On Sun, Apr 17, 2011 at 20:26, Edward Z. Yang <ezy...@mit.edu> wrote: > This is a fairly nontrivial problem. First off, let me tell you > what you do not /actually/ want to happen: you don't want the OS > level thread performing the foreign call to actually be killed...
From this I gather, one can not generally kill Haskell threads while they are in the midst of foreign calls. I guess interrupting execution to terminate the program is special since you don't expect anything to work properly afterward. > If the asynchronous API has the ability to cancel a query given > some handler, you instead want to set up a custom kill thread function > that checks if a thread has an active query and then performs > another FFI call to perform that cancellation. It turns out the PGcancel exists for this purpose. Is it safe and reasonable to make query cancellation a ThreadKilled handler in the query thread? I gather I need to write the busy loop for polling for data in Haskell. Although libpq has a procedure -- PGgetResult -- that polls for data, it would not respond to killThread. -- Jason Dusek () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
