On 09.02 22:24, Bulat Ziganshin wrote:
as i understand this idea, transformer implementing async i/o should intercept vGetBuf/vPutBuf calls for the FDs, start the appropriate async operation, and then switch to another Haskell threads. the I/O manager thread should run select() in cycle and when the request is finished, wake up the appropriate thread. what's all. if you will ever need, this implementation can then be used to extend GHC's System.IO internals with the support for new async i/o managers (as i understand, select() is now supported by GHC, but poll(), kqueue() is not supported?). the only difference that my lib gives an opportunity to test this implementation without modifying GHC I/O internals, what is somewhat simpler. so, interface for async vGetBuf/vPutBuf routines should be the same as for read/write:
type FD = Int vGetBuf_async :: FD -> Ptr a -> Int -> IO Int vPutBuf_async :: FD -> Ptr a -> Int -> IO Int
Please don't fix FD = Int, this is not true on some systems, and when implementing efficient sockets one usually wants to hold more complex state.
JM> Don't take the absence of a feature in jhc to mean I don't like or want JM> that feature. There are a lot of things I don't have but that I'd JM> definitly want to see in the language simply because I was only shooting JM> for H98 to begin with and was more interested in a lot of the back end JM> stuff. You should figure out the nicest design that uses just the JM> extensions needed for the design you want. it could help us decide what JM> goes into haskell-prime to know what is absolutely needed for good JM> design and what is just nice to have.
this simply means that the Streams library cannot be used with JHC, what is bad news, because it is even more rich than GHC's System.IO. jhc had chance to get modern I/O library. but it lost that chance :)
I think it is more like "all haskell-prime programs". Seriously, if we design a new IO subsystem it would be quite nice to be able to use it from standard conforming programs. Maybe things can be reformulated in a way that will be compatible with haskell-prime.
please look. at this moment Sreams library lacks only a few important features, already implemented in GHC's System.IO: sockets, line buffering and async i/o. moreover, i don't have an experience in implementing the async i/o, so foreign help is really necessary
If you want I can look at getting network-alt to implement the interface. - Einar Karttunen