Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 1 | /* |
Brian O'Connor | 5ab426f | 2016-04-09 01:19:45 -0700 | [diff] [blame] | 2 | * Copyright 2016-present Open Networking Laboratory |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 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.util.LinkedList; |
| 19 | import java.util.Queue; |
| 20 | import java.util.concurrent.CompletableFuture; |
| 21 | import java.util.function.Consumer; |
| 22 | |
Aaron Kruglikov | 5bb3812 | 2016-06-22 12:07:23 -0700 | [diff] [blame] | 23 | import org.junit.Ignore; |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 24 | import org.junit.Test; |
| 25 | |
| 26 | import static org.junit.Assert.*; |
| 27 | |
| 28 | import org.onosproject.cluster.Leadership; |
| 29 | import org.onosproject.cluster.NodeId; |
| 30 | import org.onosproject.event.Change; |
| 31 | |
| 32 | import io.atomix.Atomix; |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 33 | import io.atomix.AtomixClient; |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 34 | import io.atomix.resource.ResourceType; |
| 35 | |
| 36 | /** |
| 37 | * Unit tests for {@link AtomixLeaderElector}. |
| 38 | */ |
Aaron Kruglikov | 5bb3812 | 2016-06-22 12:07:23 -0700 | [diff] [blame] | 39 | @Ignore |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 40 | public class AtomixLeaderElectorTest extends AtomixTestBase { |
| 41 | |
| 42 | NodeId node1 = new NodeId("node1"); |
| 43 | NodeId node2 = new NodeId("node2"); |
| 44 | NodeId node3 = new NodeId("node3"); |
| 45 | |
| 46 | @Override |
| 47 | protected ResourceType resourceType() { |
| 48 | return new ResourceType(AtomixLeaderElector.class); |
| 49 | } |
| 50 | |
| 51 | @Test |
| 52 | public void testRun() throws Throwable { |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 53 | leaderElectorRunTests(3); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 54 | } |
| 55 | |
| 56 | private void leaderElectorRunTests(int numServers) throws Throwable { |
| 57 | createCopycatServers(numServers); |
| 58 | Atomix client1 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 59 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 60 | elector1.run("foo", node1).thenAccept(result -> { |
| 61 | assertEquals(node1, result.leaderNodeId()); |
| 62 | assertEquals(1, result.leader().term()); |
| 63 | assertEquals(1, result.candidates().size()); |
| 64 | assertEquals(node1, result.candidates().get(0)); |
| 65 | }).join(); |
| 66 | Atomix client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 67 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 68 | elector2.run("foo", node2).thenAccept(result -> { |
| 69 | assertEquals(node1, result.leaderNodeId()); |
| 70 | assertEquals(1, result.leader().term()); |
| 71 | assertEquals(2, result.candidates().size()); |
| 72 | assertEquals(node1, result.candidates().get(0)); |
| 73 | assertEquals(node2, result.candidates().get(1)); |
| 74 | }).join(); |
| 75 | } |
| 76 | |
| 77 | @Test |
| 78 | public void testWithdraw() throws Throwable { |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 79 | leaderElectorWithdrawTests(3); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 80 | } |
| 81 | |
| 82 | private void leaderElectorWithdrawTests(int numServers) throws Throwable { |
| 83 | createCopycatServers(numServers); |
| 84 | Atomix client1 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 85 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 86 | elector1.run("foo", node1).join(); |
| 87 | Atomix client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 88 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 89 | elector2.run("foo", node2).join(); |
| 90 | |
| 91 | LeaderEventListener listener1 = new LeaderEventListener(); |
| 92 | elector1.addChangeListener(listener1).join(); |
| 93 | |
| 94 | LeaderEventListener listener2 = new LeaderEventListener(); |
| 95 | elector2.addChangeListener(listener2).join(); |
| 96 | |
| 97 | elector1.withdraw("foo").join(); |
| 98 | |
| 99 | listener1.nextEvent().thenAccept(result -> { |
| 100 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 101 | assertEquals(2, result.newValue().leader().term()); |
| 102 | assertEquals(1, result.newValue().candidates().size()); |
| 103 | assertEquals(node2, result.newValue().candidates().get(0)); |
| 104 | }).join(); |
| 105 | |
