Remove support for stuck threads The experimental support for stuck threads requires access to the java.lang.management package which is not supported on Android. This change re-lands https://r.android.com/1601635 Bug: 129054170 Test: m checkbuild Change-Id: I4b37c2d09b5c68afde438c343b41fcdc788c578e (cherry picked from commit 4156f43b51c6f2d42df6e45535e1967aa46514d3)
diff --git a/README.version b/README.version index 74c20ad..ebab252 100644 --- a/README.version +++ b/README.version
@@ -5,3 +5,4 @@ Local Changes: Extra generic type information to aid certain javacs. Remove DisableOnDebug (new in 4.12) as it is not supported on Android + Remove support for stuck threads
diff --git a/src/main/java/org/junit/internal/runners/statements/FailOnTimeout.java b/src/main/java/org/junit/internal/runners/statements/FailOnTimeout.java index 9362cc1..9fad35b 100644 --- a/src/main/java/org/junit/internal/runners/statements/FailOnTimeout.java +++ b/src/main/java/org/junit/internal/runners/statements/FailOnTimeout.java
@@ -1,8 +1,5 @@ package org.junit.internal.runners.statements; -import java.util.Arrays; -import java.util.Collections; -import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutionException; @@ -10,9 +7,6 @@ import java.util.concurrent.TimeUnit; import java.util.concurrent.TimeoutException; -import org.junit.internal.management.ManagementFactory; -import org.junit.internal.management.ThreadMXBean; -import org.junit.runners.model.MultipleFailureException; import org.junit.runners.model.Statement; import org.junit.runners.model.TestTimedOutException; @@ -20,7 +14,6 @@ private final Statement originalStatement; private final TimeUnit timeUnit; private final long timeout; - private final boolean lookForStuckThread; /** * Returns a new builder for building an instance. @@ -47,7 +40,6 @@ originalStatement = statement; timeout = builder.timeout; timeUnit = builder.unit; - lookForStuckThread = builder.lookForStuckThread; } /** @@ -56,7 +48,6 @@ * @since 4.12 */ public static class Builder { - private boolean lookForStuckThread = false; private long timeout = 0; private TimeUnit unit = TimeUnit.SECONDS; @@ -89,20 +80,6 @@ } /** - * Specifies whether to look for a stuck thread. If a timeout occurs and this - * feature is enabled, the test will look for a thread that appears to be stuck - * and dump its backtrace. This feature is experimental. Behavior may change - * after the 4.12 release in response to feedback. - * - * @param enable {@code true} to enable the feature - * @return {@code this} for method chaining. - */ - public Builder withLookingForStuckThread(boolean enable) { - this.lookForStuckThread = enable; - return this; - } - - /** * Builds a {@link FailOnTimeout} instance using the values in this builder, * wrapping the given statement. * @@ -120,8 +97,7 @@ public void evaluate() throws Throwable { CallableStatement callable = new CallableStatement(); FutureTask<Throwable> task = new FutureTask<Throwable>(callable); - ThreadGroup threadGroup = threadGroupForNewThread(); - Thread thread = new Thread(threadGroup, task, "Time-limited test"); + Thread thread = new Thread(task, "Time-limited test"); thread.setDaemon(true); thread.start(); callable.awaitStarted(); @@ -131,31 +107,6 @@ } } - private ThreadGroup threadGroupForNewThread() { - if (!lookForStuckThread) { - // Use the default ThreadGroup (usually the one from the current - // thread). - return null; - } - - // Create the thread in a new ThreadGroup, so if the time-limited thread - // becomes stuck, getStuckThread() can find the thread likely to be the - // culprit. - ThreadGroup threadGroup = new ThreadGroup("FailOnTimeoutGroup"); - if (!threadGroup.isDaemon()) { - // Mark the new ThreadGroup as a daemon thread group, so it will be - // destroyed after the time-limited thread completes. By ensuring the - // ThreadGroup is destroyed, any data associated with the ThreadGroup - // (ex: via java.beans.ThreadGroupContext) is destroyed. - try { - threadGroup.setDaemon(true); - } catch (SecurityException e) { - // Swallow the exception to keep the same behavior as in JUnit 4.12. - } - } - return threadGroup; - } - /** * Wait for the test task, returning the exception thrown by the test if the * test failed, an exception indicating a timeout if the test timed out, or @@ -180,114 +131,12 @@ private Exception createTimeoutException(Thread thread) { StackTraceElement[] stackTrace = thread.getStackTrace(); - final Thread stuckThread = lookForStuckThread ? getStuckThread(thread) : null; Exception currThreadException = new TestTimedOutException(timeout, timeUnit); if (stackTrace != null) { currThreadException.setStackTrace(stackTrace); thread.interrupt(); } - if (stuckThread != null) { - Exception stuckThreadException = - new Exception("Appears to be stuck in thread " + - stuckThread.getName()); - stuckThreadException.setStackTrace(getStackTrace(stuckThread)); - return new MultipleFailureException( - Arrays.