Race condition with SQLite3Store.startCleanup #228
Description
My tests hit a race. IIUC, the cause of the race is that there is a bug in SQLite3Store.
func NewWithCleanupInterval(db *sql.DB, cleanupInterval time.Duration) *SQLite3Store {
p := &SQLite3Store{db: db}
if cleanupInterval > 0 {
go p.startCleanup(cleanupInterval)
}
return p
}Notice p.startCleanup(cleanupInterval) is called with go.
func (p *SQLite3Store) startCleanup(interval time.Duration) {
p.stopCleanup = make(chan bool)
...Observe that p.stopCleanup is written to inside that goroutine, without any lock on p.
Finally
func (p *SQLite3Store) StopCleanup() {
if p.stopCleanup != nil {
p.stopCleanup <- true
}
}The line p.stopCleanup <- true is good and race free, but p.stopCleanup != nil is a race because it is reading stopCleanup, which was written to in the startCleanup routine.
I think the solution is to change NewWithCleanupInterval to
func NewWithCleanupInterval(db *sql.DB, cleanupInterval time.Duration) *SQLite3Store {
p := &SQLite3Store{db: db}
if cleanupInterval > 0 {
p.stopCleanup = make(chan bool) // NEW!
go p.startCleanup(cleanupInterval)
}
return p
}And remove p.stopCleanup = make(chan bool) from startCleanup.