| 1 |
dl |
1.1 |
/* |
| 2 |
|
|
* Written by Doug Lea with assistance from members of JCP JSR-166 |
| 3 |
|
|
* Expert Group and released to the public domain, as explained at |
| 4 |
|
|
* http://creativecommons.org/licenses/publicdomain |
| 5 |
|
|
*/ |
| 6 |
|
|
|
| 7 |
|
|
import java.util.*; |
| 8 |
|
|
import java.util.concurrent.*; |
| 9 |
|
|
import java.util.concurrent.locks.*; |
| 10 |
|
|
import java.util.concurrent.atomic.*; |
| 11 |
|
|
import java.io.*; |
| 12 |
|
|
|
| 13 |
|
|
/** |
| 14 |
|
|
* A sample user extension of AbstractQueuedSynchronizer. |
| 15 |
|
|
*/ |
| 16 |
|
|
public final class Mutex extends AbstractQueuedSynchronizer implements Lock, java.io.Serializable { |
| 17 |
|
|
public boolean isHeldExclusively() { return getState() == 1; } |
| 18 |
|
|
|
| 19 |
|
|
public boolean tryAcquire(int acquires) { |
| 20 |
|
|
return compareAndSetState(0, 1); |
| 21 |
|
|
} |
| 22 |
|
|
|
| 23 |
|
|
public boolean tryRelease(int releases) { |
| 24 |
|
|
setState(0); |
| 25 |
|
|
return true; |
| 26 |
|
|
} |
| 27 |
|
|
public Condition newCondition() { return new ConditionObject(); } |
| 28 |
|
|
|
| 29 |
|
|
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException { |
| 30 |
|
|
s.defaultReadObject(); |
| 31 |
|
|
setState(0); // reset to unlocked state |
| 32 |
|
|
} |
| 33 |
|
|
|
| 34 |
|
|
public void lock() { |
| 35 |
|
|
acquire(1); |
| 36 |
|
|
} |
| 37 |
|
|
public boolean tryLock() { |
| 38 |
|
|
return tryAcquire(1); |
| 39 |
|
|
} |
| 40 |
|
|
public void lockInterruptibly() throws InterruptedException { |
| 41 |
|
|
acquireInterruptibly(1); |
| 42 |
|
|
} |
| 43 |
|
|
public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException { |
| 44 |
|
|
return tryAcquireNanos(1, unit.toNanos(timeout)); |
| 45 |
|
|
} |
| 46 |
|
|
public void unlock() { release(1); } |
| 47 |
|
|
} |
