Transaction Isolation in ADO.NET Entity Framework

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using EFTransactionExample.BindingUtilities;
using EFTransactionExample.Models;
using System.Threading;
using System.Windows;
using System.Windows.Threading;

namespace EFTransactionExample.ViewModels
{
    class MainWindowViewModel : ViewModelBase
    {
        // Thread safe locker
        static readonly object statuslocker = new object();
        static readonly object employeeInformationlocker
            = new object();

        // Private field
        int EmployeeID = 1;
        string EmployeeName = "Barack Hussein Obama II";
        int EmployeeOriginalSalary = 100;

        // Properties
        private IEnumerable<Employee> employeeInformation;
        public IEnumerable<Employee> EmployeeInformation
        {
            get { return employeeInformation; }
            private set
            {
                employeeInformation = value;
                NotifyPropertyChanged("EmployeeInformation");
            }
        }

        private void UpdateEmployeeInformation()
        {
            lock (employeeInformationlocker)
            {
                ApplicationModel model = new ApplicationModel();

                try
                {
                    EmployeeInformation = model.GetEmployeeInformation();
                }
                catch (Exception ex)
                {
                    string msg = "Unable to obtain employee information | "
                        + ex.Message;
                    UpdateStatusInformation(msg);
                }
            }
        }

        private string statusInformation;
        public string StatusInformation
        {
            get { return statusInformation; }
            private set
            {
                statusInformation = value;
                NotifyPropertyChanged("StatusInformation");
            }
        }


        private void UpdateStatusInformation(string msg)
        {
            lock (statuslocker)
            {
                StatusInformation = msg;
            }
        }

        private void InitiateViewModel()
        {
            UpdateEmployeeInformation();
        }

        // Commands
        public RelayCommand ResetSalaryCommand { get; private set; }
        private void ResetSalary()
        {
            ApplicationModel model = new ApplicationModel();
            model.SetEmployeeSalary(EmployeeID, EmployeeName, EmployeeOriginalSalary);
            EmployeeInformation = model.GetEmployeeInformation();
            UpdateStatusInformation("Reset employee salary completed ..");
        }

        public RelayCommand RaisetSalaryNonSerializedCommand { get; private set; }
        private void RaisetSalaryNonSerialized()
        {
            System.Threading.Thread
                CPOThread = new System.Threading.Thread(
                new System.Threading.ParameterizedThreadStart(WorkerNonSerialized));
            CPOThread.Name = "CPO Thread";

            System.Threading.Thread
                CEOThread = new System.Threading.Thread(
                new System.Threading.ParameterizedThreadStart(WorkerNonSerialized));
            CEOThread.Name = "CEO Thread";

            CPOThread.Start(new object[3] { 1, 50, 0 });
            CEOThread.Start(new object[3] { 1, 50, 2500 });
        }

        private void WorkerNonSerialized(object parameters)
        {
            object[] parameterArray
                = (object[])parameters;
            int employeeID = (int)parameterArray[0];
            int amount = (int)parameterArray[1];
            int sleepBeforeStart = (int)parameterArray[2];

            Thread.Sleep(sleepBeforeStart);
            UpdateStatusInformation(Thread.CurrentThread.Name + " Started ..");
            try
            {
                ApplicationModel model = new ApplicationModel();
                model.RaiseEmployeeSalaryNonSerialized(employeeID, amount);
                EmployeeInformation = model.GetEmployeeInformation();
            }
            catch (Exception ex)
            {
                string msg = "Unable to raise the salary for the employee | "
                    + ex.Message;
                UpdateStatusInformation(msg);
                return;
            }

            UpdateEmployeeInformation();
            UpdateStatusInformation(Thread.CurrentThread.Name + " Finished ..");
        }

        public RelayCommand RaisetSalarySerializedCommand { get; private set; }
        private void RaisetSalarySerialized()
        {
            System.Threading.Thread
                CPOThread = new System.Threading.Thread(
                new System.Threading.ParameterizedThreadStart(WorkerSerialized));
            CPOThread.Name = "CPO Thread";

            System.Threading.Thread
                CEOThread = new System.Threading.Thread(
                new System.Threading.ParameterizedThreadStart(WorkerSerialized));
            CEOThread.Name = "CEO Thread";

            CPOThread.Start(new object[3] { 1, 50, 0 });
            CEOThread.Start(new object[3] { 1, 50, 2500 });
        }

        private void WorkerSerialized(object parameters)
        {
            object[] parameterArray
                = (object[])parameters;
            int employeeID = (int)parameterArray[0];
            int amount = (int)parameterArray[1];
            int sleepBeforeStart = (int)parameterArray[2];

            Thread.Sleep(sleepBeforeStart);

            UpdateStatusInformation(Thread.CurrentThread.Name + " Started ..");

            int NoOfTries = 0;
            ApplicationModel model = new ApplicationModel();
            try
            {
                model.RaiseEmployeeSalarySerialized(employeeID, amount);
            }
            catch (Exception ex)
            {
                NoOfTries++;

                if (NoOfTries < 3)
                {
                    string msg = Thread.CurrentThread.Name
                        + " Failed to update the salary for the employ, re-trying ...";
                    UpdateStatusInformation(msg);
                }
                else
                {
                    string msg = "Unable to raise the salary for the employee" +
                        ", we have tried 3 times | " + ex.Message;
                    UpdateStatusInformation(msg);
                    return;
                }

                model.RaiseEmployeeSalarySerialized(employeeID, amount);
            }

            UpdateEmployeeInformation();
            UpdateStatusInformation(Thread.CurrentThread.Name + " Finished ..");
        }

        private void WireCommands()
        {
            ResetSalaryCommand = new RelayCommand(ResetSalary);
            ResetSalaryCommand.IsEnabled = true;

            RaisetSalaryNonSerializedCommand
                = new RelayCommand(RaisetSalaryNonSerialized);
            RaisetSalaryNonSerializedCommand.IsEnabled = true;

            RaisetSalarySerializedCommand
                = new RelayCommand(RaisetSalarySerialized);
            RaisetSalarySerializedCommand.IsEnabled = true;
        }

        public MainWindowViewModel()
        {
            InitiateViewModel();
            WireCommands();
        }
    }
}