Lock when modifying tbfe.layout.
Lock when modifying tbfe.layout.

Fix #411.

farhaanbukhsh/lime,farhaanbukhsh/lime,crr0004/lime,farhaanbukhsh/lime,crr0004/lime,farhaanbukhsh/lime,crr0004/lime,crr0004/lime,farhaanbukhsh/lime,crr0004/lime