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