| 1 |
dl |
1.1 |
|
| 2 |
|
|
import java.util.concurrent.*; |
| 3 |
|
|
import java.util.concurrent.atomic.*; |
| 4 |
|
|
import java.util.concurrent.locks.*; |
| 5 |
|
|
|
| 6 |
|
|
class Mutex100M { |
| 7 |
|
|
public static void main(String[] args) throws Exception { |
| 8 |
|
|
int x = loop((int)System.nanoTime(), 100000); |
| 9 |
|
|
x = loop(x, 100000); |
| 10 |
|
|
x = loop(x, 100000); |
| 11 |
|
|
long start = System.nanoTime(); |
| 12 |
|
|
x = loop(x, 100000000); |
| 13 |
|
|
if (x == 0) System.out.print(" "); |
| 14 |
|
|
long time = System.nanoTime() - start; |
| 15 |
|
|
double secs = (double)time / 1000000000.0; |
| 16 |
|
|
System.out.println("time: " + secs); |
| 17 |
|
|
start = System.nanoTime(); |
| 18 |
|
|
x = loop(x, 100000000); |
| 19 |
|
|
if (x == 0) System.out.print(" "); |
| 20 |
|
|
time = System.nanoTime() - start; |
| 21 |
|
|
secs = (double)time / 1000000000.0; |
| 22 |
|
|
System.out.println("time: " + secs); |
| 23 |
|
|
|
| 24 |
|
|
} |
| 25 |
|
|
|
| 26 |
|
|
static final Mutex100M.Mutex lock = new Mutex100M.Mutex(); |
| 27 |
|
|
|
| 28 |
|
|
static int loop(int x, int iters) { |
| 29 |
|
|
final Mutex100M.Mutex l = lock; |
| 30 |
|
|
for (int i = iters; i > 0; --i) { |
| 31 |
|
|
l.lock(); |
| 32 |
|
|
x = x * 134775813 + 1; |
| 33 |
|
|
l.unlock(); |
| 34 |
|
|
} |
| 35 |
|
|
return x; |
| 36 |
|
|
} |
| 37 |
|
|
|
| 38 |
|
|
|
| 39 |
|
|
static final class Mutex extends AbstractQueuedSynchronizer { |
| 40 |
|
|
public boolean isHeldExclusively() { return getState() == 1; } |
| 41 |
|
|
|
| 42 |
|
|
public boolean tryAcquire(int acquires) { |
| 43 |
|
|
return getState() == 0 && compareAndSetState(0, 1); |
| 44 |
|
|
} |
| 45 |
|
|
|
| 46 |
|
|
public boolean tryRelease(int releases) { |
| 47 |
|
|
setState(0); |
| 48 |
|
|
return true; |
| 49 |
|
|
} |
| 50 |
|
|
public Condition newCondition() { return new ConditionObject(); } |
| 51 |
|
|
|
| 52 |
|
|
public void lock() { |
| 53 |
|
|
if (!compareAndSetState(0, 1)) |
| 54 |
|
|
acquire(1); |
| 55 |
|
|
} |
| 56 |
|
|
public boolean tryLock() { |
| 57 |
|
|
return tryAcquire(1); |
| 58 |
|
|
} |
| 59 |
|
|
public void lockInterruptibly() throws InterruptedException { |
| 60 |
|
|
acquireInterruptibly(1); |
| 61 |
|
|
} |
| 62 |
|
|
public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException { |
| 63 |
|
|
return tryAcquireNanos(1, unit.toNanos(timeout)); |
| 64 |
|
|
} |
| 65 |
|
|
public void unlock() { release(1); } |
| 66 |
|
|
} |
| 67 |
|
|
|
| 68 |
|
|
} |
