On 02.07.2013 11:39, Bruce Evans wrote: > The bugs are a little different than I said above. There is no overflow > problem and no problem with invalid values being produces, since the > algorithm from ACM is careful to do everything with 32 bit signed > integers without causing overflow. The algorithm just doesn't produce > values mod 2**32 as expected by all the functions. It does what it > claims to do -- it produces values mod (2**32 - 1). The largest bug > is that RAND_MAX is off by 1. It is specified as the largest value > returned by rand(), but in FreeBSD rand() never returns it unless > USE_WEAK_SEEDING is confgured. The values should be unifornly > distributed on average beteen 0 and RAND_MAX,but that is impossible > if RADND_MAX is never returned. From libc/stdlib/srand.c:
Don't ever consider USE_WEAK_SEEDING defined - result is distributet _very_ poorly and the code should be removed long time ago. BTW, I don't understand well fixes you suggest. Is it to define RAND_MAX as 0x7ffffffe ? -- http://ache.vniz.net/ bitcoin:13fGiNutKNHcVSsgtGQ7bQ5kgUKgEQHn7N _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
