Patch Caffeine's BoundedLocalCache.PerformCleanupTask to avoid loadin…

…g ForkJoinTask before instrumentation is ready

dd-java-agent/agent-tooling/agent-tooling.gradle

@@ -3,6 +3,18 @@ apply from: "$rootDir/gradle/java.gradle"
 minimumBranchCoverage = 0.6
 excludedClassesCoverage += ['datadog.trace.agent.tooling.*']
 
+// patch inner class from Caffeine to avoid ForkJoinTask from being loaded too early
+sourceSets {
+  patch {
+    java {}
+  }
+}
+jar {
+  from(sourceSets.patch.output) {
+    include 'com/github/benmanes/caffeine/cache/BoundedLocalCache$PerformCleanupTask.class'
+  }
+}
+
 configurations {
   // classpath used by the instrumentation muzzle plugin
   instrumentationMuzzle

dd-java-agent/agent-tooling/src/patch/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2014 Ben Manes. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.github.benmanes.caffeine.cache;
+
+import java.lang.ref.WeakReference;
+
+/** skeleton outer class just for compilation purposes, not included in the final patch. */
+abstract class BoundedLocalCache<K, V> {
+  abstract void performCleanUp(Runnable task);
+
+  /** patched to not extend ForkJoinTask as we don't want that class loaded too early. */
+  static final class PerformCleanupTask implements Runnable {
+    private static final long serialVersionUID = 1L;
+
+    final WeakReference<BoundedLocalCache<?, ?>> reference;
+
+    PerformCleanupTask(BoundedLocalCache<?, ?> cache) {
+      reference = new WeakReference<BoundedLocalCache<?, ?>>(cache);
+    }
+
+    @Override
+    public void run() {
+      BoundedLocalCache<?, ?> cache = reference.get();
+      if (cache != null) {
+        cache.performCleanUp(/* ignored */ null);
+      }
+    }
+  }
+}