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 _heap->_gc_state.clear();
52 }
53
54 ShenandoahGCStateResetter::~ShenandoahGCStateResetter() {
55 _heap->_gc_state.set(_gc_state);
56 assert(_heap->gc_state() == _gc_state, "Should be restored");
57 }
58
59 void ShenandoahRootVerifier::roots_do(OopIterateClosure* oops) {
60 ShenandoahGCStateResetter resetter;
61 shenandoah_assert_safepoint();
62
63 NMethodToOopClosure blobs(oops, !NMethodToOopClosure::FixRelocations);
64 CodeCache::nmethods_do(&blobs);
65
66 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
67 ClassLoaderDataGraph::cld_do(&clds);
68
69 for (auto id : EnumRange<OopStorageSet::StrongId>()) {
70 OopStorageSet::storage(id)->oops_do(oops);
71 }
72
73 ShenandoahHeap* heap = ShenandoahHeap::heap();
74 if (heap->mode()->is_generational() && heap->active_generation()->is_young()) {
75 shenandoah_assert_safepoint();
76 ShenandoahGenerationalHeap::heap()->old_generation()->card_scan()->roots_do(oops);
77 }
78
79 // Do thread roots the last. This allows verification code to find
80 // any broken objects from those special roots first, not the accidental
81 // dangling reference from the thread root.
82 Threads::possibly_parallel_oops_do(true, oops, nullptr);
83 }
84
85 void ShenandoahRootVerifier::strong_roots_do(OopIterateClosure* oops) {
86 ShenandoahGCStateResetter resetter;
87 shenandoah_assert_safepoint();
88
89 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
90 ClassLoaderDataGraph::always_strong_cld_do(&clds);
91
92 for (auto id : EnumRange<OopStorageSet::StrongId>()) {
93 OopStorageSet::storage(id)->oops_do(oops);
94 }
95
96 ShenandoahHeap* heap = ShenandoahHeap::heap();
97 if (heap->mode()->is_generational() && heap->active_generation()->is_young()) {
98 ShenandoahGenerationalHeap::heap()->old_generation()->card_scan()->roots_do(oops);
99 }
100
101 // Do thread roots the last. This allows verification code to find
102 // any broken objects from those special roots first, not the accidental
103 // dangling reference from the thread root.
104 NMethodToOopClosure nmethods(oops, !NMethodToOopClosure::FixRelocations);
105 Threads::possibly_parallel_oops_do(true, oops, &nmethods);
106 }