1 /*
   2  * Copyright (c) 2013, 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_UTILITIES_TICKS_HPP
  26 #define SHARE_VM_UTILITIES_TICKS_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "utilities/globalDefinitions.hpp"
  30 
  31 class Ticks;
  32 
  33 class Tickspan {
  34   friend class Ticks;
  35   friend Tickspan operator-(const Ticks& end, const Ticks& start);
  36 
  37  private:
  38   jlong _span_ticks;
  39 
  40   Tickspan(const Ticks& end, const Ticks& start);
  41 
  42  public:
  43   Tickspan() : _span_ticks(0) {}
  44 
  45   Tickspan& operator+=(const Tickspan& rhs) {
  46     _span_ticks += rhs._span_ticks;
  47     return *this;
  48   }
  49 
  50   Tickspan& operator-=(const Tickspan& rhs) {
  51     _span_ticks -= rhs._span_ticks;
  52     return *this;
  53   }
  54 
  55   jlong value() const {
  56     return _span_ticks;
  57   }
  58 
  59 };
  60 
  61 class Ticks {
  62  private:
  63   jlong _stamp_ticks;
  64 
  65  public:
  66   Ticks() : _stamp_ticks(0) {
  67     assert((_stamp_ticks = invalid_time_stamp) == invalid_time_stamp,
  68       "initial unstamped time value assignment");
  69   }
  70 
  71   Ticks& operator+=(const Tickspan& span) {
  72     _stamp_ticks += span.value();
  73     return *this;
  74   }
  75 
  76   Ticks& operator-=(const Tickspan& span) {
  77     _stamp_ticks -= span.value();
  78     return *this;
  79   }
  80 
  81   void stamp();
  82 
  83   jlong value() const {
  84     return _stamp_ticks;
  85   }
  86 
  87   static const Ticks now();
  88 
  89 #ifdef ASSERT
  90   static const jlong invalid_time_stamp;
  91 #endif
  92 
  93 #ifndef PRODUCT
  94   // only for internal use by GC VM tests
  95   friend class TimePartitionPhasesIteratorTest;
  96   friend class GCTimerTest;
  97 
  98  private:
  99   // implicit type conversion
 100   Ticks(int ticks) : _stamp_ticks(ticks) {}
 101 
 102 #endif // !PRODUCT
 103 
 104 };
 105 
 106 class TicksToTimeHelper : public AllStatic {
 107  public:
 108   enum Unit {
 109     SECONDS = 1,
 110     MILLISECONDS = 1000
 111   };
 112   static double seconds(const Tickspan& span);
 113   static jlong milliseconds(const Tickspan& span);
 114 };
 115 
 116 #endif // SHARE_VM_UTILITIES_TICKS_HPP