Hi, Richard W.M. Jones wrote: > This patch adds a 'random' module which implements: > > - random > - srandom > - initstate > - setstate
This is welcome! > and replaces: > > - rand > - srand > - RAND_MAX It shouldn't do that. The random/srandom/initstate/setstate and rand/srand/RAND_MAX facilities are unrelated. See <http://www.opengroup.org/susv3/functions/random.html> <http://www.opengroup.org/susv3/functions/rand.html> > random vs random_r > ------------------ > > It has to be said that while it is nice to have separate 'random' and > 'random_r' modules, their intimate dependence on the shared RAND_MAX > constant makes that hard to support. RAND_MAX is unrelated to 'random' and 'random_r'. POSIX says that the upper bound for these two functions is 2^31-1. The glibc manual says that RAND_MAX is the upper bound for random and random_r, but this statement is only valid for glibc, since in glibc RAND_MAX = 2^31-1. > Locking > ------- > > As seems to be traditional with gnulib, I've removed the glibc > locking. cf. setenv and related modules. Strictly speaking this is a > violation of POSIX, since rand() is supposed to work even when called > in parallel from multiple threads. This is fine. We don't think much about multithread-safety at this point. > diff --git a/doc/posix-functions/rand.texi b/doc/posix-functions/rand.texi > index 8b2090f..aecfb10 100644 > --- a/doc/posix-functions/rand.texi > +++ b/doc/posix-functions/rand.texi > @@ -4,10 +4,12 @@ > > POSIX specification: @url{http://www.opengroup.org/susv3xsh/rand.html} > > -Gnulib module: --- > +Gnulib module: random > > Portability problems fixed by Gnulib: > @itemize > [EMAIL PROTECTED] > +Provides a high quality PRNG on all platforms. > @end itemize > > Portability problems not fixed by Gnulib: If you want to provide an override for the rand() function, it should IMO 1. not be automatically enabled by the 'random' or 'random_r' modules, 2. explain in the doc what you mean by not "high quality" of some implementations (a period less than 2^32? lower bits that are easy to guess?), and which implementations are affected. Bruno
