// Commit commits the transaction.
func (tx *Tx) Commit() error {
	// Check context first to avoid transaction leak.
	// If put it behind tx.done CompareAndSwap statement, we can't ensure
	// the consistency between tx.done and the real COMMIT operation.
	select {
	default:
	case <-tx.ctx.Done():
		if atomic.LoadInt32(&tx.done) == 1 {
			return ErrTxDone
		}
		return tx.ctx.Err()
	}
	if !atomic.CompareAndSwapInt32(&tx.done, 0, 1) {
		return ErrTxDone
	}

	// Cancel the Tx to release any active R-closemu locks.
	// This is safe to do because tx.done has already transitioned
	// from 0 to 1. Hold the W-closemu lock prior to rollback
	// to ensure no other connection has an active query.
	tx.cancel()
	tx.closemu.Lock()
	tx.closemu.Unlock()

	var err error
	withLock(tx.dc, func() {
		err = tx.txi.Commit()
	})
	if !errors.Is(err, driver.ErrBadConn) {
		tx.closePrepared()
	}
	tx.close(err)
	return err
}

	tx.closemu.Lock()
	tx.closemu.Unlock()