| 106 | listener2.nextEvent().thenAccept(result -> { |
| 107 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 108 | assertEquals(2, result.newValue().leader().term()); |
| 109 | assertEquals(1, result.newValue().candidates().size()); |
| 110 | assertEquals(node2, result.newValue().candidates().get(0)); |
| 111 | }).join(); |
| 112 | } |
| 113 | |
| 114 | @Test |
| 115 | public void testAnoint() throws Throwable { |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 116 | leaderElectorAnointTests(3); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 117 | } |
| 118 | |
| 119 | private void leaderElectorAnointTests(int numServers) throws Throwable { |
| 120 | createCopycatServers(numServers); |
| 121 | Atomix client1 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 122 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 123 | Atomix client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 124 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 125 | Atomix client3 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 126 | AtomixLeaderElector elector3 = client3.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 127 | elector1.run("foo", node1).join(); |
| 128 | elector2.run("foo", node2).join(); |
| 129 | |
| 130 | LeaderEventListener listener1 = new LeaderEventListener(); |
| 131 | elector1.addChangeListener(listener1).join(); |
| 132 | LeaderEventListener listener2 = new LeaderEventListener(); |
| 133 | elector2.addChangeListener(listener2); |
| 134 | LeaderEventListener listener3 = new LeaderEventListener(); |
| 135 | elector3.addChangeListener(listener3).join(); |
| 136 | |
| 137 | elector3.anoint("foo", node3).thenAccept(result -> { |
| 138 | assertFalse(result); |
| 139 | }).join(); |
| 140 | assertFalse(listener1.hasEvent()); |
| 141 | assertFalse(listener2.hasEvent()); |
| 142 | assertFalse(listener3.hasEvent()); |
| 143 | |
| 144 | elector3.anoint("foo", node2).thenAccept(result -> { |
| 145 | assertTrue(result); |
| 146 | }).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 147 | |
| 148 | listener1.nextEvent().thenAccept(result -> { |
| 149 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 150 | assertEquals(2, result.newValue().candidates().size()); |
| 151 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 152 | assertEquals(node2, result.newValue().candidates().get(1)); |
| 153 | }).join(); |
| 154 | listener2.nextEvent().thenAccept(result -> { |
| 155 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 156 | assertEquals(2, result.newValue().candidates().size()); |
| 157 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 158 | assertEquals(node2, result.newValue().candidates().get(1)); |
| 159 | }).join(); |
| 160 | listener3.nextEvent().thenAccept(result -> { |
| 161 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 162 | assertEquals(2, result.newValue().candidates().size()); |
| 163 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 164 | assertEquals(node2, result.newValue().candidates().get(1)); |
| 165 | }).join(); |
| 166 | } |
| 167 | |
| 168 | @Test |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 169 | public void testPromote() throws Throwable { |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 170 | leaderElectorPromoteTests(3); |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 171 | } |
| 172 | |
| 173 | private void leaderElectorPromoteTests(int numServers) throws Throwable { |
| 174 | createCopycatServers(numServers); |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 175 | AtomixClient client1 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 176 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 177 | AtomixClient client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 178 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 179 | AtomixClient client3 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 180 | AtomixLeaderElector elector3 = client3.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 181 | elector1.run("foo", node1).join(); |
| 182 | elector2.run("foo", node2).join(); |
| 183 | |
| 184 | LeaderEventListener listener1 = new LeaderEventListener(); |
| 185 | elector1.addChangeListener(listener1).join(); |
| 186 | LeaderEventListener listener2 = new LeaderEventListener(); |
| 187 | elector2.addChangeListener(listener2).join(); |
| 188 | LeaderEventListener listener3 = new LeaderEventListener(); |
