Simplify WeakMapSuppliers

Also move CleanerTest to PeriodicSchedulingTest

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/WeakMapSuppliers.java

@@ -3,6 +3,8 @@ package datadog.trace.agent.tooling;
 import com.blogspot.mydailyjava.weaklockfree.WeakConcurrentMap;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.MapMaker;
+import datadog.common.exec.CommonTaskExecutor;
+import datadog.common.exec.CommonTaskExecutor.Task;
 import datadog.trace.bootstrap.WeakMap;
 import java.util.concurrent.TimeUnit;
 
@@ -40,15 +42,23 @@ class WeakMapSuppliers {
     @Override
     public <K, V> WeakMap<K, V> get() {
       final WeakConcurrentMap<K, V> map = new WeakConcurrentMap<>(false, true);
-      cleaner.scheduleCleaning(map, MapCleaner.CLEANER, CLEAN_FREQUENCY_SECONDS, TimeUnit.SECONDS);
+      CommonTaskExecutor.INSTANCE.scheduleAtFixedRate(
+          MapCleaningTask.INSTANCE,
+          map,
+          CLEAN_FREQUENCY_SECONDS,
+          CLEAN_FREQUENCY_SECONDS,
+          TimeUnit.SECONDS,
+          "cleaner for " + map);
       return new Adapter<>(map);
     }
 
-    private static class MapCleaner implements Cleaner.Adapter<WeakConcurrentMap> {
-      private static final MapCleaner CLEANER = new MapCleaner();
+    // Important to use explicit class to avoid implicit hard references to target
+    private static class MapCleaningTask implements Task<WeakConcurrentMap> {
+
+      static final MapCleaningTask INSTANCE = new MapCleaningTask();
 
       @Override
-      public void clean(final WeakConcurrentMap target) {
+      public void run(final WeakConcurrentMap target) {
         target.expungeStaleEntries();
       }
     }

utils/thread-utils/src/test/groovy/datadog/common/exec/PeriodicSchedulingTest.groovy

@@ -1,10 +1,8 @@
-package datadog.trace.agent.tooling
+package datadog.common.exec
 
-import datadog.common.exec.CommonTaskExecutor
 import datadog.trace.util.gc.GCUtils
 import datadog.trace.util.test.DDSpecification
 import spock.lang.Retry
-import spock.lang.Subject
 
 import java.lang.ref.WeakReference
 import java.util.concurrent.CountDownLatch
@@ -13,19 +11,15 @@ import java.util.concurrent.atomic.AtomicInteger
 import static java.util.concurrent.TimeUnit.MILLISECONDS
 
 @Retry
-class CleanerTest extends DDSpecification {
-
-  @Subject
-  def cleaner = new Cleaner()
+class PeriodicSchedulingTest extends DDSpecification {
 
   def "test scheduling"() {
     setup:
     def latch = new CountDownLatch(2)
-    def target = new Object()
-    def action = new Cleaner.Adapter<Object>() {
+    def task = new CommonTaskExecutor.Task<CountDownLatch>() {
       @Override
-      void clean(Object t) {
-        latch.countDown()
+      void run(CountDownLatch target) {
+        target.countDown()
       }
     }
 
@@ -33,7 +27,7 @@ class CleanerTest extends DDSpecification {
     !CommonTaskExecutor.INSTANCE.isShutdown()
 
     when:
-    cleaner.scheduleCleaning(target, action, 10, MILLISECONDS)
+    CommonTaskExecutor.INSTANCE.scheduleAtFixedRate(task, latch, 10, 10, MILLISECONDS, "test")
 
     then:
     latch.await(500, MILLISECONDS)
@@ -43,10 +37,10 @@ class CleanerTest extends DDSpecification {
     setup:
     def callCount = new AtomicInteger()
     def target = new WeakReference(new Object())
-    def action = new Cleaner.Adapter<Object>() {
+    def task = new CommonTaskExecutor.Task<Object>() {
       @Override
-      void clean(Object t) {
-        callCount.incrementAndGet()
+      void run(Object t) {
+        callCount.countDown()
       }
     }
 
@@ -54,7 +48,7 @@ class CleanerTest extends DDSpecification {
     !CommonTaskExecutor.INSTANCE.isShutdown()
 
     when:
-    cleaner.scheduleCleaning(target.get(), action, 10, MILLISECONDS)
+    CommonTaskExecutor.INSTANCE.scheduleAtFixedRate(task, target.get(), 10, 10, MILLISECONDS, "test")
     GCUtils.awaitGC(target)
     Thread.sleep(1)
     def snapshot = callCount.get()
@@ -67,10 +61,10 @@ class CleanerTest extends DDSpecification {
   def "test null target"() {
     setup:
     def callCount = new AtomicInteger()
-    def action = new Cleaner.Adapter<Object>() {
+    def task = new CommonTaskExecutor.Task<Object>() {
       @Override
-      void clean(Object t) {
-        callCount.incrementAndGet()
+      void run(Object t) {
+        callCount.countDown()
       }
     }
 
@@ -78,7 +72,7 @@ class CleanerTest extends DDSpecification {
     !CommonTaskExecutor.INSTANCE.isShutdown()
 
     when:
-    cleaner.scheduleCleaning(null, action, 10, MILLISECONDS)
+    CommonTaskExecutor.INSTANCE.scheduleAtFixedRate(task, null, 10, 10, MILLISECONDS, "test")
     Thread.sleep(11)
 
     then:

utils/thread-utils/thread-utils.gradle

@@ -2,4 +2,6 @@ apply from: "${rootDir}/gradle/java.gradle"
 
 dependencies {
   compile deps.slf4j
+
+  testCompile project(':utils:test-utils')
 }