// the listener.
    executeListener(listener, executor);
  }

  /**
   * Sets the result of this {@code Future} unless this {@code Future} has already been cancelled or
   * set (including {@linkplain #setFuture set asynchronously}). When a call to this method returns,
   * the {@code Future} is guaranteed to be {@linkplain #isDone done} <b>only if</b> the call was

      for (; ; ) {
        boolean done = true;
        for (int i = 0; i < aa.length(); i++) {
          double v = aa.get(i);
          assertTrue(v >= 0);
          if (v != 0) {
            done = false;
            if (aa.compareAndSet(i, v, v - 1.0)) {
              ++counts;
            }
          }
        }
        if (done) {
          break;
        }
      }
    }

   * expect, but there are some subtleties. First, we do guarantee that, if the output future at
   * index n is done, the output future at index n-1 is also done. (But as usual with futures, some
   * listeners for future n may complete before some for future n-1.) However, it is possible, if
   * one input completes with result X and another later with result Y, for Y to come before X in

	req := updateRequest{
		Update: data,
		Fd:     fd,
		Resp:   ret,
	}
	select {
	case z.Updates <- req:
	case <-ctx.Done():
		return nil, ctx.Err()
	}

	select {
	case r := <-ret:
		return r.resp, r.err
	case <-ctx.Done():
		return nil, ctx.Err()
	}
}

    String SELF_COMBINATION_REMOVE = "remove";

    /**
     * In case of complex XML structures, combining can be done based on id.
     */
    String ID_COMBINATION_MODE_ATTRIBUTE = "combine.id";

    /**
     * In case of complex XML structures, combining can be done based on keys.
     * This is a comma separated list of attribute names.
     */
    String KEYS_COMBINATION_MODE_ATTRIBUTE = "combine.keys";

until curl --output /dev/null --silent --head --fail "$ISTIO_ENVOY_RELEASE_URL"; do
    printf '.'
    sleep $SLEEP_TIME
done
printf '\n'

printf "Verifying %s is available\n" "$ISTIO_ENVOY_ARM_RELEASE_URL"
until curl --output /dev/null --silent --head --fail "$ISTIO_ENVOY_ARM_RELEASE_URL"; do
    printf '.'
    sleep $SLEEP_TIME
done
printf '\n'

# Update the dependency in istio.deps

	h.store = queueStore
	h.storeCtxCancel = cancel
	store.StreamItems(h.store, h, ctx.Done(), h.kconfig.LogOnce)
	return
}

func (h *Target) startKafkaLogger() {
	h.logChMu.RLock()
	logCh := h.logCh
	if logCh != nil {
		// We are not allowed to add when logCh is nil
		h.wg.Add(1)
		defer h.wg.Done()

	}
	h.logChMu.RUnlock()

	if logCh == nil {
		return
	}

</p>

<pre>
var a string
var done bool

func setup() {
	a = "hello, world"
	done = true
}

func doprint() {
	if !done {
		once.Do(setup)
	}
	print(a)
}

func twoprint() {
	go doprint()
	go doprint()
}
</pre>

<p>
but there is no guarantee that, in <code>doprint</code>, observing the write to <code>done</code>

	if err != nil {
		return fmt.Errorf("failed to create CNI listener: %v", err)
	}
	go func() {
		err := s.cniListenServer.Serve(unixListener)

		select {
		case <-s.ctx.Done():
			// ctx done, we should silently go away
			return
		default:
			// If the cniListener exits, at least we should record an error log
			log.Errorf("CNI listener server exiting unexpectedly: %v", err)
		}
	}()

    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'b');

    // Iterate again to see if calculation is done again
    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'a', 'b', 'b');
  }

  @Test