xref: /reactos/sdk/lib/crt/stdlib/rand.c (revision d6eebaa4)
1 /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
2 #include <precomp.h>
3 #include <ntsecapi.h>
4 #include <internal/tls.h>
5 
6 /*
7  * @implemented
8  */
9 int
10 rand(void)
11 {
12     thread_data_t *data = msvcrt_get_thread_data();
13 
14     /* this is the algorithm used by MSVC, according to
15      * http://en.wikipedia.org/wiki/List_of_pseudorandom_number_generators */
16     data->random_seed = data->random_seed * 214013 + 2531011;
17     return (data->random_seed >> 16) & RAND_MAX;
18 }
19 
20 /*
21  * @implemented
22  */
23 void
24 srand(unsigned int seed)
25 {
26     thread_data_t *data = msvcrt_get_thread_data();
27     data->random_seed = seed;
28 }
29