1 /* 2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved. 3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHNUMBERSEQ_HPP 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHNUMBERSEQ_HPP 28 29 #include "utilities/numberSeq.hpp" 30 31 // HDR sequence stores the low-resolution high-dynamic-range values. 32 // It does so by maintaining the double array, where first array defines 33 // the magnitude of the value being stored, and the second array maintains 34 // the low resolution histogram within that magnitude. For example, storing 35 // 4.352819 * 10^3 increments the bucket _hdr[3][435]. This allows for 36 // memory efficient storage of huge amount of samples. 37 // 38 // Accepts positive numbers only. 39 class HdrSeq: public NumberSeq { 40 private: 41 enum PrivateConstants { 42 ValBuckets = 512, 43 MagBuckets = 24, 44 MagMinimum = -12 45 }; 46 int** _hdr; 47 48 public: 49 HdrSeq(); 50 ~HdrSeq(); 51 52 virtual void add(double val); 53 void add(const HdrSeq& other); 54 double percentile(double level) const; 55 void clear(); 56 }; 57 58 // Binary magnitude sequence stores the power-of-two histogram. 59 // It has very low memory requirements, and is thread-safe. When accuracy 60 // is not needed, it is preferred over HdrSeq. 61 class BinaryMagnitudeSeq : public CHeapObj<mtGC> { 62 private: 63 size_t _sum; 64 size_t* _mags; 65 66 public: 67 BinaryMagnitudeSeq(); 68 ~BinaryMagnitudeSeq(); 69 70 void add(size_t val); 71 size_t num() const; 72 size_t level(int level) const; 73 size_t sum() const; 74 int min_level() const; 75 int max_level() const; 76 void clear(); 77 }; 78 79 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHNUMBERSEQ_HPP