1 /*
   2  * Copyright (c) 2015, 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 package org.graalvm.compiler.debug.internal;
  24 
  25 import org.graalvm.compiler.debug.DebugCloseable;
  26 
  27 /**
  28  * A helper class for DebugValues that can nest and need to split out accumulated and flat values
  29  * for some kind of counter-like measurement.
  30  */
  31 abstract class CloseableCounterImpl implements DebugCloseable {
  32 
  33     protected final CloseableCounterImpl parent;
  34     protected final AccumulatedDebugValue counter;
  35     protected final long start;
  36     protected long nestedAmountToSubtract;
  37 
  38     CloseableCounterImpl(CloseableCounterImpl parent, AccumulatedDebugValue counter) {
  39         this.parent = parent;
  40         this.start = getCounterValue();
  41         this.counter = counter;
  42     }
  43 
  44     /**
  45      * A hook for subclasses. Lets them perform custom operations with the value since the last
  46      * invocation of {@link CloseableCounterImpl#close()} of this accumulated
  47      * {@link CloseableCounterImpl#counter}.
  48      *
  49      * @param difference since the last invocation of this counter flat
  50      */
  51     protected void interceptDifferenceAccm(long difference) {
  52         // hook for subclasses
  53     }
  54 
  55     /**
  56      * A hook for subclasses. Lets them perform custom operations with the value since the last
  57      * invocation of {@link CloseableCounterImpl#close()} of this flat
  58      * {@link CloseableCounterImpl#counter}.
  59      *
  60      * @param difference since the last invocation of this counter flat
  61      */
  62     protected void interceptDifferenceFlat(long difference) {
  63         // hook for subclasses
  64     }
  65 
  66     @Override
  67     public void close() {
  68         long end = getCounterValue();
  69         long difference = end - start;
  70         if (parent != null) {
  71             if (!counter.getName().equals(parent.counter.getName())) {
  72                 parent.nestedAmountToSubtract += difference;
  73                 // Look for our counter in an outer scope and fix up
  74                 // the adjustment to the flat count
  75                 CloseableCounterImpl ancestor = parent.parent;
  76                 while (ancestor != null) {
  77                     if (ancestor.counter.getName().equals(counter.getName())) {
  78                         ancestor.nestedAmountToSubtract -= difference;
  79                         break;
  80                     }
  81                     ancestor = ancestor.parent;
  82                 }
  83             }
  84         }
  85         long flatAmount = difference - nestedAmountToSubtract;
  86         counter.addToCurrentValue(difference);
  87         counter.flat.addToCurrentValue(flatAmount);
  88         interceptDifferenceAccm(difference);
  89         interceptDifferenceFlat(flatAmount);
  90     }
  91 
  92     abstract long getCounterValue();
  93 }