HHH-19551 - Address deficiencies in pessimistic locking

Author: sebersole

hibernate-core/src/main/java/org/hibernate/dialect/MariaDBDialect.java

@@ -291,6 +291,12 @@ protected boolean supportsAliasLocks() {
 		return false;
 	}
 
+	@Override
+	protected boolean supportsForShare() {
+		//only supported on MySQL
+		return false;
+	}
+
 	/**
 	 * @return {@code true} for 10.5 and above because Maria supports
 	 *         {@code insert ... returning} even though MySQL does not

hibernate-core/src/main/java/org/hibernate/dialect/lock/internal/MariaDBLockingSupport.java

@@ -5,29 +5,36 @@
 package org.hibernate.dialect.lock.internal;
 
 import jakarta.persistence.Timeout;
-import org.hibernate.Timeouts;
 import org.hibernate.dialect.DatabaseVersion;
 import org.hibernate.dialect.lock.spi.ConnectionLockTimeoutStrategy;
 import org.hibernate.dialect.lock.spi.LockTimeoutType;
 import org.hibernate.dialect.lock.spi.LockingSupport;
 import org.hibernate.dialect.lock.spi.OuterJoinLockingType;
 
+import static org.hibernate.Timeouts.NO_WAIT_MILLI;
+import static org.hibernate.Timeouts.SKIP_LOCKED_MILLI;
+import static org.hibernate.Timeouts.WAIT_FOREVER_MILLI;
 import static org.hibernate.dialect.lock.internal.MySQLLockingSupport.MYSQL_CONN_LOCK_TIMEOUT_STRATEGY;
+import static org.hibernate.dialect.lock.spi.LockTimeoutType.NONE;
+import static org.hibernate.dialect.lock.spi.LockTimeoutType.QUERY;
 
 /**
  * LockingSupport for MariaDBDialect
  *
  * @author Steve Ebersole
  */
 public class MariaDBLockingSupport implements LockingSupport, LockingSupport.Metadata {
-	private final boolean supportsSkipLocked;
-	private final boolean supportsNoWait;
-	private final boolean supportsWait;
+	private final LockTimeoutType skipLockedType;
+	private final LockTimeoutType noWaitType;
+	private final LockTimeoutType waitType;
 
 	public MariaDBLockingSupport(boolean supportsSkipLocked, boolean supportsNoWait, boolean supportsWait) {
-		this.supportsSkipLocked = supportsSkipLocked;
-		this.supportsNoWait = supportsNoWait;
-		this.supportsWait = supportsWait;
+		this.skipLockedType = supportsSkipLocked ? QUERY : NONE;
+		this.noWaitType = supportsNoWait ? QUERY : NONE;
+		// Real lock timeouts need to be applied on the Connection
+		// todo (db-locking) : integrate connection-based lock timeouts.  for now report NONE
+		//this.waitType = supportsWait ? CONNECTION : NONE;
+		this.waitType = NONE;
 	}
 
 	public MariaDBLockingSupport(boolean supportsSkipLocked, boolean supportsWait) {
@@ -48,11 +55,12 @@ public Metadata getMetadata() {
 
 	@Override
 	public LockTimeoutType getLockTimeoutType(Timeout timeout) {
-		// MariaDB supports wait and no-wait, and skip-locked after 10.6
-		if ( timeout.milliseconds() == Timeouts.SKIP_LOCKED_MILLI && !supportsSkipLocked ) {
-			return LockTimeoutType.NONE;
-		}
-		return LockTimeoutType.QUERY;
+		return switch ( timeout.milliseconds() ) {
+			case NO_WAIT_MILLI -> noWaitType;
+			case SKIP_LOCKED_MILLI -> skipLockedType;
+			case WAIT_FOREVER_MILLI -> NONE;
+			default -> waitType;
+		};
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/dialect/lock/internal/MySQLLockingSupport.java

@@ -54,7 +54,9 @@ public LockTimeoutType getLockTimeoutType(Timeout timeout) {
 			case SKIP_LOCKED_MILLI, NO_WAIT_MILLI -> laterThanVersion8 ? QUERY : NONE;
 			case WAIT_FOREVER_MILLI -> NONE;
 			// For MySQL real lock timeouts need to be applied on the Connection
-			default -> CONNECTION;
+			//default -> CONNECTION;
+			// todo (db-locking) : however, I have not yet integrated that stuff - so report NONE
+			default -> NONE;
 		};
 	}