package org.opendaylight.openflowjava.protocol.impl.core.connection;
import com.google.common.base.Preconditions;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
import java.net.InetSocketAddress;
-import java.util.ArrayDeque;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.Queue;
import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
-import org.opendaylight.openflowjava.protocol.api.connection.OutboundQueueException;
import org.opendaylight.openflowjava.protocol.api.connection.OutboundQueueHandler;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.BarrierInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.OfHeader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
-final class OutboundQueueManager<T extends OutboundQueueHandler> extends ChannelInboundHandlerAdapter implements AutoCloseable {
+final class OutboundQueueManager<T extends OutboundQueueHandler> extends AbstractOutboundQueueManager<T> {
private static final Logger LOG = LoggerFactory.getLogger(OutboundQueueManager.class);
- /**
- * This is the default upper bound we place on the flush task running
- * a single iteration. We relinquish control after about this amount
- * of time.
- */
- private static final long DEFAULT_WORKTIME_MICROS = TimeUnit.MILLISECONDS.toMicros(100);
-
- /**
- * We re-check the time spent flushing every this many messages. We do this because
- * checking after each message may prove to be CPU-intensive. Set to Integer.MAX_VALUE
- * or similar to disable the feature.
- */
- private static final int WORKTIME_RECHECK_MSGS = 64;
-
- /**
- * We maintain a cache of this many previous queues for later reuse.
- */
- private static final int QUEUE_CACHE_SIZE = 4;
-
- private final Queue<OutboundQueueImpl> queueCache = new ArrayDeque<>(QUEUE_CACHE_SIZE);
- private final Queue<OutboundQueueImpl> activeQueues = new LinkedList<>();
- private final AtomicBoolean flushScheduled = new AtomicBoolean();
- private final ConnectionAdapterImpl parent;
- private final InetSocketAddress address;
+ private final int maxNonBarrierMessages;
private final long maxBarrierNanos;
- private final long maxWorkTime;
- private final int queueSize;
- private final T handler;
// Updated from netty only
- private long lastBarrierNanos = System.nanoTime();
- private OutboundQueueImpl currentQueue;
private boolean barrierTimerEnabled;
+ private long lastBarrierNanos = System.nanoTime();
private int nonBarrierMessages;
- private long lastXid = 0;
- // Passed to executor to request triggering of flush
- private final Runnable flushRunnable = new Runnable() {
- @Override
- public void run() {
- flush();
- }
- };
+ // Passed to executor to request a periodic barrier check
private final Runnable barrierRunnable = new Runnable() {
@Override
public void run() {
};
OutboundQueueManager(final ConnectionAdapterImpl parent, final InetSocketAddress address, final T handler,
- final int queueSize, final long maxBarrierNanos) {
- this.parent = Preconditions.checkNotNull(parent);
- this.handler = Preconditions.checkNotNull(handler);
- Preconditions.checkArgument(queueSize > 0);
- this.queueSize = queueSize;
+ final int maxNonBarrierMessages, final long maxBarrierNanos) {
+ super(parent, address, handler);
+ Preconditions.checkArgument(maxNonBarrierMessages > 0);
+ this.maxNonBarrierMessages = maxNonBarrierMessages;
Preconditions.checkArgument(maxBarrierNanos > 0);
this.maxBarrierNanos = maxBarrierNanos;
- this.address = address;
- this.maxWorkTime = TimeUnit.MICROSECONDS.toNanos(DEFAULT_WORKTIME_MICROS);
-
- LOG.debug("Queue manager instantiated with queue size {}", queueSize);
- createQueue();
- }
-
- T getHandler() {
- return handler;
}
- @Override
- public void close() {
- handler.onConnectionQueueChanged(null);
- }
-
- private void retireQueue(final OutboundQueueImpl queue) {
- if (queueCache.offer(queue)) {
- LOG.trace("Saving queue {} for later reuse", queue);
- } else {
- LOG.trace("Queue {} thrown away", queue);
- }
- }
-
- private void createQueue() {
- final long baseXid = lastXid;
- lastXid += queueSize + 1;
-
- final OutboundQueueImpl cached = queueCache.poll();
- final OutboundQueueImpl queue;
- if (cached != null) {
- queue = cached.reuse(baseXid);
- LOG.trace("Reusing queue {} as {} on channel {}", cached, queue, parent.getChannel());
- } else {
- queue = new OutboundQueueImpl(this, baseXid, queueSize + 1);
- LOG.trace("Allocated new queue {} on channel {}", queue, parent.getChannel());
- }
-
- activeQueues.add(queue);
- currentQueue = queue;
- handler.onConnectionQueueChanged(queue);
- }
private void scheduleBarrierTimer(final long now) {
long next = lastBarrierNanos + maxBarrierNanos;
return;
}
- currentQueue.commitEntry(xid, handler.createBarrierRequest(xid), null);
+ currentQueue.commitEntry(xid, getHandler().createBarrierRequest(xid), null);
LOG.trace("Barrier XID {} scheduled", xid);
}
- /**
- * Flush an entry from the queue.
