1 /*
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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
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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
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17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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22  */
23 package 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  */
35 public 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")
AbstractJavaProfile(double notRecordedProbability, T[] pitems)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 
totalProbablility()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      */
isSorted()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      */
getNotRecordedProbability()81     public double getNotRecordedProbability() {
82         return notRecordedProbability;
83     }
84 
getItems()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      */
findEntry(ResolvedJavaType type)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
toString()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 
isIncluded(U item)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
equals(Object obj)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
hashCode()161     public int hashCode() {
162         return (int) Double.doubleToLongBits(notRecordedProbability) + pitems.length * 13;
163     }
164 }
165