Merge pull request #2240 from bonnefoa/fix-watch-panic

Unwatch and close connection on a batch write error

Author: jackc

pgconn/pgconn.go

@@ -1773,19 +1773,21 @@ func (pgConn *PgConn) ExecBatch(ctx context.Context, batch *Batch) *MultiResultR
 
 	batch.buf, batch.err = (&pgproto3.Sync{}).Encode(batch.buf)
 	if batch.err != nil {
+		pgConn.contextWatcher.Unwatch()
+		multiResult.err = normalizeTimeoutError(multiResult.ctx, batch.err)
 		multiResult.closed = true
-		multiResult.err = batch.err
-		pgConn.unlock()
+		pgConn.asyncClose()
 		return multiResult
 	}
 
 	pgConn.enterPotentialWriteReadDeadlock()
 	defer pgConn.exitPotentialWriteReadDeadlock()
 	_, err := pgConn.conn.Write(batch.buf)
 	if err != nil {
+		pgConn.contextWatcher.Unwatch()
+		multiResult.err = normalizeTimeoutError(multiResult.ctx, err)
 		multiResult.closed = true
-		multiResult.err = err
-		pgConn.unlock()
+		pgConn.asyncClose()
 		return multiResult
 	}
 

pgconn/pgconn_test.go

@@ -1420,6 +1420,52 @@ func TestConnExecBatch(t *testing.T) {
 	assert.Equal(t, "SELECT 1", results[2].CommandTag.String())
 }
 
+type mockConnection struct {
+	net.Conn
+	writeLatency *time.Duration
+}
+
+func (m mockConnection) Write(b []byte) (n int, err error) {
+	time.Sleep(*m.writeLatency)
+	return m.Conn.Write(b)
+}
+
+func TestConnExecBatchWriteError(t *testing.T) {
+	t.Parallel()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
+	defer cancel()
+
+	config, err := pgconn.ParseConfig(os.Getenv("PGX_TEST_DATABASE"))
+	require.NoError(t, err)
+
+	var mockConn mockConnection
+	writeLatency := 0 * time.Second
+	config.DialFunc = func(ctx context.Context, network, address string) (net.Conn, error) {
+		conn, err := net.Dial(network, address)
+		mockConn = mockConnection{conn, &writeLatency}
+		return mockConn, err
+	}
+
+	pgConn, err := pgconn.ConnectConfig(ctx, config)
+	require.NoError(t, err)
+	defer closeConn(t, pgConn)
+
+	batch := &pgconn.Batch{}
+	pgConn.Conn()
+
+	ctx2, cancel2 := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancel2()
+
+	batch.ExecParams("select $1::text", [][]byte{[]byte("ExecParams 1")}, nil, nil, nil)
+	writeLatency = 2 * time.Second
+	mrr := pgConn.ExecBatch(ctx2, batch)
+	err = mrr.Close()
+	require.Error(t, err)
+	assert.ErrorIs(t, err, context.DeadlineExceeded)
+	require.True(t, pgConn.IsClosed())
+}
+
 func TestConnExecBatchDeferredError(t *testing.T) {
 	t.Parallel()