CODEWITHSUNDEEP
haskelleventsconcurrencystm
nicolas
nicolas

Reputation: 9805

STM and outgoing IO

If I am inside a STM whose transaction fail, and I retry as part of the normal control flow (no STM collision etc..), I might want to indicate to someone outside a way to take corrective action.

If it's purely 'outgoing', then my STM can still be replayed purely.

How might I perform outgoing IO from a STM retry ?

Has anyone encountered this ? How evil is this ?

Upvotes: 5

Views: 557

Answers (1)

chi
chi

Reputation: 116139

If you are sure that the performed IO does not affect the invariants of STM, you can use unsafeIOToSTM. Use it with great care, as all the unsafe stuff.

I do, however, wonder if you really need that. It's impossible to tell from the question. If you can, you should avoid it.

Upvotes: 5

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