Multiprocessing Wrap

• Today's Agenda
  • I need to discuss how one can install a SIGCHLD handler to asynchronously monitor how child processes return, crash, stop, and restart. In particular, I need to work through these three programs.
  • I still need to work through the synchronization examples I didn't get to on Wednesday either.
    • Buggy program is here.
    • Fixed program, which relies on signals masks, is right here.
  • I want to introduce the kill system call, which allows one process to send an arbitrary signal to another.
    • The function is pretty easy to understand, but I want to work through a short programming puzzle just to make sure.
    • That programming puzzle was almost posted last Wednesday, and it can be found right here.
  • I want to give you some high-level sense as to how the OS supports multiprocessing so that each process can operate as if it owns all of its 4GB (or 256TB, in a 64-bit world) virtual address space. This part is all concept and whiteboard illustrations, but there's no code.
  • I also want you to understand how the scheduler can round-robin through all of the active processes so that each of them gets enough processor time to make progress. Again, all concept and whiteboard drawings, but no code.