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/*
* Copyright (c) 2017, 2018 Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include "precompiled.hpp"
#include "gc/shared/preservedMarks.inline.hpp"
#include "oops/oop.inline.hpp"
#include "unittest.hpp"
class ScopedDisabledBiasedLocking {
bool _orig;
public:
ScopedDisabledBiasedLocking() : _orig(UseBiasedLocking) { UseBiasedLocking = false; }
~ScopedDisabledBiasedLocking() { UseBiasedLocking = _orig; }
};
// Class to create a "fake" oop with a mark that will
// return true for calls to must_be_preserved().
class FakeOop {
oopDesc _oop;
public:
FakeOop() : _oop() { _oop.set_mark_raw(originalMark()); }
oop get_oop() { return &_oop; }
markOop mark() { return _oop.mark_raw(); }
void set_mark(markOop m) { _oop.set_mark_raw(m); }
void forward_to(oop obj) {
markOop m = markOopDesc::encode_pointer_as_mark(obj);
_oop.set_mark_raw(m);
}
static markOop originalMark() { return markOop(markOopDesc::lock_mask_in_place); }
static markOop changedMark() { return markOop(0x4711); }
};
TEST_VM(PreservedMarks, iterate_and_restore) {
// Need to disable biased locking to easily
// create oops that "must_be_preseved"
ScopedDisabledBiasedLocking dbl;
PreservedMarks pm;
FakeOop o1;
FakeOop o2;
FakeOop o3;
FakeOop o4;
// Make sure initial marks are correct.
ASSERT_EQ(o1.mark(), FakeOop::originalMark());
ASSERT_EQ(o2.mark(), FakeOop::originalMark());
ASSERT_EQ(o3.mark(), FakeOop::originalMark());
ASSERT_EQ(o4.mark(), FakeOop::originalMark());
// Change the marks and verify change.
o1.set_mark(FakeOop::changedMark());
o2.set_mark(FakeOop::changedMark());
ASSERT_EQ(o1.mark(), FakeOop::changedMark());
ASSERT_EQ(o2.mark(), FakeOop::changedMark());
// Push o1 and o2 to have their marks preserved.
pm.push(o1.get_oop(), o1.mark());
pm.push(o2.get_oop(), o2.mark());
// Fake a move from o1->o3 and o2->o4.
o1.forward_to(o3.get_oop());
o2.forward_to(o4.get_oop());
ASSERT_EQ(o1.get_oop()->forwardee(), o3.get_oop());
ASSERT_EQ(o2.get_oop()->forwardee(), o4.get_oop());
// Adjust will update the PreservedMarks stack to
// make sure the mark is updated at the new location.
pm.adjust_during_full_gc();
// Restore all preserved and verify that the changed
// mark is now present at o3 and o4.
pm.restore();
ASSERT_EQ(o3.mark(), FakeOop::changedMark());
ASSERT_EQ(o4.mark(), FakeOop::changedMark());
}
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