1 /*
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11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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13  * accompanied this code).
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23 
24 /*
25  * @test
26  * @bug 6450200
27  * @summary Test proper handling of pool state changes
28  * @library /test/lib
29  * @build jdk.test.lib.RandomFactory
30  * @run main/othervm ConfigChanges
31  * @key randomness
32  * @author Martin Buchholz
33  */
34 
35 import static java.util.concurrent.TimeUnit.MILLISECONDS;
36 import static java.util.concurrent.TimeUnit.MINUTES;
37 import static java.util.concurrent.TimeUnit.NANOSECONDS;
38 
39 import java.security.Permission;
40 import java.util.Random;
41 import java.util.concurrent.ArrayBlockingQueue;
42 import java.util.concurrent.CyclicBarrier;
43 import java.util.concurrent.ExecutorService;
44 import java.util.concurrent.RejectedExecutionException;
45 import java.util.concurrent.ThreadFactory;
46 import java.util.concurrent.ThreadPoolExecutor;
47 import java.util.function.Supplier;
48 import jdk.test.lib.RandomFactory;
49 
50 public class ConfigChanges {
51     static final ThreadGroup tg = new ThreadGroup("pool");
52 
53     static final Random rnd = RandomFactory.getRandom();
54 
report(ThreadPoolExecutor tpe)55     static void report(ThreadPoolExecutor tpe) {
56         try {
57             System.out.printf(
58                 "active=%d submitted=%d completed=%d queued=%d sizes=%d/%d/%d%n",
59                 tg.activeCount(),
60                 tpe.getTaskCount(),
61                 tpe.getCompletedTaskCount(),
62                 tpe.getQueue().size(),
63                 tpe.getPoolSize(),
64                 tpe.getCorePoolSize(),
65                 tpe.getMaximumPoolSize());
66         } catch (Throwable t) { unexpected(t); }
67     }
68 
report(String label, ThreadPoolExecutor tpe)69     static void report(String label, ThreadPoolExecutor tpe) {
70         System.out.printf("%10s ", label);
71         report(tpe);
72     }
73 
74     static class PermissiveSecurityManger extends SecurityManager {
checkPermission(Permission p)75         public void checkPermission(Permission p) { /* bien sur, Monsieur */ }
76     }
77 
checkShutdown(final ExecutorService es)78     static void checkShutdown(final ExecutorService es) {
79         final Runnable nop = new Runnable() {public void run() {}};
80         try {
81             if (new Random().nextBoolean()) {
82                 check(es.isShutdown());
83                 if (es instanceof ThreadPoolExecutor)
84                     check(((ThreadPoolExecutor) es).isTerminating()
85                           || es.isTerminated());
86                 THROWS(RejectedExecutionException.class,
87                        () -> es.execute(nop));
88             }
89         } catch (Throwable t) { unexpected(t); }
90     }
91 
checkTerminated(final ThreadPoolExecutor tpe)92     static void checkTerminated(final ThreadPoolExecutor tpe) {
93         try {
94             checkShutdown(tpe);
95             check(tpe.getQueue().isEmpty());
96             check(tpe.isTerminated());
97             check(! tpe.isTerminating());
98             equal(0, tpe.getActiveCount());
99             equal(0, tpe.getPoolSize());
100             equal(tpe.getTaskCount(), tpe.getCompletedTaskCount());
101             check(tpe.awaitTermination(0L, MINUTES));
102         } catch (Throwable t) { unexpected(t); }
103     }
104 
waiter(final CyclicBarrier barrier)105     static Runnable waiter(final CyclicBarrier barrier) {
106         return new Runnable() { public void run() {
107             try { barrier.await(); barrier.await(); }
108             catch (Throwable t) { unexpected(t); }}};
109     }
110 
111     static volatile Runnable runnableDuJour;
112 
113     static void awaitIdleness(ThreadPoolExecutor tpe, long taskCount) {
114         restart: for (;;) {
115             // check twice to make chance of race vanishingly small
116             for (int i = 0; i < 2; i++) {
117                 if (tpe.getQueue().size() != 0 ||
118                     tpe.getActiveCount() != 0 ||
119                     tpe.getCompletedTaskCount() != taskCount) {
120                     Thread.yield();
121                     continue restart;
122                 }
123             }
124             return;
125         }
126     }
127 
128     /**
129      * Waits for condition to become true, first spin-polling, then sleep-polling.
