title: Mutexes and thread priorities with regards to scheduling on POSIX systems
body: <p>In POSIX systems (linux etc), when multiple threads lock a common mutex - is it the locking order that is <em><strong>always</strong></em> observed, or does thread priority bias threads of higher priority when it comes scheduling the next thread in the critical section?</p>
  
  <p>Does the standard mention anything about the behavior? because as far as I can see it only seems to mention the required interface.</p>
  
  <p>Please note, I'm looking of guidance on any POSIX conformant system (not just linux), so feel free to suggest the behavior of other OSes (QNX, Minix etc..)</p>