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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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/* |
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* A simple test program. Feel free to play. |
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* Simple benchmark comparing various locking techniques. |
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*/ |
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|
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import java.util.*; |
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import java.util.concurrent.*; |
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import java.util.concurrent.locks.*; |
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import java.util.concurrent.CyclicBarrier; |
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import java.util.concurrent.ExecutorService; |
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import java.util.concurrent.Executors; |
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import java.util.concurrent.Semaphore; |
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import java.util.concurrent.locks.Lock; |
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import java.util.concurrent.locks.ReentrantLock; |
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import java.util.concurrent.locks.ReentrantReadWriteLock; |
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import java.util.concurrent.locks.StampedLock; |
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|
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public final class LockLoops { |
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static final ExecutorService pool = Executors.newCachedThreadPool(); |
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static boolean doBuiltin = true; |
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static boolean doReadWrite = true; |
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static boolean doSemaphore = true; |
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static boolean doStampedLock = true; |
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static boolean doFair = true; |
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|
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public static void main(String[] args) throws Exception { |
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Thread.sleep(10); |
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|
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if (print) |
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System.out.print("ReentrantReadLock "); |
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new ReentrantReadLockLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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|
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if (print) |
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System.out.print("ReentrantReadWriteLock"); |
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new ReentrantReadWriteLockLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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|
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} |
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|
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if (doSemaphore) { |
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System.out.print("FairSemaphore "); |
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new FairSemaphoreLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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– |
|
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} |
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|
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if (doFair) { |
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new FairReentrantReadWriteLockLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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} |
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|
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} |
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|
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if (doStampedLock) { |
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if (print) |
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System.out.print("StampedLockWrite "); |
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new StampedLockWriteLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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|
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if (print) |
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System.out.print("StampedLockRead "); |
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new StampedLockReadLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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|
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if (print) |
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System.out.print("StampedLockOptRead"); |
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new StampedLockOptimisticReadLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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|
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if (print) |
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System.out.print("StampedLockReadWrite"); |
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new StampedLockReadWriteLoop().test(v, nthreads, iters); |
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Thread.sleep(10); |
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} |
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} |
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abstract static class LockLoop implements Runnable { |
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} |
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} |
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|
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private static class ReentrantReadLockLoop extends LockLoop { |
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private final Lock lock = new ReentrantReadWriteLock().readLock(); |
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final int loop(int n) { |
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int sum = 0; |
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while (n-- > 0) { |
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lock.lock(); |
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try { |
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v = LoopHelpers.compute1(v); |
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} |
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finally { |
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lock.unlock(); |
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} |
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sum += LoopHelpers.compute2(v); |
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} |
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return sum; |
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} |
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} |
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|
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private static class ReentrantReadWriteLockLoop extends LockLoop { |
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private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); |
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final int loop(int n) { |
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return sum; |
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} |
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} |
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|
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private static class FairSemaphoreLoop extends LockLoop { |
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private final Semaphore sem = new Semaphore(1, true); |
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final int loop(int n) { |
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} |
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} |
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|
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private static class StampedLockWriteLoop extends LockLoop { |
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private final StampedLock lock = new StampedLock(); |
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final int loop(int n) { |
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int sum = 0; |
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while (n-- > 0) { |
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long stamp = lock.writeLock(); |
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try { |
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v = LoopHelpers.compute1(v); |
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} |
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finally { |
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lock.unlockWrite(stamp); |
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} |
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sum += LoopHelpers.compute2(v); |
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} |
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return sum; |
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} |
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} |
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|
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private static class StampedLockReadLoop extends LockLoop { |
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private final StampedLock lock = new StampedLock(); |
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final int loop(int n) { |
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int sum = 0; |
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while (n-- > 0) { |
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long stamp = lock.readLock(); |
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try { |
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v = LoopHelpers.compute1(v); |
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} |
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finally { |
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lock.unlockRead(stamp); |
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} |
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sum += LoopHelpers.compute2(v); |
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} |
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return sum; |
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} |
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} |
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|
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private static class StampedLockOptimisticReadLoop extends LockLoop { |
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private final StampedLock lock = new StampedLock(); |
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final int loop(int n) { |
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int sum = 0; |
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while (n-- > 0) { |
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long stamp; |
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do { |
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stamp = lock.tryOptimisticRead(); |
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v = LoopHelpers.compute1(v); |
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} while (!lock.validate(stamp)); |
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sum += LoopHelpers.compute2(v); |
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} |
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return sum; |
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} |
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} |
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|
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private static class StampedLockReadWriteLoop extends LockLoop { |
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private final StampedLock lock = new StampedLock(); |
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final int loop(int n) { |
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int sum = 0; |
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while (n-- > 0) { |
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int x; |
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long stamp = lock.readLock(); |
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try { |
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x = LoopHelpers.compute1(v); |
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} |
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finally { |
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lock.unlockRead(stamp); |
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} |
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stamp = lock.writeLock(); |
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try { |
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v = x; |
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} finally { |
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lock.unlockWrite(stamp); |
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} |
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sum += LoopHelpers.compute2(v); |
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} |
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return sum; |
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} |
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} |
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} |