People keep reinventing those and thread pools over and over in C++. I've been researching one of our older systems (slated for decommissioning in 2021, as is t

People keep reinventing those and thread pools over and over in C++. I've been researching one of our older systems (slated for decommissioning in 2021, as is typical that did not happen). In trying to understand it I have found many areas of concern around how they deal with concurrency, in particular they created their own queue and thread pool. Based on past experience, there's 50/50 chance for each that they were created correctly (with proper concurrency controls), and less than that that the tasks submitted to the thread pool themselves make use of proper concurrency controls rather than assuming that they can read/write whatever they want as if the system were single-threaded.