1 /*
 2  * Copyright (c) 2019, 2021, Red Hat, Inc. 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 
26 #include "precompiled.hpp"
27 
28 
29 #include "classfile/classLoaderDataGraph.hpp"
30 #include "code/codeCache.hpp"
31 #include "gc/shenandoah/shenandoahAsserts.hpp"
32 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
33 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
34 #include "gc/shenandoah/shenandoahRootVerifier.hpp"
35 #include "gc/shenandoah/shenandoahStringDedup.hpp"
36 #include "gc/shenandoah/shenandoahUtils.hpp"
37 #include "gc/shared/oopStorage.inline.hpp"
38 #include "gc/shared/oopStorageSet.hpp"
39 #include "runtime/jniHandles.hpp"
40 #include "runtime/thread.hpp"
41 #include "utilities/debug.hpp"
42 #include "utilities/enumIterator.hpp"
43 
44 ShenandoahGCStateResetter::ShenandoahGCStateResetter() :
45   _heap(ShenandoahHeap::heap()),
46   _gc_state(_heap->gc_state()) {
47   _heap->_gc_state.clear();
48 }
49 
50 ShenandoahGCStateResetter::~ShenandoahGCStateResetter() {
51   _heap->_gc_state.set(_gc_state);
52   assert(_heap->gc_state() == _gc_state, "Should be restored");
53 }
54 
55 void ShenandoahRootVerifier::roots_do(OopClosure* oops) {
56   ShenandoahGCStateResetter resetter;
57   shenandoah_assert_safepoint();
58 
59   CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
60   CodeCache::blobs_do(&blobs);
61 
62   CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
63   ClassLoaderDataGraph::cld_do(&clds);
64 
65   for (auto id : EnumRange<OopStorageSet::StrongId>()) {
66     OopStorageSet::storage(id)->oops_do(oops);
67   }
68 
69   // Do thread roots the last. This allows verification code to find
70   // any broken objects from those special roots first, not the accidental
71   // dangling reference from the thread root.
72   Threads::possibly_parallel_oops_do(true, oops, NULL);
73 }
74 
75 void ShenandoahRootVerifier::strong_roots_do(OopClosure* oops) {
76   ShenandoahGCStateResetter resetter;
77   shenandoah_assert_safepoint();
78 
79   CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
80   ClassLoaderDataGraph::always_strong_cld_do(&clds);
81 
82   for (auto id : EnumRange<OopStorageSet::StrongId>()) {
83     OopStorageSet::storage(id)->oops_do(oops);
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   CodeBlobToOopClosure blobs(oops, !CodeBlobToOopClosure::FixRelocations);
89   Threads::possibly_parallel_oops_do(true, oops, &blobs);
90 }