Safety first
The central problem with concurrency is that of ensuring safe access to shared resources even when communicating between threads. There is also the issue of threads being able to communicate and synchronize themselves.
What makes multithreaded programming such a challenge is to be able to keep track of each interaction between threads, and to ensure that each and every form of access is secured while not falling into the trap of deadlocks and data races.
In this chapter, we will look at a fairly complex example involving a task scheduler. This is a form of high-concurrency, high-throughput situation where many different requirements come together with many potential traps, as we will see in a moment.
