Running two functions concurrently

Sounds like 2 tasks with a lock should do what you want:

class Program{    static void Main(string[] args)    {        var task1 = Task.Run(() => Func1());        var task2 = Task.Run(() => Func2());        Task.WaitAll(task1, task2);    }    static object lockObj = new object();    static void Func1()    {        for (int i = 0; i < 10; i++)        {            Func3("Func1");            Thread.Sleep(1);        }    }    static void Func2()    {        for (int i = 0; i < 10; i++)        {            Func3("Func2");            Thread.Sleep(1);        }    }    static void Func3(string fromFn)    {        lock(lockObj)        {            Console.WriteLine("Called from " + fromFn);        }    }}

The lock prevents the enclosed code from running in more than one thread at once. (The Sleep statements are there purely to slow the functions down for demonstration purposes - they will have no place in your final code).

Output is:

Called from Func2Called from Func1Called from Func2Called from Func1Called from Func2Called from Func1Called from Func1Called from Func2Called from Func1Called from Func2