[Haskell] Re: ANN: HDBC (Haskell Database Connectivity)
bulatz at HotPOP.com
Thu Jan 5 05:39:54 EST 2006
Wednesday, January 04, 2006, 10:13:00 PM, you wrote:
>> I saw that you are using unsafe foreign imports everywhere in
>> Database.HDBC.PostgreSQL. The trouble with them is that all Haskell
>> threads will be suspended during the call.
it is from Haskell-Cafe:
On Wed, Dec 14, 2005 at 04:39:43PM -0000, Simon Marlow wrote:
> Do other Haskell threads get blocked during an FFI call?
> | safe unsafe
> -threaded | NO YES
> no -threaded | YES YES
this is part of the reason I'd like to see a separate 'blockable'
specifier allowed on foreign imports. so that one can write portable
thread-safe libraries. right now, if one want's to call something like
gethostbyname(3), they must call it with 'safe' so every implementation
has to pay the price of a safe call even though it is only there so ghc
won't block. (or #ifdefs, which are anoying) if blockable were separate
then it can be declared 'blockable unsafe' and ghc will interpret that
as 'safe' while non-threaded implementations will interpret it as
'unsafe' and everyone is happy.
John Meacham - ?repetae.net?john?
Bulat mailto:bulatz at HotPOP.com
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