How to detect deadlock in c# application

raghav_khunger

Hi,

I am trying to detect deadlock in my console exe via ANTS performance profiler but I am unable to find any information on how to do that:

Here is the code for console exe:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace DeadLockSimulator
{
    class Program
    {
        private static object staticObjLockA = new Object();
        private static object staticObjLockB = new Object();

        public static void Main()
        {
            // Initialize thread with address of DoWork1
            Thread thread1 = new Thread(DoWork1);

            // Initilaize thread with address of DoWork2
            Thread thread2 = new Thread(DoWork2);

            // Start the Threads.
            thread1.Start();
            thread2.Start();

            thread1.Join();
            thread2.Join();

            // This statement will never be executed.
            Console.WriteLine("Done Processing...");
        }

        private static void DoWork1()
        {
            lock (staticObjLockA)
            {
                Console.WriteLine("Trying to acquire lock on staticObjLockB");

                // Sleep to yield.
                Thread.Sleep(1000);
                lock (staticObjLockB)
                {
                    // This block will never be executed.
                    Console.WriteLine("In DoWork1 Critical Section.");
                    // Access some shared resource here.
                }
            }
        }

        private static void DoWork2()
        {
            lock (staticObjLockB)
            {
                Console.WriteLine("Trying to acquire lock on staticObjLockA");
                lock (staticObjLockA)
                {
                    // This block will never be executed.
                    Console.WriteLine("In DoWork2 Critical Section.");
                    // Access some shared resource here.
                }
            }
        }

    }
}

Attached is the output for that exe:




As you can notice the following piece of code is never executed because of a deadlock scenario:

Console.WriteLine("In DoWork1 Critical Section.");

Can you share some information on how to detect a deadlock scenario with your software?

Jessica R

Hi and thanks for your post!

I'm afraid the profiler isn't really meant to help pinpoint deadlocks so it won't automatically detect anything. Some ways it may help though:

- If there are actual errors occurring, you can check the stack trace leading up to the error
- If you take a look at the line-level timings you may be able to get an idea of where things locked up because there won't be timings for the lines of code that haven't been able to execute.
- You can take a look at the call tree/methods grid for individual threads which may shed some light on where things are going wrong.