diff options
Diffstat (limited to 'random.c')
-rw-r--r-- | random.c | 74 |
1 files changed, 57 insertions, 17 deletions
@@ -189,6 +189,7 @@ rb_genrand_real(void) #include <fcntl.h> #endif +static int seed_initialized = 0; static VALUE saved_seed = INT2FIX(0); static VALUE @@ -250,27 +251,22 @@ rand_init(vseed) return old; } -static VALUE -random_seed() +#define DEFAULT_SEED_LEN (4 * sizeof(long)) + +static void +fill_random_seed(ptr) + char *ptr; { static int n = 0; + unsigned long *seed; struct timeval tv; int fd; struct stat statbuf; + char *buf = (char*)ptr; - int seed_len; - BDIGIT *digits; - unsigned long *seed; - NEWOBJ(big, struct RBignum); - OBJSETUP(big, rb_cBignum, T_BIGNUM); - - seed_len = 4 * sizeof(long); - big->sign = 1; - big->len = seed_len / SIZEOF_BDIGITS + 1; - digits = big->digits = ALLOC_N(BDIGIT, big->len); - seed = (unsigned long *)big->digits; + seed = (unsigned long *)buf; - memset(digits, 0, big->len * SIZEOF_BDIGITS); + memset(buf, 0, DEFAULT_SEED_LEN); #ifdef S_ISCHR if ((fd = open("/dev/urandom", O_RDONLY @@ -285,7 +281,7 @@ random_seed() #endif )) >= 0) { if (fstat(fd, &statbuf) == 0 && S_ISCHR(statbuf.st_mode)) { - read(fd, seed, seed_len); + read(fd, seed, DEFAULT_SEED_LEN); } close(fd); } @@ -296,13 +292,37 @@ random_seed() seed[1] ^= tv.tv_sec; seed[2] ^= getpid() ^ (n++ << 16); seed[3] ^= (unsigned long)&seed; +} + +static VALUE +make_seed_value(char *ptr) +{ + BDIGIT *digits; + NEWOBJ(big, struct RBignum); + OBJSETUP(big, rb_cBignum, T_BIGNUM); + + RBIGNUM_SET_SIGN(big, 1); + + digits = ALLOC_N(char, DEFAULT_SEED_LEN); + RBIGNUM(big)->digits = digits; + RBIGNUM(big)->len = DEFAULT_SEED_LEN / SIZEOF_BDIGITS; + + MEMCPY(digits, ptr, char, DEFAULT_SEED_LEN); /* set leading-zero-guard if need. */ - digits[big->len-1] = digits[big->len-2] <= 1 ? 1 : 0; + digits[RBIGNUM_LEN(big)-1] = digits[RBIGNUM_LEN(big)-2] <= 1 ? 1 : 0; return rb_big_norm((VALUE)big); } +static VALUE +random_seed(void) +{ + char buf[DEFAULT_SEED_LEN]; + fill_random_seed(buf); + return make_seed_value(buf); +} + /* * call-seq: * srand(number=0) => old_seed @@ -443,6 +463,9 @@ rb_f_rand(argc, argv, obj) long val, max; rb_scan_args(argc, argv, "01", &vmax); + if (!seed_initialized) { + rand_init(random_seed()); + } switch (TYPE(vmax)) { case T_FLOAT: if (RFLOAT(vmax)->value <= LONG_MAX && RFLOAT(vmax)->value >= LONG_MIN) { @@ -490,6 +513,8 @@ rb_f_rand(argc, argv, obj) return LONG2NUM(val); } +static char initial_seed[DEFAULT_SEED_LEN]; + void rb_reset_random_seed() { @@ -497,9 +522,24 @@ rb_reset_random_seed() } void +Init_RandomSeed(void) +{ + fill_random_seed(initial_seed); + init_by_array((unsigned long*)initial_seed, DEFAULT_SEED_LEN/sizeof(unsigned long)); + seed_initialized = 1; +} + +static void +Init_RandomSeed2(void) +{ + saved_seed = make_seed_value(initial_seed); + memset(initial_seed, 0, DEFAULT_SEED_LEN); +} + +void Init_Random() { - rb_reset_random_seed(); + Init_RandomSeed2(); rb_define_global_function("srand", rb_f_srand, -1); rb_define_global_function("rand", rb_f_rand, -1); rb_global_variable(&saved_seed); |