Approach the problem this way:   the event just means, “you should not be asleep right now.”   (Not “please wake up.”)   The main-loop of the thread is driven by a set of shared flags which tell it what it should do next, one of the choices being “die now.”

while (1) {
  if (shared.die) {
    exit;
  } 
  elsif (shared.do_this) {
    do_this;
  }
  elsif (shared.do_that) {
    do_that;
  }
  ...
  else {
     wait_for_event();
  }
}
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The parent thread first sets one of the flags, then strobes the event to be sure that the child is not-asleep to respond to it.

You don’t need to invent these things from scratch.   Look at existing workhorses such as POE.