Using thread synchronization mechanisms
The thread support library from C++11 includes mutexes and condition variables that enable thread-synchronization to shared resources. A mutex allows only one thread of multiple processes to execute, while other threads that want to access a shared resource are put to sleep. Mutexes can be expensive to use in some scenarios. For this reason, the C++20 standard features several new simpler synchronization mechanisms: latches, barriers, and semaphores. Although these do not provide new use cases, they are simpler to use and can be more performant because they may internally rely on lock-free mechanisms.
At the time of writing this book, no compiler supports the C++20 thread synchronization mechanisms. Although based on the standard specifications, the sample code in this recipe could not be tested with any compiler, and we cannot guarantee their correctness.
Getting ready
The new C++20 synchronization mechanisms are defined...
