X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flib%2Frandom.c;h=6a963e21b42ccce71551e66e8dad806edd542d9a;hb=f685123e5f8e7c84648b2de810ba20e85b7d1504;hp=63d798d6bf6394dcb017f096c5980cf4722c4fb9;hpb=649df740b717000030c27d70209f4491da3a63f9;p=pintos-anon diff --git a/src/lib/random.c b/src/lib/random.c index 63d798d..6a963e2 100644 --- a/src/lib/random.c +++ b/src/lib/random.c @@ -29,8 +29,7 @@ swap_byte (uint8_t *a, uint8_t *b) *b = t; } -/* Initializes the PRNG with the given SEED. - Does nothing if the PRNG has already been initialized. */ +/* Initializes or reinitializes the PRNG with the given SEED. */ void random_init (unsigned seed) { @@ -40,7 +39,7 @@ random_init (unsigned seed) if (inited) return; - + for (i = 0; i < 256; i++) s[i] = i; for (i = j = 0; i < 256; i++) @@ -59,7 +58,9 @@ random_bytes (void *buf_, size_t size) { uint8_t *buf; - ASSERT (inited); + if (!inited) + random_init (0); + for (buf = buf_; size-- > 0; buf++) { uint8_t s_k; @@ -73,7 +74,9 @@ random_bytes (void *buf_, size_t size) } } -/* Returns a pseudo-random unsigned long. */ +/* Returns a pseudo-random unsigned long. + Use random_ulong() % n to obtain a random number in the range + 0...n (exclusive). */ unsigned long random_ulong (void) {