Signal handling

types:

• hardware-induced (e.g SIGILL)
• software-induced (e.g SIGQUIT, SIGPIPE)

actions (responses):

• Term (terminate), Ign (ignore), Core (terminate execution & OS core dump), Stop (stop execution, freeze process), Cont (continue, unfreeze processs)
• Default action on per-signal basis, which is typically overridable (but some aren’t, like SIGKILL)
• signals can typically be blocked and actions delayed (but again, some exceptions)

catching signals:

• process registers signal handler
• OS delivers signal, allows process to run handler
• current execution context has to be saved/restored

diagram example: