1/*
2 * Copyright (c) 2013, 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 */
23package jdk.vm.ci.meta;
24
25/**
26 * This object holds probability information for a set of items that were profiled at a specific
27 * BCI. The precision of the supplied values may vary, but a runtime that provides this information
28 * should be aware that it will be used to guide performance-critical decisions like speculative
29 * inlining, etc.
30 *
31 * @param <T> a subclass of AbstractProfiledItem
32 * @param <U> the class of the items that are profiled at the specific BCI and for which
33 *            probabilities are stored. E.g., a ResolvedJavaType or a ResolvedJavaMethod.
34 */
35public abstract class AbstractJavaProfile<T extends AbstractProfiledItem<U>, U> {
36
37    private final double notRecordedProbability;
38    private final T[] pitems;
39
40    /**
41     *
42     * @param notRecordedProbability
43     * @param pitems
44     */
45    @SuppressFBWarnings(value = "EI_EXPOSE_REP2", justification = "caller transfers ownership of the `pitems` array parameter")
46    public AbstractJavaProfile(double notRecordedProbability, T[] pitems) {
47        this.pitems = pitems;
48        assert !Double.isNaN(notRecordedProbability);
49        this.notRecordedProbability = notRecordedProbability;
50        assert isSorted();
51        assert totalProbablility() >= 0 && totalProbablility() <= 1.0001 : totalProbablility() + " " + this;
52    }
53
54    private double totalProbablility() {
55        double total = notRecordedProbability;
56        for (T item : pitems) {
57            total += item.probability;
58        }
59        return total;
60    }
61
62    /**
63     * Determines if an array of profiled items are sorted in descending order of their
64     * probabilities.
65     */
66    private boolean isSorted() {
67        for (int i = 1; i < pitems.length; i++) {
68            if (pitems[i - 1].getProbability() < pitems[i].getProbability()) {
69                return false;
70            }
71        }
72        return true;
73    }
74
75    /**
76     * Returns the estimated probability of all types that could not be recorded due to profiling
77     * limitations.
78     *
79     * @return double value &ge; 0.0 and &le; 1.0
80     */
81    public double getNotRecordedProbability() {
82        return notRecordedProbability;
83    }
84
85    protected T[] getItems() {
86        return pitems;
87    }
88
89    /**
90     * Searches for an entry of a given resolved Java type.
91     *
92     * @param type the type for which an entry should be searched
93     * @return the entry or null if no entry for this type can be found
94     */
95    public T findEntry(ResolvedJavaType type) {
96        if (pitems != null) {
97            for (T pt : pitems) {
98                if (pt.getItem().equals(type)) {
99                    return pt;
100                }
101            }
102        }
103        return null;
104    }
105
106    @Override
107    public String toString() {
108        StringBuilder builder = new StringBuilder();
109        builder.append(this.getClass().getName());
110        builder.append("[");
111        if (pitems != null) {
112            for (T pt : pitems) {
113                builder.append(pt.toString());
114                builder.append(", ");
115            }
116        }
117        builder.append(this.notRecordedProbability);
118        builder.append("]");
119        return builder.toString();
120    }
121
122    public boolean isIncluded(U item) {
123        if (this.getNotRecordedProbability() > 0.0) {
124            return true;
125        } else {
126            for (int i = 0; i < getItems().length; i++) {
127                T pitem = getItems()[i];
128                U curType = pitem.getItem();
129                if (curType == item) {
130                    return true;
131                }
132            }
133        }
134        return false;
135    }
136
137    @Override
138    public boolean equals(Object obj) {
139        if (obj == this) {
140            return true;
141        }
142        if (!(obj instanceof AbstractJavaProfile)) {
143            return false;
144        }
145        AbstractJavaProfile<?, ?> that = (AbstractJavaProfile<?, ?>) obj;
146        if (that.notRecordedProbability != notRecordedProbability) {
147            return false;
148        }
149        if (that.pitems.length != pitems.length) {
150            return false;
151        }
152        for (int i = 0; i < pitems.length; ++i) {
153            if (!pitems[i].equals(that.pitems[i])) {
154                return false;
155            }
156        }
157        return true;
158    }
159
160    @Override
161    public int hashCode() {
162        return (int) Double.doubleToLongBits(notRecordedProbability) + pitems.length * 13;
163    }
164}
165