Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 1 | package org.onlab.onos.store.service.impl; |
| 2 | |
Madan Jampani | 1ee9178 | 2014-11-20 20:24:24 -0800 | [diff] [blame] | 3 | import static com.google.common.base.Verify.verify; |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 4 | import static org.slf4j.LoggerFactory.getLogger; |
| 5 | |
Ray Milkey | 241b96a | 2014-11-17 13:08:20 -0800 | [diff] [blame] | 6 | import java.nio.charset.StandardCharsets; |
Madan Jampani | 1ee9178 | 2014-11-20 20:24:24 -0800 | [diff] [blame] | 7 | import java.util.Arrays; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 8 | import java.util.UUID; |
| 9 | import java.util.concurrent.CompletableFuture; |
| 10 | import java.util.concurrent.ExecutionException; |
| 11 | import java.util.concurrent.TimeUnit; |
| 12 | import java.util.concurrent.TimeoutException; |
| 13 | import java.util.concurrent.atomic.AtomicBoolean; |
| 14 | |
| 15 | import org.joda.time.DateTime; |
| 16 | import org.onlab.onos.cluster.ClusterService; |
Madan Jampani | 71582ed | 2014-11-18 10:06:01 -0800 | [diff] [blame] | 17 | import org.onlab.onos.store.service.DatabaseException; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 18 | import org.onlab.onos.store.service.DatabaseService; |
| 19 | import org.onlab.onos.store.service.Lock; |
Madan Jampani | 1ee9178 | 2014-11-20 20:24:24 -0800 | [diff] [blame] | 20 | import org.onlab.onos.store.service.VersionedValue; |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 21 | import org.slf4j.Logger; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 22 | |
| 23 | /** |
| 24 | * A distributed lock implementation. |
| 25 | */ |
| 26 | public class DistributedLock implements Lock { |
| 27 | |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 28 | private final Logger log = getLogger(getClass()); |
| 29 | |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 30 | private final DistributedLockManager lockManager; |
| 31 | private final DatabaseService databaseService; |
| 32 | private final String path; |
| 33 | private DateTime lockExpirationTime; |
| 34 | private AtomicBoolean isLocked = new AtomicBoolean(false); |
Madan Jampani | 1ee9178 | 2014-11-20 20:24:24 -0800 | [diff] [blame] | 35 | private volatile long epoch = 0; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 36 | private byte[] lockId; |
| 37 | |
| 38 | public DistributedLock( |
| 39 | String path, |
| 40 | DatabaseService databaseService, |
| 41 | ClusterService clusterService, |
| 42 | DistributedLockManager lockManager) { |
| 43 | |
| 44 | this.path = path; |
| 45 | this.databaseService = databaseService; |
| 46 | this.lockManager = lockManager; |
| 47 | this.lockId = |
Ray Milkey | 241b96a | 2014-11-17 13:08:20 -0800 | [diff] [blame] | 48 | (UUID.randomUUID().toString() + "::" + |
| 49 | clusterService.getLocalNode().id().toString()). |
| 50 | getBytes(StandardCharsets.UTF_8); |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | @Override |
| 54 | public String path() { |
| 55 | return path; |
| 56 | } |
| 57 | |
| 58 | @Override |
Madan Jampani | 71582ed | 2014-11-18 10:06:01 -0800 | [diff] [blame] | 59 | public void lock(int leaseDurationMillis) throws InterruptedException { |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 60 | try { |
| 61 | lockAsync(leaseDurationMillis).get(); |
| 62 | } catch (ExecutionException e) { |
| 63 | throw new DatabaseException(e); |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 64 | } |
| 65 | } |
| 66 | |
| 67 | @Override |
Madan Jampani | 1d3494e | 2014-11-20 11:24:22 -0800 | [diff] [blame] | 68 | public CompletableFuture<Void> lockAsync(int leaseDurationMillis) { |
Madan Jampani | ddaffd0 | 2014-11-21 13:12:09 -0800 | [diff] [blame] | 69 | try { |
| 70 | if (isLocked() || tryLock(leaseDurationMillis)) { |
| 71 | return CompletableFuture.<Void>completedFuture(null); |
| 72 | } |
| 73 | return lockManager.lockIfAvailable(this, leaseDurationMillis); |
| 74 | } catch (DatabaseException e) { |
| 75 | CompletableFuture<Void> lockFuture = new CompletableFuture<>(); |
| 76 | lockFuture.completeExceptionally(e); |
| 77 | return lockFuture; |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 78 | } |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 79 | } |
| 80 | |
| 81 | @Override |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 82 | public boolean tryLock(int leaseDurationMillis) { |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 83 | if (databaseService.putIfAbsent( |
Madan Jampani | c22123d | 2014-11-12 02:12:19 -0800 | [diff] [blame] | 84 | DistributedLockManager.ONOS_LOCK_TABLE_NAME, |
| 85 | path, |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 86 | lockId)) { |
