Batch re-transformations when there are a high number of inner classes

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/agent/ConfigurationUpdater.java

@@ -225,6 +225,28 @@ private void recordInstrumentationProgress(
   }
 
   private void retransformClasses(List<Class<?>> classesToBeTransformed) {
+    int classCount = classesToBeTransformed.size();
+    if (classCount <= 10) {
+      retransformIndividualClasses(classesToBeTransformed);
+    } else if (classCount <= 1000) {
+      retransformClassesAtOnce(classesToBeTransformed);
+    } else {
+      throw new IllegalStateException("Too many classes to retransform: " + classCount);
+    }
+  }
+
+  private void retransformClassesAtOnce(List<Class<?>> classesToBeTransformed) {
+    LOGGER.debug("Re-transforming classes: {}", classesToBeTransformed);
+    try {
+      instrumentation.retransformClasses(classesToBeTransformed.toArray(new Class[0]));
+    } catch (Exception ex) {
+      ExceptionHelper.logException(LOGGER, ex, "Re-transform error:");
+    } catch (Throwable ex) {
+      ExceptionHelper.logException(LOGGER, ex, "Re-transform throwable:");
+    }
+  }
+
+  private void retransformIndividualClasses(List<Class<?>> classesToBeTransformed) {
     for (Class<?> clazz : classesToBeTransformed) {
       try {
         LOGGER.debug("Re-transforming class: {}", clazz.getTypeName());

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/ConfigurationComparerTest.java

@@ -9,6 +9,7 @@
 import com.datadog.debugger.probe.LogProbe;
 import com.datadog.debugger.probe.ProbeDefinition;
 import datadog.trace.bootstrap.debugger.ProbeId;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -407,6 +408,22 @@ public void allLoadedChangedClassesTopLevelClassSimpleFileName() {
         probe, sourceFileMapping, MyTopLevelClass.class, false, MyTopLevelClass.class);
   }
 
+  @Test
+  public void allLoadedChangedClassesLargeInnerClasses() {
+    final String CLASS_FILENAME = "LargeInnerClasses.java";
+    Map<String, List<String>> sourceFileMapping = new HashMap<>();
+    List<String> classNames = new ArrayList<>();
+    for (int i = 0; i < 100; i++) {
+      classNames.add(
+          String.format("com.datadog.debugger.agent.LargeInnerClasses$MyInnerClass%02d", i));
+    }
+    sourceFileMapping.put(CLASS_FILENAME, classNames);
+    LogProbe probe =
+        LogProbe.builder().probeId(PROBE_ID).where(null, null, null, 6, CLASS_FILENAME).build();
+    doAllLoadedChangedClasses(
+        probe, sourceFileMapping, LargeInnerClasses.class, false, LargeInnerClasses.class);
+  }
+
   private void doAllLoadedChangedClasses(
       LogProbe probe,
       Map<String, List<String>> sourceFileMapping,

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/LargeInnerClasses.java

@@ -0,0 +1,208 @@
+package com.datadog.debugger.agent;
+
+public class LargeInnerClasses {
+
+  public static int main(String arg) {
+    return 42; // beae1817-f3b0-4ea8-a74f-000000000001
+  }
+
+  static class MyInnerClass00 {}
+
+  static class MyInnerClass01 {}
+
+  static class MyInnerClass02 {}
+
+  static class MyInnerClass03 {}
+
+  static class MyInnerClass04 {}
+
+  static class MyInnerClass05 {}
+
+  static class MyInnerClass06 {}
+
+  static class MyInnerClass07 {}
+
+  static class MyInnerClass08 {}
+
+  static class MyInnerClass09 {}
+
+  static class MyInnerClass10 {}
+
+  static class MyInnerClass11 {}
+
+  static class MyInnerClass12 {}
+
+  static class MyInnerClass13 {}
+
+  static class MyInnerClass14 {}
+
+  static class MyInnerClass15 {}
+
+  static class MyInnerClass16 {}
+
+  static class MyInnerClass17 {}
+
+  static class MyInnerClass18 {}
+
+  static class MyInnerClass19 {}
+
+  static class MyInnerClass20 {}
+
+  static class MyInnerClass21 {}
+
+  static class MyInnerClass22 {}
+
+  static class MyInnerClass23 {}
+
+  static class MyInnerClass24 {}
+
+  static class MyInnerClass25 {}
+
+  static class MyInnerClass26 {}
+
+  static class MyInnerClass27 {}
+
+  static class MyInnerClass28 {}
+
+  static class MyInnerClass29 {}
+
+  static class MyInnerClass30 {}
+
+  static class MyInnerClass31 {}
+
+  static class MyInnerClass32 {}
+
+  static class MyInnerClass33 {}
+
+  static class MyInnerClass34 {}
+
+  static class MyInnerClass35 {}
+
+  static class MyInnerClass36 {}
+
+  static class MyInnerClass37 {}
+
+  static class MyInnerClass38 {}
+
+  static class MyInnerClass39 {}
+
+  static class MyInnerClass40 {}
+
+  static class MyInnerClass41 {}
+
+  static class MyInnerClass42 {}
+
+  static class MyInnerClass43 {}
+
+  static class MyInnerClass44 {}
+
+  static class MyInnerClass45 {}
+
+  static class MyInnerClass46 {}
+
+  static class MyInnerClass47 {}
+
+  static class MyInnerClass48 {}
+
+  static class MyInnerClass49 {}
+
+  static class MyInnerClass50 {}
+
+  static class MyInnerClass51 {}
+
+  static class MyInnerClass52 {}
+
+  static class MyInnerClass53 {}
+
+  static class MyInnerClass54 {}
+
+  static class MyInnerClass55 {}
+
+  static class MyInnerClass56 {}
+
+  static class MyInnerClass57 {}
+
+  static class MyInnerClass58 {}
+
+  static class MyInnerClass59 {}
+
+  static class MyInnerClass60 {}
+
+  static class MyInnerClass61 {}
+
+  static class MyInnerClass62 {}
+
+  static class MyInnerClass63 {}
+
+  static class MyInnerClass64 {}
+
+  static class MyInnerClass65 {}
+
+  static class MyInnerClass66 {}
+
+  static class MyInnerClass67 {}
+
+  static class MyInnerClass68 {}
+
+  static class MyInnerClass69 {}
+
+  static class MyInnerClass70 {}
+
+  static class MyInnerClass71 {}
+
+  static class MyInnerClass72 {}
+
+  static class MyInnerClass73 {}
+
+  static class MyInnerClass74 {}
+
+  static class MyInnerClass75 {}
+
+  static class MyInnerClass76 {}
+
+  static class MyInnerClass77 {}
+
+  static class MyInnerClass78 {}
+
+  static class MyInnerClass79 {}
+
+  static class MyInnerClass80 {}
+
+  static class MyInnerClass81 {}
+
+  static class MyInnerClass82 {}
+
+  static class MyInnerClass83 {}
+
+  static class MyInnerClass84 {}
+
+  static class MyInnerClass85 {}
+
+  static class MyInnerClass86 {}
+
+  static class MyInnerClass87 {}
+
+  static class MyInnerClass88 {}
+
+  static class MyInnerClass89 {}
+
+  static class MyInnerClass90 {}
+
+  static class MyInnerClass91 {}
+
+  static class MyInnerClass92 {}
+
+  static class MyInnerClass93 {}
+
+  static class MyInnerClass94 {}
+
+  static class MyInnerClass95 {}
+
+  static class MyInnerClass96 {}
+
+  static class MyInnerClass97 {}
+
+  static class MyInnerClass98 {}
+
+  static class MyInnerClass99 {}
+}