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

John Goerzen jgoerzen at complete.org
Thu Sep 2 11:36:34 EDT 2010

Hi David,

I've had varying arguments from people that want me to mark things safe 
or unsafe for various performance reasons.  I'm happy to apply your 
change if you like.  Can you send me a diff (and attach your explanation 
here to it, which I'll use as a commit message for future reference)?


-- John

On 09/01/2010 09:40 PM, David Powell 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.
> Cheers,
> --
> David Powell

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