Killing a Process

You might think that the way to terminate a process is to call the obvious API call, ::TerminateProcess. Wrong. Bad Move.

When you call ::TerminateProcess, the process stops. No matter what it is doing, it dies. Instantly. If it has a semaphore locked, or a mutex, or is in the middle of kernel code, or doing something else important, too bad. Boom! No more process. Imagine lots of Hollywood special effects with massive fireballs. Not a nice way to die.

A process should always have a "clean" way to be shut down. If you have hold of the handle of a process that has a window, you can send it a WM_CLOSE message via PostMessage to that window. If it is a console app, you should provide a way for it to shut down, such as detecting EOF on stdin, or receiving a particular text string. But don't use ::TerminateProcess unless you are willing to live with potentially serious consequences.