1 | /* |
2 | * Copyright (c) 2017, 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 | #include "precompiled.hpp" |
25 | #include "gc/shared/preservedMarks.inline.hpp" |
26 | #include "oops/oop.inline.hpp" |
27 | #include "unittest.hpp" |
28 | |
29 | class ScopedDisabledBiasedLocking { |
30 | bool _orig; |
31 | public: |
32 | ScopedDisabledBiasedLocking() : _orig(UseBiasedLocking) { UseBiasedLocking = false; } |
33 | ~ScopedDisabledBiasedLocking() { UseBiasedLocking = _orig; } |
34 | }; |
35 | |
36 | // Class to create a "fake" oop with a mark that will |
37 | // return true for calls to must_be_preserved(). |
38 | class FakeOop { |
39 | oopDesc _oop; |
40 | |
41 | public: |
42 | FakeOop() : _oop() { _oop.set_mark_raw(originalMark()); } |
43 | |
44 | oop get_oop() { return &_oop; } |
45 | markOop mark() { return _oop.mark_raw(); } |
46 | void set_mark(markOop m) { _oop.set_mark_raw(m); } |
47 | void forward_to(oop obj) { |
48 | markOop m = markOopDesc::encode_pointer_as_mark(obj); |
49 | _oop.set_mark_raw(m); |
50 | } |
51 | |
52 | static markOop originalMark() { return markOop(markOopDesc::lock_mask_in_place); } |
53 | static markOop changedMark() { return markOop(0x4711); } |
54 | }; |
55 | |
56 | TEST_VM(PreservedMarks, iterate_and_restore) { |
57 | // Need to disable biased locking to easily |
58 | // create oops that "must_be_preseved" |
59 | ScopedDisabledBiasedLocking dbl; |
60 | |
61 | PreservedMarks pm; |
62 | FakeOop o1; |
63 | FakeOop o2; |
64 | FakeOop o3; |
65 | FakeOop o4; |
66 | |
67 | // Make sure initial marks are correct. |
68 | ASSERT_EQ(o1.mark(), FakeOop::originalMark()); |
69 | ASSERT_EQ(o2.mark(), FakeOop::originalMark()); |
70 | ASSERT_EQ(o3.mark(), FakeOop::originalMark()); |
71 | ASSERT_EQ(o4.mark(), FakeOop::originalMark()); |
72 | |
73 | // Change the marks and verify change. |
74 | o1.set_mark(FakeOop::changedMark()); |
75 | o2.set_mark(FakeOop::changedMark()); |
76 | ASSERT_EQ(o1.mark(), FakeOop::changedMark()); |
77 | ASSERT_EQ(o2.mark(), FakeOop::changedMark()); |
78 | |
79 | // Push o1 and o2 to have their marks preserved. |
80 | pm.push(o1.get_oop(), o1.mark()); |
81 | pm.push(o2.get_oop(), o2.mark()); |
82 | |
83 | // Fake a move from o1->o3 and o2->o4. |
84 | o1.forward_to(o3.get_oop()); |
85 | o2.forward_to(o4.get_oop()); |
86 | ASSERT_EQ(o1.get_oop()->forwardee(), o3.get_oop()); |
87 | ASSERT_EQ(o2.get_oop()->forwardee(), o4.get_oop()); |
88 | // Adjust will update the PreservedMarks stack to |
89 | // make sure the mark is updated at the new location. |
90 | pm.adjust_during_full_gc(); |
91 | |
92 | // Restore all preserved and verify that the changed |
93 | // mark is now present at o3 and o4. |
94 | pm.restore(); |
95 | ASSERT_EQ(o3.mark(), FakeOop::changedMark()); |
96 | ASSERT_EQ(o4.mark(), FakeOop::changedMark()); |
97 | } |
98 | |