130      */
131     static void spinAwait(Supplier<Boolean> waitingForGodot) {
132         for (int spins = 0; !waitingForGodot.get(); ) {
133             if ((spins = (spins + 1) & 3) > 0) {
134                 Thread.yield();
135             } else {
136                 try { Thread.sleep(4); }
137                 catch (InterruptedException unexpected) {
138                     throw new AssertionError(unexpected);
139                 }
140             }
141         }
142     }
143 
144     private static void realMain(String[] args) throws Throwable {
145         if (rnd.nextBoolean())
146             System.setSecurityManager(new PermissiveSecurityManger());
147 
148         final boolean prestart = rnd.nextBoolean();
149 
150         final Thread.UncaughtExceptionHandler handler
151             = new Thread.UncaughtExceptionHandler() {
152                     public void uncaughtException(Thread t, Throwable e) {
153                         check(! Thread.currentThread().isInterrupted());
154                         unexpected(e);
155                     }};
156 
157         final int n = 3;
158         final ThreadPoolExecutor tpe
159             = new ThreadPoolExecutor(n, 3*n,
160                                      3L, MINUTES,
161                                      new ArrayBlockingQueue<Runnable>(3*n));
162         tpe.setThreadFactory(new ThreadFactory() {
163                 public Thread newThread(Runnable r) {
164                     Thread t = new Thread(tg, r);
165                     t.setUncaughtExceptionHandler(handler);
166                     return t;
167                 }});
168 
169         if (prestart) {
170             tpe.prestartAllCoreThreads();
171             equal(n, tg.activeCount());
172             equal(n, tpe.getCorePoolSize());
173             equal(n, tpe.getLargestPoolSize());
174         }
175 
176         final Runnable runRunnableDuJour =
177             new Runnable() { public void run() {
178                 // Delay choice of action till last possible moment.
179                 runnableDuJour.run(); }};
180         final CyclicBarrier pumpedUp = new CyclicBarrier(3*n + 1);
181         runnableDuJour = waiter(pumpedUp);
182 
183         if (prestart) {
184             for (int i = 0; i < 1*n; i++)
185                 tpe.execute(runRunnableDuJour);
186             // Wait for prestarted threads to dequeue their initial tasks.
