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