1 /*

     2  * Copyright (c) 2016, 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 

    25 #ifndef SHARE_VM_JFR_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP

    26 #define SHARE_VM_JFR_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP

    27 

    28 #include "memory/allocation.hpp"

    29 #include "jfr/utilities/jfrTypes.hpp"

    30 

    31 #define USED_BIT 1

    32 #define METHOD_USED_BIT (USED_BIT << 2)

    33 #define EPOCH_1_SHIFT 0

    34 #define EPOCH_2_SHIFT 1

    35 #define LEAKP_SHIFT 8

    36 

    37 #define USED_EPOCH_1_BIT (USED_BIT << EPOCH_1_SHIFT)

    38 #define USED_EPOCH_2_BIT (USED_BIT << EPOCH_2_SHIFT)

    39 #define LEAKP_USED_EPOCH_1_BIT (USED_EPOCH_1_BIT << LEAKP_SHIFT)

    40 #define LEAKP_USED_EPOCH_2_BIT (USED_EPOCH_2_BIT << LEAKP_SHIFT)

    41 #define METHOD_USED_EPOCH_1_BIT (METHOD_USED_BIT << EPOCH_1_SHIFT)

    42 #define METHOD_USED_EPOCH_2_BIT (METHOD_USED_BIT << EPOCH_2_SHIFT)

    43 #define METHOD_AND_CLASS_IN_USE_BITS (METHOD_USED_BIT | USED_BIT)

    44 #define METHOD_AND_CLASS_IN_USE_EPOCH_1_BITS (METHOD_AND_CLASS_IN_USE_BITS << EPOCH_1_SHIFT)

    45 #define METHOD_AND_CLASS_IN_USE_EPOCH_2_BITS (METHOD_AND_CLASS_IN_USE_BITS << EPOCH_2_SHIFT)

    46 

    47 class JfrTraceIdEpoch : AllStatic {

    48   friend class JfrCheckpointManager;

    49  private:

    50   static bool _epoch_state;

    51   static void shift_epoch();

    52 

    53  public:

    54   static bool epoch() {

    55     return _epoch_state;

    56   }

    57 

    58   static jlong epoch_address() {

    59     return (jlong)&_epoch_state;

    60   }

    61 

    62   static u1 current() {

    63     return _epoch_state ? (u1)1 : (u1)0;

    64   }

    65 

    66   static u1 previous() {

    67     return _epoch_state ? (u1)0 : (u1)1;

    68   }

    69 

    70   static traceid in_use_this_epoch_bit() {

    71     return _epoch_state ? USED_EPOCH_2_BIT : USED_EPOCH_1_BIT;

    72   }

    73 

    74   static traceid in_use_prev_epoch_bit() {

    75     return _epoch_state ? USED_EPOCH_1_BIT : USED_EPOCH_2_BIT;

    76   }

    77 

    78   static traceid leakp_in_use_this_epoch_bit() {

    79     return _epoch_state ? LEAKP_USED_EPOCH_2_BIT : LEAKP_USED_EPOCH_1_BIT;

    80   }

    81 

    82   static traceid leakp_in_use_prev_epoch_bit() {

    83     return _epoch_state ? LEAKP_USED_EPOCH_1_BIT : LEAKP_USED_EPOCH_2_BIT;

    84   }

    85 

    86   static traceid method_in_use_this_epoch_bit() {

    87     return _epoch_state ? METHOD_USED_EPOCH_2_BIT : METHOD_USED_EPOCH_1_BIT;

    88   }

    89 

    90   static traceid method_in_use_prev_epoch_bit() {

    91     return _epoch_state ? METHOD_USED_EPOCH_1_BIT : METHOD_USED_EPOCH_2_BIT;

    92   }

    93 

    94   static traceid method_and_class_in_use_this_epoch_bits() {

    95     return _epoch_state ? METHOD_AND_CLASS_IN_USE_EPOCH_2_BITS : METHOD_AND_CLASS_IN_USE_EPOCH_1_BITS;

    96   }

    97 

    98   static traceid method_and_class_in_use_prev_epoch_bits() {

    99     return _epoch_state ? METHOD_AND_CLASS_IN_USE_EPOCH_1_BITS :  METHOD_AND_CLASS_IN_USE_EPOCH_2_BITS;

   100   }

   101 };

   102 

   103 #endif // SHARE_VM_JFR_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP