Jordan Halterman | a76f231 | 2018-01-25 16:56:45 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2018-present Open Networking Foundation |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onosproject.store.primitives.resources.impl; |
| 17 | |
| 18 | import java.time.Duration; |
| 19 | import java.util.Iterator; |
| 20 | import java.util.Map; |
| 21 | import java.util.Optional; |
| 22 | import java.util.concurrent.CompletableFuture; |
| 23 | import java.util.concurrent.ConcurrentHashMap; |
| 24 | import java.util.concurrent.atomic.AtomicInteger; |
| 25 | |
| 26 | import io.atomix.protocols.raft.proxy.RaftProxy; |
| 27 | import io.atomix.utils.concurrent.Futures; |
| 28 | import org.onlab.util.KryoNamespace; |
| 29 | import org.onosproject.store.serializers.KryoNamespaces; |
| 30 | import org.onosproject.store.service.AsyncDistributedLock; |
| 31 | import org.onosproject.store.service.Serializer; |
| 32 | import org.onosproject.store.service.StorageException; |
| 33 | import org.onosproject.store.service.Version; |
| 34 | |
| 35 | import static org.onosproject.store.primitives.resources.impl.AtomixDistributedLockOperations.LOCK; |
| 36 | import static org.onosproject.store.primitives.resources.impl.AtomixDistributedLockOperations.Lock; |
| 37 | import static org.onosproject.store.primitives.resources.impl.AtomixDistributedLockOperations.UNLOCK; |
| 38 | import static org.onosproject.store.primitives.resources.impl.AtomixDistributedLockOperations.Unlock; |
| 39 | |
| 40 | /** |
| 41 | * Atomix lock implementation. |
| 42 | */ |
| 43 | public class AtomixDistributedLock extends AbstractRaftPrimitive implements AsyncDistributedLock { |
| 44 | private static final Serializer SERIALIZER = Serializer.using(KryoNamespace.newBuilder() |
| 45 | .register(KryoNamespaces.BASIC) |
| 46 | .register(AtomixDistributedLockOperations.NAMESPACE) |
| 47 | .register(AtomixDistributedLockEvents.NAMESPACE) |
| 48 | .build()); |
| 49 | |
| 50 | private final Map<Integer, CompletableFuture<Version>> futures = new ConcurrentHashMap<>(); |
| 51 | private final AtomicInteger id = new AtomicInteger(); |
| 52 | private int lock; |
| 53 | |
| 54 | public AtomixDistributedLock(RaftProxy proxy) { |
| 55 | super(proxy); |
| 56 | proxy.addStateChangeListener(this::handleStateChange); |
| 57 | proxy.addEventListener(AtomixDistributedLockEvents.LOCK, SERIALIZER::decode, this::handleLocked); |
| 58 | proxy.addEventListener(AtomixDistributedLockEvents.FAIL, SERIALIZER::decode, this::handleFailed); |
| 59 | } |
| 60 | |
| 61 | private void handleLocked(LockEvent event) { |
| 62 | CompletableFuture<Version> future = futures.remove(event.id()); |
| 63 | if (future != null) { |
| 64 | this.lock = event.id(); |
| 65 | future.complete(new Version(event.version())); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | private void handleFailed(LockEvent event) { |
| 70 | CompletableFuture<Version> future = futures.remove(event.id()); |
| 71 | if (future != null) { |
| 72 | future.complete(null); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | private void handleStateChange(RaftProxy.State state) { |
| 77 | if (state != RaftProxy.State.CONNECTED) { |
| 78 | Iterator<Map.Entry<Integer, CompletableFuture<Version>>> iterator = futures.entrySet().iterator(); |
| 79 | while (iterator.hasNext()) { |
| 80 | Map.Entry<Integer, CompletableFuture<Version>> entry = iterator.next(); |
| 81 | entry.getValue().completeExceptionally(new StorageException.Unavailable()); |
| 82 | proxy.invoke(UNLOCK, SERIALIZER::encode, new Unlock(entry.getKey())); |
| 83 | iterator.remove(); |
| 84 | } |
| 85 | lock = 0; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | @Override |
| 90 | public CompletableFuture<Version> lock() { |
| 91 | RaftProxy.State state = proxy.getState(); |
| 92 | if (state != RaftProxy.State.CONNECTED) { |
| 93 | return Futures.exceptionalFuture(new StorageException.Unavailable()); |
| 94 | } |
| 95 | |
| 96 | CompletableFuture<Version> future = new CompletableFuture<>(); |
| 97 | int id = this.id.incrementAndGet(); |
| 98 | futures.put(id, future); |
| 99 | proxy.invoke(LOCK, SERIALIZER::encode, new Lock(id, -1)).whenComplete((result, error) -> { |
| 100 | if (error != null) { |
| 101 | futures.remove(id); |
| 102 | future.completeExceptionally(error); |
| 103 | } |
| 104 | }); |
| 105 | return future; |
| 106 | } |
| 107 | |
| 108 | @Override |
| 109 | public CompletableFuture<Optional<Version>> tryLock() { |
| 110 | RaftProxy.State state = proxy.getState(); |
| 111 | if (state != RaftProxy.State.CONNECTED) { |
| 112 | return Futures.exceptionalFuture(new StorageException.Unavailable()); |
| 113 | } |
| 114 | |
| 115 | CompletableFuture<Version> future = new CompletableFuture<>(); |
| 116 | int id = this.id.incrementAndGet(); |
| 117 | futures.put(id, future); |
| 118 | proxy.invoke(LOCK, SERIALIZER::encode, new Lock(id, 0)).whenComplete((result, error) -> { |
| 119 | if (error != null) { |
| 120 | futures.remove(id); |
| 121 | future.completeExceptionally(error); |
| 122 | } |
| 123 | }); |
| 124 | return future.thenApply(Optional::ofNullable); |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public CompletableFuture<Optional<Version>> tryLock(Duration timeout) { |
| 129 | RaftProxy.State state = proxy.getState(); |
| 130 | if (state != RaftProxy.State.CONNECTED) { |
| 131 | return Futures.exceptionalFuture(new StorageException.Unavailable()); |
| 132 | } |
| 133 | |
| 134 | CompletableFuture<Version> future = new CompletableFuture<>(); |
| 135 | int id = this.id.incrementAndGet(); |
| 136 | futures.put(id, future); |
| 137 | proxy.invoke(LOCK, SERIALIZER::encode, new Lock(id, timeout.toMillis())).whenComplete((result, error) -> { |
| 138 | if (error != null) { |
| 139 | futures.remove(id); |
| 140 | future.completeExceptionally(error); |
| 141 | } |
| 142 | }); |
| 143 | return future.thenApply(Optional::ofNullable); |
| 144 | } |
| 145 | |
| 146 | @Override |
| 147 | public CompletableFuture<Void> unlock() { |
| 148 | int lock = this.lock; |
| 149 | this.lock = 0; |
| 150 | if (lock != 0) { |
| 151 | return proxy.invoke(UNLOCK, SERIALIZER::encode, new Unlock(lock)); |
| 152 | } |
| 153 | return CompletableFuture.completedFuture(null); |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Closes the lock. |
| 158 | * |
| 159 | * @return a future to be completed once the lock has been closed |
| 160 | */ |
| 161 | public CompletableFuture<Void> close() { |
| 162 | return proxy.close(); |
| 163 | } |
| 164 | } |