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    SubjectRe: short read from /dev/urandom
    On Sat, Jan 15, 2005 at 07:58:23PM -0800, Ulrich Drepper wrote:
    > Matt Mackall wrote:
    > >_Neither_ case mentions signals and the "and will return as many bytes
    > >as requested" is clearly just a restatement of "does not have this
    > >limit". Whoever copied this comment to the manpage was a bit sloppy
    > >and dropped the first clause rather than the second:
    > It still means the documented API says there are no short reads.

    I maintain that it's ambiguous. And read(2) makes it clear that short
    reads can happen any time, any where. Further, your interpretation
    makes for a nonsensical API as it implies being uninterruptible for
    arbitrary lengths of time.

    Changing the longstanding, sensible code to match a silly and highly
    non-standard interpretation of the documentation doesn't fix the
    problem in apps either. Presumably they'll still be running on kernels
    older than 2.6.11 and I believe most *BSDs have /dev/urandom as well.

    > >So anyone doing a read() can expect a short read regardless of the fd
    > >and is quite clear that reads can be interrupted by signals. "It is
    > >not an error". Ever.
    > Of course are signal interruptions wrong if the signal uses SA_RESTART.

    That's a separate problem. I'll take a look at fixing that.

    Mathematics is the supreme nostalgia of our time.
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