Values Misssig using Parallel Linq In C#

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Hi All,

I'm tried Parallel Linq for adding data to an object. but some of the values are missing when clicking the button multiple times. The code is

C#

BindingList<object> addnew = new BindingList<object>();
System.Threading.Tasks.Parallel.For(0, 1000, i =>
                addnew.Add(
                new object()
                )
                );
MessageBox.Show(addnew.Count.ToString());

please give a solution if any one know about this.

Posted 26-Jul-12 23:14pm

Member 9313444

Updated 27-Jul-12 0:08am

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OriginalGriff · Accepted Answer · 2012-07-27T01:19:00

If you look at the MSDN page for BindingList[^] you will see the following at teh bottom:
"Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe."

This means that the threads are interfering with each other! You need to use a lock of some form:

C#

BindingList<object> addnew = new BindingList<object>();
    System.Threading.Tasks.Parallel.For(0, 1000, i => AddOne(addnew));
    MessageBox.Show(addnew.Count.ToString());
    }
private void AddOne(BindingList<object> list)
    {
    lock (list)
        {
        list.Add(new object());
        }
    }