*/
package org.opendaylight.openflowjava.protocol.impl.core.connection;
-import com.google.common.base.Preconditions;
-import com.google.common.base.Verify;
import com.google.common.util.concurrent.FutureCallback;
-import io.netty.channel.Channel;
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
import java.util.concurrent.atomic.AtomicLongFieldUpdater;
-import javax.annotation.Nonnull;
-import javax.annotation.concurrent.GuardedBy;
-import org.opendaylight.openflowjava.protocol.api.connection.OutboundQueue;
-import org.opendaylight.openflowjava.protocol.api.connection.OutboundQueueException;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.OfHeader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
-final class StackedOutboundQueue implements OutboundQueue {
+final class StackedOutboundQueue extends AbstractStackedOutboundQueue {
private static final Logger LOG = LoggerFactory.getLogger(StackedOutboundQueue.class);
private static final AtomicLongFieldUpdater<StackedOutboundQueue> BARRIER_XID_UPDATER = AtomicLongFieldUpdater.newUpdater(StackedOutboundQueue.class, "barrierXid");
- private static final AtomicLongFieldUpdater<StackedOutboundQueue> LAST_XID_UPDATER = AtomicLongFieldUpdater.newUpdater(StackedOutboundQueue.class, "lastXid");
- @GuardedBy("unflushedSegments")
- private volatile StackedSegment firstSegment;
- @GuardedBy("unflushedSegments")
- private final List<StackedSegment> unflushedSegments = new ArrayList<>(2);
- @GuardedBy("unflushedSegments")
- private final List<StackedSegment> uncompletedSegments = new ArrayList<>(2);
- private final OutboundQueueManager<?> manager;
-
- private volatile long allocatedXid = -1;
private volatile long barrierXid = -1;
- private volatile long lastXid = -1;
-
- @GuardedBy("unflushedSegments")
- private Integer shutdownOffset;
-
- // Accessed from Netty only
- private int flushOffset;
-
- StackedOutboundQueue(final OutboundQueueManager<?> manager) {
- this.manager = Preconditions.checkNotNull(manager);
- firstSegment = StackedSegment.create(0L);
- uncompletedSegments.add(firstSegment);
- unflushedSegments.add(firstSegment);
- }
-
- @GuardedBy("unflushedSegments")
- private void ensureSegment(final StackedSegment first, final int offset) {
- final int segmentOffset = offset / StackedSegment.SEGMENT_SIZE;
- LOG.debug("Queue {} slow offset {} maps to {} segments {}", this, offset, segmentOffset, unflushedSegments.size());
-
- for (int i = unflushedSegments.size(); i <= segmentOffset; ++i) {
- final StackedSegment newSegment = StackedSegment.create(first.getBaseXid() + (StackedSegment.SEGMENT_SIZE * i));
- LOG.debug("Adding segment {}", newSegment);
- unflushedSegments.add(newSegment);
- }
-
- allocatedXid = uncompletedSegments.get(uncompletedSegments.size() - 1).getEndXid();
- }
-
- /*
- * This method is expected to be called from multiple threads concurrently.
