Add JMH Benchmarks

dd-java-agent/benchmark/benchmark.gradle

@@ -0,0 +1,59 @@
+plugins {
+  id "me.champeau.gradle.jmh" version "0.4.4"
+}
+
+apply from: "${rootDir}/gradle/java.gradle"
+
+dependencies {
+  jmh project(':dd-trace-annotations')
+  jmh group: 'net.bytebuddy', name: 'byte-buddy-agent', version: '1.7.6'
+}
+
+configurations.testRuntimeClasspath.dependencies.clear()
+
+
+jmh {
+  timeUnit = 'us' // Output time unit. Available time units are: [m, s, ms, us, ns].
+  benchmarkMode = ['thrpt', 'avgt']
+  timeOnIteration = '1s'
+  iterations = 1 // Number of measurement iterations to do.
+  fork = 2 // How many times to forks a single benchmark. Use 0 to disable forking altogether
+//  jvmArgs = ["-Dasdf=123"]
+//  jvmArgs = ["-javaagent:${project(':dd-java-agent').shadowJar.archivePath}"]
+  failOnError = true // Should JMH fail immediately if any benchmark had experienced the unrecoverable error?
+  warmup = '2s' // Time to spend at each warmup iteration.
+  warmupIterations = 1 // Number of warmup iterations to do.
+//  warmupForks = 0 // How many warmup forks to make for a single benchmark. 0 to disable warmup forks.
+
+//  profilers = ['stack']
+  // Use profilers to collect additional data. Supported profilers: [cl, comp, gc, stack, perf, perfnorm, perfasm, xperf, xperfasm, hs_cl, hs_comp, hs_gc, hs_rt, hs_thr]
+
+//  humanOutputFile = project.file("${project.buildDir}/reports/jmh/human.txt") // human-readable output file
+//  operationsPerInvocation = 10 // Operations per invocation.
+//  synchronizeIterations = false // Synchronize iterations?
+//  timeout = '1s' // Timeout for benchmark iteration.
+  includeTests = false
+  // Allows to include test sources into generate JMH jar, i.e. use it when benchmarks depend on the test classes.
+
+  duplicateClassesStrategy = 'fail'
+  jmhVersion = '1.19' // Specifies JMH version
+}
+
+// configured as a separate task since the 'jmh' task did not like adding a javaagent argument.
+task jmhAgent(type: JavaExec, dependsOn: project.tasks.jmhCompileGeneratedClasses) {
+  classpath = files(project.jmhCompileGeneratedClasses.destinationDir)
+  classpath += sourceSets.jmh.runtimeClasspath
+  main = "org.openjdk.jmh.Main"
+  args += ["-tu", "us"]
+  args += ["-bm", "avgt"]
+  args += ["-r", "1s"]
+  args += ["-i", "1"]
+  args += ["-f", "2"]
+  args += ["-foe", "true"]
+  args += ["-w", "2s"]
+  args += ["-wi", "1"]
+//  jvmArgs = ["-javaagent:${project(':dd-java-agent').shadowJar.archivePath}"]
+}
+
+tasks.jmhAgent.dependsOn project(':dd-java-agent').shadowJar
+

dd-java-agent/benchmark/src/jmh/java/com/datadoghq/agent/ClassRetransformingBenchmark.java

@@ -0,0 +1,62 @@
+package com.datadoghq.agent;
+
+import com.datadoghq.trace.Trace;
+import java.lang.instrument.Instrumentation;
+import java.lang.instrument.UnmodifiableClassException;
+import net.bytebuddy.agent.ByteBuddyAgent;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+
+public class ClassRetransformingBenchmark {
+
+  @State(Scope.Benchmark)
+  public static class BenchmarkState {
+    private final Instrumentation inst = ByteBuddyAgent.install();
+  }
+
+  @Benchmark
+  public void testIgnoredRetransform(final BenchmarkState state) throws UnmodifiableClassException {
+    state.inst.retransformClasses(Object.class);
+  }
+
+  @Benchmark
+  public void testSimpleRetransform(final BenchmarkState state) throws UnmodifiableClassException {
+    state.inst.retransformClasses(SimpleClass.class);
+  }
+
+  @Benchmark
+  public void testDeepRetransform(final BenchmarkState state) throws UnmodifiableClassException {
+    state.inst.retransformClasses(DeepClass.class);
+  }
+
+  public static class SimpleClass {
+    @Trace
+    public void aMethodToTrace() {}
+  }
+
+  public static interface A {
+    @Trace
+    void interfaceTrace();
+  }
+
+  public static interface B extends A {
+    void something();
+  }
+
+  public static interface C extends B {
+    void somethingElse();
+  }
+
+  public static class DeepClass implements C {
+
+    @Override
+    public void interfaceTrace() {}
+
+    @Override
+    public void something() {}
+
+    @Override
+    public void somethingElse() {}
+  }
+}

gradle/dependencies.gradle

@@ -1,3 +1,6 @@
+def groovyVer = GroovySystem.version
+def spockGroovyVer = GroovySystem.version.replaceAll(/\.\d+$/, '')
+
 ext {
   version = [
     opentracing: '0.30.0',
@@ -6,8 +9,8 @@ ext {
     guava      : "21.0",
     jackson    : "2.8.7",
 
-    spock      : "1.0-groovy-2.4",
-    groovy     : "2.4.11",
+    spock      : "1.0-groovy-$spockGroovyVer",
+    groovy     : groovyVer,
     junit      : "4.12",
     logback    : "1.2.3",
   ]

settings.gradle

@@ -2,6 +2,7 @@ rootProject.name = 'dd-trace-java'
 
 include ':dd-trace'
 include ':dd-java-agent'
+include ':dd-java-agent:benchmark'
 include ':dd-java-agent:tooling'
 include ':dd-java-agent-ittests'
 include ':dd-trace-examples:async-tracing'