Changeset 25541 in webkit for trunk/JavaScriptCore/kjs/config.h

Timestamp:

Sep 13, 2007, 11:52:29 AM (18 years ago)

Author:

ggaren

Message:

2007-09-12 Geoff Garen <​[email protected]>

Reviewed by Sam Weinig.

Fixed <rdar://problem/5429064> 141885 Safari JavaScript: Math.random() slightly less randomly distributed than on Safari / Mac

Math.random was skewed slightly upward because it assumed that RAND_MAX was outside the range of
values that rand() might return. This problem was particularly pronounced on Windows because
the range of values returned by rand() on Windows is 2^{16 smaller than the range of values
return by rand() on Mac.}

Fixed by accounting for RAND_MAX return values. Also, switched Windows over to rand_s, which has
a range that's equal to rand()'s range on Mac.

• kjs/config.h:

• kjs/math_object.cpp: (MathFuncImp::callAsFunction): Use the new new thing.

• wtf/MathExtras.h: Platform abstraction for random numbers, to cover over differences on Windows. (wtf_random_init): (wtf_random):

File:

• trunk/JavaScriptCore/kjs/config.h (modified) (1 diff)

trunk/JavaScriptCore/kjs/config.h

@@ -46 +46 @@
 #define min min
 
+// We need to define this before the first #include of stdlib.h or it won't contain rand_s.
+#define _CRT_RAND_S
+
 #define HAVE_FLOAT_H 1
 #define HAVE_FUNC__FINITE 1