| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file: |
| * |
| * Written by Martin Buchholz 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 8022642 8065320 8129861 |
| * @summary Ensure relative sanity when zero core threads |
| * @library /lib/testlibrary/ |
| * @modules java.base/java.util.concurrent:open |
| */ |
| |
| import static java.util.concurrent.TimeUnit.HOURS; |
| import static java.util.concurrent.TimeUnit.MILLISECONDS; |
| |
| import java.lang.reflect.Field; |
| import java.util.concurrent.BlockingQueue; |
| import java.util.concurrent.ScheduledThreadPoolExecutor; |
| import java.util.concurrent.locks.Condition; |
| import java.util.concurrent.locks.ReentrantLock; |
| import java.util.function.BooleanSupplier; |
| import jdk.testlibrary.Utils; |
| |
| public class ZeroCoreThreads { |
| static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000); |
| |
| static long millisElapsedSince(long startTime) { |
| return (System.nanoTime() - startTime) / (1000L * 1000L); |
| } |
| |
| static void spinWaitUntil(BooleanSupplier predicate, long timeoutMillis) { |
| long startTime = -1L; |
| while (!predicate.getAsBoolean()) { |
| if (startTime == -1L) |
| startTime = System.nanoTime(); |
| else if (millisElapsedSince(startTime) > timeoutMillis) |
| throw new AssertionError( |
| String.format("timed out after %s ms", timeoutMillis)); |
| Thread.yield(); |
| } |
| } |
| |
| static boolean hasWaiters(ReentrantLock lock, Condition condition) { |
| lock.lock(); |
| try { |
| return lock.hasWaiters(condition); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| static void awaitHasWaiters(ReentrantLock lock, Condition condition, |
| long timeoutMillis) { |
| spinWaitUntil(() -> hasWaiters(lock, condition), timeoutMillis); |
| } |
| |
| static <T> T getField(Object x, String fieldName) { |
| try { |
| Field field = x.getClass().getDeclaredField(fieldName); |
| field.setAccessible(true); |
| return (T) field.get(x); |
| } catch (ReflectiveOperationException ex) { |
| throw new AssertionError(ex); |
| } |
| } |
| |
| void test(String[] args) throws Throwable { |
| ScheduledThreadPoolExecutor p = new ScheduledThreadPoolExecutor(0); |
| try { |
| test(p); |
| } finally { |
| p.shutdownNow(); |
| check(p.awaitTermination(LONG_DELAY_MS, MILLISECONDS)); |
| } |
| } |
| |
| void test(ScheduledThreadPoolExecutor p) throws Throwable { |
| Runnable dummy = new Runnable() { public void run() { |
| throw new AssertionError("shouldn't get here"); }}; |
| BlockingQueue q = p.getQueue(); |
| ReentrantLock lock = getField(q, "lock"); |
| Condition available = getField(q, "available"); |
| |
| equal(0, p.getPoolSize()); |
| equal(0, p.getLargestPoolSize()); |
| equal(0L, p.getTaskCount()); |
| equal(0L, p.getCompletedTaskCount()); |
| p.schedule(dummy, 1L, HOURS); |
| // Ensure one pool thread actually waits in timed queue poll |
| awaitHasWaiters(lock, available, LONG_DELAY_MS); |
| equal(1, p.getPoolSize()); |
| equal(1, p.getLargestPoolSize()); |
| equal(1L, p.getTaskCount()); |
| equal(0L, p.getCompletedTaskCount()); |
| } |
| |
| //--------------------- 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 ZeroCoreThreads().instanceMain(args);} |
| 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");} |
| } |