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
/*
* 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
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*/
#ifndef SHARE_GC_Z_ZNMETHODTABLEENTRY_HPP
#define SHARE_GC_Z_ZNMETHODTABLEENTRY_HPP
#include "gc/z/zBitField.hpp"
#include "memory/allocation.hpp"
//
// NMethod table entry layout
// --------------------------
//
// 6
// 3 3 2 1 0
// +--------------------------------------------------------------------+-+-+-+
// |11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111|1|1|1|
// +--------------------------------------------------------------------+-+-+-+
// | | | |
// | 2-2 Non-immediate Oops Flag (1-bits) * | |
// | | |
// | 1-1 Immediate Oops/Unregistered Flag (1-bits) * |
// | |
// | 0-0 Registered Flag (1-bits) *
// |
// * 63-3 NMethod/ZNMethodWithImmediateOops Address (61-bits)
//
class nmethod;
class ZNMethodWithImmediateOops;
class ZNMethodTableEntry : public CHeapObj<mtGC> {
private:
typedef ZBitField<uint64_t, bool, 0, 1> field_registered;
typedef ZBitField<uint64_t, bool, 1, 1> field_unregistered;
typedef ZBitField<uint64_t, bool, 1, 1> field_immediate_oops;
typedef ZBitField<uint64_t, bool, 2, 1> field_non_immediate_oops;
typedef ZBitField<uint64_t, nmethod*, 3, 61, 3> field_method;
typedef ZBitField<uint64_t, ZNMethodWithImmediateOops*, 3, 61, 3> field_method_with_immediate_oops;
uint64_t _entry;
public:
ZNMethodTableEntry(bool unregistered = false) :
_entry(field_unregistered::encode(unregistered) |
field_registered::encode(false)) {}
ZNMethodTableEntry(nmethod* method, bool non_immediate_oops) :
_entry(field_method::encode(method) |
field_non_immediate_oops::encode(non_immediate_oops) |
field_immediate_oops::encode(false) |
field_registered::encode(true)) {}
ZNMethodTableEntry(ZNMethodWithImmediateOops* method_with_immediate_oops, bool non_immediate_oops) :
_entry(field_method_with_immediate_oops::encode(method_with_immediate_oops) |
field_non_immediate_oops::encode(non_immediate_oops) |
field_immediate_oops::encode(true) |
field_registered::encode(true)) {}
bool registered() const {
return field_registered::decode(_entry);
}
bool unregistered() const {
return field_unregistered::decode(_entry);
}
bool immediate_oops() const {
return field_immediate_oops::decode(_entry);
}
bool non_immediate_oops() const {
return field_non_immediate_oops::decode(_entry);
}
nmethod* method() const {
return field_method::decode(_entry);
}
ZNMethodWithImmediateOops* method_with_immediate_oops() const {
return field_method_with_immediate_oops::decode(_entry);
}
};
#endif // SHARE_GC_Z_ZNMETHODTABLEENTRY_HPP