Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 1 | /* |
Brian O'Connor | a09fe5b | 2017-08-03 21:12:30 -0700 | [diff] [blame] | 2 | * Copyright 2016-present Open Networking Foundation |
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 | |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 23 | import io.atomix.protocols.raft.proxy.RaftProxy; |
| 24 | import io.atomix.protocols.raft.service.RaftService; |
| 25 | import org.junit.Test; |
| 26 | import org.onosproject.cluster.Leadership; |
| 27 | import org.onosproject.cluster.NodeId; |
| 28 | import org.onosproject.event.Change; |
| 29 | |
Aaron Kruglikov | 6afeccd | 2016-07-05 13:17:01 -0700 | [diff] [blame] | 30 | import static org.junit.Assert.assertEquals; |
| 31 | import static org.junit.Assert.assertFalse; |
| 32 | import static org.junit.Assert.assertTrue; |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 33 | |
| 34 | /** |
| 35 | * Unit tests for {@link AtomixLeaderElector}. |
| 36 | */ |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 37 | public class AtomixLeaderElectorTest extends AtomixTestBase<AtomixLeaderElector> { |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 38 | |
| 39 | NodeId node1 = new NodeId("node1"); |
| 40 | NodeId node2 = new NodeId("node2"); |
| 41 | NodeId node3 = new NodeId("node3"); |
| 42 | |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 43 | @Override |
| 44 | protected RaftService createService() { |
| 45 | return new AtomixLeaderElectorService(); |
Aaron Kruglikov | b5a41e5 | 2016-06-23 15:37:41 -0700 | [diff] [blame] | 46 | } |
| 47 | |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 48 | @Override |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 49 | protected AtomixLeaderElector createPrimitive(RaftProxy proxy) { |
| 50 | return new AtomixLeaderElector(proxy); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | @Test |
| 54 | public void testRun() throws Throwable { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 55 | leaderElectorRunTests(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 56 | } |
| 57 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 58 | private void leaderElectorRunTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 59 | AtomixLeaderElector elector1 = newPrimitive("test-elector-run"); |
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(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 66 | |
| 67 | AtomixLeaderElector elector2 = newPrimitive("test-elector-run"); |
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 { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 79 | leaderElectorWithdrawTests(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 80 | } |
| 81 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 82 | private void leaderElectorWithdrawTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 83 | AtomixLeaderElector elector1 = newPrimitive("test-elector-withdraw"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 84 | elector1.run("foo", node1).join(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 85 | AtomixLeaderElector elector2 = newPrimitive("test-elector-withdraw"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 86 | elector2.run("foo", node2).join(); |
| 87 | |
| 88 | LeaderEventListener listener1 = new LeaderEventListener(); |
| 89 | elector1.addChangeListener(listener1).join(); |
| 90 | |
| 91 | LeaderEventListener listener2 = new LeaderEventListener(); |
| 92 | elector2.addChangeListener(listener2).join(); |
| 93 | |
| 94 | elector1.withdraw("foo").join(); |
| 95 | |
| 96 | listener1.nextEvent().thenAccept(result -> { |
| 97 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 98 | assertEquals(2, result.newValue().leader().term()); |
| 99 | assertEquals(1, result.newValue().candidates().size()); |
| 100 | assertEquals(node2, result.newValue().candidates().get(0)); |
| 101 | }).join(); |
| 102 | |
| 103 | listener2.nextEvent().thenAccept(result -> { |
| 104 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 105 | assertEquals(2, result.newValue().leader().term()); |
| 106 | assertEquals(1, result.newValue().candidates().size()); |
| 107 | assertEquals(node2, result.newValue().candidates().get(0)); |