- */
- @Override
- public Long reserveEntry() {
- final long xid = LAST_XID_UPDATER.incrementAndGet(this);
- final StackedSegment fastSegment = firstSegment;
-
- if (xid >= fastSegment.getBaseXid() + StackedSegment.SEGMENT_SIZE) {
- if (xid >= allocatedXid) {
- // Multiple segments, this a slow path
- LOG.debug("Queue {} falling back to slow reservation for XID {}", this, xid);
-
- synchronized (unflushedSegments) {
- LOG.debug("Queue {} executing slow reservation for XID {}", this, xid);
-
- // Shutdown was scheduled, need to fail the reservation
- if (shutdownOffset != null) {
- LOG.debug("Queue {} is being shutdown, failing reservation", this);
- return null;
- }
-
- // Ensure we have the appropriate segment for the specified XID
- final StackedSegment slowSegment = firstSegment;
- final int slowOffset = (int) (xid - slowSegment.getBaseXid());
- Verify.verify(slowOffset >= 0);
-
- // Now, we let's see if we need to allocate a new segment
- ensureSegment(slowSegment, slowOffset);
-
- LOG.debug("Queue {} slow reservation finished", this);
- }
- } else {
- LOG.debug("Queue {} XID {} is already backed", this, xid);
- }
- }
- LOG.trace("Queue {} allocated XID {}", this, xid);
- return xid;
+ StackedOutboundQueue(final AbstractOutboundQueueManager<?, ?> manager) {
+ super(manager);
}
/*
*/
@Override
public void commitEntry(final Long xid, final OfHeader message, final FutureCallback<OfHeader> callback) {
- final StackedSegment fastSegment = firstSegment;
- final long calcOffset = xid - fastSegment.getBaseXid();
- Preconditions.checkArgument(calcOffset >= 0, "Commit of XID %s does not match up with base XID %s", xid, fastSegment.getBaseXid());
-
- Verify.verify(calcOffset <= Integer.MAX_VALUE);
- final int fastOffset = (int) calcOffset;
-
- final OutboundQueueEntry entry;
- if (fastOffset >= StackedSegment.SEGMENT_SIZE) {
- LOG.debug("Queue {} falling back to slow commit of XID {} at offset {}", this, xid, fastOffset);
-
- final StackedSegment segment;
- final int slowOffset;
- synchronized (unflushedSegments) {
- final StackedSegment slowSegment = firstSegment;
- final long slowCalcOffset = xid - slowSegment.getBaseXid();
- Verify.verify(slowCalcOffset >= 0 && slowCalcOffset <= Integer.MAX_VALUE);
- slowOffset = (int) slowCalcOffset;
-
- LOG.debug("Queue {} recalculated offset of XID {} to {}", this, xid, slowOffset);
- segment = unflushedSegments.get(slowOffset / StackedSegment.SEGMENT_SIZE);
- }
-
- final int segOffset = slowOffset % StackedSegment.SEGMENT_SIZE;
- entry = segment.getEntry(segOffset);
- LOG.debug("Queue {} slow commit of XID {} completed at offset {} (segment {} offset {})", this, xid, slowOffset, segment, segOffset);
- } else {
- entry = fastSegment.getEntry(fastOffset);
- }
+ final OutboundQueueEntry entry = getEntry(xid);
entry.commit(message, callback);
if (entry.isBarrier()) {
manager.ensureFlushing();
}
- /**
- * Write some entries from the queue to the channel. Guaranteed to run
- * in the corresponding EventLoop.
- *
- * @param channel Channel onto which we are writing
- * @param now
- * @return Number of entries written out
- */
- int writeEntries(@Nonnull final Channel channel, final long now) {
- // Local cache
- StackedSegment segment = firstSegment;
- int entries = 0;
-
- while (channel.isWritable()) {
- final OutboundQueueEntry entry = segment.getEntry(flushOffset);
- if (!entry.isCommitted()) {
- LOG.debug("Queue {} XID {} segment {} offset {} not committed yet", this, segment.getBaseXid() + flushOffset, segment, flushOffset);
- break;
- }
-
- LOG.trace("Queue {} flushing entry at offset {}", this, flushOffset);
- final OfHeader message = entry.takeMessage();
- flushOffset++;
- entries++;
-
- if (message != null) {
- manager.writeMessage(message, now);
- } else {
- entry.complete(null);
- }
-
- if (flushOffset >= StackedSegment.SEGMENT_SIZE) {
- /*
- * Slow path: purge the current segment unless it's the last one.
- * If it is, we leave it for replacement when a new reservation
- * is run on it.
- *
- * This costs us two slow paths, but hey, this should be very rare,
- * so let's keep things simple.
