Clear state to deactivate barriers. Indicate that state has changed
53 // so that verifier threads will use this value, rather than thread local
54 // values (which we are _not_ changing here).
55 _heap->_gc_state.clear();
56 _heap->_gc_state_changed = true;
57 }
58
59 ShenandoahGCStateResetter::~ShenandoahGCStateResetter() {
60 _heap->_gc_state.set(_gc_state);
61 _heap->_gc_state_changed = _gc_state_changed;
62 assert(_heap->gc_state() == _gc_state, "Should be restored");
63 }
64
65 void ShenandoahRootVerifier::roots_do(OopIterateClosure* oops) {
66 ShenandoahGCStateResetter resetter;
67 shenandoah_assert_safepoint();
68
69 CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
70 CodeCache::blobs_do(&blobs);
71
72 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
73 ClassLoaderDataGraph::cld_do(&clds);
74
75 for (auto id : EnumRange<OopStorageSet::StrongId>()) {
76 OopStorageSet::storage(id)->oops_do(oops);
77 }
78
79 ShenandoahHeap* heap = ShenandoahHeap::heap();
80 if (heap->mode()->is_generational() && heap->active_generation()->is_young()) {
81 shenandoah_assert_safepoint();
82 ShenandoahGenerationalHeap::heap()->old_generation()->card_scan()->roots_do(oops);
83 }
84
85 // Do thread roots the last. This allows verification code to find
86 // any broken objects from those special roots first, not the accidental
87 // dangling reference from the thread root.
88 Threads::possibly_parallel_oops_do(true, oops, nullptr);
89 }
90
91 void ShenandoahRootVerifier::strong_roots_do(OopIterateClosure* oops) {
92 ShenandoahGCStateResetter resetter;
93 shenandoah_assert_safepoint();
94
95 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
96 ClassLoaderDataGraph::always_strong_cld_do(&clds);
97
98 for (auto id : EnumRange<OopStorageSet::StrongId>()) {
99 OopStorageSet::storage(id)->oops_do(oops);
100 }
101
102 ShenandoahHeap* heap = ShenandoahHeap::heap();
103 if (heap->mode()->is_generational() && heap->active_generation()->is_young()) {
104 ShenandoahGenerationalHeap::heap()->old_generation()->card_scan()->roots_do(oops);
105 }
106
107 // Do thread roots the last. This allows verification code to find
108 // any broken objects from those special roots first, not the accidental
109 // dangling reference from the thread root.
110 CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
111 Threads::possibly_parallel_oops_do(true, oops, &blobs);
112 }