How do I safely lock this property?

Question

I have partial C# code for a blocking queue that looks like this:

private bool flushed;
private object _locker = new object();

public bool Flushed
{
    get { lock (_locker) { return flushed; } }
    set
    {
        lock (_locker)
        {
            flushed = value;
            Monitor.Pulse(queue);
        }
    }
}

The Monitor.Pulse method has a Monitor.Wait counterpart in the Dequeue() method of the blocking queue.

I want to add a method that signals end of data, which checks for the Flush condition. It will look something like this:

public bool EndOfData
{
    get { lock (_locker) { return Flushed && (queue.Count == 0); } }
}

Here is my question. Should I call the Flushed property as shown in the code above (taking a nested lock), or is it sufficient to refer to the private member variable flushed directly, as shown below, using only a single lock?

public bool EndOfData
{
    get { lock (_locker) { return flushed && (queue.Count == 0); } }
}

@Mitch: So the only reason to use `Flush` would be to insulate my code from potential logical changes to the `Flush` property itself? — Robert Harvey, Aug 06 '11 at 03:35

score 2 · Accepted Answer · answered Aug 06 '11 at 03:34

2

I don't think it makes a difference, personally I would use the nested version. I think if anything changes in the actual property by using it, Flushed, you ensure that everything is good to go.

But I truly believe this is a preference call.

answered Aug 06 '11 at 03:34

JonH

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How do I safely lock this property?

1 Answers1