test/loops/CancelledLockLoops.java

/*
 * @test
 * @summary tests lockInterruptibly
 * Checks for responsiveness of locks to interrupts. Runs under that
 * assumption that ITERS_VALUE computations require more than TIMEOUT
 * msecs to complete.
 */
/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain. Use, modify, and
 * redistribute this code in any way without acknowledgement.
 */

import java.util.concurrent.*;
import java.util.concurrent.locks.*;
import java.util.*;

public final class CancelledLockLoops {
    static final Random rng = new Random();
    static boolean print = false;
    static final int ITERS = 10000000;
    static final long TIMEOUT = 100; 

    public static void main(String[] args) throws Exception {
        int maxThreads = 100;
        if (args.length > 0) 
            maxThreads = Integer.parseInt(args[0]);

        print = true;

        for (int i = 2; i <= maxThreads; i += (i+1) >>> 1) {
            System.out.print("Threads: " + i);
            try {
                new ReentrantLockLoop(i).test();
            }
            catch(BrokenBarrierException bb) {
                // OK, ignore
            }
        }
    }

    static final class ReentrantLockLoop implements Runnable {
        private int v = rng.nextInt();
        private int completed;
        private volatile int result = 17;
        private final ReentrantLock lock = new ReentrantLock();
        private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
        private final CyclicBarrier barrier;
        private final int nthreads;
        ReentrantLockLoop(int nthreads) {
            this.nthreads = nthreads;
            barrier = new CyclicBarrier(nthreads+1, timer);
        }

        final void test() throws Exception {
            Thread[] threads = new Thread[nthreads];
            for (int i = 0; i < threads.length; ++i) 
                threads[i] = new Thread(this);
            for (int i = 0; i < threads.length; ++i) 
                threads[i].start();
            Thread[] cancels = (Thread[]) (threads.clone());
            Collections.shuffle(Arrays.asList(cancels), rng);
            barrier.await();
            Thread.sleep(TIMEOUT);
            for (int i = 0; i < cancels.length-2; ++i) {
                cancels[i].interrupt();
                // make sure all OK even when cancellations spaced out
                if ( (i & 3) == 0) 
                    Thread.sleep(1 + rng.nextInt(10));
            }
            barrier.await();
            if (print) {
                long time = timer.getTime();
                double secs = (double)(time) / 1000000000.0;
                System.out.println("\t " + secs + "s run time");
            }

            int c;
            lock.lock();
            try {
                c = completed;
            }
            finally {
                lock.unlock();
            }
            if (completed != 2)
                throw new Error("Completed != 2");
            int r = result;
            if (r == 0) // avoid overoptimization
                System.out.println("useless result: " + r);
        }

        public final void run() {
            try {
                barrier.await(); 
                int sum = v;
                int x = 0;
                int n = ITERS;
                boolean done = false;
                do {
                    try {
                        lock.lockInterruptibly();
                    }
                    catch (InterruptedException ie) {
                        break;
                    }
                    try {
                        v = x = LoopHelpers.compute1(v);
                    }
                    finally {
                        lock.unlock();
                    }
                    sum += LoopHelpers.compute2(x);
                } while (n-- > 0);
                if (n <= 0) {
                    lock.lock(); 
                    try {
                        ++completed;
                    }
                    finally {
                        lock.unlock();
                    }
                }
                barrier.await();
                result += sum;
            }
            catch (Exception ex) { 
                //                ex.printStackTrace();
                return; 
            }
        }
    }

}
Revision:	1.1
Committed:	Mon May 2 19:19:38 2005 UTC (19 years ago) by dl
Branch:	MAIN
Log Message:	Put misc performance tests into CVS
#	User	Rev	Content
1	dl	1.1	/*
2			* @test
3			* @summary tests lockInterruptibly
4			* Checks for responsiveness of locks to interrupts. Runs under that
5			* assumption that ITERS_VALUE computations require more than TIMEOUT
6			* msecs to complete.
7			*/
8			/*
9			* Written by Doug Lea with assistance from members of JCP JSR-166
10			* Expert Group and released to the public domain. Use, modify, and
11			* redistribute this code in any way without acknowledgement.
12			*/
13
14			import java.util.concurrent.*;
15			import java.util.concurrent.locks.*;
16			import java.util.*;
17
18			public final class CancelledLockLoops {
19			static final Random rng = new Random();
20			static boolean print = false;
21			static final int ITERS = 10000000;
22			static final long TIMEOUT = 100;
23
24			public static void main(String[] args) throws Exception {
25			int maxThreads = 100;
26			if (args.length > 0)
27			maxThreads = Integer.parseInt(args[0]);
28
29			print = true;
30
31			for (int i = 2; i <= maxThreads; i += (i+1) >>> 1) {
32			System.out.print("Threads: " + i);
33			try {
34			new ReentrantLockLoop(i).test();
35			}
36			catch(BrokenBarrierException bb) {
37			// OK, ignore
38			}
39			}
40			}
41
42			static final class ReentrantLockLoop implements Runnable {
43			private int v = rng.nextInt();
44			private int completed;
45			private volatile int result = 17;
46			private final ReentrantLock lock = new ReentrantLock();
47			private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
48			private final CyclicBarrier barrier;
49			private final int nthreads;
50			ReentrantLockLoop(int nthreads) {
51			this.nthreads = nthreads;
52			barrier = new CyclicBarrier(nthreads+1, timer);
53			}
54
55			final void test() throws Exception {
56			Thread[] threads = new Thread[nthreads];
57			for (int i = 0; i < threads.length; ++i)
58			threads[i] = new Thread(this);
59			for (int i = 0; i < threads.length; ++i)
60			threads[i].start();
61			Thread[] cancels = (Thread[]) (threads.clone());
62			Collections.shuffle(Arrays.asList(cancels), rng);
63			barrier.await();
64			Thread.sleep(TIMEOUT);
65			for (int i = 0; i < cancels.length-2; ++i) {
66			cancels[i].interrupt();
67			// make sure all OK even when cancellations spaced out
68			if ( (i & 3) == 0)
69			Thread.sleep(1 + rng.nextInt(10));
70			}
71			barrier.await();
72			if (print) {
73			long time = timer.getTime();
74			double secs = (double)(time) / 1000000000.0;
75			System.out.println("\t " + secs + "s run time");
76			}
77
78			int c;
79			lock.lock();
80			try {
81			c = completed;
82			}
83			finally {
84			lock.unlock();
85			}
86			if (completed != 2)
87			throw new Error("Completed != 2");
88			int r = result;
89			if (r == 0) // avoid overoptimization
90			System.out.println("useless result: " + r);
91			}
92
93			public final void run() {
94			try {
95			barrier.await();
96			int sum = v;
97			int x = 0;
98			int n = ITERS;
99			boolean done = false;
100			do {
101			try {
102			lock.lockInterruptibly();
103			}
104			catch (InterruptedException ie) {
105			break;
106			}
107			try {
108			v = x = LoopHelpers.compute1(v);
109			}
110			finally {
111			lock.unlock();
112			}
113			sum += LoopHelpers.compute2(x);
114			} while (n-- > 0);
115			if (n <= 0) {
116			lock.lock();
117			try {
118			++completed;
119			}
120			finally {
121			lock.unlock();
122			}
123			}
124			barrier.await();
125			result += sum;
126			}
127			catch (Exception ex) {
128			// ex.printStackTrace();
129			return;
130			}
131			}
132			}
133
134			}