1 /*
 2  * Copyright (c) 2023, 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.foreign;
24 
25 import java.lang.foreign.Arena;
26 import java.lang.foreign.MemorySegment;
27 
28 import java.lang.invoke.MethodHandle;
29 import java.lang.invoke.MethodHandles;
30 import java.lang.invoke.MethodType;
31 import java.lang.invoke.VarHandle;
32 
33 import org.openjdk.jmh.annotations.Benchmark;
34 import org.openjdk.jmh.annotations.BenchmarkMode;
35 import org.openjdk.jmh.annotations.Fork;
36 import org.openjdk.jmh.annotations.Measurement;
37 import org.openjdk.jmh.annotations.Mode;
38 import org.openjdk.jmh.annotations.OutputTimeUnit;
39 import org.openjdk.jmh.annotations.Setup;
40 import org.openjdk.jmh.annotations.State;
41 import org.openjdk.jmh.annotations.Warmup;
42 import sun.misc.Unsafe;
43 
44 import java.util.concurrent.TimeUnit;
45 
46 import static java.lang.foreign.ValueLayout.*;
47 
48 @BenchmarkMode(Mode.AverageTime)
49 @Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
50 @Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
51 @State(org.openjdk.jmh.annotations.Scope.Thread)
52 @OutputTimeUnit(TimeUnit.NANOSECONDS)
53 @Fork(value = 3, jvmArgsAppend = {"--enable-native-access=ALL-UNNAMED"})
54 public class MemorySegmentGetUnsafe {
55 
56     static final Unsafe UNSAFE = Utils.unsafe;
57     static final MethodHandle OF_ADDRESS_UNSAFE;
58 
59     static {
60         try {
61             OF_ADDRESS_UNSAFE = MethodHandles.lookup().findStatic(MemorySegmentGetUnsafe.class,
62                     "ofAddressUnsafe", MethodType.methodType(MemorySegment.class, long.class));
63         } catch (ReflectiveOperationException e) {
64             throw new ExceptionInInitializerError(e);
65         }
66     }
67 
68     static final VarHandle INT_HANDLE = adaptSegmentHandle(JAVA_INT.varHandle());
69 
70     static VarHandle adaptSegmentHandle(VarHandle handle) {
71         handle = MethodHandles.insertCoordinates(handle, 1, 0L);
72         handle = MethodHandles.filterCoordinates(handle, 0, OF_ADDRESS_UNSAFE);
73         return handle;
74     }
75 
76     static MemorySegment ofAddressUnsafe(long address) {
77         return MemorySegment.ofAddress(address).reinterpret(JAVA_INT.byteSize());
78     }
79 
80     long addr;
81 
82     @Setup
83     public void setup() throws Throwable {
84         addr = Arena.global().allocate(JAVA_INT).address();
85     }
86 
87     @Benchmark
88     public int panama() {
89         return (int) INT_HANDLE.get(addr);
90     }
91 
92     @Benchmark
93     public int unsafe() {
94         return UNSAFE.getInt(addr);
95     }
96 }