Enable virtual threads on Jetty

Closes gh-35703

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/reactive/ReactiveManagementChildContextConfiguration.java

@@ -26,6 +26,7 @@ import org.springframework.boot.actuate.autoconfigure.web.server.ManagementServe
 import org.springframework.boot.actuate.autoconfigure.web.server.ManagementWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
+import org.springframework.boot.autoconfigure.web.embedded.JettyVirtualThreadsWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.web.embedded.JettyWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.web.embedded.NettyWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.web.embedded.TomcatVirtualThreadsWebServerFactoryCustomizer;
@@ -79,7 +80,8 @@ public class ReactiveManagementChildContextConfiguration {
 			super(beanFactory, ReactiveWebServerFactoryCustomizer.class, TomcatWebServerFactoryCustomizer.class,
 					TomcatReactiveWebServerFactoryCustomizer.class,
 					TomcatVirtualThreadsWebServerFactoryCustomizer.class, JettyWebServerFactoryCustomizer.class,
-					UndertowWebServerFactoryCustomizer.class, NettyWebServerFactoryCustomizer.class);
+					JettyVirtualThreadsWebServerFactoryCustomizer.class, UndertowWebServerFactoryCustomizer.class,
+					NettyWebServerFactoryCustomizer.class);
 		}
 
 	}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/servlet/ServletManagementChildContextConfiguration.java

@@ -39,6 +39,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplicat
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
 import org.springframework.boot.autoconfigure.condition.SearchStrategy;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.autoconfigure.web.embedded.JettyVirtualThreadsWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.web.embedded.JettyWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.web.embedded.TomcatVirtualThreadsWebServerFactoryCustomizer;
 import org.springframework.boot.autoconfigure.web.embedded.TomcatWebServerFactoryCustomizer;
@@ -124,8 +125,8 @@ class ServletManagementChildContextConfiguration {
 		ServletManagementWebServerFactoryCustomizer(ListableBeanFactory beanFactory) {
 			super(beanFactory, ServletWebServerFactoryCustomizer.class, TomcatServletWebServerFactoryCustomizer.class,
 					TomcatWebServerFactoryCustomizer.class, TomcatVirtualThreadsWebServerFactoryCustomizer.class,
-					JettyWebServerFactoryCustomizer.class, UndertowServletWebServerFactoryCustomizer.class,
+					JettyWebServerFactoryCustomizer.class, JettyVirtualThreadsWebServerFactoryCustomizer.class,
-					UndertowWebServerFactoryCustomizer.class);
+					UndertowServletWebServerFactoryCustomizer.class, UndertowWebServerFactoryCustomizer.class);
 		}
 
 		@Override

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/EmbeddedWebServerFactoryCustomizerAutoConfiguration.java

@@ -84,6 +84,13 @@ public class EmbeddedWebServerFactoryCustomizerAutoConfiguration {
 			return new JettyWebServerFactoryCustomizer(environment, serverProperties);
 		}
 
+		@Bean
+		@ConditionalOnVirtualThreads
+		JettyVirtualThreadsWebServerFactoryCustomizer jettyVirtualThreadsWebServerFactoryCustomizer(
+				ServerProperties serverProperties) {
+			return new JettyVirtualThreadsWebServerFactoryCustomizer(serverProperties);
+		}
+
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyThreadPool.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      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 org.springframework.boot.autoconfigure.web.embedded;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.SynchronousQueue;
+
+import org.eclipse.jetty.util.BlockingArrayQueue;
+import org.eclipse.jetty.util.thread.QueuedThreadPool;
+import org.eclipse.jetty.util.thread.ThreadPool;
+
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+
+/**
+ * Creates a {@link ThreadPool} for Jetty, applying the
+ * {@link ServerProperties.Jetty.Threads} properties.
+ *
+ * @author Moritz Halbritter
+ */
+final class JettyThreadPool {
+
+	private JettyThreadPool() {
+	}
+
+	static QueuedThreadPool create(ServerProperties.Jetty.Threads properties) {
+		BlockingQueue<Runnable> queue = determineBlockingQueue(properties.getMaxQueueCapacity());
+		int maxThreadCount = (properties.getMax() > 0) ? properties.getMax() : 200;
+		int minThreadCount = (properties.getMin() > 0) ? properties.getMin() : 8;
+		int threadIdleTimeout = (properties.getIdleTimeout() != null) ? (int) properties.getIdleTimeout().toMillis()
+				: 60000;
+		return new QueuedThreadPool(maxThreadCount, minThreadCount, threadIdleTimeout, queue);
+	}
+
+	private static BlockingQueue<Runnable> determineBlockingQueue(Integer maxQueueCapacity) {
+		if (maxQueueCapacity == null) {
+			return null;
+		}
+		if (maxQueueCapacity == 0) {
+			return new SynchronousQueue<>();
+		}
+		else {
+			return new BlockingArrayQueue<>(maxQueueCapacity);
+		}
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyVirtualThreadsWebServerFactoryCustomizer.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      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 org.springframework.boot.autoconfigure.web.embedded;
+
+import org.eclipse.jetty.util.VirtualThreads;
+import org.eclipse.jetty.util.thread.QueuedThreadPool;
+
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.web.embedded.jetty.ConfigurableJettyWebServerFactory;
+import org.springframework.boot.web.server.WebServerFactoryCustomizer;
+import org.springframework.core.Ordered;
+import org.springframework.util.Assert;
+
+/**
+ * Activates virtual threads on the {@link ConfigurableJettyWebServerFactory}.
+ *
+ * @author Moritz Halbritter
+ * @since 3.2.0
+ */
+public class JettyVirtualThreadsWebServerFactoryCustomizer
+		implements WebServerFactoryCustomizer<ConfigurableJettyWebServerFactory>, Ordered {
+
+	private final ServerProperties serverProperties;
+
+	public JettyVirtualThreadsWebServerFactoryCustomizer(ServerProperties serverProperties) {
+		this.serverProperties = serverProperties;
+	}
+
+	@Override
+	public void customize(ConfigurableJettyWebServerFactory factory) {
+		Assert.state(VirtualThreads.areSupported(), "Virtual threads are not supported");
+		QueuedThreadPool threadPool = JettyThreadPool.create(this.serverProperties.getJetty().getThreads());
+		threadPool.setVirtualThreadsExecutor(VirtualThreads.getDefaultVirtualThreadsExecutor());
+		factory.setThreadPool(threadPool);
+	}
+
+	@Override
+	public int getOrder() {
+		return JettyWebServerFactoryCustomizer.ORDER + 1;
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyWebServerFactoryCustomizer.java

