On 2007-10-17, Simon Marlow
Note that forkProcess doesn't currently work with +RTS -N2 (or any value larger than 1), and it isn't likely to in the future. I suspect forkProcess should be deprecated.
That would be most annoying, and would render HSH unable to function without using FFI to import fork from C. I suspect that forkProcess has some more intelligence to it than that, though I haven't looked. System.Process is not powerful enough to do serious work on POSIX, and perhaps it never can be. The mechanism for setting up a direct pipeline with more than 2 processes is extremely inconvenient at best, and it does not seem possible to create n-process pipelines using System.Process without having to resort to copying data in the Haskell process at some point. (This even putting aside the instant bug) Not only that, but the ProcessHandle system doesn't: * Let me get the child process's PID * Send arbitrary signals to the child process * Handle SIGCHLD in a custom and sane way * Get full exit status information (stopped by a particular signal, etc) Now, there are likely perfectly valid cross-platform reasons that it doesn't do this. I am merely trying to point out that removing forkProcess in favor of System.Process will shut out a large number of very useful things. Don't forget either that there are a whole class of programs whose multithreading needs may be better addressed by forkProcess, executeFile, and clever management of subprograms rather than by a threaded RTS. forkProcess, with the ability to dupTo, closeFd, and executeFile is still mighty useful in my book.