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comparison src/share/vm/utilities/intHisto.hpp @ 342:37f87013dfd8

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6711316: Open source the Garbage-First garbage collector Summary: First mercurial integration of the code for the Garbage-First garbage collector. Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
author ysr
date Thu, 05 Jun 2008 15:57:56 -0700
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children c18cbe5936b8
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189:0b27f3512f9e 342:37f87013dfd8
1 /*
2 * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 // This class implements a simple histogram.
26
27 // A histogram summarizes a series of "measurements", each of which is
28 // assumed (required in this implementation) to have an outcome that is a
29 // non-negative integer. The histogram efficiently maps measurement outcomes
30 // to the number of measurements had that outcome.
31
32 // To print the results, invoke print() on your Histogram*.
33
34 // Note: there is already an existing "Histogram" class, in file
35 // histogram.{hpp,cpp}, but to my mind that's not a histogram, it's a table
36 // mapping strings to counts. To be a histogram (IMHO) it needs to map
37 // numbers (in fact, integers) to number of occurrences of that number.
38
39 // ysr: (i am not sure i agree with the above note.) i suspect we want to have a
40 // histogram template that will map an arbitrary type (with a defined order
41 // relation) to a count.
42
43
44 class IntHistogram : public CHeapObj {
45 protected:
46 int _max;
47 int _tot;
48 GrowableArray<int>* _elements;
49
50 public:
51 // Create a new, empty table. "est" is an estimate of the maximum outcome
52 // that will be added, and "max" is an outcome such that all outcomes at
53 // least that large will be bundled with it.
54 IntHistogram(int est, int max);
55 // Add a measurement with the given outcome to the sequence.
56 void add_entry(int outcome);
57 // Return the number of entries recorded so far with the given outcome.
58 int entries_for_outcome(int outcome);
59 // Return the total number of entries recorded so far.
60 int total_entries() { return _tot; }
61 // Return the number of entries recorded so far with the given outcome as
62 // a fraction of the total number recorded so far.
63 double fraction_for_outcome(int outcome) {
64 return
65 (double)entries_for_outcome(outcome)/
66 (double)total_entries();
67 }
68 // Print the histogram on the given output stream.
69 void print_on(outputStream* st) const;
70 };