| 108 | }).join(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 109 | |
| 110 | Leadership leadership1 = elector1.getLeadership("foo").join(); |
| 111 | assertEquals(node2, leadership1.leader().nodeId()); |
| 112 | assertEquals(1, leadership1.candidates().size()); |
| 113 | |
| 114 | Leadership leadership2 = elector2.getLeadership("foo").join(); |
| 115 | assertEquals(node2, leadership2.leader().nodeId()); |
| 116 | assertEquals(1, leadership2.candidates().size()); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 117 | } |
| 118 | |
| 119 | @Test |
| 120 | public void testAnoint() throws Throwable { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 121 | leaderElectorAnointTests(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 122 | } |
| 123 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 124 | private void leaderElectorAnointTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 125 | AtomixLeaderElector elector1 = newPrimitive("test-elector-anoint"); |
| 126 | AtomixLeaderElector elector2 = newPrimitive("test-elector-anoint"); |
| 127 | AtomixLeaderElector elector3 = newPrimitive("test-elector-anoint"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 128 | elector1.run("foo", node1).join(); |
| 129 | elector2.run("foo", node2).join(); |
| 130 | |
| 131 | LeaderEventListener listener1 = new LeaderEventListener(); |
| 132 | elector1.addChangeListener(listener1).join(); |
| 133 | LeaderEventListener listener2 = new LeaderEventListener(); |
| 134 | elector2.addChangeListener(listener2); |
| 135 | LeaderEventListener listener3 = new LeaderEventListener(); |
| 136 | elector3.addChangeListener(listener3).join(); |
| 137 | |
| 138 | elector3.anoint("foo", node3).thenAccept(result -> { |
| 139 | assertFalse(result); |
| 140 | }).join(); |
| 141 | assertFalse(listener1.hasEvent()); |
| 142 | assertFalse(listener2.hasEvent()); |
| 143 | assertFalse(listener3.hasEvent()); |
| 144 | |
| 145 | elector3.anoint("foo", node2).thenAccept(result -> { |
| 146 | assertTrue(result); |
| 147 | }).join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 148 | |
| 149 | listener1.nextEvent().thenAccept(result -> { |
| 150 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 151 | assertEquals(2, result.newValue().candidates().size()); |
| 152 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 153 | assertEquals(node2, result.newValue().candidates().get(1)); |
| 154 | }).join(); |
| 155 | listener2.nextEvent().thenAccept(result -> { |
| 156 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 157 | assertEquals(2, result.newValue().candidates().size()); |
| 158 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 159 | assertEquals(node2, result.newValue().candidates().get(1)); |
| 160 | }).join(); |
| 161 | listener3.nextEvent().thenAccept(result -> { |
| 162 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 163 | assertEquals(2, result.newValue().candidates().size()); |
| 164 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 165 | assertEquals(node2, result.newValue().candidates().get(1)); |
| 166 | }).join(); |
| 167 | } |
| 168 | |
| 169 | @Test |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 170 | public void testPromote() throws Throwable { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 171 | leaderElectorPromoteTests(); |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 172 | } |
| 173 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 174 | private void leaderElectorPromoteTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 175 | AtomixLeaderElector elector1 = newPrimitive("test-elector-promote"); |
| 176 | AtomixLeaderElector elector2 = newPrimitive("test-elector-promote"); |
| 177 | AtomixLeaderElector elector3 = newPrimitive("test-elector-promote"); |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 178 | elector1.run("foo", node1).join(); |
| 179 | elector2.run("foo", node2).join(); |
| 180 | |
| 181 | LeaderEventListener listener1 = new LeaderEventListener(); |
| 182 | elector1.addChangeListener(listener1).join(); |
| 183 | LeaderEventListener listener2 = new LeaderEventListener(); |
| 184 | elector2.addChangeListener(listener2).join(); |
