On Sat, Apr 7, 2012 at 5:21 PM, Ben Pfaff <blp@xxxxxxxxxxxxxxx> wrote: > "H. Peter Anvin" <hpa@xxxxxxxxx> writes: > >> On 04/06/2012 02:54 AM, Alexey Dobriyan wrote: >>> >>> Without proc knowledge about fdtable is gathered linearly and still unreliable. >>> With nextfd(2), even procful environments could lose several failure branches. >>> And they can keep old dumb fd++ or smart /proc/self/fd loops for a change. >>> >> >> Incidentally, if we were to create a system call for this -- which I so >> far see no reason for -- I would make it return a select-style bitmask >> of file descriptors in use, not a "next fd" which would require a system >> call per iteration. > > It's already possible to do something a little like that with the > existing "poll" system call: > > #include <stdio.h> > #include <sys/poll.h> > > int > main(void) > { > enum { N_FDS = 1024 }; > struct pollfd fds[N_FDS]; Your code has a muximum fd assumption here. that is one of that we really want to avoid. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html