report the name of the ConnectionProvider along with the other info

documentation/src/main/asciidoc/introduction/Introduction.adoc

@@ -186,23 +186,19 @@ dependencies {
     // the GOAT ORM
     implementation 'org.hibernate.orm:hibernate-core:{fullVersion}'
 
+    // Hibernate Processor
+    annotationProcessor 'org.hibernate.orm:hibernate-processor:{fullVersion}'
+
     // Hibernate Validator
     implementation 'org.hibernate.validator:hibernate-validator:8.0.1.Final'
     implementation 'org.glassfish:jakarta.el:4.0.2'
 
     // Agroal connection pool
-    implementation 'org.hibernate.orm:hibernate-agroal:{fullVersion}'
-    implementation 'io.agroal:agroal-pool:2.1'
+    runtimeOnly 'org.hibernate.orm:hibernate-agroal:{fullVersion}'
+    runtimeOnly 'io.agroal:agroal-pool:2.5'
 
     // logging via Log4j
-    implementation 'org.apache.logging.log4j:log4j-core:2.24.1'
-
-    // Hibernate Processor
-    annotationProcessor 'org.hibernate.orm:hibernate-processor:{fullVersion}'
-
-    // Compile-time checking for HQL
-    //implementation 'org.hibernate:query-validator:2.0-SNAPSHOT'
-    //annotationProcessor 'org.hibernate:query-validator:2.0-SNAPSHOT'
+    runtimeOnly 'org.apache.logging.log4j:log4j-core:2.24.1'
 
     // H2 database
     runtimeOnly 'com.h2database:h2:2.3.232'
@@ -281,8 +277,8 @@ public class Main {
                         // use H2 in-memory database
                         .jdbcUrl("jdbc:h2:mem:db1")
                         .jdbcCredentials("sa", "")
-                        // use Agroal connection pool
-                        .property("hibernate.agroal.maxSize", 20)
+                        // set the Agroal connection pool size
+                        .jdbcPoolSize(16)
                         // display SQL in console
                         .showSql(true, true, true)
                         .createEntityManagerFactory();

documentation/src/main/asciidoc/introduction/Tuning.adoc

@@ -35,7 +35,9 @@ the connection pool.
 The connection pool built in to Hibernate is suitable for testing, but isn't intended for use in production.
 Instead, Hibernate supports several different connection pools, including our favorite, Agroal.
 
-To select and configure Agroal, you'll need to set some extra configuration properties, in addition to the settings we already saw in <<basic-configuration-settings>>.
+Hibernate will automatically make use of `AgroalConnectionProvider` if the module `org.hibernate.orm:hibernate-agroal` is available at runtime.
+
+To properly configure Agroal, you'll need to set some extra configuration properties, in addition to the settings we already saw in <<basic-configuration-settings>>.
 Properties with the prefix `hibernate.agroal` are passed through to Agroal:
 
 [source,properties]
@@ -47,7 +49,6 @@ hibernate.agroal.acquisitionTimeout PT1s
 hibernate.agroal.reapTimeout PT10s
 ----
 
-As long as you set at least one property with the prefix `hibernate.agroal`, the `AgroalConnectionProvider` will be selected automatically.
 There are many to choose from, as enumerated by link:{doc-javadoc-url}/org/hibernate/cfg/AgroalSettings.html[`AgroalSettings`]:
 
 .Settings for configuring Agroal
@@ -78,7 +79,7 @@ The following settings are common to all connection pools supported by Hibernate
 |===
 
 A popular alternative to Agroal is HikariCP.
-Its setting are enumerated by link:{doc-javadoc-url}/org/hibernate/cfg/HikariCPSettings.html[`HikariCPSettings`].
+Its settings are enumerated by link:{doc-javadoc-url}/org/hibernate/cfg/HikariCPSettings.html[`HikariCPSettings`].
 
 .Container-managed datasources
 ****

hibernate-agroal/src/main/java/org/hibernate/agroal/internal/AgroalConnectionProvider.java

@@ -167,6 +167,7 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect) {
 				agroalDataSource.getConfiguration().connectionPoolConfiguration();
 		final AgroalConnectionFactoryConfiguration acfc = acpc.connectionFactoryConfiguration();
 		return new DatabaseConnectionInfoImpl(
+				AgroalConnectionProvider.class,
 				acfc.jdbcUrl(),
 				// Attempt to resolve the driver name from the dialect,
 				// in case it wasn't explicitly set and access to the

hibernate-c3p0/src/main/java/org/hibernate/c3p0/internal/C3P0ConnectionProvider.java

@@ -74,11 +74,11 @@ public class C3P0ConnectionProvider
 	private static final String C3P0_STYLE_MAX_STATEMENTS = "c3p0.maxStatements";
 	private static final String C3P0_STYLE_ACQUIRE_INCREMENT = "c3p0.acquireIncrement";
 	private static final String C3P0_STYLE_IDLE_CONNECTION_TEST_PERIOD = "c3p0.idleConnectionTestPeriod";
-
-	//swaldman 2006-08-28: define c3p0-style configuration parameters for initialPoolSize, which
-	//                     hibernate sensibly lets default to minPoolSize, but we'll let users
-	//                     override it with the c3p0-style property if they want.
+	//swaldman 2006-08-28: define c3p0-style configuration parameters for initialPoolSize,
+	//                     which hibernate sensibly lets default to minPoolSize, but we'll
+	//                     let users override it with the c3p0-style property if they want.
 	private static final String C3P0_STYLE_INITIAL_POOL_SIZE = "c3p0.initialPoolSize";
+
 	private DataSource dataSource;
 	private Integer isolation;
 	private boolean autocommit;
@@ -144,6 +144,10 @@ public void configure(Map<String, Object> properties) {
 
 		loadDriverClass( jdbcDriverClass );
 
