2 * Copyright (c) 2015 Pantheon Technologies s.r.o. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.openflowjava.protocol.impl.core.connection;
10 import com.google.common.base.Preconditions;
11 import com.google.common.base.Verify;
12 import com.google.common.util.concurrent.FutureCallback;
13 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
14 import javax.annotation.Nonnull;
15 import org.opendaylight.openflowjava.protocol.api.connection.OutboundQueue;
16 import org.opendaylight.openflowjava.protocol.api.connection.DeviceRequestFailedException;
17 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.Error;
18 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.OfHeader;
19 import org.slf4j.Logger;
20 import org.slf4j.LoggerFactory;
22 final class OutboundQueueImpl implements OutboundQueue {
23 private static final Logger LOG = LoggerFactory.getLogger(OutboundQueueImpl.class);
24 private static final AtomicIntegerFieldUpdater<OutboundQueueImpl> CURRENT_OFFSET_UPDATER =
25 AtomicIntegerFieldUpdater.newUpdater(OutboundQueueImpl.class, "reserveOffset");
26 private static final AtomicIntegerFieldUpdater<OutboundQueueImpl> BARRIER_OFFSET_UPDATER =
27 AtomicIntegerFieldUpdater.newUpdater(OutboundQueueImpl.class, "barrierOffset");
28 private final OutboundQueueManager<?> manager;
29 private final OutboundQueueEntry[] queue;
30 private final long baseXid;
31 private final long endXid;
32 private final int reserve;
34 // Updated concurrently
35 private volatile int barrierOffset = -1;
36 private volatile int reserveOffset = 0;
38 // Updated from Netty only
39 private int flushOffset;
40 private int completeCount;
41 private int lastBarrierOffset = -1;
43 OutboundQueueImpl(final OutboundQueueManager<?> manager, final long baseXid, final int maxQueue) {
45 * We use the last entry as an emergency should a timeout-triggered
46 * flush request race with normal users for the last entry in this
47 * queue. In that case the flush request will take the last entry and
48 * schedule a flush, which means that we will get around sending the
49 * message as soon as the user finishes the reservation.
51 Preconditions.checkArgument(maxQueue > 1);
52 this.baseXid = baseXid;
53 this.endXid = baseXid + maxQueue;
54 this.reserve = maxQueue - 1;
55 this.manager = Preconditions.checkNotNull(manager);
56 queue = new OutboundQueueEntry[maxQueue];
57 for (int i = 0; i < maxQueue; ++i) {
58 queue[i] = new OutboundQueueEntry();
62 private OutboundQueueImpl(final OutboundQueueManager<?> manager, final long baseXid, final OutboundQueueEntry[] queue) {
63 this.manager = Preconditions.checkNotNull(manager);
64 this.queue = Preconditions.checkNotNull(queue);
65 this.baseXid = baseXid;
66 this.endXid = baseXid + queue.length;
67 this.reserve = queue.length - 1;
68 for (OutboundQueueEntry element : queue) {
73 OutboundQueueImpl reuse(final long baseXid) {
74 return new OutboundQueueImpl(manager, baseXid, queue);
78 public Long reserveEntry() {
79 return reserveEntry(false);
83 public void commitEntry(final Long xid, final OfHeader message, final FutureCallback<OfHeader> callback) {
84 final int offset = (int)(xid - baseXid);
85 if (message != null) {
86 Preconditions.checkArgument(xid.equals(message.getXid()), "Message %s has wrong XID %s, expected %s", message, message.getXid(), xid);
89 final OutboundQueueEntry entry = queue[offset];
90 entry.commit(message, callback);
91 LOG.debug("Queue {} XID {} at offset {} (of {}) committed", this, xid, offset, reserveOffset);
93 if (entry.isBarrier()) {
96 final int prev = BARRIER_OFFSET_UPDATER.getAndSet(this, my);
98 LOG.debug("Queue {} recorded pending barrier offset {}", this, my);
102 // We have traveled back, recover
107 manager.ensureFlushing(this);
110 private Long reserveEntry(final boolean forBarrier) {
111 final int offset = CURRENT_OFFSET_UPDATER.getAndIncrement(this);
112 if (offset >= reserve) {
114 LOG.debug("Queue {} offset {}/{}, using emergency slot", this, offset, queue.length);
117 LOG.debug("Queue {} offset {}/{}, not allowing reservation", this, offset, queue.length);
122 final Long xid = baseXid + offset;
123 LOG.debug("Queue {} allocated XID {} at offset {}", this, xid, offset);
127 Long reserveBarrierIfNeeded() {
128 final int bo = barrierOffset;
129 if (bo >= flushOffset) {
130 LOG.debug("Barrier found at offset {} (currently at {})", bo, flushOffset);
133 return reserveEntry(true);
138 * An empty queue is a queue which has no further unflushed entries.
