When to start debugging

Ideally, one would test and validate one's code every time one has reached a certain milestone, whether it's for a singular module, a number of modules, or the application as a whole. It's important to ascertain that the assumptions one makes match up with the ultimate functionality.

Especially, with multithreaded code, there's a large element of coincidence in that a particular error state is not guaranteed to be reached during each run of the application. Signs of an improperly implemented multithreaded application may result in symptoms such as seemingly random crashes.

Likely the first hint one will get that something isn't correct is when the application crashes, and one is left with a core dump. This is a file which contains the memory content of the application at the time when it crashed, including the stack.

This core dump can be used in almost the same fashion as running a debugger with the running process. It is particularly useful to examine the location...