Mastering the C++17 STL

"Taking locks" the right way

Recall from Chapter 6, Smart Pointers, that one of the major problems of programs written in C and "old-style" C++ is the presence of pointer bugs--memory leaks, double-frees, and heap corruption--and that the way we eliminate those bugs from "new-style" C++ programs is via the use of RAII types such as std::unique_ptr<T>. Multi-threaded programming with raw mutexes have failure modes that are analogous to the failure modes of heap programming with raw pointers:

• Lock leaks: You might take a lock on a particular mutex, and accidentally forget to write the code that frees it.
• Lock leaks: You might have written that code, but due to an early return or an exception being thrown, the code never runs and the mutex ...