Messages in this thread | | | Date | Fri, 8 Jun 2007 11:19:09 +0200 | From | Eric Dumazet <> | Subject | Re: O_CLOEXEC: An alternate proposal |
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On Fri, 8 Jun 2007 03:47:12 -0400 (EDT) "Daniel Colascione" <danc@merrillpress.com> wrote:
> Hey, this is my first post to linux-kernel, so please be kind. :-)
Welcome Daniel
> > Linus Torvalds wrote on May 31: > > I'm with Uli on this one. "Stateful" stuff is bad. It's essentially > > impossible to handle with libraries - either the library would have to > > explciitly always turn the state the way _it_ needs it, or the library > > will do the wrogn thing. > > I agree that stateful stuff is generally not very elegant, > but I think it's a win here -- we wouldn't have to create any > new APIs except for the state-setting stuff. > > The state just has to be thread-local. > > If it's thread-local, a library, say, glibc, > can use code like this: > > /* Internal library function */ > old_fd_flags = kernel_default_fd_flags(FD_CLOEXEC | FD_RANDFD);
<race here if a signal handler runs some user code messing with a thread-local fd_flags >
> event_fd = super_duper_event_polling_mechanism_fd(); > kernel_default_fd_flags(old_fd_flags); > > I think that's a lot cleaner than augmenting every > present and future fd-creating syscall to take some kind > of flags parameter and adding some kind of funny dup(). >
Thats funny, you probably missed Linus syscall_indirect() proposal, which is basically doing the thing but with one syscall (so no races, and faster)
http://marc.info/?l=linux-kernel&m=118124716616552&w=2
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