1 /*
   2  * Copyright (c) 2017, 2018, 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_ZALLOCATIONFLAGS_HPP
  25 #define SHARE_GC_Z_ZALLOCATIONFLAGS_HPP
  26 
  27 #include "gc/z/zBitField.hpp"
  28 #include "memory/allocation.hpp"
  29 
  30 //
  31 // Allocation flags layout
  32 // -----------------------
  33 //
  34 //   7    3 2 1 0
  35 //  +----+-+-+-+-+
  36 //  |0000|1|1|1|1|
  37 //  +----+-+-+-+-+
  38 //  |    | | | |
  39 //  |    | | | * 0-0 Worker Thread Flag (1-bit)
  40 //  |    | | |
  41 //  |    | | * 1-1 Non-Blocking Flag (1-bit)
  42 //  |    | |
  43 //  |    | * 2-2 Relocation Flag (1-bit)
  44 //  |    |
  45 //  |    * 3-3 No Reserve Flag (1-bit)
  46 //  |
  47 //  * 7-4 Unused (4-bits)
  48 //
  49 
  50 class ZAllocationFlags {
  51 private:
  52   typedef ZBitField<uint8_t, bool, 0, 1> field_worker_thread;
  53   typedef ZBitField<uint8_t, bool, 1, 1> field_non_blocking;
  54   typedef ZBitField<uint8_t, bool, 2, 1> field_relocation;
  55   typedef ZBitField<uint8_t, bool, 3, 1> field_no_reserve;
  56 
  57   uint8_t _flags;
  58 
  59 public:
  60   ZAllocationFlags() :
  61       _flags(0) {}
  62 
  63   void set_worker_thread() {
  64     _flags |= field_worker_thread::encode(true);
  65   }
  66 
  67   void set_non_blocking() {
  68     _flags |= field_non_blocking::encode(true);
  69   }
  70 
  71   void set_relocation() {
  72     _flags |= field_relocation::encode(true);
  73   }
  74 
  75   void set_no_reserve() {
  76     _flags |= field_no_reserve::encode(true);
  77   }
  78 
  79   bool worker_thread() const {
  80     return field_worker_thread::decode(_flags);
  81   }
  82 
  83   bool non_blocking() const {
  84     return field_non_blocking::decode(_flags);
  85   }
  86 
  87   bool relocation() const {
  88     return field_relocation::decode(_flags);
  89   }
  90 
  91   bool no_reserve() const {
  92     return field_no_reserve::decode(_flags);
  93   }
  94 };
  95 
  96 #endif // SHARE_GC_Z_ZALLOCATIONFLAGS_HPP