stm
Software Transactional Memory
The stm Package 
See stm on Hackage for more information.
Install
cabal install stm- nats (>= 0.1.3 && < 0.3) || (>= 1 && < 1.2)
- semigroups >=0.18.6 && <0.21
- base >= 4.4 && < 4.22
- array >= 0.3 && < 0.6
- 2.5.3.1
- 2.5.3.0
- 2.5.2.1
- 2.5.2.0
- 2.5.1.0
- 2.5.0.2
- 2.5.0.1
- 2.5.0.0
- 2.4.5.1
- 2.4.5.0
- 2.4.4.1
- 2.4.4
- 2.4.3
- 2.4.2
- 2.4
- 2.3
- 2.2.0.1
- 2.2.0.0
- 2.1.2.2
- 2.1.2.1
- 2.1.2.0
- 2.1.1.2
- 2.1.1.0
- 2.1