Checks if the state of an element is locked.
If the state of an element is locked, state changes of the parent don't
affect the element.
This way you can leave currently unused elements inside bins. Just lock their
state before changing the state from GST_STATE_NULL
Checks if the state of an element is locked. If the state of an element is locked, state changes of the parent don't affect the element. This way you can leave currently unused elements inside bins. Just lock their state before changing the state from GST_STATE_NULL
MT safe.