* @return null if the current build could be cancelled cleanly, otherwise the result of stopping the daemon
     */
    @Nullable
    private DaemonStopState cancelNow() {
        CountdownTimer timer = Time.startCountdownTimer(cancelTimeoutMs);

        LOGGER.debug("Cancel requested: will wait for daemon to become idle.");
        try {
            cancellationToken.cancel();
        } catch (Exception ex) {

        // For stats we don't really care about thread safety
        private int cacheMiss;
        private int cacheHit;
        private int evict;

        private CountdownTimer cleanupTimer = Time.startCountdownTimer(MINIMAL_CLEANUP_INTERVAL);

        private static class MethodInvocationKey {
            private final SoftReference<Class<?>> lookupClass;
            private final String methodName;