When debugging multi-threaded apps, sometimes I get a hang when breakpoint is hit. And sometimes VS would hang (hourglass) when I tried to look at a variable by right-clicking on the variable within the code.
I googled and found a hint that explained, that when VS breaks, it evaluates all the variables in the locals and watch panes, in order to display them. But in threaded apps, this can cause deadlocks if the code takes locks when evaluating values, for example in property getters.
By closing the locals pane before I break, I avoided the hangs.
I'm not explaining this very well. I tried googling again to find the original hint, but did not succeed.
It may have been this: Why does Visual Studio stall while debugging?.