Java Benchmark 基准测试

import java.util.Arrays;
import java.util.concurrent.TimeUnit;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

@BenchmarkMode(Mode.Throughput)//基准测试类型
@OutputTimeUnit(TimeUnit.SECONDS)//基准测试结果的时间类型
@Warmup(iterations = 3)//预热的迭代次数
@Threads(2)//测试线程数量
@State(Scope.Thread)//该状态为每个线程独享
//度量:iterations进行测试的轮次，time每轮进行的时长，timeUnit时长单位,batchSize批次数量
@Measurement(iterations = 2, time = -1, timeUnit = TimeUnit.SECONDS, batchSize = -1)
public class InstructionsBenchmark{
    static int staticPos = 0;
    //String src = "SELECT a FROM ab             , ee.ff AS f,(SELECT a FROM `schema_bb`.`tbl_bb`,(SELECT a FROM ccc AS c, `dddd`));";
    final byte[] srcBytes = {83, 69, 76, 69, 67, 84, 32, 97, 32, 70, 82, 79, 77, 32, 97, 98, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 44, 32, 101, 101, 46, 102, 102, 32, 65, 83, 32, 102, 44, 40, 83, 69, 76, 69, 67, 84, 32, 97, 32, 70, 82, 79, 77, 32, 96, 115, 99, 104, 101, 109, 97, 95, 98, 98, 96, 46, 96, 116, 98, 108, 95, 98, 98, 96, 44, 40, 83, 69, 76, 69, 67, 84, 32, 97, 32, 70, 82, 79, 77, 32, 99, 99, 99, 32, 65, 83, 32, 99, 44, 32, 96, 100, 100, 100, 100, 96, 41, 41, 59};
    int len = srcBytes.length;
    byte[] array = new byte[8192];
    int memberVariable = 0;

    //run
    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
                .include(InstructionsBenchmark.class.getSimpleName())
                .forks(1)
                //     使用之前要安装hsdis
                //-XX:-TieredCompilation 关闭分层优化 -server
                //-XX:+LogCompilation  运行之后项目路径会出现按照测试顺序输出hotspot_pid<PID>.log文件,可以使用JITWatch进行分析,可以根据最后运行的结果的顺序按文件时间找到对应的hotspot_pid<PID>.log文件
                .jvmArgs("-XX:+UnlockDiagnosticVMOptions", "-XX:+LogCompilation", "-XX:+TraceClassLoading", "-XX:+PrintAssembly")
                //  .addProfiler(CompilerProfiler.class)    // report JIT compiler profiling via standard MBeans
                //  .addProfiler(GCProfiler.class)    // report GC time
                // .addProfiler(StackProfiler.class) // report method stack execution profile
                // .addProfiler(PausesProfiler.class)
                /*
                WinPerfAsmProfiler
                You must install Windows Performance Toolkit. Once installed, locate directory with xperf.exe file
                and either add it to PATH environment variable, or set it to jmh.perfasm.xperf.dir system property.
                 */
                //.addProfiler(WinPerfAsmProfiler.class)
                //更多Profiler,请看JMH介绍
                //.output("InstructionsBenchmark.log")//输出信息到文件
                .build();
        new Runner(opt).run();
    }


    //空循环 对照项
    @Benchmark
    public int emptyLoop() {
        int pos = 0;
        while (pos < len) {
            ++pos;
        }
        return pos;
    }

    @Benchmark
    public int increment() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            ++result;
            ++pos;
        }
        return result;
    }

    @Benchmark
    public int decrement() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            --result;
            ++pos;
        }
        return result;
    }

    @Benchmark
    public int ifElse() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            if (pos == 10) {
                ++result;
                ++pos;
            } else {
                ++pos;
            }
        }
        return result;
    }

    @Benchmark
    public int ifElse2() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            if (pos == 10) {
                ++result;
                ++pos;
            } else if (pos == 20) {
                ++result;
                ++pos;
            } else {
                ++pos;
            }
        }
        return result;
    }

    @Benchmark
    public int ifnotElse() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            if (pos != 10) {
                ++pos;
            } else {
                ++result;
                ++pos;
            }
        }
        return result;
    }

    @Benchmark
    public int ifLessthanElse() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            if (pos < 10) {
                ++pos;
            } else {
                ++result;
                ++pos;
            }
        }
        return result;
    }

    @Benchmark
    public int ifGreaterthanElse() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            if (pos > 10) {
                ++pos;
            } else {
                ++result;
                ++pos;
            }
        }
        return result;
    }

    @Benchmark
    public int readMemberVariable_a_byteArray() {
        int pos = 0;
        int result = 0;
        while (pos < len) {
            result = srcBytes[pos];
            pos++;
        }
        return result;
    }

}

 ops/time：标识每秒钟执行的次数

 依赖jar包：

<dependency>
			<groupId>org.openjdk.jmh</groupId>
			<artifactId>jmh-core</artifactId>
			<version>${jmh.version}</version>
		</dependency>
		<dependency>
			<groupId>org.openjdk.jmh</groupId>
			<artifactId>jmh-generator-annprocess</artifactId>
			<version>${jmh.version}</version>
			<scope>provided</scope>
		</dependency>

 

<build>
		<plugins>
			<plugin>
				<groupId>org.codehaus.mojo</groupId>
				<artifactId>exec-maven-plugin</artifactId>
				<executions>
					<execution>
						<id>run-benchmarks</id>
						<phase>integration-test</phase>
						<goals>
							<goal>exec</goal>
						</goals>
						<configuration>
							<classpathScope>test</classpathScope>
							<executable>java</executable>
							<arguments>
								<argument>-classpath</argument>
								<classpath />
								<argument>org.openjdk.jmh.Main</argument>
								<argument>.*</argument>
							</arguments>
						</configuration>
					</execution>
				</executions>
			</plugin>
		</plugins>
	</build>