Replace dynamic proxy used for queue-slot release with explicit handler wrapper.

Author: arturobernalg

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncClientExchangeHandlerProxy.java

@@ -334,7 +334,7 @@ public final H2AsyncClientBuilder disableRequestPriority() {
      *
      * @param max maximum number of queued requests; {@code <= 0} to disable the cap
      * @return this builder
-     * @since 5.6
+     * @since 5.7
      */
     @Experimental
     public final H2AsyncClientBuilder setMaxQueuedRequests(final int max) {

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/H2AsyncClientBuilder.java

@@ -909,7 +909,7 @@ public HttpAsyncClientBuilder disableContentCompression() {
      *
      * @param max maximum number of queued requests; <= 0 to disable the cap
      * @return this builder
-     * @since 5.6
+     * @since 5.7
      */
     @Experimental
     public HttpAsyncClientBuilder setMaxQueuedRequests(final int max) {

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java

@@ -293,7 +293,7 @@ public Cancellable execute(
             return Operations.nonCancellable();
         }
         final AsyncClientExchangeHandler actual = sharedQueued != null
-                ? AsyncClientExchangeHandlerProxy.newProxy(exchangeHandler, this::releaseSlot)
+                ? new ReleasingAsyncClientExchangeHandler(exchangeHandler, this::releaseSlot)
                 : exchangeHandler;
         final ComplexCancellable complexCancellable = new ComplexCancellable();
         final IOSession session = endpoint.session;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalH2AsyncExecRuntime.java

@@ -324,7 +324,7 @@ private AsyncClientExchangeHandler guard(final AsyncClientExchangeHandler handle
         if (sharedQueued == null) {
             return handler;
         }
-        return AsyncClientExchangeHandlerProxy.newProxy(handler, this::releaseSlot);
+        return new ReleasingAsyncClientExchangeHandler(handler, this::releaseSlot);
     }
 
     @Override

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalHttpAsyncExecRuntime.java

@@ -0,0 +1,122 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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
+ *
+ *   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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.hc.client5.http.impl.async;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.apache.hc.core5.annotation.Internal;
+import org.apache.hc.core5.http.EntityDetails;
+import org.apache.hc.core5.http.Header;
+import org.apache.hc.core5.http.HttpException;
+import org.apache.hc.core5.http.HttpResponse;
+import org.apache.hc.core5.http.nio.AsyncClientExchangeHandler;
+import org.apache.hc.core5.http.nio.CapacityChannel;
+import org.apache.hc.core5.http.nio.DataStreamChannel;
+import org.apache.hc.core5.http.nio.RequestChannel;
+import org.apache.hc.core5.http.protocol.HttpContext;
+
+@Internal
+final class ReleasingAsyncClientExchangeHandler implements AsyncClientExchangeHandler {
+
+    private final AsyncClientExchangeHandler handler;
+    private final Runnable onRelease;
+    private final AtomicBoolean released;
+
+    ReleasingAsyncClientExchangeHandler(final AsyncClientExchangeHandler handler, final Runnable onRelease) {
+        this.handler = handler;
+        this.onRelease = onRelease;
+        this.released = new AtomicBoolean(false);
+    }
+
+    @Override
+    public void produceRequest(final RequestChannel channel, final HttpContext context) throws HttpException, IOException {
+        handler.produceRequest(channel, context);
+    }
+
+    @Override
+    public void consumeResponse(final HttpResponse response, final EntityDetails entityDetails, final HttpContext context)
+            throws HttpException, IOException {
+        handler.consumeResponse(response, entityDetails, context);
+    }
+
+    @Override
+    public void consumeInformation(final HttpResponse response, final HttpContext context) throws HttpException, IOException {
+        handler.consumeInformation(response, context);
+    }
+
+    @Override
+    public int available() {
+        return handler.available();
+    }
+
+    @Override
+    public void produce(final DataStreamChannel channel) throws IOException {
+        handler.produce(channel);
+    }
+
+    @Override
+    public void updateCapacity(final CapacityChannel capacityChannel) throws IOException {
+        handler.updateCapacity(capacityChannel);
+    }
+
+    @Override
+    public void consume(final ByteBuffer src) throws IOException {
+        handler.consume(src);
+    }
+
+    @Override
+    public void streamEnd(final List<? extends Header> trailers) throws HttpException, IOException {
+        handler.streamEnd(trailers);
+    }
+
+    @Override
+    public void failed(final Exception cause) {
+        handler.failed(cause);
+    }
+
+    @Override
+    public void cancel() {
+        handler.cancel();
+    }
+
+    @Override
+    public void releaseResources() {
+        try {
+            handler.releaseResources();
+        } finally {
+            if (released.compareAndSet(false, true)) {
+                try {
+                    onRelease.run();
+                } catch (final RuntimeException ignore) {
+                }
+            }
+        }
+    }
+}