Thanks, Chris. On Sat, Feb 9, 2019 at 6:34 AM Chris Hegarty <chris.hega...@oracle.com> wrote:
> 8215359: InnocuousForkJoinWorkerThread.setContextClassLoader needlessly > throws > > https://cr.openjdk.java.net/~martin/webrevs/jdk/jsr166-integration/InnocuousForkJoinWorkerThread/index.html > > > Looks good. A positive test for setContextClassLoader(null) could be > added. > good point - let's improve the test: --- ForkJoinPool9Test.java 14 Dec 2018 02:48:21 -0000 1.6 +++ ForkJoinPool9Test.java 9 Feb 2019 19:18:10 -0000 @@ -11,6 +11,8 @@ import java.util.concurrent.ForkJoinPool; import java.util.concurrent.ForkJoinTask; import java.util.concurrent.Future; +import java.util.concurrent.ThreadLocalRandom; +import java.util.stream.Stream; import junit.framework.Test; import junit.framework.TestSuite; @@ -40,25 +42,32 @@ .findVarHandle(Thread.class, "contextClassLoader", ClassLoader.class); ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader(); boolean haveSecurityManager = (System.getSecurityManager() != null); - CountDownLatch taskStarted = new CountDownLatch(1); + CountDownLatch runInCommonPoolStarted = new CountDownLatch(1); ClassLoader classLoaderDistinctFromSystemClassLoader = ClassLoader.getPlatformClassLoader(); assertNotSame(classLoaderDistinctFromSystemClassLoader, systemClassLoader); Runnable runInCommonPool = () -> { - taskStarted.countDown(); + runInCommonPoolStarted.countDown(); assertTrue(ForkJoinTask.inForkJoinPool()); - assertSame(ForkJoinPool.commonPool(), - ForkJoinTask.getPool()); - assertSame(systemClassLoader, - Thread.currentThread().getContextClassLoader()); - assertSame(systemClassLoader, - CCL.get(Thread.currentThread())); + assertSame(ForkJoinPool.commonPool(), ForkJoinTask.getPool()); + Thread currentThread = Thread.currentThread(); + + Stream.of(systemClassLoader, null).forEach(cl -> { + if (ThreadLocalRandom.current().nextBoolean()) + // should always be permitted, without effect + currentThread.setContextClassLoader(cl); + }); + + Stream.of(currentThread.getContextClassLoader(), + (ClassLoader) CCL.get(currentThread)) + .forEach(cl -> assertTrue(cl == systemClassLoader || cl == null)); + if (haveSecurityManager) assertThrows( SecurityException.class, () -> System.getProperty("foo"), - () -> Thread.currentThread().setContextClassLoader( + () -> currentThread.setContextClassLoader( classLoaderDistinctFromSystemClassLoader)); // TODO ? // if (haveSecurityManager @@ -69,7 +78,7 @@ Future<?> f = ForkJoinPool.commonPool().submit(runInCommonPool); // Ensure runInCommonPool is truly running in the common pool, // by giving this thread no opportunity to "help" on get(). - await(taskStarted); + await(runInCommonPoolStarted); assertNull(f.get()); }
