From: Charley Wang <chwang@redhat.com>
Date: Wed, 23 Sep 2009 18:00:33 +0000 (-0400)
Subject: PR1062: runtime function
X-Git-Tag: release-1.0.9~181^2~4
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=dc0c46f5f74a9e0468236b31c8d9364eb24c3624;p=systemtap.git

PR1062: runtime function

* arith.c (_stp_random_pm_u): New function.
---

diff --git a/runtime/arith.c b/runtime/arith.c
index d1d0da29b..4b0e6c9e7 100644
--- a/runtime/arith.c
+++ b/runtime/arith.c
@@ -106,6 +106,28 @@ static int _stp_random_pm (int n)
 #endif /* _STP_TEST_ */
 
 
+#ifndef _STP_TEST_
+/** Return a random integer between 0 and n - 1.
+ * @param n how far from zero to go.  Make it positive but less than a million or so.
+ */
+static int _stp_random_pm_u (int n)
+{
+	static unsigned long seed;
+	static int initialized_p = 0;
+
+	if (unlikely (! initialized_p)) {
+		seed = (unsigned long) jiffies;
+		initialized_p = 1;
+	}
+
+	/* from glibc rand man page */
+	seed = seed * 1103515245 + 12345;
+
+	return (seed % n);
+}
+#endif /* _STP_TEST_ */
+
+
 #if defined (__i386__) || defined (__arm__)
 
 /* 64-bit division functions extracted from libgcc */