- *
- * @param now Time reference for 'now'. We take this as an argument, as
- * we need a timestamp to mark barrier messages we see swinging
- * by. That timestamp does not need to be completely accurate,
- * hence we use the flush start time. Alternative would be to
- * measure System.nanoTime() for each barrier -- needlessly
- * adding overhead.
- *
- * @return Entry which was flushed, null if no entry is ready.
- */
- OfHeader flushEntry(final long now) {
- final OfHeader message = currentQueue.flushEntry();
- if (currentQueue.isFlushed()) {
- LOG.debug("Queue {} is fully flushed", currentQueue);
- createQueue();
- }
-
- if (message == null) {
- return null;
- }
-
- if (message instanceof BarrierInput) {
- LOG.trace("Barrier message seen, resetting counters");
- nonBarrierMessages = 0;
- lastBarrierNanos = now;
- } else {
- nonBarrierMessages++;
- if (nonBarrierMessages >= queueSize) {
- LOG.trace("Scheduled barrier request after {} non-barrier messages", nonBarrierMessages);
- scheduleBarrierMessage();
- } else if (!barrierTimerEnabled) {
- scheduleBarrierTimer(now);
- }
- }
-
- return message;
- }
-
- /**
- * Invoked whenever a message comes in from the switch. Runs matching
- * on all active queues in an attempt to complete a previous request.
- *
- * @param message Potential response message
- * @return True if the message matched a previous request, false otherwise.
- */
- boolean onMessage(final OfHeader message) {
- LOG.trace("Attempting to pair message {} to a request", message);
-
- Iterator<OutboundQueueImpl> it = activeQueues.iterator();
- while (it.hasNext()) {
- final OutboundQueueImpl queue = it.next();
- final OutboundQueueEntry entry = queue.pairRequest(message);
-
- if (entry == null) {
- continue;
- }
-
- LOG.trace("Queue {} accepted response {}", queue, message);
-
- // This has been a barrier request, we need to flush all
- // previous queues
- if (entry.isBarrier() && activeQueues.size() > 1) {
- LOG.trace("Queue {} indicated request was a barrier", queue);
-
- it = activeQueues.iterator();
- while (it.hasNext()) {
- final OutboundQueueImpl q = it.next();
-
- // We want to complete all queues before the current one, we will
- // complete the current queue below
- if (!queue.equals(q)) {
- LOG.trace("Queue {} is implied finished", q);
- q.completeAll();
- it.remove();
- retireQueue(q);
- } else {
- break;
- }
- }
- }
-
- if (queue.isFinished()) {
- LOG.trace("Queue {} is finished", queue);
- it.remove();
- retireQueue(queue);
- }
-
- return true;
- }
-
- LOG.debug("Failed to find completion for message {}", message);
- return false;
- }
-
- private void scheduleFlush() {
- if (parent.getChannel().isWritable()) {
- if (flushScheduled.compareAndSet(false, true)) {
- LOG.trace("Scheduling flush task on channel {}", parent.getChannel());
- parent.getChannel().eventLoop().execute(flushRunnable);
- } else {
- LOG.trace("Flush task is already present on channel {}", parent.getChannel());
- }
- } else {
- LOG.trace("Channel {} is not writable, not issuing a flush", parent.getChannel());
- }
- }
-
- void ensureFlushing(final OutboundQueueImpl queue) {
- Preconditions.checkState(currentQueue.equals(queue));
- scheduleFlush();
- }
/**
* Periodic barrier check.
protected void barrier() {
LOG.debug("Channel {} barrier timer expired", parent.getChannel());
barrierTimerEnabled = false;
- if (currentQueue == null) {
+ if (shuttingDown) {
LOG.trace("Channel shut down, not processing barrier");
return;
}
}
/**
- * Perform a single flush operation.
