Remove finalizer in ActiveContainer

No instances of the log message has been detected the last month, which
indicates that the finalizer is not necessary.

3 files changed, 1 insertions, 102 deletions

diff --git a/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainer.java b/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainer.java
index 51a84a4a6c6..fbc45f000d2 100644
--- a/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainer.java
+++ b/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainer.java
@@ -17,15 +17,12 @@ import com.yahoo.jdisc.service.ServerProvider;
 
 import java.net.URI;
 import java.util.Map;
-import java.util.logging.Logger;
 
 /**
  * @author <a href="mailto:simon@yahoo-inc.com">Simon Thoresen</a>
  */
 public class ActiveContainer extends AbstractResource implements CurrentContainer {
 
-    private static final Logger log = Logger.getLogger(ActiveContainer.class.getName());
-
     private final ContainerTermination termination;
     private final Injector guiceInjector;
     private final Iterable<ServerProvider> serverProviders;
@@ -67,22 +64,6 @@ public class ActiveContainer extends AbstractResource implements CurrentContaine
         termination.run();
     }
 
-    // TODO Get rid of finalizer and use PhantomReference or Java 9 Cleaner instead
-    @Override
-    protected void finalize() throws Throwable {
-        try {
-            int retainCount = retainCount();
-            if (retainCount > 0) {
-                log.severe("Destructing " + this + " through finalizer since reference count never reached zero. " +
-                        "This is an indication of either a resource leak or invalid use of reference counting. " +
-                        "Retained references as this moment: " + retainCount);
-                destroy();
-            }
-        } finally {
-            super.finalize();
-        }
-    }
-
     /**
      * Make this instance retain a reference to the resource until it is destroyed.
      */
diff --git a/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java b/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java
index a6b4ef03c61..0004d1d818b 100644
--- a/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java
+++ b/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java
@@ -60,7 +60,7 @@ class ActiveContainerDeactivationWatchdog implements ActiveContainerMetrics, Aut
                 WATCHDOG_FREQUENCY.getSeconds(),
                 TimeUnit.SECONDS);
         this.scheduler.scheduleAtFixedRate(
-                ActiveContainerDeactivationWatchdog::triggerGc,
+                System::gc,
                 GC_TRIGGER_FREQUENCY.getSeconds(),
                 GC_TRIGGER_FREQUENCY.getSeconds(),
                 TimeUnit.SECONDS);
@@ -107,13 +107,6 @@ class ActiveContainerDeactivationWatchdog implements ActiveContainerMetrics, Aut
         }
     }
 
-    private static void triggerGc() {
-        // ActiveContainer has a finalizer, so gc -> finalizer -> gc is required.
-        System.gc();
-        System.runFinalization();
-        System.gc();
-    }
-
     private List<DeactivatedContainer> getDeactivatedContainersSnapshot() {
         Instant now = clock.instant();
         synchronized (monitor) {
diff --git a/jdisc_core/src/test/java/com/yahoo/jdisc/core/ActiveContainerFinalizerTest.java b/jdisc_core/src/test/java/com/yahoo/jdisc/core/ActiveContainerFinalizerTest.java
deleted file mode 100644
index b2fd357b30c..00000000000
--- a/jdisc_core/src/test/java/com/yahoo/jdisc/core/ActiveContainerFinalizerTest.java
+++ /dev/null
@@ -1,75 +0,0 @@
-// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.jdisc.core;
-
-import com.yahoo.jdisc.Container;
-import com.yahoo.jdisc.Request;
-import com.yahoo.jdisc.test.TestDriver;
-
-import java.net.URI;
-import java.util.concurrent.TimeUnit;
-
-import org.junit.Test;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-
-/**
- * @author <a href="mailto:simon@yahoo-inc.com">Simon Thoresen Hult</a>
- */
-@SuppressWarnings("UnusedAssignment")
-public class ActiveContainerFinalizerTest {
-
-    @Test
-    public void requireThatMissingContainerReleaseDoesNotPreventShutdown() throws InterruptedException {
-        final TestDriver driver = TestDriver.newSimpleApplicationInstanceWithoutOsgi();
-        driver.activateContainer(driver.newContainerBuilder());
-        Container container = driver.newReference(URI.create("scheme://host"));
-        assertNotNull(container);
-
-        final Termination termination = new Termination();
-        driver.activateContainer(null).notifyTermination(termination);
-        assertFalse(termination.await(100, TimeUnit.MILLISECONDS));
-
-        container = null; // intentionally doing this instead of container.release()
-        assertTrue(termination.await(600, TimeUnit.SECONDS));
-        assertTrue(driver.close());
-    }
-
-    @Test
-    public void requireThatMissingRequestReleaseDoesNotPreventShutdown() throws InterruptedException {
-        final TestDriver driver = TestDriver.newSimpleApplicationInstanceWithoutOsgi();
-        driver.activateContainer(driver.newContainerBuilder());
-        Request request = new Request(driver, URI.create("scheme://host"));
-        assertNotNull(request);
-
-        final Termination termination = new Termination();
-        driver.activateContainer(null).notifyTermination(termination);
-        assertFalse(termination.await(100, TimeUnit.MILLISECONDS));
-
-        request = null; // intentionally doing this instead of request.release()
-        assertTrue(termination.await(600, TimeUnit.SECONDS));
-        assertTrue(driver.close());
-    }
-
-    private static class Termination implements Runnable {
-
-        volatile boolean done;
-
-        @Override
-        public void run() {
-            done = true;
-        }
-
-        boolean await(final int timeout, final TimeUnit unit) throws InterruptedException {
-            final long timeoutAt = System.currentTimeMillis() + unit.toMillis(timeout);
-            while (!done) {
-                if (System.currentTimeMillis() > timeoutAt) {
-                    return false;
-                }
-                Thread.sleep(10);
-                System.gc();
-            }
-            return true;
-        }
-    }
-}