jdk/src/hotspot/share/oops/objLayout.cpp
2024-11-15 21:21:03 +00:00

51 lines
1.9 KiB
C++

/*
* Copyright Amazon.com Inc. 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 "oops/markWord.hpp"
#include "oops/objLayout.hpp"
#include "runtime/globals.hpp"
#include "utilities/debug.hpp"
ObjLayout::Mode ObjLayout::_klass_mode = ObjLayout::Undefined;
int ObjLayout::_oop_base_offset_in_bytes = 0;
bool ObjLayout::_oop_has_klass_gap = false;
void ObjLayout::initialize() {
assert(_klass_mode == Undefined, "ObjLayout initialized twice");
if (UseCompactObjectHeaders) {
_klass_mode = Compact;
_oop_base_offset_in_bytes = sizeof(markWord);
_oop_has_klass_gap = false;
} else if (UseCompressedClassPointers) {
_klass_mode = Compressed;
_oop_base_offset_in_bytes = sizeof(markWord) + sizeof(narrowKlass);
_oop_has_klass_gap = true;
} else {
_klass_mode = Uncompressed;
_oop_base_offset_in_bytes = sizeof(markWord) + sizeof(Klass*);
_oop_has_klass_gap = false;
}
}