package org.openjdk.jmh.profile;
import org.openjdk.jmh.infra.BenchmarkParams;
import org.openjdk.jmh.infra.IterationParams;
import org.openjdk.jmh.results.*;
import java.lang.management.ClassLoadingMXBean;
import java.lang.management.ManagementFactory;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.TimeUnit;
public class ClassloaderProfiler implements InternalProfiler {
private long loadedClasses;
private long unloadedClasses;
private long beforeTime;
private long afterTime;
@Override
public String getDescription() {
return "Classloader profiling via standard MBeans";
}
@Override
public void beforeIteration(BenchmarkParams benchmarkParams, IterationParams iterationParams) {
ClassLoadingMXBean cl = ManagementFactory.getClassLoadingMXBean();
this.beforeTime = System.nanoTime();
try {
loadedClasses = cl.getTotalLoadedClassCount();
} catch (UnsupportedOperationException e) {
}
try {
unloadedClasses = cl.getUnloadedClassCount();
} catch (UnsupportedOperationException e) {
}
}
@Override
public Collection<? extends Result> afterIteration(BenchmarkParams benchmarkParams, IterationParams iterationParams, IterationResult result) {
afterTime = System.nanoTime();
List<Result> results = new ArrayList<>();
ClassLoadingMXBean cl = ManagementFactory.getClassLoadingMXBean();
long allOps = result.getMetadata().getAllOps();
double time = 1.0 * TimeUnit.SECONDS.toNanos(1) / (afterTime - beforeTime);
try {
long loadedClassCount = cl.getTotalLoadedClassCount();
long loaded = loadedClassCount - loadedClasses;
results.add(new ScalarResult(Defaults.PREFIX + "class.load", loaded / time, "classes/sec", AggregationPolicy.AVG));
results.add(new ScalarResult(Defaults.PREFIX + "class.load.norm", 1.0 * loaded / allOps, "classes/op", AggregationPolicy.AVG));
} catch (UnsupportedOperationException e) {
}
try {
long unloadedClassCount = cl.getUnloadedClassCount();
long unloaded = unloadedClassCount - unloadedClasses;
results.add(new ScalarResult(Defaults.PREFIX + "class.unload", unloaded / time, "classes/sec", AggregationPolicy.AVG));
results.add(new ScalarResult(Defaults.PREFIX + "class.unload.norm", 1.0 * unloaded / allOps, "classes/op", AggregationPolicy.AVG));
} catch (UnsupportedOperationException e) {
}
return results;
}
}