Why doesn't ConcurrentQueue<T>.Count return 0 when IsEmpty == true?
- by DanTup - Danny Tuppeny
I was reading about the new concurrent collection classes in .NET 4 on James Michael Hare's blog, and the page talking about ConcurrentQueue<T> says:
It’s still recommended, however, that
for empty checks you call IsEmpty
instead of comparing Count to zero.
I'm curious - if there is a reason to use IsEmpty instead of comparing Count to 0, why does the class not internally check IsEmpty and return 0 before doing any of the expensive work to count?
E.g.:
public int Count
{
get
{
// Check IsEmpty so we can bail out quicker
if (this.IsEmpty)
return 0;
// Rest of "expensive" counting code
}
}
It seems strange to suggest this if it could be "fixed" so easily with no side-effects?
