blob: 299fceb8d7f5e46530833d3d18d3baf63a64bd94 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.vespa.curator;
import com.google.common.util.concurrent.UncheckedTimeoutException;
import com.yahoo.path.Path;
import com.yahoo.transaction.Mutex;
import org.apache.curator.framework.recipes.locks.InterProcessLock;
import java.time.Duration;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;
/**
* A cluster-wide re-entrant mutex which is released on (the last symmetric) close.
*
* Re-entrancy is limited to the instance of this. To ensure re-entrancy callers should access the lock through
* {@link Curator#lock(Path, Duration)} instead of constructing this directly.
*
* @author bratseth
*/
public class Lock implements Mutex {
private final ReentrantLock lock;
private final InterProcessLock mutex;
private final String lockPath;
public Lock(String lockPath, Curator curator) {
this.lockPath = lockPath;
this.lock = new ReentrantLock(true);
mutex = curator.createMutex(lockPath);
}
/** Take the lock with the given timeout. This may be called multiple times from the same thread - each matched by a close */
public void acquire(Duration timeout) throws UncheckedTimeoutException {
ThreadLockInfo threadLockInfo = getThreadLockInfo();
threadLockInfo.invokingAcquire(timeout);
try {
if ( ! mutex.acquire(timeout.toMillis(), TimeUnit.MILLISECONDS)) {
threadLockInfo.acquireTimedOut();
throw new UncheckedTimeoutException("Timed out after waiting " + timeout +
" to acquire lock '" + lockPath + "'");
}
threadLockInfo.lockAcquired();
if ( ! lock.tryLock()) { // Should be available to only this thread, while holding the above mutex.
release();
threadLockInfo.failedToAcquireReentrantLock();
throw new IllegalStateException("InterProcessMutex acquired, but guarded lock held by someone else, for lock '" + lockPath + "'");
}
}
catch (UncheckedTimeoutException | IllegalStateException e) {
throw e;
}
catch (Exception e) {
throw new RuntimeException("Exception acquiring lock '" + lockPath + "'", e);
}
}
@Override
public void close() {
try {
lock.unlock();
}
finally {
release();
}
}
private void release() {
getThreadLockInfo().lockReleased();
try {
mutex.release();
}
catch (Exception e) {
throw new RuntimeException("Exception releasing lock '" + lockPath + "'");
}
}
private ThreadLockInfo getThreadLockInfo() {
return ThreadLockInfo.getCurrentThreadLockInfo(lockPath, lock);
}
}
|
