Home / cs-notes / Architecture / Components / Netty / Channel / AbstractNioChannel / AbstractNioUnsafe / forceFlush

        @Override
        protected final void flush0() {
            // Flush immediately only when there's no pending flush.
            // If there's a pending flush operation, event loop will call forceFlush() later,
            // and thus there's no need to call it now.
            if (!isFlushPending()) {
                super.flush0();
            }
        }

        @Override
        public final void forceFlush() {
            // directly call super.flush0() to force a flush now
            super.flush0();
        }

        private boolean isFlushPending() {
            SelectionKey selectionKey = selectionKey();
            return selectionKey.isValid() && (selectionKey.interestOps() & SelectionKey.OP_WRITE) != 0;
        }