Obvious deadlock - How do i fix this appropriately

class Program
    {
        static void Main(string[] args)
        {
            Thread thread1 = new Thread((ThreadStart)D开发者_运维百科LockSample.FunctionA);
            Thread therad2 = new Thread((ThreadStart)DLockSample.FunctionB);
            thread1.Start();
            therad2.Start();
        }
    }

    public class DLockSample
    {
static object object1 = new object();
        static object object2 = new object();

        public static void FunctionA()
        {
            lock (object1)
            {
                Thread.Sleep(1000);
                lock (object2)
                {
                    Thread.Sleep(1000);
                    Console.WriteLine("heart beat - object2");
                }
            }
        }
        public static void FunctionB()
        {
            lock (object2)
            {

                lock (object1)
                {
                    Thread.Sleep(1000);
                    Console.WriteLine("heart beat - object1");
                }
            }
        }    }

Always enter the locks in the same order in all threads. See also hierarchy of critical sections I.e. FunctionB needs to be:

public static void FunctionB()
        {
            lock (object1)
            {

                lock (object2)
    ...

That's a pretty abstact problem to fix. Just a few tips:

• Always lock on objects in the same order
• If it's impossible to lock in the same order, use object's fields to preserve the order (for example, if A.Id > B.Id then always lock on A before B).