EV_UNDEF

guaranteed to be invalid

no events

ev_io detected read will not block

ev_io detected write will not block

internal use only

alias for type-detection

periodic timer timed out

signal was received

child/pid had status change

stat data changed

event loop is idling

event loop about to poll

event loop finished poll

embedded event loop needs sweep

event loop resumed in child

async intra-loop signal

for use by user code

sent when an error occurs