Remove deprecated stuff around ResourceLeakDetector (#11572)

Motivation:
A number of classes and APIs around the ResourceLeakDetector have been deprecated for removal in Netty 5.x, because better alternatives exist.

Modification:
Remove everything in and around ResourceLeakDetector that is deprecated, and fix the few usages that were found.

Result:
Less deprecated code.

common/src/main/java/io/netty/util/ResourceLeak.java

@@ -1,42 +0,0 @@
-/*
- * Copyright 2013 The Netty Project
- *
- * The Netty Project licenses this file to you 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:
- *
- *   https://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 io.netty.util;
-
-/**
- * @deprecated please use {@link ResourceLeakTracker} as it may lead to false-positives.
- */
-@Deprecated
-public interface ResourceLeak {
-    /**
-     * Records the caller's current stack trace so that the {@link ResourceLeakDetector} can tell where the leaked
-     * resource was accessed lastly. This method is a shortcut to {@link #record(Object) record(null)}.
-     */
-    void record();
-
-    /**
-     * Records the caller's current stack trace and the specified additional arbitrary information
-     * so that the {@link ResourceLeakDetector} can tell where the leaked resource was accessed lastly.
-     */
-    void record(Object hint);
-
-    /**
-     * Close the leak so that {@link ResourceLeakDetector} does not warn about leaked resources.
-     *
-     * @return {@code true} if called first time, {@code false} if called already
-     */
-    boolean close();
-}

common/src/main/java/io/netty/util/ResourceLeakDetector.java

@@ -114,14 +114,6 @@ public class ResourceLeakDetector<T> {
         }
     }
 
-    /**
-     * @deprecated Use {@link #setLevel(Level)} instead.
-     */
-    @Deprecated
-    public static void setEnabled(boolean enabled) {
-        setLevel(enabled? Level.SIMPLE : Level.DISABLED);
-    }
-
     /**
      * Returns {@code true} if resource leak detection is enabled.
      */
@@ -154,70 +146,15 @@ public class ResourceLeakDetector<T> {
     private final int samplingInterval;
 
     /**
-     * @deprecated use {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class, int, long)}.
-     */
-    @Deprecated
-    public ResourceLeakDetector(Class<?> resourceType) {
-        this(simpleClassName(resourceType));
-    }
-
-    /**
-     * @deprecated use {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class, int, long)}.
-     */
-    @Deprecated
-    public ResourceLeakDetector(String resourceType) {
-        this(resourceType, DEFAULT_SAMPLING_INTERVAL, Long.MAX_VALUE);
-    }
-
-    /**
-     * @deprecated Use {@link ResourceLeakDetector#ResourceLeakDetector(Class, int)}.
-     * <p>
      * This should not be used directly by users of {@link ResourceLeakDetector}.
      * Please use {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class)}
-     * or {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class, int, long)}
+     * or {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class, int)}
-     *
-     * @param maxActive This is deprecated and will be ignored.
      */
-    @Deprecated
-    public ResourceLeakDetector(Class<?> resourceType, int samplingInterval, long maxActive) {
-        this(resourceType, samplingInterval);
-    }
-
-    /**
-     * This should not be used directly by users of {@link ResourceLeakDetector}.
-     * Please use {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class)}
-     * or {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class, int, long)}
-     */
-    @SuppressWarnings("deprecation")
     public ResourceLeakDetector(Class<?> resourceType, int samplingInterval) {
-        this(simpleClassName(resourceType), samplingInterval, Long.MAX_VALUE);
+        this.resourceType = simpleClassName(resourceType);
-    }
-
-    /**
-     * @deprecated use {@link ResourceLeakDetectorFactory#newResourceLeakDetector(Class, int, long)}.
-     * <p>
-     * @param maxActive This is deprecated and will be ignored.
-     */
-    @Deprecated
-    public ResourceLeakDetector(String resourceType, int samplingInterval, long maxActive) {
-        requireNonNull(resourceType, "resourceType");
-
-        this.resourceType = resourceType;
         this.samplingInterval = samplingInterval;
     }
 
