src/share/vm/utilities/histogram.hpp

Thu, 20 Nov 2008 16:56:09 -0800

author
ysr
date
Thu, 20 Nov 2008 16:56:09 -0800
changeset 888
c96030fff130
parent 435
a61af66fc99e
child 1907
c18cbe5936b8
permissions
-rw-r--r--

6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa

duke@435 1 /*
duke@435 2 * Copyright 1998-2000 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 // This class provides a framework for collecting various statistics.
duke@435 26 // The current implementation is oriented towards counting invocations
duke@435 27 // of various types, but that can be easily changed.
duke@435 28 //
duke@435 29 // To use it, you need to declare a Histogram*, and a subtype of
duke@435 30 // HistogramElement:
duke@435 31 //
duke@435 32 // HistogramElement* MyHistogram;
duke@435 33 //
duke@435 34 // class MyHistogramElement : public HistogramElement {
duke@435 35 // public:
duke@435 36 // MyHistogramElement(char* name);
duke@435 37 // };
duke@435 38 //
duke@435 39 // MyHistogramElement::MyHistogramElement(char* elementName) {
duke@435 40 // _name = elementName;
duke@435 41 //
duke@435 42 // if(MyHistogram == NULL)
duke@435 43 // MyHistogram = new Histogram("My Call Counts",100);
duke@435 44 //
duke@435 45 // MyHistogram->add_element(this);
duke@435 46 // }
duke@435 47 //
duke@435 48 // #define MyCountWrapper(arg) static MyHistogramElement* e = new MyHistogramElement(arg); e->increment_count()
duke@435 49 //
duke@435 50 // This gives you a simple way to count invocations of specfic functions:
duke@435 51 //
duke@435 52 // void a_function_that_is_being_counted() {
duke@435 53 // MyCountWrapper("FunctionName");
duke@435 54 // ...
duke@435 55 // }
duke@435 56 //
duke@435 57 // To print the results, invoke print() on your Histogram*.
duke@435 58
duke@435 59 #ifdef ASSERT
duke@435 60
duke@435 61 class HistogramElement : public CHeapObj {
duke@435 62 protected:
duke@435 63 jint _count;
duke@435 64 const char* _name;
duke@435 65
duke@435 66 public:
duke@435 67 HistogramElement();
duke@435 68 virtual int count();
duke@435 69 virtual const char* name();
duke@435 70 virtual void increment_count();
duke@435 71 void print_on(outputStream* st) const;
duke@435 72 virtual int compare(HistogramElement* e1,HistogramElement* e2);
duke@435 73 };
duke@435 74
duke@435 75 class Histogram : public CHeapObj {
duke@435 76 protected:
duke@435 77 GrowableArray<HistogramElement*>* _elements;
duke@435 78 GrowableArray<HistogramElement*>* elements() { return _elements; }
duke@435 79 const char* _title;
duke@435 80 const char* title() { return _title; }
duke@435 81 static int sort_helper(HistogramElement** e1,HistogramElement** e2);
duke@435 82 virtual void print_header(outputStream* st);
duke@435 83 virtual void print_elements(outputStream* st);
duke@435 84
duke@435 85 public:
duke@435 86 Histogram(const char* title,int estimatedSize);
duke@435 87 virtual void add_element(HistogramElement* element);
duke@435 88 void print_on(outputStream* st) const;
duke@435 89 };
duke@435 90
duke@435 91 #endif

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