- */
- synchronized (unflushedSegments) {
- LOG.debug("Flush offset {} unflushed segments {}", flushOffset, unflushedSegments.size());
-
- // We may have raced ahead of reservation code and need to allocate a segment
- ensureSegment(segment, flushOffset);
-
- // Remove the segment, update the firstSegment and reset flushOffset
- final StackedSegment oldSegment = unflushedSegments.remove(0);
- if (oldSegment.isComplete()) {
- uncompletedSegments.remove(oldSegment);
- oldSegment.recycle();
- }
-
- // Reset the first segment and add it to the uncompleted list
- segment = unflushedSegments.get(0);
- uncompletedSegments.add(segment);
-
- // Update the shutdown offset
- if (shutdownOffset != null) {
- shutdownOffset -= StackedSegment.SEGMENT_SIZE;
- }
-
- // Allow reservations back on the fast path by publishing the new first segment
- firstSegment = segment;
-
- flushOffset = 0;
- LOG.debug("Queue {} flush moved to segment {}", this, segment);
- }
- }
+ Long reserveBarrierIfNeeded() {
+ if (isBarrierNeeded()) {
+ return reserveEntry();
}
-
- return entries;
+ return null;
}
- Long reserveBarrierIfNeeded() {
+ /**
+ * Checks if Barrier Request is the last message enqueued. If not, one needs
+ * to be scheduled in order to collect data about previous messages.
+ * @return true if last enqueued message is Barrier Request, false otherwise
+ */
+ boolean isBarrierNeeded() {
final long bXid = barrierXid;
final long fXid = firstSegment.getBaseXid() + flushOffset;
if (bXid >= fXid) {
LOG.debug("Barrier found at XID {} (currently at {})", bXid, fXid);
- return null;
- } else {
- return reserveEntry();
- }
- }
-
- boolean pairRequest(final OfHeader message) {
- Iterator<StackedSegment> it = uncompletedSegments.iterator();
- while (it.hasNext()) {
- final StackedSegment 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() && uncompletedSegments.size() > 1) {
- LOG.trace("Queue {} indicated request was a barrier", queue);
-
- it = uncompletedSegments.iterator();
- while (it.hasNext()) {
- final StackedSegment 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();
- q.recycle();
- } else {
- break;
- }
- }
- }
-
- if (queue.isComplete()) {
- LOG.trace("Queue {} is finished", queue);
- it.remove();
- queue.recycle();
- }
-
- return true;
- }
-
- LOG.debug("Failed to find completion for message {}", message);
- return false;
- }
-
- long startShutdown(final Channel channel) {
- /*
- * We are dealing with a multi-threaded shutdown, as the user may still
- * be reserving entries in the queue. We are executing in a netty thread,
- * so neither flush nor barrier can be running, which is good news.
- *
- * We will eat up all the slots in the queue here and mark the offset first
- * reserved offset and free up all the cached queues. We then schedule
- * the flush task, which will deal with the rest of the shutdown process.
- */
- synchronized (unflushedSegments) {
- // Increment the offset by the segment size, preventing fast path allocations,
- // since we are holding the slow path lock, any reservations will see the queue
- // in shutdown and fail accordingly.
- final long xid = LAST_XID_UPDATER.addAndGet(this, StackedSegment.SEGMENT_SIZE);
- shutdownOffset = (int) (xid - firstSegment.getBaseXid() - StackedSegment.SEGMENT_SIZE);
-
- return lockedShutdownFlush();
- }
- }
-
- @GuardedBy("unflushedSegments")
- private long lockedShutdownFlush() {
- long entries = 0;
-
- // Fail all queues
- final Iterator<StackedSegment> it = uncompletedSegments.iterator();
- while (it.hasNext()) {
- final StackedSegment segment = it.next();
-
- entries += segment.failAll(OutboundQueueException.DEVICE_DISCONNECTED);
- if (segment.isComplete()) {
- LOG.trace("Cleared segment {}", segment);
- it.remove();
- }
- }
-
- return entries;
- }
-
- boolean finishShutdown() {
- synchronized (unflushedSegments) {
- lockedShutdownFlush();
- }
-
- return !needsFlush();
- }
-
- boolean needsFlush() {
- // flushOffset always points to the first entry, which can be changed only
- // from Netty, so we are fine here.
- if (firstSegment.getBaseXid() + flushOffset > lastXid) {
return false;
}
-
- if (shutdownOffset != null && flushOffset >= shutdownOffset) {
- return false;
- }
-
- return firstSegment.getEntry(flushOffset).isCommitted();
+ return true;
}
}
Code Review / openflowjava.git / blobdiff