-    /**
-     * Creates a new {@link ResourceLeak} which is expected to be closed via {@link ResourceLeak#close()} when the
-     * related resource is deallocated.
-     *
-     * @return the {@link ResourceLeak} or {@code null}
-     * @deprecated use {@link #track(Object)}
-     */
-    @Deprecated
-    public final ResourceLeak open(T obj) {
-        return track0(obj);
-    }
-
     /**
      * Creates a new {@link ResourceLeakTracker} which is expected to be closed via
      * {@link ResourceLeakTracker#close(Object)} when the related resource is deallocated.
@@ -326,9 +263,8 @@ public class ResourceLeakDetector<T> {
     protected void reportInstancesLeak(String resourceType) {
     }
 
-    @SuppressWarnings("deprecation")
     private static final class DefaultResourceLeak<T>
-            extends WeakReference<Object> implements ResourceLeakTracker<T>, ResourceLeak {
+            extends WeakReference<Object> implements ResourceLeakTracker<T> {
 
         @SuppressWarnings("unchecked") // generics and updaters do not mix.
         private static final AtomicReferenceFieldUpdater<DefaultResourceLeak<?>, TraceRecord> headUpdater =
@@ -438,7 +374,11 @@ public class ResourceLeakDetector<T> {
         }
 
         @Override
-        public boolean close() {
+        public boolean close(T trackedObject) {
+            // Ensure that the object that was tracked is the same as the one that was passed to close(...).
+            assert trackedHash == System.identityHashCode(trackedObject);
+
+            try {
                 if (allLeaks.remove(this)) {
                     // Call clear so the reference is not even enqueued.
                     clear();
@@ -446,15 +386,6 @@ public class ResourceLeakDetector<T> {
                     return true;
                 }
                 return false;
-        }
-
-        @Override
-        public boolean close(T trackedObject) {
-            // Ensure that the object that was tracked is the same as the one that was passed to close(...).
-            assert trackedHash == System.identityHashCode(trackedObject);
-
-            try {
-                return close();
             } finally {
                 // Ensure the tracked object remain live and strongly referenced, until close() has finished.
                 Reference.reachabilityFence(trackedObject);
@@ -518,7 +449,7 @@ public class ResourceLeakDetector<T> {
     private static final AtomicReference<String[]> excludedMethods =
             new AtomicReference<>(EmptyArrays.EMPTY_STRINGS);
 
-    public static void addExclusions(Class clz, String ... methodNames) {
+    public static void addExclusions(Class<?> clz, String ... methodNames) {
         Set<String> nameSet = new HashSet<>(Arrays.asList(methodNames));
         // Use loop rather than lookup. This avoids knowing the parameters, and doesn't have to handle
         // NoSuchMethodException.

common/src/main/java/io/netty/util/ResourceLeakDetectorFactory.java

@@ -66,39 +66,20 @@ public abstract class ResourceLeakDetectorFactory {
     }
 
     /**
-     * @deprecated Use {@link #newResourceLeakDetector(Class, int)} instead.
-     * <p>
      * Returns a new instance of a {@link ResourceLeakDetector} with the given resource class.
      *
      * @param resource the resource class used to initialize the {@link ResourceLeakDetector}
      * @param samplingInterval the interval on which sampling takes place
-     * @param maxActive This is deprecated and will be ignored.
      * @param <T> the type of the resource class
      * @return a new instance of {@link ResourceLeakDetector}
      */
-    @Deprecated
     public abstract <T> ResourceLeakDetector<T> newResourceLeakDetector(
-            Class<T> resource, int samplingInterval, long maxActive);
+            Class<T> resource, int samplingInterval);
-
-    /**
-     * Returns a new instance of a {@link ResourceLeakDetector} with the given resource class.
-     *
-     * @param resource the resource class used to initialize the {@link ResourceLeakDetector}
-     * @param samplingInterval the interval on which sampling takes place
-     * @param <T> the type of the resource class
-     * @return a new instance of {@link ResourceLeakDetector}
-     */
-    @SuppressWarnings("deprecation")
-    public <T> ResourceLeakDetector<T> newResourceLeakDetector(Class<T> resource, int samplingInterval) {
-        ObjectUtil.checkPositive(samplingInterval, "samplingInterval");
-        return newResourceLeakDetector(resource, samplingInterval, Long.MAX_VALUE);
-    }
 
