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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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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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// Yet another contended object monitor throughput test |
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// adapted from bug reports |
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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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|
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class Producer extends Thread |
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{ |
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// private static Hashtable buddiesOnline = new Hashtable(); |
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private static Map buddiesOnline = new ConcurrentHashMap(); |
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public Producer(String name) { super(name); } |
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|
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public void run() { |
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Object key = null; |
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final ReentrantLock dr = RLJBar.DeathRow; |
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final ReentrantLock bar = RLJBar.bar; |
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final ReentrantLock end = RLJBar.End; |
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final Condition endCondition = RLJBar.EndCondition; |
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if (RLJBar.OneKey) key = new Integer(0); // per-thread v. per iteration |
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|
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// The barrier has a number of interesting effects: |
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// 1. It enforces full LWP provisioning on T1. |
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// (nearly all workers park concurrently). |
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// 2. It gives the C2 compiler thread(s) a chance to run. |
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// By transiently quiescing the workings the C2 threads |
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// might avoid starvation. |
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// |
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|
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try { |
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bar.lock(); |
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try { |
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++RLJBar.nUp; |
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if (RLJBar.nUp == RLJBar.nThreads) { |
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if (RLJBar.quiesce != 0) { |
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RLJBar.barCondition.awaitNanos(RLJBar.quiesce * 1000000); |
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} |
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RLJBar.epoch = System.currentTimeMillis(); |
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RLJBar.barCondition.signalAll(); |
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// System.out.print ("Consensus "); |
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} |
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if (RLJBar.UseBar) { |
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while (RLJBar.nUp != RLJBar.nThreads) { |
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RLJBar.barCondition.await(); |
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} |
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} |
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} |
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finally { |
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bar.unlock(); |
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} |
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} catch (Exception ex) { |
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System.out.println("Exception in barrier: " + ex); |
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} |
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|
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// Main execution time ... the code being timed ... |
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// HashTable.get() is highly contended (serial). |
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for (int loop = 1; loop < 100000 ;loop++) { |
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if (!RLJBar.OneKey) key = new Integer(0); |
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buddiesOnline.get(key); |
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} |
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|
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// Mutator epilog: |
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// The following code determines if the test will/wont include (measure) |
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// thread death time. |
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|
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end.lock(); |
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try { |
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++RLJBar.nDead; |
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if (RLJBar.nDead == RLJBar.nUp) { |
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// System.out.print((System.currentTimeMillis()-RLJBar.epoch) + " ms"); |
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endCondition.signalAll(); |
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} |
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} |
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finally { |
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end.unlock(); |
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} |
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dr.lock(); |
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dr.unlock(); |
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} |
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} |
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|
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public class RLJBar // ProdConsTest |
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{ |
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|
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public static final int ITERS = 10; |
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public static boolean OneKey = false; // alloc once or once per iteration |
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|
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public static boolean UseBar = false; |
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public static int nThreads = 100; |
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public static int nUp = 0; |
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public static int nDead = 0; |
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public static ReentrantLock bar = new ReentrantLock(); |
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public static Condition barCondition = bar.newCondition(); |
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public static long epoch; |
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public static ReentrantLock DeathRow = new ReentrantLock(); |
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public static ReentrantLock End = new ReentrantLock(); |
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public static int quiesce = 0; |
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public static Condition EndCondition = End.newCondition(); |
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|
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public static void main(String[] args) { |
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int argix = 0; |
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if (argix < args.length && args[argix].equals("-o")) { |
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++argix; |
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OneKey = true; |
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System.out.println("OneKey"); |
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} |
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if (argix < args.length && args[argix].equals ("-b")) { |
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++argix; |
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UseBar = true; |
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System.out.println("UseBar"); |
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} |
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if (argix < args.length && args[argix].equals ("-q")) { |
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++argix; |
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if (argix < args.length) { |
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quiesce = Integer.parseInt(args[argix++]); |
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System.out.println("Quiesce " + quiesce + " msecs"); |
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} |
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} |
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for (int k = 0; k < ITERS; ++k) |
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oneRun(); |
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} |
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|
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public static void oneRun() { |
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DeathRow = new ReentrantLock(); |
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End = new ReentrantLock(); |
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EndCondition = End.newCondition(); |
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|
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nDead = nUp = 0; |
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long cyBase = System.currentTimeMillis(); |
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DeathRow.lock(); |
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try { |
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for (int i = 1; i <= nThreads; i++) { |
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new Producer("Producer" + i).start(); |
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} |
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try { |
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End.lock(); |
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try { |
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while (nDead != nThreads) |
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EndCondition.await(); |
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} |
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finally { |
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End.unlock(); |
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} |
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} catch (Exception ex) { |
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System.out.println("Exception in End: " + ex); |
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} |
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} |
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finally { |
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DeathRow.unlock(); |
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} |
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System.out.println("Outer time: " + (System.currentTimeMillis()-cyBase)); |
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|
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// Let workers quiesce/exit. |
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try { Thread.sleep (1000); } catch (Exception ex) {} |
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} |
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} |