+		// c3p0 returns Connections with autocommit enabled, but for
+		// historical reasons we default to calling setAutocommit(false)
+		// as soon as we obtain a new connection. This maybe isn't ideal,
+		// and it's not what we do with Agroal or Hikari.
 		autocommit = getBoolean( JdbcSettings.AUTOCOMMIT, properties ); // defaults to false
 		isolation = ConnectionProviderInitiator.extractIsolation( properties );
 
@@ -152,11 +156,12 @@ public void configure(Map<String, Object> properties) {
 		dataSource = createDataSource( jdbcUrl, connectionProps, poolSettings );
 
 		dbInfoProducer = dialect -> new DatabaseConnectionInfoImpl(
+				C3P0ConnectionProvider.class,
 				jdbcUrl,
 				jdbcDriverClass,
 				dialect.getVersion(),
 				Boolean.toString( autocommit ),
-				isolation != null ? ConnectionProviderInitiator.toIsolationNiceName( isolation ) : null,
+				isolation == null ? null : ConnectionProviderInitiator.toIsolationNiceName( isolation ),
 				requireNonNullElse( getInteger( C3P0_STYLE_MIN_POOL_SIZE.substring( 5 ), poolSettings ),
 						DEFAULT_MIN_POOL_SIZE ),
 				requireNonNullElse( getInteger( C3P0_STYLE_MAX_POOL_SIZE.substring( 5 ), poolSettings ),

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/internal/DatabaseConnectionInfoImpl.java

@@ -9,6 +9,7 @@
 import org.hibernate.cfg.JdbcSettings;
 import org.hibernate.dialect.DatabaseVersion;
 import org.hibernate.dialect.Dialect;
+import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
 import org.hibernate.engine.jdbc.connections.spi.DatabaseConnectionInfo;
 import org.hibernate.internal.util.NullnessHelper;
 import org.hibernate.internal.util.StringHelper;
@@ -27,6 +28,7 @@
 public class DatabaseConnectionInfoImpl implements DatabaseConnectionInfo {
 	public static final String DEFAULT = "undefined/unknown";
 
+	private final Class<?> connectionProviderClass;
 	protected final String jdbcUrl;
 	protected final String jdbcDriver;
 	protected final DatabaseVersion dialectVersion;
@@ -36,13 +38,15 @@ public class DatabaseConnectionInfoImpl implements DatabaseConnectionInfo {
 	protected final Integer poolMaxSize;
 
 	public DatabaseConnectionInfoImpl(
+			Class<? extends ConnectionProvider> connectionProviderClass,
 			String jdbcUrl,
 			String jdbcDriver,
 			DatabaseVersion dialectVersion,
 			String autoCommitMode,
 			String isolationLevel,
 			Integer poolMinSize,
 			Integer poolMaxSize) {
+		this.connectionProviderClass = connectionProviderClass;
 		this.jdbcUrl = nullIfEmpty( jdbcUrl );
 		this.jdbcDriver = nullIfEmpty( jdbcDriver );
 		this.dialectVersion = dialectVersion;
@@ -54,6 +58,7 @@ public DatabaseConnectionInfoImpl(
 
 	public DatabaseConnectionInfoImpl(Map<String, Object> settings, Dialect dialect) {
 		this(
+				null,
 				determineUrl( settings ),
 				determineDriver( settings ),
 				dialect.getVersion(),
@@ -66,7 +71,7 @@ public DatabaseConnectionInfoImpl(Map<String, Object> settings, Dialect dialect)
 	}
 
 	public DatabaseConnectionInfoImpl(Dialect dialect) {
-		this( null, null, dialect.getVersion(), null, null, null, null );
+		this( null, null, null, dialect.getVersion(), null, null, null, null );
 	}
 
 	@Override
@@ -111,6 +116,7 @@ public String toInfoString() {
 				"\n\tDatabase version: " + handleEmpty( dialectVersion ) +
 				"\n\tAutocommit mode: " + handleEmpty( autoCommitMode ) +
 				"\n\tIsolation level: " + handleEmpty( isolationLevel ) +
+				"\n\tPool: " + handleEmpty( connectionProviderClass ) +
 				"\n\tMinimum pool size: " + handleEmpty( poolMinSize ) +
 				"\n\tMaximum pool size: " + handleEmpty( poolMaxSize );
 	}
@@ -127,6 +133,10 @@ private static String handleEmpty(Integer value) {
 		return value != null ? value.toString() : DEFAULT;
 	}
 
+	private static String handleEmpty(Class<?> value) {
+		return value != null ? value.getSimpleName() : DEFAULT;
+	}
+
 
 	@SuppressWarnings("deprecation")
 	private static String determineUrl(Map<String, Object> settings) {

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/internal/DatasourceConnectionProviderImpl.java

@@ -150,6 +150,7 @@ public boolean supportsAggressiveRelease() {
 	@Override
 	public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect) {
 		return new DatabaseConnectionInfoImpl(
+				DatasourceConnectionProviderImpl.class,
 				null,
 				null,
 				dialect.getVersion(),