     /**
      * Default implementation that loads custom leak detector via system property
      */
     private static final class DefaultResourceLeakDetectorFactory extends ResourceLeakDetectorFactory {
-        private final Constructor<?> obsoleteCustomClassConstructor;
         private final Constructor<?> customClassConstructor;
 
         DefaultResourceLeakDetectorFactory() {
@@ -110,30 +91,12 @@ public abstract class ResourceLeakDetectorFactory {
                 customLeakDetector = null;
             }
             if (customLeakDetector == null) {
-                obsoleteCustomClassConstructor = customClassConstructor = null;
+                customClassConstructor = null;
             } else {
-                obsoleteCustomClassConstructor = obsoleteCustomClassConstructor(customLeakDetector);
                 customClassConstructor = customClassConstructor(customLeakDetector);
             }
         }
 
-        private static Constructor<?> obsoleteCustomClassConstructor(String customLeakDetector) {
-            try {
-                final Class<?> detectorClass = Class.forName(customLeakDetector, true,
-                        PlatformDependent.getSystemClassLoader());
-
-                if (ResourceLeakDetector.class.isAssignableFrom(detectorClass)) {
-                    return detectorClass.getConstructor(Class.class, int.class, long.class);
-                } else {
-                    logger.error("Class {} does not inherit from ResourceLeakDetector.", customLeakDetector);
-                }
-            } catch (Throwable t) {
-                logger.error("Could not load custom resource leak detector class provided: {}",
-                        customLeakDetector, t);
-            }
-            return null;
-        }
-
         private static Constructor<?> customClassConstructor(String customLeakDetector) {
             try {
                 final Class<?> detectorClass = Class.forName(customLeakDetector, true,
@@ -151,34 +114,9 @@ public abstract class ResourceLeakDetectorFactory {
             return null;
         }
 
-        @SuppressWarnings("deprecation")
-        @Override
-        public <T> ResourceLeakDetector<T> newResourceLeakDetector(Class<T> resource, int samplingInterval,
-                                                                   long maxActive) {
-            if (obsoleteCustomClassConstructor != null) {
-                try {
-                    @SuppressWarnings("unchecked")
-                    ResourceLeakDetector<T> leakDetector =
-                            (ResourceLeakDetector<T>) obsoleteCustomClassConstructor.newInstance(
-                                    resource, samplingInterval, maxActive);
-                    logger.debug("Loaded custom ResourceLeakDetector: {}",
-                            obsoleteCustomClassConstructor.getDeclaringClass().getName());
-                    return leakDetector;
-                } catch (Throwable t) {
-                    logger.error(
-                            "Could not load custom resource leak detector provided: {} with the given resource: {}",
-                            obsoleteCustomClassConstructor.getDeclaringClass().getName(), resource, t);
-                }
-            }
-
-            ResourceLeakDetector<T> resourceLeakDetector = new ResourceLeakDetector<>(resource, samplingInterval,
-                    maxActive);
-            logger.debug("Loaded default ResourceLeakDetector: {}", resourceLeakDetector);
-            return resourceLeakDetector;
-        }
-
         @Override
         public <T> ResourceLeakDetector<T> newResourceLeakDetector(Class<T> resource, int samplingInterval) {
+            ObjectUtil.checkPositive(samplingInterval, "samplingInterval");
             if (customClassConstructor != null) {
                 try {
                     @SuppressWarnings("unchecked")

