[greatlrd] 23799: Implement RtlRandomEx by copy RtlRandom code. ms have two different implement, One random is faster that other, (in some doc I read (maybe from osr) some year ago), the RtlRandomEx is not document in the free ddk/sdk, but it is include in ddk/ifs kit, according the doc.

Author: greatlrd
Date: Wed Aug 30 14:13:01 2006
New Revision: 23799

URL: http://svn.reactos.org/svn/reactos?rev=23799&view=rev
Log:
Implement RtlRandomEx by copy RtlRandom code. 
ms have two different implement, One random is faster that other, (in some doc I read (maybe from osr) some year ago),  the RtlRandomEx  is not document in the free ddk/sdk, but it is include in ddk/ifs kit, according the doc.

Modified:
    trunk/reactos/lib/rtl/random.c

Modified: trunk/reactos/lib/rtl/random.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/rtl/random.c?rev=23799&...
==============================================================================
--- trunk/reactos/lib/rtl/random.c (original)
+++ trunk/reactos/lib/rtl/random.c Wed Aug 30 14:13:01 2006
@@ -83,16 +83,26 @@
 }

/*
-* @unimplemented
+* @implemented
 */
 ULONG
 NTAPI
-RtlRandomEx(
-	PULONG Seed
+RtlRandomEx( IN OUT PULONG Seed
    )
 {
-	UNIMPLEMENTED;
-	return 0;
+   ULONG Rand;
+   int Pos;
+   ULONG Result;
+
+   PAGED_CODE_RTL();
+
+   Rand = (*Seed * 0x7fffffed + 0x7fffffc3) % 0x7fffffff;
+   *Seed = (Rand * 0x7fffffed + 0x7fffffc3) % 0x7fffffff;
+   Pos = *Seed & 0x7f;
+   Result = SavedValue[Pos];
+   SavedValue[Pos] = Rand;
+
+   return Result;
 }