From 37da2899f40661e3e9631e497da8dc59b971cbd0 Mon Sep 17 00:00:00 2001 From: "Charles.Forsyth" Date: Fri, 22 Dec 2006 17:07:39 +0000 Subject: 20060303a --- libsec/port/nfastrand.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 libsec/port/nfastrand.c (limited to 'libsec/port/nfastrand.c') diff --git a/libsec/port/nfastrand.c b/libsec/port/nfastrand.c new file mode 100644 index 00000000..7394a132 --- /dev/null +++ b/libsec/port/nfastrand.c @@ -0,0 +1,22 @@ +#include "os.h" +#include + +#define Maxrand ((1UL<<31)-1) + +ulong +nfastrand(ulong n) +{ + ulong m, r; + + /* + * set m to the maximum multiple of n <= 2^31-1 + * so we want a random number < m. + */ + if(n > Maxrand) + sysfatal("nfastrand: n too large"); + + m = Maxrand - Maxrand % n; + while((r = fastrand()) >= m) + ; + return r%n; +} -- cgit v1.2.3