- */
- protected void flush() {
- final long start = System.nanoTime();
- final long deadline = start + maxWorkTime;
-
- LOG.debug("Dequeuing messages to channel {}", parent.getChannel());
-
- long messages = 0;
- for (;; ++messages) {
- if (!parent.getChannel().isWritable()) {
- LOG.trace("Channel is no longer writable");
- break;
- }
-
- final OfHeader message = flushEntry(start);
- if (message == null) {
- LOG.trace("The queue is completely drained");
- break;
- }
-
- final Object wrapper;
- if (address == null) {
- wrapper = new MessageListenerWrapper(message, null);
- } else {
- wrapper = new UdpMessageListenerWrapper(message, null, address);
- }
- parent.getChannel().write(wrapper);
-
- /*
- * Check every WORKTIME_RECHECK_MSGS for exceeded time.
- *
- * XXX: given we already measure our flushing throughput, we
- * should be able to perform dynamic adjustments here.
- * is that additional complexity needed, though?
- */
- if ((messages % WORKTIME_RECHECK_MSGS) == 0 && System.nanoTime() >= deadline) {
- LOG.trace("Exceeded allotted work time {}us",
- TimeUnit.NANOSECONDS.toMicros(maxWorkTime));
- break;
- }
- }
-
- if (messages > 0) {
- LOG.debug("Flushing {} message(s) to channel {}", messages, parent.getChannel());
- parent.getChannel().flush();
- }
-
- final long stop = System.nanoTime();
- LOG.debug("Flushed {} messages in {}us to channel {}",
- messages, TimeUnit.NANOSECONDS.toMicros(stop - start), parent.getChannel());
-
- /*
- * We are almost ready to terminate. This is a bit tricky, because
- * we do not want to have a race window where a message would be
- * stuck on the queue without a flush being scheduled.
- *
- * So we mark ourselves as not running and then re-check if a
- * flush out is needed. That will re-synchronized with other threads
- * such that only one flush is scheduled at any given time.
- */
- if (!flushScheduled.compareAndSet(true, false)) {
- LOG.warn("Channel {} queue {} flusher found unscheduled", parent.getChannel(), this);
- }
-
- conditionalFlush();
- }
-
-
- /**
- * Schedule a queue flush if it is not empty and the channel is found
- * to be writable. May only be called from Netty context.
+ * Write a message into the underlying channel.
+ *
+ * @param now Time reference for 'now'. We take this as an argument, as
+ * we need a timestamp to mark barrier messages we see swinging
+ * by. That timestamp does not need to be completely accurate,
+ * hence we use the flush start time. Alternative would be to
+ * measure System.nanoTime() for each barrier -- needlessly
+ * adding overhead.
*/
- private void conditionalFlush() {
- if (!currentQueue.isEmpty()) {
- scheduleFlush();
- } else {
- LOG.trace("Queue is empty, no flush needed");
- }
- }
-
- private void conditionalFlush(final ChannelHandlerContext ctx) {
- Preconditions.checkState(ctx.channel().equals(parent.getChannel()), "Inconsistent channel %s with context %s", parent.getChannel(), ctx);
- conditionalFlush();
- }
-
- @Override
- public void channelActive(final ChannelHandlerContext ctx) throws Exception {
- super.channelActive(ctx);
- conditionalFlush(ctx);
- }
-
- @Override
- public void channelWritabilityChanged(final ChannelHandlerContext ctx) throws Exception {
- super.channelWritabilityChanged(ctx);
- conditionalFlush(ctx);
- }
-
@Override
- public void channelInactive(final ChannelHandlerContext ctx) throws Exception {
- super.channelInactive(ctx);
-
- long entries = 0;
- LOG.debug("Channel shutdown, flushing queue...");
- handler.onConnectionQueueChanged(null);
-
- for (OutboundQueueImpl queue : activeQueues) {
- entries += queue.failAll(OutboundQueueException.DEVICE_DISCONNECTED);
+ void writeMessage(final OfHeader message, final long now) {
+ super.writeMessage(message, now);
+ if (message instanceof BarrierInput) {
+ LOG.trace("Barrier message seen, resetting counters");
+ nonBarrierMessages = 0;
+ lastBarrierNanos = now;
+ } else {
+ nonBarrierMessages++;
+ if (nonBarrierMessages >= maxNonBarrierMessages) {
+ LOG.trace("Scheduled barrier request after {} non-barrier messages", nonBarrierMessages);
+ scheduleBarrierMessage();
+ } else if (!barrierTimerEnabled) {
+ scheduleBarrierTimer(now);
+ }
}
- activeQueues.clear();
-
- LOG.debug("Flushed {} queue entries", entries);
- }
-
- @Override
- public String toString() {
- return String.format("Channel %s queue [flushing=%s]", parent.getChannel(), flushScheduled.get());
}
}