Sender.java

/*
 * Copyright 2014-2017 Real Logic Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.aeron.driver;

import io.aeron.driver.media.ControlTransportPoller;
import io.aeron.driver.media.SendChannelEndpoint;
import io.aeron.driver.cmd.SenderCmd;
import org.agrona.collections.ArrayUtil;
import org.agrona.concurrent.Agent;
import org.agrona.concurrent.status.AtomicCounter;
import org.agrona.concurrent.NanoClock;
import org.agrona.concurrent.OneToOneConcurrentArrayQueue;

import java.net.InetSocketAddress;
import java.util.function.Consumer;

import static io.aeron.driver.status.SystemCounterDescriptor.BYTES_SENT;

class SenderLhsPadding
{
    @SuppressWarnings("unused")
    protected long p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15;
}

class SenderHotFields extends SenderLhsPadding
{
    protected long controlPollTimeoutNs;
    protected int dutyCycleCounter;
    protected int roundRobinIndex = 0;
}

class SenderRhsPadding extends SenderHotFields
{
    @SuppressWarnings("unused")
    protected long p16, p17, p18, p19, p20, p21, p22, p23, p24, p25, p26, p27, p28, p29, p30;
}

/**
 * Agent that iterates over {@link NetworkPublication}s for sending them to registered subscribers.
 */
public class Sender extends SenderRhsPadding implements Agent, Consumer<SenderCmd>
{
    private static final NetworkPublication[] EMPTY_PUBLICATIONS = new NetworkPublication[0];

    private final long statusMessageReadTimeoutNs;
    private final int dutyCycleRatio;
    private final ControlTransportPoller controlTransportPoller;
    private final OneToOneConcurrentArrayQueue<SenderCmd> commandQueue;
    private final AtomicCounter totalBytesSent;
    private final NanoClock nanoClock;

    private NetworkPublication[] networkPublications = EMPTY_PUBLICATIONS;

    public Sender(final MediaDriver.Context ctx)
    {
        this.controlTransportPoller = ctx.controlTransportPoller();
        this.commandQueue = ctx.senderCommandQueue();
        this.totalBytesSent = ctx.systemCounters().get(BYTES_SENT);
        this.nanoClock = ctx.nanoClock();
        this.statusMessageReadTimeoutNs = ctx.statusMessageTimeout() / 2;
        this.dutyCycleRatio = Configuration.sendToStatusMessagePollRatio();
    }

    public void onClose()
    {
        controlTransportPoller.close();
    }

    public int doWork()
    {
        final int workCount = commandQueue.drain(this);

        final long nowNs = nanoClock.nanoTime();
        final int bytesSent = doSend(nowNs);

        int bytesReceived = 0;

        if (0 == bytesSent || ++dutyCycleCounter == dutyCycleRatio || nowNs >= controlPollTimeoutNs)
        {
            bytesReceived = controlTransportPoller.pollTransports();

            dutyCycleCounter = 0;
            controlPollTimeoutNs = nowNs + statusMessageReadTimeoutNs;
        }

        return workCount + bytesSent + bytesReceived;
    }

    public String roleName()
    {
        return "sender";
    }

    public void onRegisterSendChannelEndpoint(final SendChannelEndpoint channelEndpoint)
    {
        channelEndpoint.openChannel();
        channelEndpoint.registerForRead(controlTransportPoller);
        channelEndpoint.indicateActive();
    }

    public void onCloseSendChannelEndpoint(final SendChannelEndpoint channelEndpoint)
    {
        channelEndpoint.close();
    }

    public void onNewNetworkPublication(final NetworkPublication publication)
    {
        networkPublications = ArrayUtil.add(networkPublications, publication);
        publication.channelEndpoint().registerForSend(publication);
    }

    public void onRemoveNetworkPublication(final NetworkPublication publication)
    {
        networkPublications = ArrayUtil.remove(networkPublications, publication);
        publication.channelEndpoint().unregisterForSend(publication);
        publication.senderRelease();
    }

    public void onAddDestination(final SendChannelEndpoint channelEndpoint, final InetSocketAddress address)
    {
        channelEndpoint.addDestination(address);
    }

    public void onRemoveDestination(final SendChannelEndpoint channelEndpoint, final InetSocketAddress address)
    {
        channelEndpoint.removeDestination(address);
    }

    public void accept(final SenderCmd cmd)
    {
        cmd.execute(this);
    }

    private int doSend(final long nowNs)
    {
        int bytesSent = 0;
        final NetworkPublication[] publications = this.networkPublications;
        final int length = publications.length;

        int startingIndex = roundRobinIndex++;
        if (startingIndex >= length)
        {
            roundRobinIndex = startingIndex = 0;
        }

        for (int i = startingIndex; i < length; i++)
        {
            bytesSent += publications[i].send(nowNs);
        }

        for (int i = 0; i < startingIndex; i++)
        {
            bytesSent += publications[i].send(nowNs);
        }

        totalBytesSent.addOrdered(bytesSent);

        return bytesSent;
    }
}