STM Finalizers
This is some work I did as part of my master's thesis [1]. It's an extension to GHC's STM implementation. The main idea is to introduce a new primitive function
atomicallyWithIO :: STM a -> (a -> IO b) -> IO bLike the existing atomically operation, atomicallyWithIO performs an STM computation. Additionally, it takes a finalizer, which is an arbitrary I/O action that can depend on the result of the STM computation, and combines it with the transaction in such a way that:
- The finalizer is only performed if the STM transaction is guaranteed to commit.
- The STM transaction only commits if the finalizer finishes without raising an exception.
A detailed specification, including an operational semantics, as well as a discussion of the implementation, can be found in chapter 2 of my thesis [1].
I actually did this work quite some time ago, and even announced it on the mailing list [2] to some positive feedback, but then never got around to actually submitting a patch. Last week Charles Strahan wrote me on GitHub and got me motivated again, so here I am :)
I'm submitting a code review to Phabricator right now and will link it to this ticket.
[1] https://github.com/mcschroeder/thesis
[2] https://mail.haskell.org/pipermail/haskell-cafe/2015-July/120589.html
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.1 |
| Type | FeatureRequest |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Runtime System |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | simonmar |
| Operating system | |
| Architecture |