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
#	Content
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	}