A word of caution when using any kind of locking is that you should carefully design and code to prevent the dreaded deadlock scenarios that could arise (more on this in the next chapter in the The lock validator lockdep – catch locking issues early section).
Aside from deadlocks, there is another risky scenario that arises when using the mutex: that of priority inversion (again, we will not delve into the details in this book). Suffice it to say that the unbounded priority inversion case can be a deadly one; the end result is that the product's high(est) priority thread is kept off the CPU for too long.
As I covered in some detail in my earlier book, Hands-on System Programming with Linux, it's precisely this priority inversion issue that struck NASA's Mars Pathfinder robot, on the Martian surface no less, back in July 1997! See the Further reading section of this chapter for&...
