concurrent/ConcurrentQueues/RemovePollRace.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

/*
 * @test
 * @bug 6785442
 * @summary Checks race between poll and remove(Object), while
 * occasionally moonlighting as a microbenchmark.
 * @run main RemovePollRace 1234
 */

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedDeque;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.atomic.AtomicLong;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Queue;
import java.util.Map;

public class RemovePollRace {
    // Suitable for benchmarking.  Overridden by args[0] for testing.
    int count = 1024 * 1024;

    final Map<String,String> results = new ConcurrentHashMap<>();

    Collection<Queue<Boolean>> concurrentQueues() {
        List<Queue<Boolean>> queues = new ArrayList<>();
        queues.add(new ConcurrentLinkedDeque<Boolean>());
        queues.add(new ConcurrentLinkedQueue<Boolean>());
        queues.add(new ArrayBlockingQueue<Boolean>(count, false));
        queues.add(new ArrayBlockingQueue<Boolean>(count, true));
        queues.add(new LinkedBlockingQueue<Boolean>());
        queues.add(new LinkedBlockingDeque<Boolean>());
        queues.add(new LinkedTransferQueue<Boolean>());

        // Following additional implementations are available from:
        // http://gee.cs.oswego.edu/dl/concurrency-interest/index.html
        // queues.add(new SynchronizedLinkedListQueue<Boolean>());

        // Avoid "first fast, second slow" benchmark effect.
        Collections.shuffle(queues);
        return queues;
    }

    void prettyPrintResults() {
        List<String> classNames = new ArrayList<>(results.keySet());
        Collections.sort(classNames);
        int maxClassNameLength = 0;
        int maxNanosLength = 0;
        for (String name : classNames) {
            if (maxClassNameLength < name.length())
                maxClassNameLength = name.length();
            if (maxNanosLength < results.get(name).length())
                maxNanosLength = results.get(name).length();
        }
        String format = String.format("%%%ds %%%ds nanos/item%%n",
                                      maxClassNameLength, maxNanosLength);
        for (String name : classNames)
            System.out.printf(format, name, results.get(name));
    }

    void test(String[] args) throws Throwable {
        if (args.length > 0)
            count = Integer.valueOf(args[0]);

        // Warmup
        for (Queue<Boolean> queue : concurrentQueues())
            test(queue);
        results.clear();
        for (Queue<Boolean> queue : concurrentQueues())
            test(queue);

        prettyPrintResults();
    }

    void await(CountDownLatch latch) {
        try { latch.await(); }
        catch (InterruptedException e) { unexpected(e); }
    }

    void test(final Queue<Boolean> q) throws Throwable {
        long t0 = System.nanoTime();
        final int SPINS = 5;
        final AtomicLong removes = new AtomicLong(0);
        final AtomicLong polls = new AtomicLong(0);

        // We need at least 3 threads, but we don't want to use too
        // many on massively multi-core systems.
        final int cpus = Runtime.getRuntime().availableProcessors();
        final int threadsToUse = Math.max(3, Math.min(cpus, 16));
        final int adderCount = threadsToUse / 3;
        final int removerCount = adderCount;
        final int pollerCount = removerCount;
        final int threadCount = adderCount + removerCount + pollerCount;

        final CountDownLatch startingGate = new CountDownLatch(1);
        final CountDownLatch addersDone = new CountDownLatch(adderCount);
        final Runnable remover = new Runnable() {
            public void run() {
                await(startingGate);
                int spins = 0;
                for (;;) {
                    boolean quittingTime = (addersDone.getCount() == 0);
                    if (q.remove(Boolean.TRUE))
                        removes.getAndIncrement();
                    else if (quittingTime)
                        break;
                    else if (++spins > SPINS) {
                        Thread.yield();
                        spins = 0;
                    }}}};
        final Runnable poller = new Runnable() {
            public void run() {
                await(startingGate);
                int spins = 0;
                for (;;) {
                    boolean quittingTime = (addersDone.getCount() == 0);
                    if (q.poll() == Boolean.TRUE)
                        polls.getAndIncrement();
                    else if (quittingTime)
                        break;
                    else if (++spins > SPINS) {
                        Thread.yield();
                        spins = 0;
                    }}}};
        final Runnable adder = new Runnable() {
            public void run() {
                await(startingGate);
                for (int i = 0; i < count; i++) {
                    for (;;) {
                        try { q.add(Boolean.TRUE); break; }
                        catch (IllegalStateException e) { Thread.yield(); }
                    }
                }
                addersDone.countDown();
            }};

        final List<Thread> adders   = new ArrayList<>();
        final List<Thread> removers = new ArrayList<>();
        final List<Thread> pollers  = new ArrayList<>();
        for (int i = 0; i < adderCount; i++)
            adders.add(checkedThread(adder));
        for (int i = 0; i < removerCount; i++)
            removers.add(checkedThread(remover));
        for (int i = 0; i < pollerCount; i++)
            pollers.add(checkedThread(poller));

        final List<Thread> allThreads = new ArrayList<>();
        allThreads.addAll(removers);
        allThreads.addAll(pollers);
        allThreads.addAll(adders);

        for (Thread t : allThreads)
            t.start();
        startingGate.countDown();
        for (Thread t : allThreads)
            t.join();