Madan Jampani | 1ee9178 | 2014-11-20 20:24:24 -0800 | [diff] [blame] | 87 | VersionedValue vv = |
| 88 | databaseService.get(DistributedLockManager.ONOS_LOCK_TABLE_NAME, path); |
| 89 | verify(Arrays.equals(vv.value(), lockId)); |
| 90 | epoch = vv.version(); |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 91 | isLocked.set(true); |
| 92 | lockExpirationTime = DateTime.now().plusMillis(leaseDurationMillis); |
| 93 | return true; |
| 94 | } |
| 95 | return false; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | @Override |
| 99 | public boolean tryLock( |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 100 | int waitTimeMillis, |
Madan Jampani | 71582ed | 2014-11-18 10:06:01 -0800 | [diff] [blame] | 101 | int leaseDurationMillis) throws InterruptedException { |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 102 | if (isLocked() || tryLock(leaseDurationMillis)) { |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 103 | return true; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 104 | } |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 105 | |
| 106 | CompletableFuture<Void> future = |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 107 | lockManager.lockIfAvailable(this, waitTimeMillis, leaseDurationMillis); |
| 108 | try { |
Madan Jampani | 1769a1a | 2014-11-19 21:51:44 -0800 | [diff] [blame] | 109 | future.get(waitTimeMillis, TimeUnit.MILLISECONDS); |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 110 | return true; |
Madan Jampani | 71582ed | 2014-11-18 10:06:01 -0800 | [diff] [blame] | 111 | } catch (ExecutionException e) { |
| 112 | throw new DatabaseException(e); |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 113 | } catch (TimeoutException e) { |
| 114 | log.debug("Timed out waiting to acquire lock for {}", path); |
| 115 | return false; |
| 116 | } |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 117 | } |
| 118 | |
| 119 | @Override |
| 120 | public boolean isLocked() { |
| 121 | if (isLocked.get()) { |
| 122 | // We rely on local information to check |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 123 | // if the lock expired. |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 124 | // This should should make this call |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 125 | // light weight, while still retaining the |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 126 | // safety guarantees. |
| 127 | if (DateTime.now().isAfter(lockExpirationTime)) { |
| 128 | isLocked.set(false); |
| 129 | return false; |
Madan Jampani | f5d263b | 2014-11-13 10:04:40 -0800 | [diff] [blame] | 130 | } else { |
| 131 | return true; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 132 | } |
| 133 | } |
Madan Jampani | f5d263b | 2014-11-13 10:04:40 -0800 | [diff] [blame] | 134 | return false; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 135 | } |
| 136 | |
| 137 | @Override |
Madan Jampani | 1ee9178 | 2014-11-20 20:24:24 -0800 | [diff] [blame] | 138 | public long epoch() { |
| 139 | return epoch; |
| 140 | } |
| 141 | |
| 142 | @Override |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 143 | public void unlock() { |
| 144 | if (!isLocked()) { |
| 145 | return; |
| 146 | } else { |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 147 | if (databaseService.removeIfValueMatches(DistributedLockManager.ONOS_LOCK_TABLE_NAME, path, lockId)) { |
| 148 | isLocked.set(false); |
| 149 | } |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 150 | } |
| 151 | } |
| 152 | |
| 153 | @Override |
| 154 | public boolean extendExpiration(int leaseDurationMillis) { |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 155 | if (!isLocked()) { |
| 156 | log.warn("Ignoring request to extend expiration for lock {}." |
| 157 | + " ExtendExpiration must be called for locks that are already acquired.", path); |
Pavlin Radoslavov | 20ded69 | 2014-11-17 16:03:15 -0800 | [diff] [blame] | 158 | return false; |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | if (databaseService.putIfValueMatches( |
| 162 | DistributedLockManager.ONOS_LOCK_TABLE_NAME, |
| 163 | path, |
| 164 | lockId, |
| 165 | lockId)) { |
| 166 | lockExpirationTime = DateTime.now().plusMillis(leaseDurationMillis); |
| 167 | log.debug("Succeeded in extending lock {} expiration time to {}", lockExpirationTime); |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 168 | return true; |
| 169 | } else { |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 170 | log.info("Failed to extend expiration for {}", path); |
| 171 | return false; |
Madan Jampani | 12390c1 | 2014-11-12 00:35:56 -0800 | [diff] [blame] | 172 | } |
| 173 | } |
Madan Jampani | a88d1f5 | 2014-11-14 16:45:24 -0800 | [diff] [blame] | 174 | } |