What does it actually mean in windows when the cursor turns into an hourglass?

Question

We're all familiar with the little hourglass mouse on our pcs, but what does it mean when:

• There's an hourglass next to the pointer
• the pointer disappears and there's just an hourglass, locking out all clicks

Obviously it shows that you computer's busy, but it doesn't seem to be directly correlated with cpu usage or ram. Does it have to do with the current application? How does windows judge that its busy enough to halt all clicks by the user?

Answer 1

I think the hourglass whitout pointer says that you have to wait, the hourglass with pointer are background actions where you can resume working.

Answer 2

It depends on the application, although windows may display a busy cursor for background tasks that it is running. When I write a program there are certain actions, such as when I open a new window that I include a specific instruction to display the busy cursor. Windows then displays the hourglass over my application window until I send another instruction to display the default cursor. The clicks do register, but because the application is busy in code it may not catch them, or it may catch them after running whatever code it was running, and then unpredictable things happen.

the pseudo code would be something like:

cursor = curors.wait;
... do something
cursor = cursors.default;