187             while (! tpe.getQueue().isEmpty())
188                 Thread.sleep(1);
189             for (int i = 0; i < 5*n; i++)
190                 tpe.execute(runRunnableDuJour);
191         } else {
192             for (int i = 0; i < 6*n; i++)
193                 tpe.execute(runRunnableDuJour);
194         }
195 
196         //report("submitted", tpe);
197         pumpedUp.await();
198         equal(3*n, tg.activeCount());
199         equal(3*n, tpe.getMaximumPoolSize());
200         equal(3*n, tpe.getLargestPoolSize());
201         equal(n, tpe.getCorePoolSize());
202         equal(3*n, tpe.getActiveCount());
203         equal(6L*n, tpe.getTaskCount());
204         equal(0L, tpe.getCompletedTaskCount());
205 
206         //report("pumped up", tpe);
207         tpe.setMaximumPoolSize(4*n);
208         equal(4*n, tpe.getMaximumPoolSize());
209         //report("pumped up2", tpe);
210         final CyclicBarrier pumpedUp2 = new CyclicBarrier(n + 1);
211         runnableDuJour = waiter(pumpedUp2);
212         for (int i = 0; i < 1*n; i++)
213             tpe.execute(runRunnableDuJour);
214         pumpedUp2.await();
215         equal(4*n, tg.activeCount());
216         equal(4*n, tpe.getMaximumPoolSize());
217         equal(4*n, tpe.getLargestPoolSize());
218         equal(4*n, tpe.getActiveCount());
219         equal(7L*n, tpe.getTaskCount());
220         equal(0L, tpe.getCompletedTaskCount());
221         //report("pumped up2", tpe);
222         runnableDuJour = new Runnable() { public void run() {}};
223 
224         tpe.setMaximumPoolSize(2*n);
225         //report("after setMaximumPoolSize", tpe);
226 
227         pumpedUp2.await();
228         pumpedUp.await();
229 
230         spinAwait(() -> tg.activeCount() == 2*n);
231         equal(2*n, tpe.getMaximumPoolSize());
232         equal(4*n, tpe.getLargestPoolSize());
233 
234         //report("draining", tpe);
235         awaitIdleness(tpe, 7L*n);
236 
237         equal(2*n, tg.activeCount());
238         equal(2*n, tpe.getMaximumPoolSize());
239         equal(4*n, tpe.getLargestPoolSize());
240 
241         equal(7L*n, tpe.getTaskCount());
242         equal(7L*n, tpe.getCompletedTaskCount());
243         equal(0, tpe.getActiveCount());
244 
245         equal(3L, tpe.getKeepAliveTime(MINUTES));
246         long t0 = System.nanoTime();
247         tpe.setKeepAliveTime(7L, MILLISECONDS);
248         equal(7L, tpe.getKeepAliveTime(MILLISECONDS));
249         spinAwait(() -> tg.activeCount() == n);
250         check(System.nanoTime() - t0 >= tpe.getKeepAliveTime(NANOSECONDS));
251 
252         //report("idle", tpe);
253         check(! tpe.allowsCoreThreadTimeOut());
254         t0 = System.nanoTime();
255         tpe.allowCoreThreadTimeOut(true);
256         check(tpe.allowsCoreThreadTimeOut());
257         spinAwait(() -> tg.activeCount() == 0);
258 
259         // The following assertion is almost always true, but may
260         // exceptionally not be during a transition from core count
261         // too high to allowCoreThreadTimeOut.  Users will never
262         // notice, and we accept the small loss of testability.
263         //
264         // check(System.nanoTime() - t0 >= tpe.getKeepAliveTime(NANOSECONDS));
265 
266         //report("idle", tpe);
267 
268         tpe.shutdown();
269         checkShutdown(tpe);
270         check(tpe.awaitTermination(3L, MINUTES));
271         checkTerminated(tpe);
272     }
273 
274     //--------------------- Infrastructure ---------------------------
275     static volatile int passed = 0, failed = 0;
276     static void pass() {passed++;}
277     static void fail() {failed++; Thread.dumpStack();}
278     static void fail(String msg) {System.out.println(msg); fail();}
279     static void unexpected(Throwable t) {failed++; t.printStackTrace();}
280     static void check(boolean cond) {if (cond) pass(); else fail();}
281     static void equal(Object x, Object y) {
282         if (x == null ? y == null : x.equals(y)) pass();
283         else fail(x + " not equal to " + y);}
284     public static void main(String[] args) throws Throwable {
285         try {realMain(args);} catch (Throwable t) {unexpected(t);}
286         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
287         if (failed > 0) throw new AssertionError("Some tests failed");}
288     interface Fun {void f() throws Throwable;}
289     static void THROWS(Class<? extends Throwable> k, Fun... fs) {
290         for (Fun f : fs)
291             try { f.f(); fail("Expected " + k.getName() + " not thrown"); }
292             catch (Throwable t) {
293                 if (k.isAssignableFrom(t.getClass())) pass();
294                 else unexpected(t);}}
295 }
296