Process life cycle

The creation of a new process can happen in two different ways:

• Using a fork: This duplicates the calling process. The child (new process) is an exact copy (memory) of the parent (calling process), except for the following:
  • PIDs are different.
  • The PPID of the child equals the PID of the parent.
  • The child does not inherit the following from the parent:
    • Memory locks
    • Semaphore adjustments
    • Outstanding asynchronous I/O operations
    • Asynchronous I/O contexts
• Using an exec: This replaces the current process image with a new one, loading the program into the current process space and running it from its entry point.