jdk-24/src/hotspot/share/gc/z/zPageTableEntry.hpp
Per Lidén e7af7a4aef 8204210: Implementation: JEP 333: ZGC: A Scalable Low-Latency Garbage Collector (Experimental)
Co-authored-by: Stefan Karlsson <stefan.karlsson@oracle.com>
Co-authored-by: Erik Osterlund <erik.osterlund@oracle.com>
Co-authored-by: Mikael Gerdin <mikael.gerdin@oracle.com>
Co-authored-by: Kim Barrett <kim.barrett@oracle.com>
Co-authored-by: Nils Eliasson <nils.eliasson@oracle.com>
Co-authored-by: Rickard Backman <rickard.backman@oracle.com>
Co-authored-by: Roland Westrelin <rwestrel@redhat.com>
Co-authored-by: Coleen Phillimore <coleen.phillimore@oracle.com>
Co-authored-by: Robbin Ehn <robbin.ehn@oracle.com>
Co-authored-by: Gerard Ziemski <gerard.ziemski@oracle.com>
Co-authored-by: Hugh Wilkinson <hugh.wilkinson@intel.com>
Co-authored-by: Sandhya Viswanathan <sandhya.viswanathan@intel.com>
Co-authored-by: Bill Wheeler <bill.npo.wheeler@intel.com>
Co-authored-by: Vinay K. Awasthi <vinay.k.awasthi@intel.com>
Co-authored-by: Yasumasa Suenaga <yasuenag@gmail.com>
Reviewed-by: pliden, stefank, eosterlund, ehelin, sjohanss, rbackman, coleenp, ihse, jgeorge, lmesnik, rkennke
2018-06-12 17:40:28 +02:00

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/*
* Copyright (c) 2017, 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.
*/
#ifndef SHARE_GC_Z_ZPAGETABLEENTRY_HPP
#define SHARE_GC_Z_ZPAGETABLEENTRY_HPP
#include "gc/z/zBitField.hpp"
#include "memory/allocation.hpp"
//
// Page table entry layout
// -----------------------
//
// 6
// 3 1 0
// +----------------------------------------------------------------------+-+
// |11111111 11111111 11111111 11111111 11111111 11111111 11111111 1111111|1|
// +----------------------------------------------------------------------+-+
// | |
// | 0-0 Relocating Flag (1-bit) *
// |
// |
// |
// * 63-1 Page address (63-bits)
//
class ZPage;
class ZPageTableEntry {
private:
typedef ZBitField<uint64_t, bool, 0, 1> field_relocating;
typedef ZBitField<uint64_t, ZPage*, 1, 63, 1> field_page;
uint64_t _entry;
public:
ZPageTableEntry() :
_entry(0) {}
ZPageTableEntry(ZPage* page, bool relocating) :
_entry(field_page::encode(page) |
field_relocating::encode(relocating)) {}
bool relocating() const {
return field_relocating::decode(_entry);
}
ZPage* page() const {
return field_page::decode(_entry);
}
};
#endif // SHARE_GC_Z_ZPAGETABLEENTRY_HPP