        String className = q.getClass().getSimpleName();
        long elapsed = System.nanoTime() - t0;
        int nanos = (int) ((double) elapsed / (adderCount * count));
        results.put(className, String.valueOf(nanos));
        if (removes.get() + polls.get() != adderCount * count) {
            String msg = String.format
                ("class=%s removes=%s polls=%d count=%d",
                 className, removes.get(), polls.get(), count);
            fail(msg);
        }
    }

    //--------------------- Infrastructure ---------------------------
    volatile int passed = 0, failed = 0;
    void pass() {passed++;}
    void fail() {failed++; Thread.dumpStack();}
    void fail(String msg) {System.err.println(msg); fail();}
    void unexpected(Throwable t) {failed++; t.printStackTrace();}
    void check(boolean cond) {if (cond) pass(); else fail();}
    void equal(Object x, Object y) {
        if (x == null ? y == null : x.equals(y)) pass();
        else fail(x + " not equal to " + y);}
    public static void main(String[] args) throws Throwable {
        new RemovePollRace().instanceMain(args);}
    public void instanceMain(String[] args) throws Throwable {
        try {test(args);} catch (Throwable t) {unexpected(t);}
        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
        if (failed > 0) throw new AssertionError("Some tests failed");}
    Thread checkedThread(final Runnable r) {
        return new Thread() {public void run() {
            try {r.run();} catch (Throwable t) {unexpected(t);}}};}
}
Revision:	1.9
Committed:	Wed Jan 4 04:46:19 2017 UTC (7 years, 5 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.8:	+7 -7 lines
Log Message:	convert to Diamond
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	*/
6
7	/*
8	* @test
9	* @bug 6785442
10	* @summary Checks race between poll and remove(Object), while
11	* occasionally moonlighting as a microbenchmark.
12	* @run main RemovePollRace 1234
13	*/
14
15	import java.util.concurrent.ArrayBlockingQueue;
16	import java.util.concurrent.ConcurrentHashMap;
17	import java.util.concurrent.ConcurrentLinkedDeque;
18	import java.util.concurrent.ConcurrentLinkedQueue;
19	import java.util.concurrent.CountDownLatch;
20	import java.util.concurrent.LinkedBlockingDeque;
21	import java.util.concurrent.LinkedBlockingQueue;
22	import java.util.concurrent.LinkedTransferQueue;
23	import java.util.concurrent.atomic.AtomicLong;
24	import java.util.ArrayList;
25	import java.util.Collection;
26	import java.util.Collections;
27	import java.util.List;
28	import java.util.Queue;
29	import java.util.Map;
30
31	public class RemovePollRace {
32	// Suitable for benchmarking. Overridden by args[0] for testing.
33	int count = 1024 * 1024;
34
35	final Map<String,String> results = new ConcurrentHashMap<>();
36
37	Collection<Queue<Boolean>> concurrentQueues() {
38	List<Queue<Boolean>> queues = new ArrayList<>();
39	queues.add(new ConcurrentLinkedDeque<Boolean>());
40	queues.add(new ConcurrentLinkedQueue<Boolean>());
41	queues.add(new ArrayBlockingQueue<Boolean>(count, false));
42	queues.add(new ArrayBlockingQueue<Boolean>(count, true));
43	queues.add(new LinkedBlockingQueue<Boolean>());
44	queues.add(new LinkedBlockingDeque<Boolean>());
45	queues.add(new LinkedTransferQueue<Boolean>());
46
47	// Following additional implementations are available from:
48	// http://gee.cs.oswego.edu/dl/concurrency-interest/index.html
49	// queues.add(new SynchronizedLinkedListQueue<Boolean>());
50
51	// Avoid "first fast, second slow" benchmark effect.
52	Collections.shuffle(queues);
53	return queues;
54	}
55
56	void prettyPrintResults() {
57	List<String> classNames = new ArrayList<>(results.keySet());
58	Collections.sort(classNames);
59	int maxClassNameLength = 0;
60	int maxNanosLength = 0;
61	for (String name : classNames) {
62	if (maxClassNameLength < name.length())
63	maxClassNameLength = name.length();
64	if (maxNanosLength < results.get(name).length())
65	maxNanosLength = results.get(name).length();
66	}
67	String format = String.format("%%%ds %%%ds nanos/item%%n",
68	maxClassNameLength, maxNanosLength);
69	for (String name : classNames)
70	System.out.printf(format, name, results.get(name));
71	}
72
73	void test(String[] args) throws Throwable {
74	if (args.length > 0)
