[Pharo-dev] Thread pre-emption semantics

I have a general idea of thread pre-emption semantics, but just trying to pin it down for some documentation. I found reference that thread context switches can only happen on: * backward branches * activation of non-primitive sends but I believe also that context switches can't occur between inlined message send like ifNil:ifNotNil: ? Are there any other I missed? cheers -ben