140 * @return True if this queue does not have unprocessed entries.
143 int ro = reserveOffset;
145 if (queue[reserve].isCommitted()) {
152 LOG.debug("Effective flush/reserve offset {}/{}", flushOffset, ro);
153 return ro <= flushOffset;
157 * A queue is finished when all of its entries have been completed.
159 * @return False if there are any uncompleted requests.
161 boolean isFinished() {
162 if (completeCount < reserve) {
166 // We need to check if the last entry was used
167 final OutboundQueueEntry last = queue[reserve];
168 return !last.isCommitted() || last.isCompleted();
171 boolean isFlushed() {
172 LOG.debug("Check queue {} for completeness (offset {}, reserve {})", flushOffset, reserve);
173 if (flushOffset < reserve) {
177 // flushOffset implied == reserve
178 return flushOffset >= queue.length || !queue[reserve].isCommitted();
181 OfHeader flushEntry() {
185 LOG.trace("Flushed all reserved entries up to ", flushOffset);
189 final OutboundQueueEntry entry = queue[flushOffset];
190 if (!entry.isCommitted()) {
191 LOG.trace("Request at offset {} not ready yet, giving up", flushOffset);
195 final OfHeader msg = entry.getMessage();
201 LOG.trace("Null message, skipping to offset {}", flushOffset);
205 // Argument is 'long' to explicitly convert before performing operations
206 private boolean xidInRange(final long xid) {
207 return xid < endXid && (xid >= baseXid || baseXid > endXid);
210 private static boolean completeEntry(final OutboundQueueEntry entry, final OfHeader response) {
211 if (response instanceof Error) {
212 final Error err = (Error)response;
213 LOG.debug("Device-reported request XID {} failed {}:{}", response.getXid(), err.getTypeString(), err.getCodeString());
214 entry.fail(new DeviceRequestFailedException("Device-side failure", err));
217 return entry.complete(response);
222 * Return the request entry corresponding to a response. Returns null
223 * if there is no request matching the response.
225 * @param response Response message
226 * @return Matching request entry, or null if no match is found.
228 OutboundQueueEntry pairRequest(@Nonnull final OfHeader response) {
229 final Long xid = response.getXid();
230 if (!xidInRange(xid)) {
231 LOG.debug("Queue {} {}/{} ignoring XID {}", this, baseXid, queue.length, xid);
235 final int offset = (int)(xid - baseXid);
236 final OutboundQueueEntry entry = queue[offset];
237 if (entry.isCompleted()) {
238 LOG.debug("Entry {} already is completed, not accepting response {}", entry, response);
242 if (entry.isBarrier()) {
243 // This has been a barrier -- make sure we complete all preceding requests.
244 // XXX: Barriers are expected to complete in one message.
245 // If this assumption is changed, this logic will need to be expanded
246 // to ensure that the requests implied by the barrier are reported as
247 // completed *after* the barrier.
248 LOG.trace("Barrier XID {} completed, cascading completion to XIDs {} to {}", xid, baseXid + lastBarrierOffset + 1, xid - 1);
249 completeRequests(offset);
250 lastBarrierOffset = offset;
252 final boolean success = completeEntry(entry, response);
253 Verify.verify(success, "Barrier request failed to complete");
255 } else if (completeEntry(entry, response)) {
262 private void completeRequests(final int toOffset) {
263 for (int i = lastBarrierOffset + 1; i < toOffset; ++i) {
264 final OutboundQueueEntry entry = queue[i];
265 if (!entry.isCompleted() && entry.complete(null)) {
272 completeRequests(queue.length);
275 int failAll(final Throwable cause) {
277 for (int i = lastBarrierOffset + 1; i < queue.length; ++i) {
278 final OutboundQueueEntry entry = queue[i];
279 if (!entry.isCompleted()) {