8204210: Implementation: JEP 333: ZGC: A Scalable Low-Latency Garbage Collector (Experimental)
Reviewed-by: pliden, stefank, eosterlund, ehelin, sjohanss, rbackman, coleenp, ihse, jgeorge, lmesnik, rkennke
Contributed-by: per.liden@oracle.com, stefan.karlsson@oracle.com, erik.osterlund@oracle.com, mikael.gerdin@oracle.com, kim.barrett@oracle.com, nils.eliasson@oracle.com, rickard.backman@oracle.com, rwestrel@redhat.com, coleen.phillimore@oracle.com, robbin.ehn@oracle.com, gerard.ziemski@oracle.com, hugh.wilkinson@intel.com, sandhya.viswanathan@intel.com, bill.npo.wheeler@intel.com, vinay.k.awasthi@intel.com, yasuenag@gmail.com
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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.
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#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