3 |
|
* Expert Group and released to the public domain, as explained at |
4 |
|
* http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
|
*/ |
6 |
+ |
|
7 |
|
/* |
8 |
< |
* A simple test program. Feel free to play. |
8 |
> |
* Simple benchmark comparing various locking techniques. |
9 |
|
*/ |
10 |
|
|
11 |
+ |
import java.util.*; |
12 |
|
import java.util.concurrent.*; |
13 |
|
import java.util.concurrent.locks.*; |
12 |
– |
import java.util.*; |
14 |
|
|
15 |
|
public final class LockLoops { |
16 |
|
static final ExecutorService pool = Executors.newCachedThreadPool(); |
19 |
|
static boolean doBuiltin = true; |
20 |
|
static boolean doReadWrite = true; |
21 |
|
static boolean doSemaphore = true; |
22 |
+ |
static boolean doStampedLock = true; |
23 |
|
static boolean doFair = true; |
24 |
|
|
25 |
|
public static void main(String[] args) throws Exception { |
92 |
|
Thread.sleep(10); |
93 |
|
|
94 |
|
if (print) |
95 |
+ |
System.out.print("ReentrantReadLock "); |
96 |
+ |
new ReentrantReadLockLoop().test(v, nthreads, iters); |
97 |
+ |
Thread.sleep(10); |
98 |
+ |
|
99 |
+ |
if (print) |
100 |
|
System.out.print("ReentrantReadWriteLock"); |
101 |
|
new ReentrantReadWriteLockLoop().test(v, nthreads, iters); |
102 |
|
Thread.sleep(10); |
96 |
– |
|
103 |
|
} |
104 |
|
|
105 |
|
if (doSemaphore) { |
112 |
|
System.out.print("FairSemaphore "); |
113 |
|
new FairSemaphoreLoop().test(v, nthreads, iters); |
114 |
|
Thread.sleep(10); |
109 |
– |
|
115 |
|
} |
116 |
|
|
117 |
|
if (doFair) { |
131 |
|
new FairReentrantReadWriteLockLoop().test(v, nthreads, iters); |
132 |
|
Thread.sleep(10); |
133 |
|
} |
129 |
– |
|
134 |
|
} |
135 |
|
|
136 |
+ |
if (doStampedLock) { |
137 |
+ |
if (print) |
138 |
+ |
System.out.print("StampedLockWrite "); |
139 |
+ |
new StampedLockWriteLoop().test(v, nthreads, iters); |
140 |
+ |
Thread.sleep(10); |
141 |
+ |
|
142 |
+ |
if (print) |
143 |
+ |
System.out.print("StampedLockRead "); |
144 |
+ |
new StampedLockReadLoop().test(v, nthreads, iters); |
145 |
+ |
Thread.sleep(10); |
146 |
+ |
|
147 |
+ |
if (print) |
148 |
+ |
System.out.print("StampedLockOptRead"); |
149 |
+ |
new StampedLockOptimisticReadLoop().test(v, nthreads, iters); |
150 |
+ |
Thread.sleep(10); |
151 |
+ |
|
152 |
+ |
if (print) |
153 |
+ |
System.out.print("StampedLockReadWrite"); |
154 |
+ |
new StampedLockReadWriteLoop().test(v, nthreads, iters); |
155 |
+ |
Thread.sleep(10); |
156 |
+ |
} |
157 |
|
} |
158 |
|
|
159 |
|
abstract static class LockLoop implements Runnable { |
289 |
|
} |
290 |
|
} |
291 |
|
|
292 |
+ |
private static class ReentrantReadLockLoop extends LockLoop { |
293 |
+ |
private final Lock lock = new ReentrantReadWriteLock().readLock(); |
294 |
+ |
final int loop(int n) { |
295 |
+ |
int sum = 0; |
296 |
+ |
while (n-- > 0) { |
297 |
+ |
lock.lock(); |
298 |
+ |
try { |
299 |
+ |
v = LoopHelpers.compute1(v); |
300 |
+ |
} |
301 |
+ |
finally { |