common/src/main/java/io/netty/util/ResourceLeakException.java

@@ -1,70 +0,0 @@
-/*
- * Copyright 2013 The Netty Project
- *
- * The Netty Project licenses this file to you 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:
- *
- *   https://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 io.netty.util;
-
-import java.util.Arrays;
-
-/**
- * @deprecated This class will be removed in the future version.
- */
-@Deprecated
-public class ResourceLeakException extends RuntimeException {
-
-    private static final long serialVersionUID = 7186453858343358280L;
-
-    private final StackTraceElement[] cachedStackTrace;
-
-    public ResourceLeakException() {
-        cachedStackTrace = getStackTrace();
-    }
-
-    public ResourceLeakException(String message) {
-        super(message);
-        cachedStackTrace = getStackTrace();
-    }
-
-    public ResourceLeakException(String message, Throwable cause) {
-        super(message, cause);
-        cachedStackTrace = getStackTrace();
-    }
-
-    public ResourceLeakException(Throwable cause) {
-        super(cause);
-        cachedStackTrace = getStackTrace();
-    }
-
-    @Override
-    public int hashCode() {
-        int hashCode = 0;
-        for (StackTraceElement e: cachedStackTrace) {
-            hashCode = hashCode * 31 + e.hashCode();
-        }
-        return hashCode;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (!(o instanceof ResourceLeakException)) {
-            return false;
-        }
-        if (o == this) {
-            return true;
-        }
-
-        return Arrays.equals(cachedStackTrace, ((ResourceLeakException) o).cachedStackTrace);
-    }
-}

common/src/test/java/io/netty/util/ResourceLeakDetectorTest.java

@@ -76,8 +76,8 @@ public class ResourceLeakDetectorTest {
                         }
                         boolean closed = r.close();
                         if (checkClosed && !closed) {
-                            error.compareAndSet(null,
+                            error.compareAndSet(null, new AssertionError(
-                                    new AssertionError("ResourceLeak.close() returned 'false' but expected 'true'"));
+                                    "ResourceLeakTracker.close() returned 'false' but expected 'true'"));
                             return true;
                         }
                     }
@@ -121,8 +121,7 @@ public class ResourceLeakDetectorTest {
 
     private static final class DefaultResource implements Resource {
         // Sample every allocation
-        static final TestResourceLeakDetector<Resource> detector = new TestResourceLeakDetector<>(
+        static final TestResourceLeakDetector<Resource> detector = new TestResourceLeakDetector<>(Resource.class, 1);
-                Resource.class, 1, Integer.MAX_VALUE);
 
         @Override
         public boolean close() {
@@ -145,8 +144,8 @@ public class ResourceLeakDetectorTest {
 
         private final AtomicReference<Throwable> error = new AtomicReference<>();
 
-        TestResourceLeakDetector(Class<?> resourceType, int samplingInterval, long maxActive) {
+        TestResourceLeakDetector(Class<?> resourceType, int samplingInterval) {
-            super(resourceType, samplingInterval, maxActive);
+            super(resourceType, samplingInterval);
         }
 
         @Override

microbench/src/main/java/io/netty/microbench/util/ResourceLeakDetectorBenchmark.java

@@ -26,11 +26,11 @@ public class ResourceLeakDetectorBenchmark extends AbstractMicrobenchmark {
 
     @Setup
     public void setup() {
-        detector = new ResourceLeakDetector<>(getClass(), 128, Long.MAX_VALUE);
+        detector = new ResourceLeakDetector<>(getClass(), 128);
     }
 
     @Benchmark
     public Object open() {
-        return detector.open(DUMMY);
+        return detector.track(DUMMY);
     }
 }

microbench/src/main/java/io/netty/microbench/util/ResourceLeakDetectorRecordBenchmark.java

@@ -32,8 +32,7 @@ public class ResourceLeakDetectorRecordBenchmark extends AbstractMicrobenchmark
     private int recordTimes;
     private ResourceLeakDetector.Level level;
 
-    ResourceLeakDetector<Object> detector = new ResourceLeakDetector<Object>(
+    ResourceLeakDetector<Object> detector = new ResourceLeakDetector<Object>(Object.class, 1) {
-            Object.class, 1, Integer.MAX_VALUE) {
         @Override
         protected void reportTracedLeak(String resourceType, String records) {
             // noop