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