| 185 | LeaderEventListener listener3 = new LeaderEventListener(); |
| 186 | elector3.addChangeListener(listener3).join(); |
| 187 | |
| 188 | elector3.promote("foo", node3).thenAccept(result -> { |
| 189 | assertFalse(result); |
| 190 | }).join(); |
| 191 | |
| 192 | assertFalse(listener1.hasEvent()); |
| 193 | assertFalse(listener2.hasEvent()); |
| 194 | assertFalse(listener3.hasEvent()); |
| 195 | |
| 196 | elector3.run("foo", node3).join(); |
| 197 | |
Madan Jampani | 630e7ac | 2016-05-31 11:34:05 -0700 | [diff] [blame] | 198 | listener1.nextEvent().thenAccept(result -> { |
| 199 | assertEquals(node3, result.newValue().candidates().get(2)); |
| 200 | }).join(); |
| 201 | listener2.nextEvent().thenAccept(result -> { |
| 202 | assertEquals(node3, result.newValue().candidates().get(2)); |
| 203 | }).join(); |
| 204 | listener3.nextEvent().thenAccept(result -> { |
| 205 | assertEquals(node3, result.newValue().candidates().get(2)); |
| 206 | }).join(); |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 207 | |
| 208 | elector3.promote("foo", node3).thenAccept(result -> { |
| 209 | assertTrue(result); |
| 210 | }).join(); |
| 211 | |
| 212 | listener1.nextEvent().thenAccept(result -> { |
| 213 | assertEquals(node3, result.newValue().candidates().get(0)); |
| 214 | }).join(); |
| 215 | listener2.nextEvent().thenAccept(result -> { |
| 216 | assertEquals(node3, result.newValue().candidates().get(0)); |
| 217 | }).join(); |
| 218 | listener3.nextEvent().thenAccept(result -> { |
| 219 | assertEquals(node3, result.newValue().candidates().get(0)); |
| 220 | }).join(); |
| 221 | } |
| 222 | |
| 223 | @Test |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 224 | public void testLeaderSessionClose() throws Throwable { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 225 | leaderElectorLeaderSessionCloseTests(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 226 | } |
| 227 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 228 | private void leaderElectorLeaderSessionCloseTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 229 | AtomixLeaderElector elector1 = newPrimitive("test-elector-leader-session-close"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 230 | elector1.run("foo", node1).join(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 231 | AtomixLeaderElector elector2 = newPrimitive("test-elector-leader-session-close"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 232 | LeaderEventListener listener = new LeaderEventListener(); |
| 233 | elector2.run("foo", node2).join(); |
| 234 | elector2.addChangeListener(listener).join(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 235 | elector1.proxy.close(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 236 | listener.nextEvent().thenAccept(result -> { |
| 237 | assertEquals(node2, result.newValue().leaderNodeId()); |
| 238 | assertEquals(1, result.newValue().candidates().size()); |
| 239 | assertEquals(node2, result.newValue().candidates().get(0)); |
| 240 | }).join(); |
| 241 | } |
| 242 | |
| 243 | @Test |
| 244 | public void testNonLeaderSessionClose() throws Throwable { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 245 | leaderElectorNonLeaderSessionCloseTests(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 246 | } |
| 247 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 248 | private void leaderElectorNonLeaderSessionCloseTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 249 | AtomixLeaderElector elector1 = newPrimitive("test-elector-non-leader-session-close"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 250 | elector1.run("foo", node1).join(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 251 | AtomixLeaderElector elector2 = newPrimitive("test-elector-non-leader-session-close"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 252 | LeaderEventListener listener = new LeaderEventListener(); |
| 253 | elector2.run("foo", node2).join(); |
| 254 | elector1.addChangeListener(listener).join(); |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 255 | elector2.proxy.close().join(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 256 | listener.nextEvent().thenAccept(result -> { |
| 257 | assertEquals(node1, result.newValue().leaderNodeId()); |
