From: Nicholas Nethercote <njn@valgrind.org>
Date: Fri, 8 Jul 2005 04:08:59 +0000 (+0000)
Subject: Add a simple random number generator to m_libcbase so we don't have
X-Git-Tag: svn/VALGRIND_3_0_0~188
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=91c18e835ee51b0a7fbd5932fd44ad9f0f40cb6e;p=thirdparty%2Fvalgrind.git

Add a simple random number generator to m_libcbase so we don't have
to use the one from glibc.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4130
---

diff --git a/coregrind/m_libcbase.c b/coregrind/m_libcbase.c
index 7369cb38ce..f8c4275edd 100644
--- a/coregrind/m_libcbase.c
+++ b/coregrind/m_libcbase.c
@@ -471,6 +471,21 @@ void VG_(ssort)( void* base, SizeT nmemb, SizeT size,
    #undef SORT
 }
 
+static UInt seed = 0;
+
+void VG_(srandom)(UInt s)
+{
+   seed = s;
+}
+
+// This random number generator is based on the one suggested in Kernighan
+// and Ritchie's "The C Programming Language".
+UInt VG_(random)(void)
+{
+   seed = (1103515245*seed + 12345);
+   return seed;
+}
+
 /*--------------------------------------------------------------------*/
 /*--- end                                                          ---*/
 /*--------------------------------------------------------------------*/
diff --git a/coregrind/m_skiplist.c b/coregrind/m_skiplist.c
index 796b1d39d7..f9ca188068 100644
--- a/coregrind/m_skiplist.c
+++ b/coregrind/m_skiplist.c
@@ -93,8 +93,6 @@
 #include "pub_core_mallocfree.h"
 #include "pub_core_skiplist.h"
 
-#include <stdlib.h>
-
 #define SKIPLIST_DEBUG	0
 
 #define SK_MAXHEIGHT	20	/* 2^20 elements */
@@ -121,7 +119,7 @@ static inline Int get_height(void)
 {
    UInt ret = 0;
 
-   while((ret < SK_MAXHEIGHT - 1) && (random() & 1))
+   while((ret < SK_MAXHEIGHT - 1) && (VG_(random)() & 1))
       ret++;
 
    return ret;
diff --git a/include/pub_tool_libcbase.h b/include/pub_tool_libcbase.h
index fb59b39b93..d1f7f5c1d1 100644
--- a/include/pub_tool_libcbase.h
+++ b/include/pub_tool_libcbase.h
@@ -114,6 +114,11 @@ extern void VG_(ssort)( void* base, SizeT nmemb, SizeT size,
 /* Returns the base-2 logarithm of x. */
 extern Int VG_(log2) ( Int x );
 
+// A pseudo-random number generator returning a random UInt,  and its
+// seed function.
+extern void VG_(srandom) ( UInt seed );
+extern UInt VG_(random)  ( void );
+
 #endif   // __PUB_TOOL_LIBCBASE_H
 
 /*--------------------------------------------------------------------*/