diff --git a/src/main/java/com/google/gwtorm/client/OrmRunnable.java b/src/main/java/com/google/gwtorm/client/OrmRunnable.java
new file mode 100644
index 0000000..5083928
--- /dev/null
+++ b/src/main/java/com/google/gwtorm/client/OrmRunnable.java
@@ -0,0 +1,43 @@
+// Copyright 2009 Google Inc.
+//
+// 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.gwtorm.client;
+
+/**
+ * Runs within an isolated database transaction, retrying if necessary.
+ * <p>
+ * The {@link Schema} is free to invoke this runnable multiple times if an
+ * {@link OrmConcurrencyException} is thrown by the run method.
+ * 
+ * @param <T> type of object the run method returns.
+ * @param <S> type of schema the run method needs to perform its work.
+ */
+public interface OrmRunnable<T, S extends Schema> {
+  /**
+   * Execute the task once.
+   * <p>
+   * Implementations should read any state they need within the method, to
+   * ensure they are looking at the most current copy of the data from the
+   * database. If a method is invoked a second time to recover from a
+   * concurrency error it would need to read the data again.
+   * 
+   * @param db active schema handle to query through, and make updates on.
+   * @param txn the current transaction handle. Commit is invoked by the caller.
+   * @param retry true if this is not the first attempt to execute this task.
+   * @return the return value of the function, if any.
+   * @throws OrmException any database error. {@link OrmConcurrencyException}
+   *         may cause the transaction to be retried.
+   */
+  T run(S db, Transaction txn, boolean retry) throws OrmException;
+}
diff --git a/src/main/java/com/google/gwtorm/client/Schema.java b/src/main/java/com/google/gwtorm/client/Schema.java
index b28da3f..84d52d5 100644
--- a/src/main/java/com/google/gwtorm/client/Schema.java
+++ b/src/main/java/com/google/gwtorm/client/Schema.java
@@ -77,6 +77,17 @@
   Transaction beginTransaction() throws OrmException;
 
   /**
+   * Execute a task within a transaction, restarting it if necessary.
+   * 
+   * @param <T> type of return value for the task.
+   * @param <S> type of <code>this</code>.
+   * @param task the task to execute.
+   * @return the return value of the task.
+   * @throws OrmException the task could not be completed successfully.
+   */
+  <T, S extends Schema> T run(OrmRunnable<T, S> task) throws OrmException;
+
+  /**
    * Close the schema and release all resources.
    */
   void close();
diff --git a/src/main/java/com/google/gwtorm/jdbc/JdbcSchema.java b/src/main/java/com/google/gwtorm/jdbc/JdbcSchema.java
index 17b6cc0..6645c79 100644
--- a/src/main/java/com/google/gwtorm/jdbc/JdbcSchema.java
+++ b/src/main/java/com/google/gwtorm/jdbc/JdbcSchema.java
@@ -14,7 +14,9 @@
 
 package com.google.gwtorm.jdbc;
 
+import com.google.gwtorm.client.OrmConcurrencyException;
 import com.google.gwtorm.client.OrmException;
+import com.google.gwtorm.client.OrmRunnable;
 import com.google.gwtorm.client.Schema;
 import com.google.gwtorm.client.Transaction;
 import com.google.gwtorm.schema.RelationModel;
@@ -29,6 +31,7 @@
 
 /** Internal base class for implementations of {@link Schema}. */
 public abstract class JdbcSchema implements Schema {
+  private static final int MAX_TRIES = 10;
   private final Database<?> dbDef;
   private Connection conn;
 
@@ -45,6 +48,27 @@
     return dbDef.getDialect();
   }
 
+  public <T, S extends Schema> T run(final OrmRunnable<T, S> task)
+      throws OrmException {
+    for (int attempts = 1;; attempts++) {
+      try {
+        final Transaction txn = beginTransaction();
+        try {
+          return task.run((S) this, txn, attempts > 1);
+        } finally {
+          txn.commit();
+        }
+      } catch (OrmConcurrencyException err) {
+        // If the commit failed, our implementation rolled back automatically.
+        //
+        if (attempts < MAX_TRIES) {
+          continue;
+        }
+        throw err;
+      }
+    }
+  }
+
   public void createSchema() throws OrmException {
     final SqlDialect dialect = dbDef.getDialect();
     final SchemaModel model = dbDef.getSchemaModel();