writabilityOfParentIsRespected() — netty Function Reference

Source Code

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexTest.java lines 1109–1158

    @Test
    public void writabilityOfParentIsRespected() {
        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter());
        childChannel.config().setWriteBufferWaterMark(new WriteBufferWaterMark(2048, 4096));
        parentChannel.config().setWriteBufferWaterMark(new WriteBufferWaterMark(256, 512));
        assertTrue(childChannel.isWritable());
        assertTrue(parentChannel.isActive());

        childChannel.writeAndFlush(new DefaultHttp2HeadersFrame(new DefaultHttp2Headers()));
        parentChannel.flush();

        assertTrue(childChannel.isWritable());
        childChannel.write(new DefaultHttp2DataFrame(Unpooled.buffer().writeZero(256)));
        assertTrue(childChannel.isWritable());
        childChannel.writeAndFlush(new DefaultHttp2DataFrame(Unpooled.buffer().writeZero(512)));

        long bytesBeforeUnwritable = childChannel.bytesBeforeUnwritable();
        assertNotEquals(0, bytesBeforeUnwritable);
        // Add something to the ChannelOutboundBuffer of the parent to simulate queuing in the parents channel buffer
        // and verify that this only affect the writability of the parent channel while the child stays writable
        // until it used all of its credits.
        parentChannel.unsafe().outboundBuffer().addMessage(
                Unpooled.buffer().writeZero(800), 800, parentChannel.voidPromise());
        assertFalse(parentChannel.isWritable());

        assertTrue(childChannel.isWritable());
        assertEquals(4097, childChannel.bytesBeforeUnwritable());

        // Flush everything which simulate writing everything to the socket.
        parentChannel.flush();
        assertTrue(parentChannel.isWritable());
        assertTrue(childChannel.isWritable());
        assertEquals(bytesBeforeUnwritable, childChannel.bytesBeforeUnwritable());

        ChannelFuture future = childChannel.writeAndFlush(new DefaultHttp2DataFrame(
                Unpooled.buffer().writeZero((int) bytesBeforeUnwritable)));
        assertFalse(childChannel.isWritable());
        assertTrue(parentChannel.isWritable());

        parentChannel.flush();
        assertFalse(future.isDone());
        assertTrue(parentChannel.isWritable());
        assertFalse(childChannel.isWritable());

        // Now write an window update frame for the stream which then should ensure we will flush the bytes that were
        // queued in the RemoteFlowController before for the stream.
        frameInboundWriter.writeInboundWindowUpdate(childChannel.stream().id(), (int) bytesBeforeUnwritable);
        assertTrue(childChannel.isWritable());
        assertTrue(future.isDone());
    }