75	count = Integer.valueOf(args[0]);
76
77	// Warmup
78	for (Queue<Boolean> queue : concurrentQueues())
79	test(queue);
80	results.clear();
81	for (Queue<Boolean> queue : concurrentQueues())
82	test(queue);
83
84	prettyPrintResults();
85	}
86
87	void await(CountDownLatch latch) {
88	try { latch.await(); }
89	catch (InterruptedException e) { unexpected(e); }
90	}
91
92	void test(final Queue<Boolean> q) throws Throwable {
93	long t0 = System.nanoTime();
94	final int SPINS = 5;
95	final AtomicLong removes = new AtomicLong(0);
96	final AtomicLong polls = new AtomicLong(0);
97
98	// We need at least 3 threads, but we don't want to use too
99	// many on massively multi-core systems.
100	final int cpus = Runtime.getRuntime().availableProcessors();
101	final int threadsToUse = Math.max(3, Math.min(cpus, 16));
102	final int adderCount = threadsToUse / 3;
103	final int removerCount = adderCount;
104	final int pollerCount = removerCount;
105	final int threadCount = adderCount + removerCount + pollerCount;
106
107	final CountDownLatch startingGate = new CountDownLatch(1);
108	final CountDownLatch addersDone = new CountDownLatch(adderCount);
109	final Runnable remover = new Runnable() {
110	public void run() {
111	await(startingGate);
112	int spins = 0;
113	for (;;) {
114	boolean quittingTime = (addersDone.getCount() == 0);
115	if (q.remove(Boolean.TRUE))
116	removes.getAndIncrement();
117	else if (quittingTime)
118	break;
119	else if (++spins > SPINS) {
120	Thread.yield();
121	spins = 0;
122	}}}};
123	final Runnable poller = new Runnable() {
124	public void run() {
125	await(startingGate);
126	int spins = 0;
127	for (;;) {
128	boolean quittingTime = (addersDone.getCount() == 0);
129	if (q.poll() == Boolean.TRUE)
130	polls.getAndIncrement();
131	else if (quittingTime)
132	break;
133	else if (++spins > SPINS) {
134	Thread.yield();
135	spins = 0;
136	}}}};
137	final Runnable adder = new Runnable() {
138	public void run() {
139	await(startingGate);
140	for (int i = 0; i < count; i++) {
141	for (;;) {
142	try { q.add(Boolean.TRUE); break; }
143	catch (IllegalStateException e) { Thread.yield(); }
144	}
145	}
146	addersDone.countDown();
147	}};
148
149	final List<Thread> adders = new ArrayList<>();
150	final List<Thread> removers = new ArrayList<>();
151	final List<Thread> pollers = new ArrayList<>();
152	for (int i = 0; i < adderCount; i++)
153	adders.add(checkedThread(adder));
154	for (int i = 0; i < removerCount; i++)
155	removers.add(checkedThread(remover));
156	for (int i = 0; i < pollerCount; i++)
157	pollers.add(checkedThread(poller));
158
159	final List<Thread> allThreads = new ArrayList<>();
160	allThreads.addAll(removers);
161	allThreads.addAll(pollers);
162	allThreads.addAll(adders);
163
164	for (Thread t : allThreads)
165	t.start();
166	startingGate.countDown();
167	for (Thread t : allThreads)
168	t.join();
169
170	String className = q.getClass().getSimpleName();
171	long elapsed = System.nanoTime() - t0;
172	int nanos = (int) ((double) elapsed / (adderCount * count));
173	results.put(className, String.valueOf(nanos));
174	if (removes.get() + polls.get() != adderCount * count) {
175	String msg = String.format
176	("class=%s removes=%s polls=%d count=%d",
177	className, removes.get(), polls.get(), count);
178	fail(msg);
179	}
180	}
181
182	//--------------------- Infrastructure ---------------------------
183	volatile int passed = 0, failed = 0;
184	void pass() {passed++;}
185	void fail() {failed++; Thread.dumpStack();}
186	void fail(String msg) {System.err.println(msg); fail();}
187	void unexpected(Throwable t) {failed++; t.printStackTrace();}
188	void check(boolean cond) {if (cond) pass(); else fail();}
189	void equal(Object x, Object y) {
190	if (x == null ? y == null : x.equals(y)) pass();
191	else fail(x + " not equal to " + y);}
192	public static void main(String[] args) throws Throwable {
193	new RemovePollRace().instanceMain(args);}
194	public void instanceMain(String[] args) throws Throwable {
195	try {test(args);} catch (Throwable t) {unexpected(t);}
196	System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
197	if (failed > 0) throw new AssertionError("Some tests failed");}
198	Thread checkedThread(final Runnable r) {
199	return new Thread() {public void run() {
200	try {r.run();} catch (Throwable t) {unexpected(t);}}};}
201	}