302 |
+ |
lock.unlock(); |
303 |
+ |
} |
304 |
+ |
sum += LoopHelpers.compute2(v); |
305 |
+ |
} |
306 |
+ |
return sum; |
307 |
+ |
} |
308 |
+ |
} |
309 |
+ |
|
310 |
|
private static class ReentrantReadWriteLockLoop extends LockLoop { |
311 |
|
private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); |
312 |
|
final int loop(int n) { |
373 |
|
return sum; |
374 |
|
} |
375 |
|
} |
376 |
+ |
|
377 |
|
private static class FairSemaphoreLoop extends LockLoop { |
378 |
|
private final Semaphore sem = new Semaphore(1, true); |
379 |
|
final int loop(int n) { |
423 |
|
} |
424 |
|
} |
425 |
|
|
426 |
+ |
private static class StampedLockWriteLoop extends LockLoop { |
427 |
+ |
private final StampedLock lock = new StampedLock(); |
428 |
+ |
final int loop(int n) { |
429 |
+ |
int sum = 0; |
430 |
+ |
while (n-- > 0) { |
431 |
+ |
long stamp = lock.writeLock(); |
432 |
+ |
try { |
433 |
+ |
v = LoopHelpers.compute1(v); |
434 |
+ |
} |
435 |
+ |
finally { |
436 |
+ |
lock.unlockWrite(stamp); |
437 |
+ |
} |
438 |
+ |
sum += LoopHelpers.compute2(v); |
439 |
+ |
} |
440 |
+ |
return sum; |
441 |
+ |
} |
442 |
+ |
} |
443 |
+ |
|
444 |
+ |
private static class StampedLockReadLoop extends LockLoop { |
445 |
+ |
private final StampedLock lock = new StampedLock(); |
446 |
+ |
final int loop(int n) { |
447 |
+ |
int sum = 0; |
448 |
+ |
while (n-- > 0) { |
449 |
+ |
long stamp = lock.readLock(); |
450 |
+ |
try { |
451 |
+ |
v = LoopHelpers.compute1(v); |
452 |
+ |
} |
453 |
+ |
finally { |
454 |
+ |
lock.unlockRead(stamp); |
455 |
+ |
} |
456 |
+ |
sum += LoopHelpers.compute2(v); |
457 |
+ |
} |
458 |
+ |
return sum; |
459 |
+ |
} |
460 |
+ |
} |
461 |
+ |
|
462 |
+ |
private static class StampedLockOptimisticReadLoop extends LockLoop { |
463 |
+ |
private final StampedLock lock = new StampedLock(); |
464 |
+ |
final int loop(int n) { |
465 |
+ |
int sum = 0; |
466 |
+ |
while (n-- > 0) { |
467 |
+ |
long stamp; |
468 |
+ |
do { |
469 |
+ |
stamp = lock.tryOptimisticRead(); |
470 |
+ |
v = LoopHelpers.compute1(v); |
471 |
+ |
} while (!lock.validate(stamp)); |
472 |
+ |
sum += LoopHelpers.compute2(v); |
473 |
+ |
} |
474 |
+ |
return sum; |
475 |
+ |
} |
476 |
+ |
} |
477 |
|
|
478 |
+ |
private static class StampedLockReadWriteLoop extends LockLoop { |
479 |
+ |
private final StampedLock lock = new StampedLock(); |
480 |
+ |
final int loop(int n) { |
481 |
+ |
int sum = 0; |
482 |
+ |
while (n-- > 0) { |
483 |
+ |
int x; |
484 |
+ |
long stamp = lock.readLock(); |
485 |
+ |
try { |
486 |
+ |
x = LoopHelpers.compute1(v); |
487 |
+ |
} |
488 |
+ |
finally { |
489 |
+ |
lock.unlockRead(stamp); |
490 |
+ |
} |
491 |
+ |
stamp = lock.writeLock(); |
492 |
+ |
try { |
493 |
+ |
v = x; |
494 |
+ |
} finally { |
495 |
+ |
lock.unlockWrite(stamp); |
496 |
+ |
} |
497 |
+ |
sum += LoopHelpers.compute2(v); |
498 |
+ |
} |
499 |
+ |
return sum; |
500 |
+ |
} |
501 |
+ |
} |
502 |
|
} |