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
   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  */
  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
  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
  71     public void baselineRaw() throws Throwable {
  72         i = (int) body1.invoke(this, i);
  73     }
  74 
  75     @Benchmark
  76     public void baselineCS() throws Throwable {
  77         i = (int) cs.getTarget().invoke(this, i);
  78     }
  79 
  80     @Benchmark
  81     public void testValid() throws Throwable {
  82         i = (int) guard1.invoke(this, i);
  83     }
  84 
  85     @Benchmark
  86     public void testInvalid() throws Throwable {
  87         i = (int) guard2.invoke(this, i);
  88     }
  89 
  90     public int body1(int i) {
  91         return i + 1;
  92     }
  93 
  94     public int body2(int i) {
  95         return i + 1;
  96     }
  97 
  98 
  99 }