perf: use direct executor

src/main/java/com/google/cloud/spanner/connection/ConnectionOptionsHelper.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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
+ *
+ *       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.
+ */
+
+package com.google.cloud.spanner.connection;
+
+import com.google.api.core.InternalApi;
+import com.google.cloud.spanner.connection.StatementExecutor.StatementExecutorType;
+
+@InternalApi
+public class ConnectionOptionsHelper {
+
+  @InternalApi
+  public static ConnectionOptions.Builder useDirectExecutorIfNotUseVirtualThreads(
+      String uri, ConnectionOptions.Builder builder) {
+    ConnectionState connectionState = new ConnectionState(ConnectionProperties.parseValues(uri));
+    if (!connectionState.getValue(ConnectionProperties.USE_VIRTUAL_THREADS).getValue()) {
+      return builder.setStatementExecutorType(StatementExecutorType.DIRECT_EXECUTOR);
+    }
+    return builder;
+  }
+
+  @InternalApi
+  public static boolean usesDirectExecutor(ConnectionOptions options) {
+    return options.getStatementExecutorType() == StatementExecutorType.DIRECT_EXECUTOR;
+  }
+
+  private ConnectionOptionsHelper() {}
+}

src/main/java/com/google/cloud/spanner/jdbc/AbstractJdbcConnection.java

@@ -21,6 +21,7 @@
 import com.google.cloud.spanner.SpannerException;
 import com.google.cloud.spanner.connection.AbstractStatementParser;
 import com.google.cloud.spanner.connection.ConnectionOptions;
+import com.google.cloud.spanner.connection.ConnectionOptionsHelper;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.rpc.Code;
 import java.sql.CallableStatement;
@@ -53,6 +54,7 @@ abstract class AbstractJdbcConnection extends AbstractJdbcWrapper
   private final ConnectionOptions options;
   private final com.google.cloud.spanner.connection.Connection spanner;
   private final Properties clientInfo;
+  private final boolean usesDirectExecutor;
   private AbstractStatementParser parser;
 
   private SQLWarning firstWarning = null;
@@ -63,6 +65,7 @@ abstract class AbstractJdbcConnection extends AbstractJdbcWrapper
     this.options = options;
     this.spanner = options.getConnection();
     this.clientInfo = new Properties(JdbcDatabaseMetaData.getDefaultClientInfoProperties());
+    this.usesDirectExecutor = ConnectionOptionsHelper.usesDirectExecutor(options);
   }
 
   /** Return the corresponding {@link com.google.cloud.spanner.connection.Connection} */
@@ -83,6 +86,10 @@ Spanner getSpanner() {
     return this.spanner.getSpanner();
   }
 
+  boolean usesDirectExecutor() {
+    return this.usesDirectExecutor;
+  }
+
   @Override
   public Dialect getDialect() {
     return spanner.getDialect();

src/main/java/com/google/cloud/spanner/jdbc/AbstractJdbcStatement.java

@@ -33,6 +33,8 @@
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -41,6 +43,8 @@ abstract class AbstractJdbcStatement extends AbstractJdbcWrapper implements Stat
   private static final String CURSORS_NOT_SUPPORTED = "Cursors are not supported";
   private static final String ONLY_FETCH_FORWARD_SUPPORTED = "Only fetch_forward is supported";
   final AbstractStatementParser parser;
+  private final Lock executingLock;
+  private volatile Thread executingThread;
   private boolean closed;
   private boolean closeOnCompletion;
   private boolean poolable;
@@ -50,6 +54,11 @@ abstract class AbstractJdbcStatement extends AbstractJdbcWrapper implements Stat
   AbstractJdbcStatement(JdbcConnection connection) throws SQLException {
     this.connection = connection;
     this.parser = connection.getParser();
+    if (connection.usesDirectExecutor()) {
+      this.executingLock = new ReentrantLock();
+    } else {
+      this.executingLock = null;
+    }
   }
 
   @Override
@@ -228,6 +237,10 @@ private <T> T doWithStatementTimeout(
       Supplier<T> runnable, Function<T, Boolean> shouldResetTimeout) throws SQLException {
     StatementTimeout originalTimeout = setTemporaryStatementTimeout();
     T result = null;
+    if (this.executingLock != null) {
+      this.executingLock.lock();
+      this.executingThread = Thread.currentThread();
+    }
     try {
       Stopwatch stopwatch = Stopwatch.createStarted();
       result = runnable.get();
@@ -237,6 +250,10 @@ private <T> T doWithStatementTimeout(
     } catch (SpannerException spannerException) {
       throw JdbcSqlExceptionFactory.of(spannerException);
     } finally {
+      if (this.executingLock != null) {
+        this.executingThread = null;
+        this.executingLock.unlock();
+      }
       if (shouldResetTimeout.apply(result)) {
         resetStatementTimeout(originalTimeout);
       }
@@ -330,7 +347,16 @@ public void setQueryTimeout(int seconds) throws SQLException {
   @Override
   public void cancel() throws SQLException {
     checkClosed();
-    connection.getSpannerConnection().cancel();
+    if (this.executingThread != null) {
+      // This is a best-effort operation. It could be that the executing thread is set to null
+      // between the if-check and the actual execution. Just ignore if that happens.
+      try {
+        this.executingThread.interrupt();
+      } catch (NullPointerException ignore) {
+      }
+    } else {
+      connection.getSpannerConnection().cancel();
+    }
   }
 
