HSEARCH-5132 Do not directly rely on the Security Manager in Embedded…

…ThreadProvider

engine/src/main/java/org/hibernate/search/engine/environment/thread/impl/EmbeddedThreadProvider.java

@@ -6,14 +6,53 @@
  */
 package org.hibernate.search.engine.environment.thread.impl;
 
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.concurrent.ThreadFactory;
+import java.util.function.Supplier;
 
 import org.hibernate.search.engine.environment.thread.spi.ThreadProvider;
+import org.hibernate.search.engine.logging.impl.Log;
 import org.hibernate.search.util.common.annotation.impl.SuppressForbiddenApis;
+import org.hibernate.search.util.common.logging.impl.LoggerFactory;
 
 public final class EmbeddedThreadProvider implements ThreadProvider {
 
+	private static final Log log = LoggerFactory.make( Log.class, MethodHandles.lookup() );
+
 	public static final String NAME = "embedded";
+	private static final Supplier<ThreadGroup> THREAD_GROUP_PROVIDER;
+
+	static {
+		Supplier<ThreadGroup> provider = null;
+		try {
+			// if the SM is loaded then it means it is still around and we'll try getting the thread group out of it if it is configured:
+			Class<?> smClass = Thread.currentThread().getContextClassLoader().loadClass( "java.lang.SecurityManager" );
+			Method getSecurityManager = System.class.getDeclaredMethod( "getSecurityManager" );
+			Method getThreadGroup = smClass.getDeclaredMethod( "getThreadGroup" );
+
+			provider = () -> {
+				Object sm;
+				try {
+					sm = getSecurityManager.invoke( null );
+					if ( sm != null ) {
+						return (ThreadGroup) getThreadGroup.invoke( sm );
+					}
+				}
+				catch (InvocationTargetException | IllegalAccessException e) {
+					// shouldn't really happen, but just in case:
+					throw log.securityManagerInvocationProblem( e.getMessage(), e );
+				}
+
+				return Thread.currentThread().getThreadGroup();
+			};
+		}
+		catch (ClassNotFoundException | NoSuchMethodException e) {
+			provider = () -> Thread.currentThread().getThreadGroup();
+		}
+		THREAD_GROUP_PROVIDER = provider;
+	}
 
 	private final String commonThreadNamePrefix;
 
@@ -34,16 +73,12 @@ public String createThreadName(String prefix, int threadNumber) {
 	@SuppressForbiddenApis(reason = "It's unclear how we will handle this without the security manager;"
 			+ " we'll see when the security manager actually gets removed from the JDK")
 	public ThreadFactory createThreadFactory(String prefix) {
-		@SuppressWarnings("removal")
-		SecurityManager s = System.getSecurityManager();
-		@SuppressWarnings({ "removal", "deprecation" })
-		ThreadGroup group = ( s != null ) ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
+		ThreadGroup group = THREAD_GROUP_PROVIDER.get();
 		String namePrefix = createFullThreadNamePrefix( prefix );
 		return new SimpleThreadFactory( group, namePrefix );
 	}
 
 	private String createFullThreadNamePrefix(String prefix) {
 		return commonThreadNamePrefix + prefix + " - ";
 	}
-
 }

engine/src/main/java/org/hibernate/search/engine/logging/impl/Log.java

@@ -607,4 +607,7 @@ SearchException unexpectedQueryParameterType(String name, @FormatWith(ClassForma
 					+ " but instead got a value of type %3$s.")
 	SearchException namedValuesParameterIncorrectType(String name, @FormatWith(ClassFormatter.class) Class<?> expected,
 			@FormatWith(ClassFormatter.class) Class<?> actual);
+
+	@Message(id = ID_OFFSET + 128, value = "Unable to get a thread group from the SecurityManager: %1$s")
+	SearchException securityManagerInvocationProblem(String causeMessage, @Cause Exception cause);
 }