@@ -18,8 +18,6 @@ package org.springframework.boot.autoconfigure.web.embedded;
 
 import java.time.Duration;
 import java.util.Arrays;
-import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.SynchronousQueue;
 
 import org.eclipse.jetty.server.AbstractConnector;
 import org.eclipse.jetty.server.ConnectionFactory;
@@ -31,9 +29,6 @@ import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.handler.ContextHandler;
 import org.eclipse.jetty.server.handler.HandlerCollection;
 import org.eclipse.jetty.server.handler.HandlerWrapper;
-import org.eclipse.jetty.util.BlockingArrayQueue;
-import org.eclipse.jetty.util.thread.QueuedThreadPool;
-import org.eclipse.jetty.util.thread.ThreadPool;
 
 import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.cloud.CloudPlatform;
@@ -60,6 +55,8 @@ import org.springframework.util.unit.DataSize;
 public class JettyWebServerFactoryCustomizer
 		implements WebServerFactoryCustomizer<ConfigurableJettyWebServerFactory>, Ordered {
 
+	static final int ORDER = 0;
+
 	private final Environment environment;
 
 	private final ServerProperties serverProperties;
@@ -71,7 +68,7 @@ public class JettyWebServerFactoryCustomizer
 
 	@Override
 	public int getOrder() {
-		return 0;
+		return ORDER;
 	}
 
 	@Override
@@ -79,7 +76,7 @@ public class JettyWebServerFactoryCustomizer
 		ServerProperties.Jetty properties = this.serverProperties.getJetty();
 		factory.setUseForwardHeaders(getOrDeduceUseForwardHeaders());
 		ServerProperties.Jetty.Threads threadProperties = properties.getThreads();
-		factory.setThreadPool(determineThreadPool(properties.getThreads()));
+		factory.setThreadPool(JettyThreadPool.create(properties.getThreads()));
 		PropertyMapper map = PropertyMapper.get().alwaysApplyingWhenNonNull();
 		map.from(properties::getMaxConnections).to(factory::setMaxConnections);
 		map.from(threadProperties::getAcceptors).to(factory::setAcceptors);
@@ -151,27 +148,6 @@ public class JettyWebServerFactoryCustomizer
 		});
 	}
 
-	private ThreadPool determineThreadPool(ServerProperties.Jetty.Threads properties) {
-		BlockingQueue<Runnable> queue = determineBlockingQueue(properties.getMaxQueueCapacity());
-		int maxThreadCount = (properties.getMax() > 0) ? properties.getMax() : 200;
-		int minThreadCount = (properties.getMin() > 0) ? properties.getMin() : 8;
-		int threadIdleTimeout = (properties.getIdleTimeout() != null) ? (int) properties.getIdleTimeout().toMillis()
-				: 60000;
-		return new QueuedThreadPool(maxThreadCount, minThreadCount, threadIdleTimeout, queue);
-	}
-
-	private BlockingQueue<Runnable> determineBlockingQueue(Integer maxQueueCapacity) {
-		if (maxQueueCapacity == null) {
-			return null;
-		}
-		if (maxQueueCapacity == 0) {
-			return new SynchronousQueue<>();
-		}
-		else {
-			return new BlockingArrayQueue<>(maxQueueCapacity);
-		}
-	}
-
 	private void customizeAccessLog(ConfigurableJettyWebServerFactory factory,
 			ServerProperties.Jetty.Accesslog properties) {
 		factory.addServerCustomizers((server) -> {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/JettyVirtualThreadsWebServerFactoryCustomizerTests.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      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 org.springframework.boot.autoconfigure.web.embedded;
+
+import org.eclipse.jetty.util.thread.QueuedThreadPool;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
+
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.web.embedded.jetty.ConfigurableJettyWebServerFactory;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.assertArg;
+import static org.mockito.BDDMockito.then;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link JettyVirtualThreadsWebServerFactoryCustomizer}.
+ *
+ * @author Moritz Halbritter
+ */
+class JettyVirtualThreadsWebServerFactoryCustomizerTests {
+
+	@Test
+	@EnabledForJreRange(min = JRE.JAVA_21)
+	void shouldConfigureVirtualThreads() {
+		ServerProperties properties = new ServerProperties();
+		JettyVirtualThreadsWebServerFactoryCustomizer customizer = new JettyVirtualThreadsWebServerFactoryCustomizer(
+				properties);
+		ConfigurableJettyWebServerFactory factory = mock(ConfigurableJettyWebServerFactory.class);
+		customizer.customize(factory);
+		then(factory).should().setThreadPool(assertArg((threadPool) -> {
+			assertThat(threadPool).isInstanceOf(QueuedThreadPool.class);
+			QueuedThreadPool queuedThreadPool = (QueuedThreadPool) threadPool;
+			assertThat(queuedThreadPool.getVirtualThreadsExecutor()).isNotNull();
+		}));
+	}
+
+}