From ab497c6bbe5b978c0882fd7d1208ba8755ad3616 Mon Sep 17 00:00:00 2001
From: Magnus Persson <1431685+magnusp@users.noreply.github.com>
Date: Sat, 24 Oct 2026 20:31:37 +0200
Subject: [PATCH] fix(jdbc): read updateCount under the statement lock

---
 .../libsql/jdbc/LibsqlPreparedStatement.java        |  2 +-
 .../github/magnusp/libsql/jdbc/LibsqlStatement.java | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlPreparedStatement.java b/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlPreparedStatement.java
index 4496eac..2176622 100644
--- a/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlPreparedStatement.java
+++ b/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlPreparedStatement.java
@@ -100,7 +100,7 @@ public int executeUpdate() throws SQLException {
             throw new SQLException("Query returns results");
         }
         execute();
-        return (int) updateCount;
+        return snapshotUpdateCount();
     }
 
     private static boolean returnsResultSet(String sql) {
diff --git a/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlStatement.java b/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlStatement.java
index 7fad62c..a479628 100644
--- a/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlStatement.java
+++ b/libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlStatement.java
@@ -135,7 +135,18 @@ protected void assignResultSet(
     @Override
     public int executeUpdate(String sql) throws SQLException {
         execute(sql);
-        return (int) updateCount;
+        return snapshotUpdateCount();
+    }
+
+    /**
+     * Reads the update count under {@link #stateLock}, the lock every write to the field holds.
+     * The execute paths that return a count use this instead of reading the field directly, so the
+     * value they hand back has the same happens-before edge as {@link #getUpdateCount()}.
+     */
+    protected int snapshotUpdateCount() {
+        synchronized (stateLock) {
+            return (int) updateCount;
+        }
     }
 
     @Override