我得到了一个类似于以下的卡尺基准测试:
public Course timeCourseCreation( int i ) {
return createCourse( i );
}
public Course createCourse( int t ) {
Course course = new Course();
for ( int i = 0 + t; i < this.students + t; i++ ) {
Student student = new Student();
student.setAge( ( int ) ( 100 * Math.random() ) + t );
student.setName( UUID.randomUUID().toString() );
course.getStudents().add( student );
}
for ( int i = 0 + t; i < this.courses + t; i++ ) {
Topic topic = new Topic();
topic.setDescription( UUID.randomUUID().toString() );
topic.setDifficulty( ( int ) ( 10 * Math.random() ) + t );
topic.setName( UUID.randomUUID().toString() );
topic.setRating( ( int ) ( 10 * Math.random() ) + t );
course.getTopics().add( topic );
}
return course;
}
所以,我有一个可以创建数据结构的方法(
createCourse(...)
)并且我想测量创建此结构所需的时间。然而,当我运行基准测试时,我会得到以下异常:
Failed to execute java -cp C:\Users\tuhrig\workspace\XmlVsJson\target\classes;C:\Users\tuhrig\.m2\repository\javax\xml\bind\jaxb-api\2.2.11\jaxb-api-2.2.11.jar;C:\Users\tuhrig\.m2\repository\com\google\code\gson\gson\2.2.4\gson-2.2.4.jar;C:\Users\tuhrig\.m2\repository\com\google\caliper\caliper\0.5-rc1\caliper-0.5-rc1.jar;C:\Users\tuhrig\.m2\repository\com\google\code\findbugs\jsr305\1.3.9\jsr305-1.3.9.jar;C:\Users\tuhrig\.m2\repository\com\google\guava\guava\11.0.1\guava-11.0.1.jar;C:\Users\tuhrig\.m2\repository\com\google\code\java-allocation-instrumenter\java-allocation-instrumenter\2.0\java-allocation-instrumenter-2.0.jar;C:\Users\tuhrig\.m2\repository\asm\asm\3.3.1\asm-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-analysis\3.3.1\asm-analysis-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-commons\3.3.1\asm-commons-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-tree\3.3.1\asm-tree-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-util\3.3.1\asm-util-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-xml\3.3.1\asm-xml-3.3.1.jar com.google.caliper.InProcessRunner --warmupMillis 3000 --runMillis 1000 --measurementType TIME --marker //ZxJ/ -Dbenchmark=CourseCreation de.tuhrig.Benchmark
starting Scenario{vm=java, trial=0, benchmark=CourseCreation}
[caliper] [starting warmup]
[caliper] [starting measured section]
[caliper] [done measured section]
[caliper] [starting measured section]
...
Error: Doing 2x as much work didn't take 2x as much time! Is the JIT optimizing away the body of your benchmark?
...
An exception was thrown from the benchmark code.
com.google.caliper.ConfigurationException: Failed to execute java -cp C:\Users\tuhrig\workspace\XmlVsJson\target\classes;C:\Users\tuhrig\.m2\repository\javax\xml\bind\jaxb-api\2.2.11\jaxb-api-2.2.11.jar;C:\Users\tuhrig\.m2\repository\com\google\code\gson\gson\2.2.4\gson-2.2.4.jar;C:\Users\tuhrig\.m2\repository\com\google\caliper\caliper\0.5-rc1\caliper-0.5-rc1.jar;C:\Users\tuhrig\.m2\repository\com\google\code\findbugs\jsr305\1.3.9\jsr305-1.3.9.jar;C:\Users\tuhrig\.m2\repository\com\google\guava\guava\11.0.1\guava-11.0.1.jar;C:\Users\tuhrig\.m2\repository\com\google\code\java-allocation-instrumenter\java-allocation-instrumenter\2.0\java-allocation-instrumenter-2.0.jar;C:\Users\tuhrig\.m2\repository\asm\asm\3.3.1\asm-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-analysis\3.3.1\asm-analysis-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-commons\3.3.1\asm-commons-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-tree\3.3.1\asm-tree-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-util\3.3.1\asm-util-3.3.1.jar;C:\Users\tuhrig\.m2\repository\asm\asm-xml\3.3.1\asm-xml-3.3.1.jar com.google.caliper.InProcessRunner --warmupMillis 3000 --runMillis 1000 --measurementType TIME --marker //ZxJ/ -Dbenchmark=CourseCreation de.tuhrig.Benchmark
at com.google.caliper.Runner.measure(Runner.java:309)
at com.google.caliper.Runner.runScenario(Runner.java:229)
at com.google.caliper.Runner.runOutOfProcess(Runner.java:378)
at com.google.caliper.Runner.run(Runner.java:97)
at com.google.caliper.Runner.main(Runner.java:423)
at de.tuhrig.CaliperRunner.main(CaliperRunner.java:22)
该异常告诉我基准测试失败是因为JIT编译。那么,我应该如何在此处防止JIT编译?
我已经尝试使用随机值初始化数据结构(如您在代码中所见),我尝试在我的测试中返回一个值(如您在代码中所见),以及尝试使用course对象,例如调用course.getSize()。但是都不起作用。