@Override
        boolean completedQuietPeriod() {
            if (shutdownStartTimeNanos == 0) {
                shutdownStartTimeNanos = readTicker();
            }

            if (pendingResponses() != 0 || !completedBlockingTasks()) {
                return false;
            }

            final long shutdownStartTimeNanos = this.shutdownStartTimeNanos;
            final long currentTimeNanos = ticker.read();
            final long durationNanos;
            if (lastResTimeNanos != 0) {
                durationNanos = Math.min(currentTimeNanos - shutdownStartTimeNanos,
                                         currentTimeNanos - lastResTimeNanos);
            } else {
                durationNanos = currentTimeNanos - shutdownStartTimeNanos;
            }

            return durationNanos >= quietPeriodNanos;
        }
Declared as non-volatile because using {@link #pendingResponses} as a memory barrier.
core/src/main/java/com/linecorp/armeria/server/GracefulShutdownSupport.java