path: root/include
diff options
authorache <>2013-07-03 21:21:54 +0000
committerache <>2013-07-03 21:21:54 +0000
commit295fb8ce1a43fcd088b63b8b28a6b34191a4faab (patch)
tree1741a11f1eb25d7ff1fecb14fab8e90d942fec2b /include
parent9256efca5e1c834cea4f307b2f9a54f095eb1753 (diff)
1) POSIX requires rand(3) return values to be in the [0, RAND_MAX] range,
but ACM formula we use have internal state (and return value) in the [1, 0x7ffffffe] range, so our RAND_MAX (0x7fffffff) is never reached because it is off by one, zero is not reached too. Correct both RAND_MAX and rand(3) return value, shifting last one to the 0 by 1 subtracted, resulting POSIXed [0, 0x7ffffffd(=new RAND_MAX)] range. 2) Add a checks for not overflowing on too big seeds. It may happens on the machines, where sizeof(unsigned int) > 32 bits. Reviewed by: bde [1] MFC after: 2 weeks
Diffstat (limited to 'include')
1 files changed, 1 insertions, 1 deletions
diff --git a/include/stdlib.h b/include/stdlib.h
index b73a54f..cc92273 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -69,7 +69,7 @@ typedef struct {
#define EXIT_FAILURE 1
#define EXIT_SUCCESS 0
-#define RAND_MAX 0x7fffffff
+#define RAND_MAX 0x7ffffffd
#ifdef _XLOCALE_H_
OpenPOWER on IntegriCloud