After doing a bit of digging through the source code, a co-worker of
mine (Bai Dongqiang) found something that might not be bad enough to be
classified as a bug, but should probably be fixed anyway. The problem
is that it is possible for the same value to be returned by
get_current_time() in getuuid.c which could then theoretically cause the
generated UUID to be the same. He found this in 1.5.2, but it is
probably also in previous versions as well.
We know that the timestamp resolution is actually 1/10 of a microsecond,
but for the sake of explanation, let's assume that the microsecond used
in get_current_time() went in the order of 1, 1, 2. The values returned
would be 1, 2, 2 respectively when it should be 1, 2, 3. The quick and
easy fix for this would be to alter the if statement on line 161 from
`time_last + fudge > time_now` to `time_last + fudge >= time_now`.
He looped through get_current_time() 10 million times to confirm his
suspicions and it has in fact returned the same value. The UUID however
was always different, but this seems to be caused by the fact that the
memcpy statement in apr_uuid_get actually takes about 5 microseconds,
fudging the results a bit.
Not sure if this should be considered a bug or not so I figured I'd post
it in the mailing list and see how it went.
Thanks
