Hi Don, Sorry ..I wasn't clear enough.I am trying to determine from the Haskell FFI doc what datatype to use in order to model C's "void *", e.g. for mmap http://www.opengroup.org/onlinepubs/000095399/functions/mmap.html Regards, Vasili On 1/16/08, Don Stewart wrote:

vigalchin:

...

Hello,

In the ghc libraries directory I can't find the Haskell .hs/.lhsthat implements Posix select. ?? I found Select.c.

In Control.Concurrent

forkIO threadDelay threadWaitRead threadWaitWrite

The thread primitives are implemented in terms of select, and give you a cleaner interface.

Also, with Control.Concurrent.STM.

atomically orElse retry

You can have threads wait on one of a series of alternative events. Using STM, you'll be able to compose blocks of such code, which you can't do with select.

-- Don

Hi Don, I am looking at the code for ghc-6.8.2 but don't see the mmap support. Is this newly wriiten by you? I would also like to help round out the Posix functionality in Haskell. Is there an accurate list of what needs to be done given the fact that maybe some work is in progress but not "checked in"? Thank you, Vasili On 1/16/08, Don Stewart wrote:

vigalchin:

...

Hi Don,

Sorry ..I wasn't clear enough.I am trying to determine from the Haskell FFI doc what datatype to use in order to model C's "void *", e.g. for mmap [1]http://www.opengroup.org/onlinepubs/000095399/functions/mmap.html

Regards, Vasili

In the System.IO.Posix.MMap module, mmap is imported as:

foreign import ccall unsafe "hs_bytestring_mmap.h hs_bytestring_mmap" c_mmap :: CSize -> CInt -> IO (Ptr Word8)

foreign import ccall unsafe "hs_bytestring_mmap.h munmap" c_munmap :: Ptr Word8 -> CSize -> IO CInt

You can see the full binding to mmap here:

http://hackage.haskell.org/cgi-bin/hackage-scripts/package/bytestring-mmap

Cheers, Don

On Wed, Jan 16, 2008 at 12:40:22PM -0800, Donald Bruce Stewart wrote:

If something you need is missing from there, write it as a patch against the darcs repository for `unix', http://darcs.haskell.org/packages/unix/, and submit it to libraries@haskell.org for inclusion in the next release of that library.

Please note that patches for the unix library should follow the library submissions process: http://www.haskell.org/haskellwiki/Library_submissions Thanks Ian

Spencer Janssen wrote:

For C's "void *", I'd use "Ptr ()".

"Ptr a" seems to be more usual, and hews closer to the idea that it's a pointer to an opaque value.