   @Override

src/main/java/com/google/cloud/spanner/jdbc/JdbcDriver.java

@@ -23,6 +23,7 @@
 import com.google.cloud.spanner.SpannerException;
 import com.google.cloud.spanner.connection.ConnectionOptions;
 import com.google.cloud.spanner.connection.ConnectionOptions.ConnectionProperty;
+import com.google.cloud.spanner.connection.ConnectionOptionsHelper;
 import com.google.rpc.Code;
 import io.opentelemetry.api.OpenTelemetry;
 import java.sql.Connection;
@@ -244,6 +245,9 @@ private ConnectionOptions buildConnectionOptions(String connectionUrl, Propertie
     // Enable multiplexed sessions by default for the JDBC driver.
     builder.setSessionPoolOptions(
         SessionPoolOptionsHelper.useMultiplexedSessions(SessionPoolOptions.newBuilder()).build());
+    // Enable direct executor for JDBC, as we don't use the async API.
+    builder =
+        ConnectionOptionsHelper.useDirectExecutorIfNotUseVirtualThreads(connectionUrl, builder);
     return builder.build();
   }
 

src/test/java/com/google/cloud/spanner/jdbc/JdbcStatementTimeoutTest.java

@@ -19,25 +19,52 @@
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThrows;
 
 import com.google.cloud.spanner.MockSpannerServiceImpl.SimulatedExecutionTime;
 import com.google.cloud.spanner.connection.AbstractMockServerTest;
+import com.google.cloud.spanner.jdbc.JdbcSqlExceptionFactory.JdbcSqlExceptionImpl;
 import com.google.cloud.spanner.jdbc.JdbcSqlExceptionFactory.JdbcSqlTimeoutException;
+import com.google.rpc.Code;
+import com.google.spanner.v1.ExecuteSqlRequest;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
 
 /**
  * Tests setting a statement timeout. This test is by default not included in unit test runs, as the
  * minimum timeout value in JDBC is 1 second, which again makes this test relatively slow.
  */
-@RunWith(JUnit4.class)
+@RunWith(Parameterized.class)
 public class JdbcStatementTimeoutTest extends AbstractMockServerTest {
 
+  @Parameter public boolean useVirtualThreads;
+
+  @Parameters(name = "useVirtualThreads = {0}")
+  public static Object[] data() {
+    return new Boolean[] {false, true};
+  }
+
+  @Override
+  protected String getBaseUrl() {
+    return super.getBaseUrl() + ";useVirtualThreads=" + this.useVirtualThreads;
+  }
+
+  @After
+  public void resetExecutionTimes() {
+    mockSpanner.removeAllExecutionTimes();
+  }
+
   @Test
   public void testExecuteTimeout() throws SQLException {
     try (java.sql.Connection connection = createJdbcConnection()) {
@@ -118,4 +145,35 @@ public void testExecuteBatchTimeout() throws SQLException {
       }
     }
   }
+
+  @Test
+  public void testCancel() throws Exception {
+    ExecutorService service = Executors.newSingleThreadExecutor();
+    String sql = INSERT_STATEMENT.getSql();
+
+    try (java.sql.Connection connection = createJdbcConnection();
+        Statement statement = connection.createStatement()) {
+      mockSpanner.freeze();
+      Future<Void> future =
+          service.submit(
+              () -> {
+                // Wait until the request has landed on the server and then cancel the statement.
+                mockSpanner.waitForRequestsToContain(
+                    message ->
+                        message instanceof ExecuteSqlRequest
+                            && ((ExecuteSqlRequest) message).getSql().equals(sql),
+                    5000L);
+                System.out.println("Cancelling statement");
+                statement.cancel();
+                return null;
+              });
+      JdbcSqlExceptionImpl exception =
+          assertThrows(JdbcSqlExceptionImpl.class, () -> statement.execute(sql));
+      assertEquals(Code.CANCELLED, exception.getCode());
+      assertNull(future.get());
+    } finally {
+      mockSpanner.unfreeze();
+      service.shutdown();
+    }
+  }
 }