I am practicing about threads and concurrency in C# and tried to implement the basic odd-even sort algorithm using a thread for even and another for odd sorting.
static bool Sort(int startPosition, List<int> list)
{
bool result = true;
do
{
for (int i = startPosition; i <= list.Count - 2; i = i + 2)
{
if (list[i] > list[i + 1])
{
int temp = list[i];
list[i] = list[i + 1];
list[i + 1] = temp;
result = false;
}
}
} while (!result);
return result;
}
While the main method is like this:
static void Main(string[] args)
{
bool isOddSorted = false;
bool isEvenSorted = false;
List<int> list = new List<int>();
while (list.Count < 15)
{
list.Add(new Random().Next(0, 20));
}
var evenThread = new Thread(() =>
{
isEvenSorted = Sort(0, list);
});
evenThread.Start();
var oddThread = new Thread(() =>
{
isOddSorted = Sort(1, list);
});
oddThread.Start();
while (true)
{
if (isEvenSorted && isOddSorted)
{
foreach (int i in list)
{
Console.WriteLine(i);
}
break;
}
}
}
Understandably, the loop in Sort method works forever because the result variable is never set to true. However the way it works manages to sort the list. It just doesn't break at any time.
However the moment I add a "result = true" to the first line of do-scope of Sort function, the sorting messes up. 
I couldn't figure out how to fix this.
