WriteTimeoutTask Class — netty Architecture

Source Code

handler/src/main/java/io/netty/handler/timeout/WriteTimeoutHandler.java lines 186–235

    private final class WriteTimeoutTask implements Runnable, ChannelFutureListener {

        private final ChannelHandlerContext ctx;
        private final ChannelPromise promise;

        // WriteTimeoutTask is also a node of a doubly-linked list
        WriteTimeoutTask prev;
        WriteTimeoutTask next;

        Future<?> scheduledFuture;

        WriteTimeoutTask(ChannelHandlerContext ctx, ChannelPromise promise) {
            this.ctx = ctx;
            this.promise = promise;
        }

        @Override
        public void run() {
            // Was not written yet so issue a write timeout
            // The promise itself will be failed with a ClosedChannelException once the close() was issued
            // See https://github.com/netty/netty/issues/2159
            if (!promise.isDone()) {
                try {
                    writeTimedOut(ctx);
                } catch (Throwable t) {
                    ctx.fireExceptionCaught(t);
                }
            }
            removeWriteTimeoutTask(this);
        }

        @Override
        public void operationComplete(ChannelFuture future) throws Exception {
            // scheduledFuture has already be set when reaching here
            scheduledFuture.cancel(false);

            // Check if its safe to modify the "doubly-linked-list" that we maintain. If its not we will schedule the
            // modification so its picked up by the executor..
            if (ctx.executor().inEventLoop()) {
                removeWriteTimeoutTask(this);
            } else {
                // So let's just pass outself to the executor which will then take care of remove this task
                // from the doubly-linked list. Schedule ourself is fine as the promise itself is done.
                //
                // This fixes https://github.com/netty/netty/issues/11053
                assert promise.isDone();
                ctx.executor().execute(this);
            }
        }
    }