windows - CreateThread vs fork()

Question

Do we have any sort of relationship between fork() and CreateThread? Is there anything that CreateThread internally calls fork()?

Answer 1

In NT, the fundamental working unit is called a thread (ie NT schedules threads, not processes.). User threads run in the context of a process. When you call CreateThread, you request the NT kernel to allocate a working unit within the context of your process (you also have fibres that are basically threads you can schedule yourself but that's beyond the topic of your question).

When you call CreateThread you provide the function with an entry point that is going to be run after the function is called. The code must be within the virtual space of the process and the page must have execution rights. Put simply, you give a function pointer. ;)

fork() is an UNIX function that requests the kernel to create copy of the running process. The parent process gets the pid of the child process and the child process gets 0 (this way you know who you are).

If you wish to create a process in Windows, you call the CreateProcess function, but that doesn't behave like fork(). The reason being that most of the time you will create threads, not processes.

As you can see, there is no relation between CreateThread and fork.