From 5dc0189a160a9ab4d6c9c2865fc8ff5d7ca32d69 Mon Sep 17 00:00:00 2001
From: Mattes D <github@xoft.cz>
Date: Tue, 28 Mar 2017 16:37:25 +0200
Subject: FastRandom: Added test of class re-creation. (#3648)

Tests for the precondition of #2935 (re-created cFastRandom generates the same sequence of numbers).
---
 tests/FastRandom/FastRandomTest.cpp | 62 ++++++++++++++++++++++++++++++++-----
 1 file changed, 55 insertions(+), 7 deletions(-)

diff --git a/tests/FastRandom/FastRandomTest.cpp b/tests/FastRandom/FastRandomTest.cpp
index e7729382d..9ab775936 100644
--- a/tests/FastRandom/FastRandomTest.cpp
+++ b/tests/FastRandom/FastRandomTest.cpp
@@ -7,6 +7,9 @@
 #include "FastRandom.h"
 
 
+
+
+
 static void TestInts(void)
 {
 	cFastRandom rnd;
@@ -24,14 +27,17 @@ static void TestInts(void)
 		sum += v;
 	}
 	double avg = static_cast<double>(sum) / ITER;
-	printf("avg: %f\n", avg);
+	LOG("avg: %f", avg);
 	for (int i = 0; i < BUCKETS; i++)
 	{
-		printf("  bucket %d: %d\n", i, Counts[i]);
+		LOG("  bucket %d: %d", i, Counts[i]);
 	}
 }
 
 
+
+
+
 static void TestFloats(void)
 {
 	cFastRandom rnd;
@@ -49,23 +55,65 @@ static void TestFloats(void)
 		sum += v;
 	}
 	sum = sum / ITER;
-	printf("avg: %f\n", sum);
+	LOG("avg: %f", sum);
 	for (int i = 0; i < BUCKETS; i++)
 	{
-		printf("  bucket %d: %d\n", i, Counts[i]);
+		LOG("  bucket %d: %d", i, Counts[i]);
+	}
+}
+
+
+
+
+
+/** Checks whether re-creating the cFastRandom class produces the same initial number over and over (#2935) */
+static void TestReCreation(void)
+{
+	const int ITER = 10000;
+	int lastVal = 0;
+	int numSame = 0;
+	int maxNumSame = 0;
+	for (int i = 0; i < ITER; ++i)
+	{
+		cFastRandom rnd;
+		int val = rnd.NextInt(10);
+		if (val == lastVal)
+		{
+			numSame += 1;
+		}
+		else
+		{
+			if (numSame > maxNumSame)
+			{
+				maxNumSame = numSame;
+			}
+			numSame = 0;
+			lastVal = val;
+		}
 	}
+	if (numSame > maxNumSame)
+	{
+		maxNumSame = numSame;
+	}
+	LOG("Out of %d creations, there was a chain of at most %d same numbers generated.", ITER, maxNumSame);
 }
 
 
+
+
+
 int main(void)
 {
-	LOGD("FastRandom Test started");
+	LOG("FastRandom Test started");
 
-	LOGD("Testing ints");
+	LOG("Testing ints");
 	TestInts();
 
-	LOGD("Testing floats");
+	LOG("Testing floats");
 	TestFloats();
 
+	LOG("Testing re-creation");
+	TestReCreation();
+
 	LOG("FastRandom test finished");
 }
-- 
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