1 /*
   2  * Copyright (c) 2014, 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 #include "precompiled.hpp"
  26 #include "jfr/leakprofiler/utilities/granularTimer.hpp"
  27 
  28 long GranularTimer::_granularity = 0;
  29 long GranularTimer::_counter = 0;
  30 JfrTicks GranularTimer::_finish_time_ticks = 0;
  31 JfrTicks GranularTimer::_start_time_ticks = 0;
  32 bool GranularTimer::_finished = false;
  33 
  34 void GranularTimer::start(jlong duration_ticks, long granularity) {
  35   assert(granularity > 0, "granularity must be at least 1");
  36   _granularity = granularity;
  37   _counter = granularity;
  38   _start_time_ticks = JfrTicks::now();
  39   const jlong end_time_ticks = _start_time_ticks.value() + duration_ticks;
  40   _finish_time_ticks = end_time_ticks < 0 ? JfrTicks(max_jlong) : JfrTicks(end_time_ticks);
  41   _finished = _finish_time_ticks == _start_time_ticks;
  42   assert(_finish_time_ticks.value() >= 0, "invariant");
  43   assert(_finish_time_ticks >= _start_time_ticks, "invariant");
  44 }
  45 void GranularTimer::stop() {
  46   if (!_finished) {
  47     _finish_time_ticks = JfrTicks::now();
  48   }
  49 }
  50 const JfrTicks& GranularTimer::start_time() {
  51   return _start_time_ticks;
  52 }
  53 
  54 const JfrTicks& GranularTimer::end_time() {
  55   return _finish_time_ticks;
  56 }
  57 
  58 bool GranularTimer::is_finished() {
  59   assert(_granularity != 0, "GranularTimer::is_finished must be called after GranularTimer::start");
  60   if (--_counter == 0) {
  61     if (_finished) {
  62       // reset so we decrease to zero at next iteration
  63       _counter = 1;
  64       return true;
  65     }
  66     if (JfrTicks::now() > _finish_time_ticks) {
  67       _finished = true;
  68       _counter = 1;
  69       return true;
  70     }
  71     assert(_counter == 0, "invariant");
  72     _counter = _granularity; // restore next batch
  73   }
  74   return false;
  75 }