Process Termination

• A process enters the exiting state for one of the following reasons:
  • normal completion: Once a process executes its final instruction, a call to exit() is made.
  • abnormal termination: programming errors.
  • run time.
  • I/O.
  • user intervention.
• Even if the user did not program in a call to exit(), the compiler will have appended one to int main()
  • The final result of the process from its int main() is returned to the parent, with a call to wait() if necessary.
  • Process' resources are deallocated by operating system.
• Parent may terminate execution of children processes (abort)
  • Child has exceeded allocated resources.
  • Task assigned to child is no longer required.
  • Parent is exiting
    • Operating system does not allow child to continue if its parent terminates.
    • Cascading termination.