1 /*
  2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 #ifndef SHARE_GC_Z_ZNMETHODTABLEENTRY_HPP
 25 #define SHARE_GC_Z_ZNMETHODTABLEENTRY_HPP
 26 
 27 #include "gc/z/zBitField.hpp"
 28 #include "memory/allocation.hpp"
 29 
 30 //
 31 // NMethod table entry layout
 32 // --------------------------
 33 //
 34 //   6
 35 //   3                                                                  3 2 1 0
 36 //  +--------------------------------------------------------------------+-+-+-+
 37 //  |11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111|1|1|1|
 38 //  +--------------------------------------------------------------------+-+-+-+
 39 //  |                                                                    | | |
 40 //  |                               2-2 Non-immediate Oops Flag (1-bits) * | |
 41 //  |                                                                      | |
 42 //  |                        1-1 Immediate Oops/Unregistered Flag (1-bits) * |
 43 //  |                                                                        |
 44 //  |                                           0-0 Registered Flag (1-bits) *
 45 //  |
 46 //  * 63-3 NMethod/ZNMethodWithImmediateOops Address (61-bits)
 47 //
 48 
 49 class nmethod;
 50 class ZNMethodWithImmediateOops;
 51 
 52 class ZNMethodTableEntry : public CHeapObj<mtGC> {
 53 private:
 54   typedef ZBitField<uint64_t, bool,                       0,  1>    field_registered;
 55   typedef ZBitField<uint64_t, bool,                       1,  1>    field_unregistered;
 56   typedef ZBitField<uint64_t, bool,                       1,  1>    field_immediate_oops;
 57   typedef ZBitField<uint64_t, bool,                       2,  1>    field_non_immediate_oops;
 58   typedef ZBitField<uint64_t, nmethod*,                   3, 61, 3> field_method;
 59   typedef ZBitField<uint64_t, ZNMethodWithImmediateOops*, 3, 61, 3> field_method_with_immediate_oops;
 60 
 61   uint64_t _entry;
 62 
 63 public:
 64   ZNMethodTableEntry(bool unregistered = false) :
 65       _entry(field_unregistered::encode(unregistered) |
 66              field_registered::encode(false)) {}
 67 
 68   ZNMethodTableEntry(nmethod* method, bool non_immediate_oops) :
 69       _entry(field_method::encode(method) |
 70              field_non_immediate_oops::encode(non_immediate_oops) |
 71              field_immediate_oops::encode(false) |
 72              field_registered::encode(true)) {}
 73 
 74   ZNMethodTableEntry(ZNMethodWithImmediateOops* method_with_immediate_oops, bool non_immediate_oops) :
 75       _entry(field_method_with_immediate_oops::encode(method_with_immediate_oops) |
 76              field_non_immediate_oops::encode(non_immediate_oops) |
 77              field_immediate_oops::encode(true) |
 78              field_registered::encode(true)) {}
 79 
 80   bool registered() const {
 81     return field_registered::decode(_entry);
 82   }
 83 
 84   bool unregistered() const {
 85     return field_unregistered::decode(_entry);
 86   }
 87 
 88   bool immediate_oops() const {
 89     return field_immediate_oops::decode(_entry);
 90   }
 91 
 92   bool non_immediate_oops() const {
 93     return field_non_immediate_oops::decode(_entry);
 94   }
 95 
 96   nmethod* method() const {
 97     return field_method::decode(_entry);
 98   }
 99 
100   ZNMethodWithImmediateOops* method_with_immediate_oops() const {
101     return field_method_with_immediate_oops::decode(_entry);
102   }
103 };
104 
105 #endif // SHARE_GC_Z_ZNMETHODTABLEENTRY_HPP