From 8c57745c8207fd1850231ffbf3d255219125f365 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Thu, 20 Aug 2020 17:55:56 +0100
Subject: [PATCH] Un-deadlock device database

---
 .../storage/devices/sqlite3/devices_table.go  | 62 +++++++------------
 userapi/storage/devices/sqlite3/storage.go    |  8 +--
 2 files changed, 28 insertions(+), 42 deletions(-)

diff --git a/userapi/storage/devices/sqlite3/devices_table.go b/userapi/storage/devices/sqlite3/devices_table.go
index c902adc76..ddb2dbe45 100644
--- a/userapi/storage/devices/sqlite3/devices_table.go
+++ b/userapi/storage/devices/sqlite3/devices_table.go
@@ -138,19 +138,13 @@ func (s *devicesStatements) insertDevice(
 ) (*api.Device, error) {
 	createdTimeMS := time.Now().UnixNano() / 1000000
 	var sessionID int64
-	err := s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
-		countStmt := sqlutil.TxStmt(txn, s.selectDevicesCountStmt)
-		insertStmt := sqlutil.TxStmt(txn, s.insertDeviceStmt)
-		if err := countStmt.QueryRowContext(ctx).Scan(&sessionID); err != nil {
-			return err
-		}
-		sessionID++
-		if _, err := insertStmt.ExecContext(ctx, id, localpart, accessToken, createdTimeMS, displayName, sessionID); err != nil {
-			return err
-		}
-		return nil
-	})
-	if err != nil {
+	countStmt := sqlutil.TxStmt(txn, s.selectDevicesCountStmt)
+	insertStmt := sqlutil.TxStmt(txn, s.insertDeviceStmt)
+	if err := countStmt.QueryRowContext(ctx).Scan(&sessionID); err != nil {
+		return nil, err
+	}
+	sessionID++
+	if _, err := insertStmt.ExecContext(ctx, id, localpart, accessToken, createdTimeMS, displayName, sessionID); err != nil {
 		return nil, err
 	}
 	return &api.Device{
@@ -164,11 +158,9 @@ func (s *devicesStatements) insertDevice(
 func (s *devicesStatements) deleteDevice(
 	ctx context.Context, txn *sql.Tx, id, localpart string,
 ) error {
-	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
-		stmt := sqlutil.TxStmt(txn, s.deleteDeviceStmt)
-		_, err := stmt.ExecContext(ctx, id, localpart)
-		return err
-	})
+	stmt := sqlutil.TxStmt(txn, s.deleteDeviceStmt)
+	_, err := stmt.ExecContext(ctx, id, localpart)
+	return err
 }
 
 func (s *devicesStatements) deleteDevices(
@@ -179,36 +171,30 @@ func (s *devicesStatements) deleteDevices(
 	if err != nil {
 		return err
 	}
-	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
-		stmt := sqlutil.TxStmt(txn, prep)
-		params := make([]interface{}, len(devices)+1)
-		params[0] = localpart
-		for i, v := range devices {
-			params[i+1] = v
-		}
-		_, err = stmt.ExecContext(ctx, params...)
-		return err
-	})
+	stmt := sqlutil.TxStmt(txn, prep)
+	params := make([]interface{}, len(devices)+1)
+	params[0] = localpart
+	for i, v := range devices {
+		params[i+1] = v
+	}
+	_, err = stmt.ExecContext(ctx, params...)
+	return err
 }
 
 func (s *devicesStatements) deleteDevicesByLocalpart(
 	ctx context.Context, txn *sql.Tx, localpart string,
 ) error {
-	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
-		stmt := sqlutil.TxStmt(txn, s.deleteDevicesByLocalpartStmt)
-		_, err := stmt.ExecContext(ctx, localpart)
-		return err
-	})
+	stmt := sqlutil.TxStmt(txn, s.deleteDevicesByLocalpartStmt)
+	_, err := stmt.ExecContext(ctx, localpart)
+	return err
 }
 
 func (s *devicesStatements) updateDeviceName(
 	ctx context.Context, txn *sql.Tx, localpart, deviceID string, displayName *string,
 ) error {
-	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
-		stmt := sqlutil.TxStmt(txn, s.updateDeviceNameStmt)
-		_, err := stmt.ExecContext(ctx, displayName, localpart, deviceID)
-		return err
-	})
+	stmt := sqlutil.TxStmt(txn, s.updateDeviceNameStmt)
+	_, err := stmt.ExecContext(ctx, displayName, localpart, deviceID)
+	return err
 }
 
 func (s *devicesStatements) selectDeviceByToken(
diff --git a/userapi/storage/devices/sqlite3/storage.go b/userapi/storage/devices/sqlite3/storage.go
index 99d4b1fb9..e46ad981d 100644
--- a/userapi/storage/devices/sqlite3/storage.go
+++ b/userapi/storage/devices/sqlite3/storage.go
@@ -140,7 +140,7 @@ func generateDeviceID() (string, error) {
 func (d *Database) UpdateDevice(
 	ctx context.Context, localpart, deviceID string, displayName *string,
 ) error {
-	return sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
+	return d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
 		return d.devices.updateDeviceName(ctx, txn, localpart, deviceID, displayName)
 	})
 }
@@ -152,7 +152,7 @@ func (d *Database) UpdateDevice(
 func (d *Database) RemoveDevice(
 	ctx context.Context, deviceID, localpart string,
 ) error {
-	return sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
+	return d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
 		if err := d.devices.deleteDevice(ctx, txn, deviceID, localpart); err != sql.ErrNoRows {
 			return err
 		}
@@ -167,7 +167,7 @@ func (d *Database) RemoveDevice(
 func (d *Database) RemoveDevices(
 	ctx context.Context, localpart string, devices []string,
 ) error {
-	return sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
+	return d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
 		if err := d.devices.deleteDevices(ctx, txn, localpart, devices); err != sql.ErrNoRows {
 			return err
 		}
@@ -181,7 +181,7 @@ func (d *Database) RemoveDevices(
 func (d *Database) RemoveAllDevices(
 	ctx context.Context, localpart string,
 ) error {
-	return sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
+	return d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
 		if err := d.devices.deleteDevicesByLocalpart(ctx, txn, localpart); err != sql.ErrNoRows {
 			return err
 		}