| 258 | assertEquals(1, result.newValue().candidates().size()); |
| 259 | assertEquals(node1, result.newValue().candidates().get(0)); |
| 260 | }).join(); |
| 261 | } |
| 262 | |
| 263 | @Test |
| 264 | public void testQueries() throws Throwable { |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 265 | leaderElectorQueryTests(); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 266 | } |
| 267 | |
Aaron Kruglikov | c38dc7f | 2016-07-19 10:00:11 -0700 | [diff] [blame] | 268 | private void leaderElectorQueryTests() throws Throwable { |
Jordan Halterman | 2bf177c | 2017-06-29 01:49:08 -0700 | [diff] [blame] | 269 | AtomixLeaderElector elector1 = newPrimitive("test-elector-query"); |
| 270 | AtomixLeaderElector elector2 = newPrimitive("test-elector-query"); |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 271 | elector1.run("foo", node1).join(); |
| 272 | elector2.run("foo", node2).join(); |
| 273 | elector2.run("bar", node2).join(); |
| 274 | elector1.getElectedTopics(node1).thenAccept(result -> { |
| 275 | assertEquals(1, result.size()); |
| 276 | assertTrue(result.contains("foo")); |
| 277 | }).join(); |
| 278 | elector2.getElectedTopics(node1).thenAccept(result -> { |
| 279 | assertEquals(1, result.size()); |
| 280 | assertTrue(result.contains("foo")); |
| 281 | }).join(); |
| 282 | elector1.getLeadership("foo").thenAccept(result -> { |
| 283 | assertEquals(node1, result.leaderNodeId()); |
| 284 | assertEquals(node1, result.candidates().get(0)); |
| 285 | assertEquals(node2, result.candidates().get(1)); |
| 286 | }).join(); |
| 287 | elector2.getLeadership("foo").thenAccept(result -> { |
| 288 | assertEquals(node1, result.leaderNodeId()); |
| 289 | assertEquals(node1, result.candidates().get(0)); |
| 290 | assertEquals(node2, result.candidates().get(1)); |
| 291 | }).join(); |
| 292 | elector1.getLeadership("bar").thenAccept(result -> { |
| 293 | assertEquals(node2, result.leaderNodeId()); |
| 294 | assertEquals(node2, result.candidates().get(0)); |
| 295 | }).join(); |
| 296 | elector2.getLeadership("bar").thenAccept(result -> { |
| 297 | assertEquals(node2, result.leaderNodeId()); |
| 298 | assertEquals(node2, result.candidates().get(0)); |
| 299 | }).join(); |
| 300 | elector1.getLeaderships().thenAccept(result -> { |
| 301 | assertEquals(2, result.size()); |
| 302 | Leadership fooLeadership = result.get("foo"); |
| 303 | assertEquals(node1, fooLeadership.leaderNodeId()); |
| 304 | assertEquals(node1, fooLeadership.candidates().get(0)); |
| 305 | assertEquals(node2, fooLeadership.candidates().get(1)); |
| 306 | Leadership barLeadership = result.get("bar"); |
| 307 | assertEquals(node2, barLeadership.leaderNodeId()); |
| 308 | assertEquals(node2, barLeadership.candidates().get(0)); |
| 309 | }).join(); |
| 310 | elector2.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 | } |
| 321 | |
| 322 | private static class LeaderEventListener implements Consumer<Change<Leadership>> { |
| 323 | Queue<Change<Leadership>> eventQueue = new LinkedList<>(); |
| 324 | CompletableFuture<Change<Leadership>> pendingFuture; |
| 325 | |
| 326 | @Override |
| 327 | public void accept(Change<Leadership> change) { |
| 328 | synchronized (this) { |
| 329 | if (pendingFuture != null) { |
| 330 | pendingFuture.complete(change); |
| 331 | pendingFuture = null; |
| 332 | } else { |
| 333 | eventQueue.add(change); |
| 334 | } |
| 335 | } |
| 336 | } |
| 337 | |
| 338 | public boolean hasEvent() { |
| 339 | return !eventQueue.isEmpty(); |
| 340 | } |
| 341 | |
Madan Jampani | 0c0cdc6 | 2016-02-22 16:54:06 -0800 | [diff] [blame] | 342 | public void clearEvents() { |
| 343 | eventQueue.clear(); |
| 344 | } |
| 345 | |
Madan Jampani | 5e5b3d6 | 2016-02-01 16:03:33 -0800 | [diff] [blame] | 346 | public CompletableFuture<Change<Leadership>> nextEvent() { |
| 347 | synchronized (this) { |
| 348 | if (eventQueue.isEmpty()) { |
| 349 | if (pendingFuture == null) { |
| 350 | pendingFuture = new CompletableFuture<>(); |
| 351 | } |
| 352 | return pendingFuture; |
| 353 | } else { |
| 354 | return CompletableFuture.completedFuture(eventQueue.poll()); |
| 355 | } |
| 356 | } |
| 357 | } |
| 358 | } |
| 359 | } |