重庆分公司,新征程启航
为企业提供网站建设、域名注册、服务器等服务
Java Benchmark 基准测试的实例详解
成都创新互联公司主营平山网站建设的网络公司,主营网站建设方案,成都app软件开发,平山h5重庆小程序开发公司搭建,平山网站营销推广欢迎平山等地区企业咨询
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.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 .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:
org.openjdk.jmh jmh-core ${jmh.version} org.openjdk.jmh jmh-generator-annprocess ${jmh.version} provided
org.codehaus.mojo exec-maven-plugin run-benchmarks integration-test exec test java -classpath org.openjdk.jmh.Main .*
以上就是Java Benchmark 基准测试,如有疑问请留言或者到本站社区交流讨论,感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!