This is very much the model of Win32. Everything thatbexists at least partially in the kernel is exposed as a handle. There are a lot of different types of handles, but all of them can have CloseHandle called on them (maybe there are exceptions? I don't know). Most of them can be used with calls like WaitForSingleObject or WaitForMultipleObjects. So in a way, Windows implements exactly that model.
File descriptors and Windows handles are pretty much the same concept. Just that the former is an int, and the latter is packed into a pointer typedef. Your WaitForMultipleObjects example is not radically different from the poll family of syscalls. (Although there aren't named mutex file descriptors and the like... But Linux has some concepts that remind me of Win32 handle types, such as eventfd(2)).
