Simon Marlow wrote:
John Goerzen wrote:
Hi Bulat,
My contribution to the survey: I've used forkProcess to daemonize a ghc program inside the haskell fuse bindings: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HFuse http://code.haskell.org/hfuse/System/Fuse.hsc
If removing the non-threaded RTS would break forkProcess entirely, these bindings would have to do something different. The issue: users of the FUSE C api will get daemonized using daemon(2); it'd be nice if GHC fuse programs could behave similarly. I also use forkProcess extensively: in HSH, for instance, which is used by hpodder, twidge, and a host of other tools. Removing the ability to use forkProcess removes the ability to write a Unix shell in Haskell, or to do anything shell-like, or anything even mildly advanced involving
Brian B wrote: piping, file descriptors, and the like. I would see it as a significant regression.
Have you tried those apps with the threaded RTS? I'd be interested to know whether they work as expected.
I have, and it didn't work well. But it's been awhile, and I can't tell you anymore what version of GHC or what exactly the problem was. I was most certainly 6.8 or older. Once 6.10 hits Debian, I could test again there. But see below...
I'm not suggesting we remove the non-threaded RTS, however perhaps there's an argument for making -threaded the default. After all, that's what you get with GHCi by default right now.
That's probably an OK solution. I would also add: does the threaded RTS support all platforms? For instance, GHC runs on my Alpha and on AIX, unregisterised. ghci doesn't run there, but GHC does. If you drop the non-threaded RTS, does that mean that GHC doesn't work there at all?
The System.Process calls, last I checked (in 6.8.x) were both too buggy to use for complex tasks, and too inadequate for some (though the adequacy has been improving.)
If there's bugginess we need to get it fixed - please report those bugs!
Already done: http://hackage.haskell.org/trac/ghc/ticket/1780 (still open since Nov 2007) There was also a thread here regarding problems with the threaded RTS: http://www.mail-archive.com/glasgow-haskell-users@haskell.org/msg11573.html Not sure if that has been fixed, or was an error on my part, but see your reply at: http://www.mail-archive.com/glasgow-haskell-users@haskell.org/msg11585.html I admit I haven't had the chance to reread that whole thread, so my apologies if this is a red herring. -- John