| 189 | elector3.addChangeListener(listener3).join(); |
| 190 | |
| 191 | elector3.promote("foo", node3).thenAccept(result -> { |
| 192 | assertFalse(result); |
| 193 | }).join(); |
| 194 | |
| 195 | assertFalse(listener1.hasEvent()); |
| 196 | assertFalse(listener2.hasEvent()); |
| 197 | assertFalse(listener3.hasEvent()); |
| 198 | |
| 199 | elector3.run("foo", node3).join(); |
| 200 | |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 201 | listener1.nextEvent().thenAccept(result -> { |
| 202 | assertEquals(node3, result.newValue().candidates().get(2)); |
| 203 | }).join(); |
| 204 | listener2.nextEvent().thenAccept(result -> { |
| 205 | assertEquals(node3, result.newValue().candidates().get(2)); |
| 206 | }).join(); |
| 207 | listener3.nextEvent().thenAccept(result -> { |
| 208 | assertEquals(node3, result.newValue().candidates().get(2)); |
| 209 | }).join(); |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 210 | |
| 211 | elector3.promote("foo", node3).thenAccept(result -> { |
| 212 | assertTrue(result); |
| 213 | }).join(); |
| 214 | |
| 215 | listener1.nextEvent().thenAccept(result -> { |
| 216 | assertEquals(node3, result.newValue().candidates().get(0)); |
| 217 | }).join(); |
| 218 | listener2.nextEvent().thenAccept(result -> { |
| 219 | assertEquals(node3, result.newValue().candidates().get(0)); |
| 220 | }).join(); |
| 221 | listener3.nextEvent().thenAccept(result -> { |
| 222 | assertEquals(node3, result.newValue().candidates().get(0)); |
| 223 | }).join(); |
| 224 | } |
| 225 | |
| 226 | @Test |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 227 | public void testLeaderSessionClose() throws Throwable { |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 228 | leaderElectorLeaderSessionCloseTests(3); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 229 | } |
| 230 | |
| 231 | private void leaderElectorLeaderSessionCloseTests(int numServers) throws Throwable { |
| 232 | createCopycatServers(numServers); |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 233 | AtomixClient client1 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 234 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 235 | elector1.run("foo", node1).join(); |
| 236 | Atomix client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 237 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 238 | LeaderEventListener listener = new LeaderEventListener(); |
| 239 | elector2.run("foo", node2).join(); |
| 240 | elector2.addChangeListener(listener).join(); |
| 241 | client1.close(); |
| 242 | listener.nextEvent().thenAccept(result -> { |
| 243 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 244 | assertEquals(1, result.newValue().candidates().size()); |
| 245 | assertEquals(node2, result.newValue().candidates().get(0)); |
| 246 | }).join(); |
| 247 | } |
| 248 | |
| 249 | @Test |
| 250 | public void testNonLeaderSessionClose() throws Throwable { |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 251 | leaderElectorNonLeaderSessionCloseTests(3); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 252 | } |
| 253 | |
| 254 | private void leaderElectorNonLeaderSessionCloseTests(int numServers) throws Throwable { |
| 255 | createCopycatServers(numServers); |
| 256 | Atomix client1 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 257 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 258 | elector1.run("foo", node1).join(); |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 259 | AtomixClient client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 260 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 261 | LeaderEventListener listener = new LeaderEventListener(); |
| 262 | elector2.run("foo", node2).join(); |
| 263 | elector1.addChangeListener(listener).join(); |
| 264 | client2.close().join(); |
| 265 | listener.nextEvent().thenAccept(result -> { |
| 266 | assertEquals(node1, result.newValue().leaderNodeId()); |
| 267 | assertEquals(1, result.newValue().candidates().size()); |
| 268 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 269 | }).join(); |
| 270 | } |
| 271 | |
| 272 | @Test |
| 273 | public void testQueries() throws Throwable { |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 274 | leaderElectorQueryTests(3); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 275 | } |
| 276 | |
