Rework the configuration API slightly

src/main/java/org/jboss/logmanager/ExtHandler.java

@@ -22,6 +22,7 @@
 import java.io.Flushable;
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.security.Permission;
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
@@ -51,13 +52,13 @@ public abstract class ExtHandler extends Handler implements AutoCloseable, Flush
     private volatile Filter filter;
     private volatile Formatter formatter;
     private volatile Level level = Level.ALL;
-    private volatile ErrorManager errorManager = new ErrorManager();
+    private volatile ErrorManager errorManager;
     // (skip `encoding` because we replace it with `charset` below)
 
     private volatile boolean autoFlush = true;
     private volatile boolean enabled = true;
     private volatile boolean closeChildren;
-    private volatile Charset charset = Charset.defaultCharset();
+    private volatile Charset charset = StandardCharsets.UTF_8;
 
     /**
      * The sub-handlers for this handler. May only be updated using the {@link #handlersUpdater} atomic updater. The array
@@ -78,7 +79,7 @@ public abstract class ExtHandler extends Handler implements AutoCloseable, Flush
     protected ExtHandler() {
         handlersUpdater.clear(this);
         closeChildren = true;
-        super.setErrorManager(DEFAULT_ERROR_MANAGER);
+        errorManager = DEFAULT_ERROR_MANAGER;
     }
 
     /** {@inheritDoc} */
@@ -388,7 +389,7 @@ public Filter getFilter() {
      */
     @Override
     public void setEncoding(final String encoding) throws SecurityException, UnsupportedEncodingException {
-        if (encoding != null)
+        if (encoding != null) {
             try {
                 setCharset(Charset.forName(encoding));
             } catch (IllegalArgumentException e) {
@@ -397,6 +398,9 @@ public void setEncoding(final String encoding) throws SecurityException, Unsuppo
                 e2.initCause(e);
                 throw e2;
             }
+        } else {
+            setCharset(StandardCharsets.UTF_8);
+        }
     }
 
     /**
@@ -522,7 +526,8 @@ public boolean isCallerCalculationRequired() {
 
     @Override
     protected void reportError(String msg, Exception ex, int code) {
-        super.reportError(msg, ex, code);
+        final ErrorManager errorManager = this.errorManager;
+        errorManager.error(msg, ex, code);
     }
 
     /**

src/main/java/org/jboss/logmanager/LogContext.java

@@ -529,6 +529,20 @@ public void close() throws Exception {
             for (AutoCloseable handler : closeHandlers) {
                 handler.close();
             }
+            synchronized (this) {
+                attachmentKey1 = null;
+                attachmentKey2 = null;
+                final var value1 = attachmentValue1;
+                attachmentValue1 = null;
+                if (value1 instanceof AutoCloseable) {
+                    ((AutoCloseable) value1).close();
+                }
+                final var value2 = attachmentValue2;
+                attachmentValue2 = null;
+                if (value2 instanceof AutoCloseable) {
+                    ((AutoCloseable) value2).close();
+                }
+            }
         } finally {
             treeLock.unlock();
         }

src/main/java/org/jboss/logmanager/configuration/ConfigurationResource.java

@@ -0,0 +1,56 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ *
+ * Copyright 2022 Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags.
+ *
+ * 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 org.jboss.logmanager.configuration;
+
+import java.util.function.Supplier;
+
+/**
+ * Represents a configuration resource. If the resource is a {@link AutoCloseable}, then invoking {@link #close()} on
+ * this resource will close the resource.
+ *
+ * @author <a href="mailto:jperkins@redhat.com">James R. Perkins</a>
+ */
+public interface ConfigurationResource<T> extends Supplier<T>, AutoCloseable {
+
+    /**
+     * Creates a configuration resource which lazily invokes the supplier. Note that {@link #close()} will only close
+     * the resource if {@link #get()} was first invoked to retrieve the value from the supplier.
+     *
+     * @param supplier the supplier used to create the configuration resource
+     * @return the configuration resource represented by a lazy instance
+     */
+    static <T> ConfigurationResource<T> of(final Supplier<T> supplier) {
+        if (supplier instanceof ConfigurationResource) {
+            return (ConfigurationResource<T>) supplier;
+        }
+        return new LazyConfigurationResource<>(supplier);
+    }
+
+    /**
+     * Creates a configuration resource with the instance as a constant. Note that if {@link #close()} is invoked,
+     * {@link #get()} will return {@code null}.
+     *
+     * @param instance the constant instance
+     * @return the configuration resource represented by a constant instance
+     */
+    static <T> ConfigurationResource<T> of(final T instance) {
+        return new ConstantConfigurationResource<>(instance);
+    }
+}

src/main/java/org/jboss/logmanager/configuration/ConstantConfigurationResource.java

@@ -0,0 +1,46 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ *
+ * Copyright 2023 Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags.
+ *
+ * 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 org.jboss.logmanager.configuration;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * @author <a href="mailto:jperkins@redhat.com">James R. Perkins</a>
+ */
+class ConstantConfigurationResource<T> implements ConfigurationResource<T> {
+    private AtomicReference<T> instance;
+
+    ConstantConfigurationResource(final T instance) {
+        this.instance = new AtomicReference<>(instance);
+    }
+
+    @Override
+    public T get() {
+        return instance.get();
+    }
+
+    @Override
+    public void close() throws Exception {
+        final T instance = this.instance.getAndSet(null);
+        if (instance instanceof AutoCloseable) {
+            ((AutoCloseable) instance).close();
+        }
+    }
+}