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