1 /*
2  * Copyright (c) 2014 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
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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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23 package org.openjdk.bench.java.lang.invoke;
24 
25 import org.openjdk.jmh.annotations.Benchmark;
26 import org.openjdk.jmh.annotations.BenchmarkMode;
27 import org.openjdk.jmh.annotations.Mode;
28 import org.openjdk.jmh.annotations.OutputTimeUnit;
29 import org.openjdk.jmh.annotations.Scope;
30 import org.openjdk.jmh.annotations.Setup;
31 import org.openjdk.jmh.annotations.State;
32 
33 import java.lang.invoke.*;
34 import java.util.concurrent.TimeUnit;
35 
36 /**
37  * Benchmark assessing SwitchPoint performance.
38  */
39 @BenchmarkMode(Mode.AverageTime)
40 @OutputTimeUnit(TimeUnit.NANOSECONDS)
41 @State(Scope.Thread)
42 public class SwitchPointGuard {
43 
44     /*
45      * Implementation notes:
46      *   - this test asserts SwitchPoint performance in both valid and invalid cases
47      *   - this test does not assert invalidation performance (hard to do with irreversible SwitchPoint)
48      *   - raw baseline gives the idea for MethodHandle invocation cost
49      *   - CS baseline gives the idea for additional dereference cost
50      */
51 
52     private MethodHandle body1, body2;
53     private int i;
54     private SwitchPoint sw1, sw2;
55     private CallSite cs;
56     private MethodHandle guard1, guard2;
57 
58     @Setup
setup()59     public void setup() throws NoSuchMethodException, IllegalAccessException {
60         sw1 = new SwitchPoint();
61         sw2 = new SwitchPoint();
62         SwitchPoint.invalidateAll(new SwitchPoint[]{sw2});
63         body1 = MethodHandles.lookup().findVirtual(SwitchPointGuard.class, "body1", MethodType.methodType(int.class, int.class));
64         body2 = MethodHandles.lookup().findVirtual(SwitchPointGuard.class, "body2", MethodType.methodType(int.class, int.class));
65         guard1 = sw1.guardWithTest(body1, body2);
66         guard2 = sw2.guardWithTest(body1, body2);
67         cs = new MutableCallSite(body1);
68     }
69 
70     @Benchmark
baselineRaw()71     public void baselineRaw() throws Throwable {
72         i = (int) body1.invoke(this, i);
73     }
74 
75     @Benchmark
baselineCS()76     public void baselineCS() throws Throwable {
77         i = (int) cs.getTarget().invoke(this, i);
78     }
79 
80     @Benchmark
testValid()81     public void testValid() throws Throwable {
82         i = (int) guard1.invoke(this, i);
83     }
84 
85     @Benchmark
testInvalid()86     public void testInvalid() throws Throwable {
87         i = (int) guard2.invoke(this, i);
88     }
89 
body1(int i)90     public int body1(int i) {
91         return i + 1;
92     }
93 
body2(int i)94     public int body2(int i) {
95         return i + 1;
96     }
97 
98 
99 }
100