It would be blocking by the definition used here, because the workers that  
acquired all of the threads block all other workers sharing the same pool  
 from making progress for an indefinite amount of time. The way the  
definition is constructed (not by me, but various others) is so that it  
fits nicely in the framework of progress conditions (non-blocking  
properties) below. So I definitely want to keep it. On the other hand I  
never care about names, so we can rename it.