Protect exception advices from NoClassDefFound (#9769)

* Protect exception advices from NoClassDefFound

* review

Author: amarziali

dd-java-agent/agent-bootstrap/src/main/java11/datadog/trace/bootstrap/instrumentation/jfr/exceptions/ExceptionProfiling.java

@@ -2,23 +2,41 @@
 
 import datadog.trace.api.Config;
 import datadog.trace.bootstrap.CallDepthThreadLocalMap;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * JVM-wide singleton exception profiling service. Uses {@linkplain Config} class to configure
  * itself using either system properties, environment or properties override.
  */
-public final class ExceptionProfiling {
+public interface ExceptionProfiling {
+
+  void start();
+
+  ExceptionSampleEvent process(final Throwable t);
+
+  boolean recordExceptionMessage();
 
   /** Lazy initialization-on-demand. */
-  private static final class Holder {
-    static final ExceptionProfiling INSTANCE = new ExceptionProfiling(Config.get());
+  final class Holder {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ExceptionProfiling.class);
+    static final ExceptionProfiling INSTANCE = create();
+
+    private static ExceptionProfiling create() {
+      try {
+        return new ExceptionProfilingImpl(Config.get());
+      } catch (Throwable t) {
+        LOGGER.debug("Unable to create ExceptionProfiling", t);
+        return new NoOpExceptionProfiling();
+      }
+    }
   }
 
   /**
    * Support for excluding certain exception types because they are used for control flow or leak
    * detection.
    */
-  public static final class Exclusion {
+  final class Exclusion {
     public static void enter() {
       CallDepthThreadLocalMap.incrementCallDepth(Exclusion.class);
     }
@@ -37,46 +55,67 @@ public static boolean isEffective() {
    *
    * @return the shared instance
    */
-  public static ExceptionProfiling getInstance() {
+  static ExceptionProfiling getInstance() {
     return Holder.INSTANCE;
   }
 
-  private final ExceptionHistogram histogram;
-  private final ExceptionSampler sampler;
-  private final boolean recordExceptionMessage;
+  final class NoOpExceptionProfiling implements ExceptionProfiling {
+    @Override
+    public void start() {}
 
-  private ExceptionProfiling(final Config config) {
-    this(
-        new ExceptionSampler(config),
-        new ExceptionHistogram(config),
-        config.isProfilingRecordExceptionMessage());
-  }
+    @Override
+    public ExceptionSampleEvent process(Throwable t) {
+      return null;
+    }
 
-  ExceptionProfiling(
-      final ExceptionSampler sampler,
-      final ExceptionHistogram histogram,
-      boolean recordExceptionMessage) {
-    this.sampler = sampler;
-    this.histogram = histogram;
-    this.recordExceptionMessage = recordExceptionMessage;
+    @Override
+    public boolean recordExceptionMessage() {
+      return false;
+    }
   }
 
-  public void start() {
-    sampler.start();
-  }
+  final class ExceptionProfilingImpl implements ExceptionProfiling {
 
-  public ExceptionSampleEvent process(final Throwable t) {
-    // always record the exception in histogram
-    final boolean firstHit = histogram.record(t);
+    private final ExceptionHistogram histogram;
+    private final ExceptionSampler sampler;
+    private final boolean recordExceptionMessage;
 
-    final boolean sampled = sampler.sample();
-    if (firstHit || sampled) {
-      return new ExceptionSampleEvent(t, sampled, firstHit);
+    ExceptionProfilingImpl(final Config config) {
+      this(
+          new ExceptionSampler(config),
+          new ExceptionHistogram(config),
+          config.isProfilingRecordExceptionMessage());
+    }
+
+    ExceptionProfilingImpl(
+        final ExceptionSampler sampler,
+        final ExceptionHistogram histogram,
+        boolean recordExceptionMessage) {
+      this.sampler = sampler;
+      this.histogram = histogram;
+      this.recordExceptionMessage = recordExceptionMessage;
+    }
+
+    @Override
+    public void start() {
+      sampler.start();
     }
-    return null;
-  }
 
-  boolean recordExceptionMessage() {
-    return recordExceptionMessage;
+    @Override
+    public ExceptionSampleEvent process(final Throwable t) {
+      // always record the exception in histogram
+      final boolean firstHit = histogram.record(t);
+
+      final boolean sampled = sampler.sample();
+      if (firstHit || sampled) {
+        return new ExceptionSampleEvent(t, sampled, firstHit);
+      }
+      return null;
+    }
+
+    @Override
+    public boolean recordExceptionMessage() {
+      return recordExceptionMessage;
+    }
   }
 }