close() — netty Function Reference

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2Connection.java lines 118–168

    @Override
    public Future<Void> close(final Promise<Void> promise) {
        checkNotNull(promise, "promise");
        // Since we allow this method to be called multiple times, we must make sure that all the promises are notified
        // when all streams are removed and the close operation completes.
        if (closePromise != null) {
            if (closePromise == promise) {
                // Do nothing
            } else if (promise instanceof ChannelPromise && ((ChannelFuture) closePromise).isVoid()) {
                closePromise = promise;
            } else {
                PromiseNotifier.cascade(closePromise, promise);
            }
        } else {
            closePromise = promise;
        }
        if (isStreamMapEmpty()) {
            promise.trySuccess(null);
            return promise;
        }

        Iterator<PrimitiveEntry<Http2Stream>> itr = streamMap.entries().iterator();
        // We must take care while iterating the streamMap as to not modify while iterating in case there are other code
        // paths iterating over the active streams.
        if (activeStreams.allowModifications()) {
            activeStreams.incrementPendingIterations();
            try {
                while (itr.hasNext()) {
                    DefaultStream stream = (DefaultStream) itr.next().value();
                    if (stream.id() != CONNECTION_STREAM_ID) {
                        // If modifications of the activeStream map is allowed, then a stream close operation will also
                        // modify the streamMap. Pass the iterator in so that remove will be called to prevent
                        // concurrent modification exceptions.
                        stream.close(itr);
                    }
                }
            } finally {
                activeStreams.decrementPendingIterations();
            }
        } else {
            while (itr.hasNext()) {
                Http2Stream stream = itr.next().value();
                if (stream.id() != CONNECTION_STREAM_ID) {
                    // We are not allowed to make modifications, so the close calls will be executed after this
                    // iteration completes.
                    stream.close();
                }
            }
        }
        return closePromise;
    }