| 277 | private void leaderElectorQueryTests(int numServers) throws Throwable { |
| 278 | createCopycatServers(numServers); |
| 279 | Atomix client1 = createAtomixClient(); |
| 280 | Atomix client2 = createAtomixClient(); |
Madan Jampani | 65f24bb | 2016-03-15 15:16:18 -0700 | [diff] [blame] | 281 | AtomixLeaderElector elector1 = client1.getResource("test-elector", AtomixLeaderElector.class).join(); |
| 282 | AtomixLeaderElector elector2 = client2.getResource("test-elector", AtomixLeaderElector.class).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 283 | elector1.run("foo", node1).join(); |
| 284 | elector2.run("foo", node2).join(); |
| 285 | elector2.run("bar", node2).join(); |
| 286 | elector1.getElectedTopics(node1).thenAccept(result -> { |
| 287 | assertEquals(1, result.size()); |
| 288 | assertTrue(result.contains("foo")); |
| 289 | }).join(); |
| 290 | elector2.getElectedTopics(node1).thenAccept(result -> { |
| 291 | assertEquals(1, result.size()); |
| 292 | assertTrue(result.contains("foo")); |
| 293 | }).join(); |
| 294 | elector1.getLeadership("foo").thenAccept(result -> { |
| 295 | assertEquals(node1, result.leaderNodeId()); |
| 296 | assertEquals(node1, result.candidates().get(0)); |
| 297 | assertEquals(node2, result.candidates().get(1)); |
| 298 | }).join(); |
| 299 | elector2.getLeadership("foo").thenAccept(result -> { |
| 300 | assertEquals(node1, result.leaderNodeId()); |
| 301 | assertEquals(node1, result.candidates().get(0)); |
| 302 | assertEquals(node2, result.candidates().get(1)); |
| 303 | }).join(); |
| 304 | elector1.getLeadership("bar").thenAccept(result -> { |
| 305 | assertEquals(node2, result.leaderNodeId()); |
| 306 | assertEquals(node2, result.candidates().get(0)); |
| 307 | }).join(); |
| 308 | elector2.getLeadership("bar").thenAccept(result -> { |
| 309 | assertEquals(node2, result.leaderNodeId()); |
| 310 | assertEquals(node2, result.candidates().get(0)); |
| 311 | }).join(); |
| 312 | elector1.getLeaderships().thenAccept(result -> { |
| 313 | assertEquals(2, result.size()); |
| 314 | Leadership fooLeadership = result.get("foo"); |
| 315 | assertEquals(node1, fooLeadership.leaderNodeId()); |
| 316 | assertEquals(node1, fooLeadership.candidates().get(0)); |
| 317 | assertEquals(node2, fooLeadership.candidates().get(1)); |
| 318 | Leadership barLeadership = result.get("bar"); |
| 319 | assertEquals(node2, barLeadership.leaderNodeId()); |
| 320 | assertEquals(node2, barLeadership.candidates().get(0)); |
| 321 | }).join(); |
| 322 | elector2.getLeaderships().thenAccept(result -> { |
| 323 | assertEquals(2, result.size()); |
| 324 | Leadership fooLeadership = result.get("foo"); |
| 325 | assertEquals(node1, fooLeadership.leaderNodeId()); |
| 326 | assertEquals(node1, fooLeadership.candidates().get(0)); |
| 327 | assertEquals(node2, fooLeadership.candidates().get(1)); |
| 328 | Leadership barLeadership = result.get("bar"); |
| 329 | assertEquals(node2, barLeadership.leaderNodeId()); |
| 330 | assertEquals(node2, barLeadership.candidates().get(0)); |
| 331 | }).join(); |
| 332 | } |
| 333 | |
| 334 | private static class LeaderEventListener implements Consumer<Change<Leadership>> { |
| 335 | Queue<Change<Leadership>> eventQueue = new LinkedList<>(); |
| 336 | CompletableFuture<Change<Leadership>> pendingFuture; |
| 337 | |
| 338 | @Override |
| 339 | public void accept(Change<Leadership> change) { |
| 340 | synchronized (this) { |
| 341 | if (pendingFuture != null) { |
| 342 | pendingFuture.complete(change); |
| 343 | pendingFuture = null; |
| 344 | } else { |
| 345 | eventQueue.add(change); |
| 346 | } |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | public boolean hasEvent() { |
| 351 | return !eventQueue.isEmpty(); |
| 352 | } |
| 353 | |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 354 | public void clearEvents() { |
| 355 | eventQueue.clear(); |
| 356 | } |
| 357 | |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 358 | public CompletableFuture<Change<Leadership>> nextEvent() { |
| 359 | synchronized (this) { |
| 360 | if (eventQueue.isEmpty()) { |
| 361 | if (pendingFuture == null) { |
| 362 | pendingFuture = new CompletableFuture<>(); |
| 363 | } |
| 364 | return pendingFuture; |
| 365 | } else { |
| 366 | return CompletableFuture.completedFuture(eventQueue.poll()); |
| 367 | } |
| 368 | } |
| 369 | } |
| 370 | } |
| 371 | } |