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author | Taru Karttunen <taruti@taruti.net> | 2011-03-30 15:46:40 +0300 |
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committer | Taru Karttunen <taruti@taruti.net> | 2011-03-30 15:46:40 +0300 |
commit | e5888a1ffdae813d7575f5fb02275c6bb07e5199 (patch) | |
tree | d8d51eac403f07814b9e936eed0c9a79195e2450 /sys/src/cmd/unix/drawterm/libsec/nfastrand.c |
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/cmd/unix/drawterm/libsec/nfastrand.c')
-rwxr-xr-x | sys/src/cmd/unix/drawterm/libsec/nfastrand.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/sys/src/cmd/unix/drawterm/libsec/nfastrand.c b/sys/src/cmd/unix/drawterm/libsec/nfastrand.c new file mode 100755 index 000000000..fa042b00c --- /dev/null +++ b/sys/src/cmd/unix/drawterm/libsec/nfastrand.c @@ -0,0 +1,23 @@ +#include <u.h> +#include <libc.h> +#include <libsec.h> + +#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) + abort(); + + m = Maxrand - Maxrand % n; + while((r = fastrand()) >= m) + ; + return r%n; +} |