<Throwable>asList(currThreadException, stuckThreadException)); - } else { - return currThreadException; - } - } - - /** - * Retrieves the stack trace for a given thread. - * @param thread The thread whose stack is to be retrieved. - * @return The stack trace; returns a zero-length array if the thread has - * terminated or the stack cannot be retrieved for some other reason. - */ - private StackTraceElement[] getStackTrace(Thread thread) { - try { - return thread.getStackTrace(); - } catch (SecurityException e) { - return new StackTraceElement[0]; - } - } - - /** - * Determines whether the test appears to be stuck in some thread other than - * the "main thread" (the one created to run the test). This feature is experimental. - * Behavior may change after the 4.12 release in response to feedback. - * @param mainThread The main thread created by {@code evaluate()} - * @return The thread which appears to be causing the problem, if different from - * {@code mainThread}, or {@code null} if the main thread appears to be the - * problem or if the thread cannot be determined. The return value is never equal - * to {@code mainThread}. - */ - private Thread getStuckThread(Thread mainThread) { - List<Thread> threadsInGroup = getThreadsInGroup(mainThread.getThreadGroup()); - if (threadsInGroup.isEmpty()) { - return null; - } - - // Now that we have all the threads in the test's thread group: Assume that - // any thread we're "stuck" in is RUNNABLE. Look for all RUNNABLE threads. - // If just one, we return that (unless it equals threadMain). If there's more - // than one, pick the one that's using the most CPU time, if this feature is - // supported. - Thread stuckThread = null; - long maxCpuTime = 0; - for (Thread thread : threadsInGroup) { - if (thread.getState() == Thread.State.RUNNABLE) { - long threadCpuTime = cpuTime(thread); - if (stuckThread == null || threadCpuTime > maxCpuTime) { - stuckThread = thread; - maxCpuTime = threadCpuTime; - } - } - } - return (stuckThread == mainThread) ? null : stuckThread; - } - - /** - * Returns all active threads belonging to a thread group. - * @param group The thread group. - * @return The active threads in the thread group. The result should be a - * complete list of the active threads at some point in time. Returns an empty list - * if this cannot be determined, e.g. because new threads are being created at an - * extremely fast rate. - */ - private List<Thread> getThreadsInGroup(ThreadGroup group) { - final int activeThreadCount = group.activeCount(); // this is just an estimate - int threadArraySize = Math.max(activeThreadCount * 2, 100); - for (int loopCount = 0; loopCount < 5; loopCount++) { - Thread[] threads = new Thread[threadArraySize]; - int enumCount = group.enumerate(threads); - if (enumCount < threadArraySize) { - return Arrays.asList(threads).subList(0, enumCount); - } - // if there are too many threads to fit into the array, enumerate's result - // is >= the array's length; therefore we can't trust that it returned all - // the threads. Try again. - threadArraySize += 100; - } - // threads are proliferating too fast for us. Bail before we get into - // trouble. - return Collections.emptyList(); - } - - /** - * Returns the CPU time used by a thread, if possible. - * @param thr The thread to query. - * @return The CPU time used by {@code thr}, or 0 if it cannot be determined. - */ - private long cpuTime(Thread thr) { - ThreadMXBean mxBean = ManagementFactory.getThreadMXBean(); - if (mxBean.isThreadCpuTimeSupported()) { - try { - return mxBean.getThreadCpuTime(thr.getId()); - } catch (UnsupportedOperationException e) { - } - } - return 0; + return currThreadException; } private class CallableStatement implements Callable<Throwable> {
diff --git a/src/main/java/org/junit/rules/Timeout.java b/src/main/java/org/junit/rules/Timeout.java index 334a923..5cf905a 100644 --- a/src/main/java/org/junit/rules/Timeout.java +++ b/src/main/java/org/junit/rules/Timeout.java
@@ -40,7 +40,6 @@ public class Timeout implements TestRule { private final long timeout; private final TimeUnit timeUnit; - private final boolean lookForStuckThread; /** * Returns a new builder for building an instance. @@ -80,7 +79,6 @@ public Timeout(long timeout, TimeUnit timeUnit) { this.timeout = timeout; this.timeUnit = timeUnit; - lookForStuckThread = false; } /** @@ -92,7 +90,6 @@ protected Timeout(Builder builder) { timeout = builder.getTimeout(); timeUnit = builder.getTimeUnit(); - lookForStuckThread = builder.getLookingForStuckThread(); } /** @@ -125,16 +122,6 @@ } /** - * Gets whether this {@code Timeout} will look for a stuck thread - * when the test times out. - * - * @since 4.12 - */ - protected final boolean getLookingForStuckThread() { - return lookForStuckThread; - } - - /** * Creates a {@link Statement} that will run the given * {@code statement}, and timeout the operation based * on the values configured in this rule. Subclasses @@ -146,7 +133,6 @@ Statement statement) throws Exception { return FailOnTimeout.builder() .withTimeout(timeout, timeUnit) - .withLookingForStuckThread(lookForStuckThread) .build(statement); } @@ -205,25 +191,6 @@ } /** - * Specifies whether to look for a stuck thread. If a timeout occurs and this - * feature is enabled, the rule will look for a thread that appears to be stuck - * and dump its backtrace. This feature is experimental. Behavior may change - * after the 4.12 release in response to feedback. - * - * @param enable {@code true} to enable the feature - * @return {@code this} for method chaining. - */ - public Builder withLookingForStuckThread(boolean enable) { - this.lookForStuckThread = enable; - return this; - } - - protected boolean getLookingForStuckThread() { - return lookForStuckThread; - } - - - /** * Builds a {@link Timeout} instance using the values in this builder., */ public Timeout build() {