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view src/share/vm/utilities/intHisto.hpp @ 10405:f2110083203d
8005849: JEP 167: Event-Based JVM Tracing
Reviewed-by: acorn, coleenp, sla
Contributed-by: Karen Kinnear <karen.kinnear@oracle.com>, Bengt Rutisson <bengt.rutisson@oracle.com>, Calvin Cheung <calvin.cheung@oracle.com>, Erik Gahlin <erik.gahlin@oracle.com>, Erik Helin <erik.helin@oracle.com>, Jesper Wilhelmsson <jesper.wilhelmsson@oracle.com>, Keith McGuigan <keith.mcguigan@oracle.com>, Mattias Tobiasson <mattias.tobiasson@oracle.com>, Markus Gronlund <markus.gronlund@oracle.com>, Mikael Auno <mikael.auno@oracle.com>, Nils Eliasson <nils.eliasson@oracle.com>, Nils Loodin <nils.loodin@oracle.com>, Rickard Backman <rickard.backman@oracle.com>, Staffan Larsen <staffan.larsen@oracle.com>, Stefan Karlsson <stefan.karlsson@oracle.com>, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>
author | sla |
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date | Mon, 10 Jun 2013 11:30:51 +0200 |
parents | b9a9ed0f8eeb |
children |
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/* * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_UTILITIES_INTHISTO_HPP #define SHARE_VM_UTILITIES_INTHISTO_HPP #include "memory/allocation.hpp" #include "utilities/growableArray.hpp" // This class implements a simple histogram. // A histogram summarizes a series of "measurements", each of which is // assumed (required in this implementation) to have an outcome that is a // non-negative integer. The histogram efficiently maps measurement outcomes // to the number of measurements had that outcome. // To print the results, invoke print() on your Histogram*. // Note: there is already an existing "Histogram" class, in file // histogram.{hpp,cpp}, but to my mind that's not a histogram, it's a table // mapping strings to counts. To be a histogram (IMHO) it needs to map // numbers (in fact, integers) to number of occurrences of that number. // ysr: (i am not sure i agree with the above note.) i suspect we want to have a // histogram template that will map an arbitrary type (with a defined order // relation) to a count. class IntHistogram : public CHeapObj<mtInternal> { protected: int _max; int _tot; GrowableArray<int>* _elements; public: // Create a new, empty table. "est" is an estimate of the maximum outcome // that will be added, and "max" is an outcome such that all outcomes at // least that large will be bundled with it. IntHistogram(int est, int max); // Add a measurement with the given outcome to the sequence. void add_entry(int outcome); // Return the number of entries recorded so far with the given outcome. int entries_for_outcome(int outcome); // Return the total number of entries recorded so far. int total_entries() { return _tot; } // Return the number of entries recorded so far with the given outcome as // a fraction of the total number recorded so far. double fraction_for_outcome(int outcome) { return (double)entries_for_outcome(outcome)/ (double)total_entries(); } // Print the histogram on the given output stream. void print_on(outputStream* st) const; }; #endif // SHARE_VM_UTILITIES_INTHISTO_HPP