[Haskell-cafe] HDBC-postgresql and safe/unsafe FFI calls

[Jason Dagit]

On Wed, Sep 1, 2010 at 7:40 PM, David Powell <david at drp.id.au> wrote:
> Greetings,
>
> I'm having an issue with the HDBC-postgresql package that requires me to
> manually patch it before installation for most of my use cases.
>
> All the FFI calls in this package are marked "unsafe".  Unfortunately, this
> means that whenever I issue a slow sql query, all other processing stops.
> In most places that I want to use this module, I've had to manually patch it
> to at least mark the PQexec and PQexecParams calls as "safe".
>
> Is there any reason these calls should not be marked as "safe"?  I
> understand that there a little extra runtime overhead with this, but I'd
> have thought that negligible given all the other processing that goes on
> with these particular calls under the hood.

Have you read this?
http://blog.ezyang.com/2010/07/safety-first-ffi-and-threading/

Perhaps it answers your questions?

Jason