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.Iterator;
import java.util.concurrent.atomic.AtomicLongFieldUpdater;
-import javax.annotation.Nonnull;
-import javax.annotation.concurrent.GuardedBy;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.OfHeader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
private static final Logger LOG = LoggerFactory.getLogger(StackedOutboundQueue.class);
private static final AtomicLongFieldUpdater<StackedOutboundQueue> BARRIER_XID_UPDATER = AtomicLongFieldUpdater.newUpdater(StackedOutboundQueue.class, "barrierXid");
- private volatile long allocatedXid = -1;
private volatile long barrierXid = -1;
StackedOutboundQueue(final AbstractOutboundQueueManager<?, ?> manager) {
super(manager);
}
- @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;
- }
-
/*
* This method is expected to be called from multiple threads concurrently
*/
manager.ensureFlushing();
}
- @Override
- 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);
- }
- }
- }
-
- return entries;
- }
-
Long reserveBarrierIfNeeded() {
final long bXid = barrierXid;
final long fXid = firstSegment.getBaseXid() + flushOffset;
Code Review / openflowjava.git / blobdiff