OnDone registers a callback on a context when it's done The ctx.Err() is passed as is to the callback function.

WithSignal return a context that is canceld if any of the specified signals was received.

DefaultTerminateSignals default signals to handle if not signals are provided NOTE: we use the default st here instead of ALL signals to avoid dying on signals like SIGCHLD and others that are not intend to terminate the process.

Mark defined a placeholder where multiple routines can use to synchronize their operation.