Question

Is it a performace cost to use a nested locks to the same object.

Say we have:

    public void AddRange(IEnumeratable<Item> items)
    {
        lock (_syncObject)
        {
            foreach (Item item in items)
            {
                InsertItem(item);
            }
        }
    }

    public void InsertItem(Item item)
    {
        lock (_syncObject)
        {
            //..
        }
    }

Is it ok to do so “the performance side”?

Thanks in advance.

Answer 1

Lock has costs, I suggest you to implement your code like this:

public void AddRange(IEnumeratable<Item> items)
{
    lock (_syncObject) // Locking only once.
    {
        foreach (Item item in items)
        {
            InsertItemImpl(item);
        }
    }
}

private void InsertItemImpl(Item item)
{
     // inserting the item
}

public void InsertItem(Item item)
{
    lock (_syncObject)
    {
        InsertItemImpl(item);
    }
}