One of the key reasons that multithreading is powerful and makes a big impact performance-wise is that it lends itself to the notion of parallelism or concurrency; from what we learned in the previous Chapter 14, Multithreading with Pthreads Part I - Essentials, we understand that multiple threads of a process can (and indeed do) execute in parallel. On large multicore systems (multicore is pretty much the norm now, even in embedded systems), the effect is magnified.
However, as experience teaches us, there's always a trade-off. With parallelism comes the ugly potential for races and the subsequent defects. Not only that, situations like this typically become extremely hard to debug, ...
