* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
-
package org.opendaylight.yangtools.util.concurrent;
import static com.google.common.base.Preconditions.checkState;
import static java.util.Objects.requireNonNull;
-import com.google.common.util.concurrent.ForwardingListenableFuture;
+import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Supplier;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
/**
- * An implementation of ListeningExecutorService that attempts to detect deadlock scenarios that
- * could occur if clients invoke the returned Future's <code>get</code> methods synchronously.
+ * An implementation of ListeningExecutorService that attempts to detect deadlock scenarios that could occur if clients
+ * invoke the returned Future's <code>get</code> methods synchronously.
*
- * <p>Deadlock scenarios are most apt to occur with a backing single-threaded executor where setting of
- * the Future's result is executed on the single thread. Here's a scenario:
+ * <p>Deadlock scenarios are most apt to occur with a backing single-threaded executor where setting of the Future's
+ * result is executed on the single thread. Here's a scenario:
* <ul>
* <li>Client code is currently executing in an executor's single thread.</li>
* <li>The client submits another task to the same executor.</li>
* <li>The client calls <code>get()</code> synchronously on the returned Future</li>
* </ul>
- * The second submitted task will never execute since the single thread is currently executing
- * the client code which is blocked waiting for the submitted task to complete. Thus, deadlock has
- * occurred.
+ * The second submitted task will never execute since the single thread is currently executing the client code which
+ * is blocked waiting for the submitted task to complete. Thus, deadlock has occurred.
*
- * <p>This class prevents this scenario via the use of a ThreadLocal variable. When a task is invoked,
- * the ThreadLocal is set and, when a task completes, the ThreadLocal is cleared. Futures returned
- * from this class override the <code>get</code> methods to check if the ThreadLocal is set. If it is,
- * an ExecutionException is thrown with a custom cause.
+ * <p>This class prevents this scenario via the use of a ThreadLocal variable. When a task is invoked, the ThreadLocal
+ * is set and, when a task completes, the ThreadLocal is cleared. Futures returned from this class override
+ * the {@code get} methods to check if the ThreadLocal is set. If it is, an ExecutionException is thrown with a custom
+ * cause.
*
- * <p>Note that the ThreadLocal is not removed automatically, so some state may be left hanging off of
- * threads which have encountered this class. If you need to clean that state up, use
- * {@link #cleanStateForCurrentThread()}.
+ * <p>Note that the ThreadLocal is not removed automatically, so some state may be left hanging off of threads which
+ * have encountered this class. If you need to clean that state up, use {@link #cleanStateForCurrentThread()}.
*
* @author Thomas Pantelis
* @author Robert Varga
* tasks may be submitted to underlay and some to overlay service -- and the two cases need to
* be discerned reliably.
*/
- private final SettableBooleanThreadLocal deadlockDetector = new SettableBooleanThreadLocal();
- private final Supplier<Exception> deadlockExceptionFunction;
+ private final @NonNull SettableBooleanThreadLocal deadlockDetector = new SettableBooleanThreadLocal();
+ private final @NonNull Supplier<Exception> deadlockExceptionFunction;
/**
* Constructor.
* @param deadlockExceptionSupplier Supplier that returns an Exception instance to set as the
* cause of the ExecutionException when a deadlock is detected.
*/
- public DeadlockDetectingListeningExecutorService(final ExecutorService delegate,
- @Nonnull final Supplier<Exception> deadlockExceptionSupplier) {
+ public DeadlockDetectingListeningExecutorService(final @NonNull ExecutorService delegate,
+ final @NonNull Supplier<Exception> deadlockExceptionSupplier) {
this(delegate, deadlockExceptionSupplier, null);
}
* @param listenableFutureExecutor the executor used to run listener callbacks asynchronously.
* If null, no executor is used.
*/
- public DeadlockDetectingListeningExecutorService(final ExecutorService delegate,
- @Nonnull final Supplier<Exception> deadlockExceptionSupplier,
+ public DeadlockDetectingListeningExecutorService(final @NonNull ExecutorService delegate,
+ @NonNull final Supplier<Exception> deadlockExceptionSupplier,
@Nullable final Executor listenableFutureExecutor) {
super(delegate, listenableFutureExecutor);
this.deadlockExceptionFunction = requireNonNull(deadlockExceptionSupplier);
}
@Override
- public void execute(@Nonnull final Runnable command) {
+ public void execute(final Runnable command) {
getDelegate().execute(wrapRunnable(command));
}
- @Nonnull
@Override
public <T> ListenableFuture<T> submit(final Callable<T> task) {
return wrapListenableFuture(super.submit(wrapCallable(task)));
}
- @Nonnull
@Override
public ListenableFuture<?> submit(final Runnable task) {
return wrapListenableFuture(super.submit(wrapRunnable(task)));
}
- @Nonnull
@Override
public <T> ListenableFuture<T> submit(final Runnable task, final T result) {
return wrapListenableFuture(super.submit(wrapRunnable(task), result));
deadlockDetector.remove();
}
- private SettableBoolean primeDetector() {
+ private @NonNull SettableBoolean primeDetector() {
final SettableBoolean b = deadlockDetector.get();
checkState(!b.isSet(), "Detector for {} has already been primed", this);
b.set();
return b;
}
- private Runnable wrapRunnable(final Runnable task) {
+ private @NonNull Runnable wrapRunnable(final @Nullable Runnable task) {
+ requireNonNull(task);
return () -> {
final SettableBoolean b = primeDetector();
try {
};
}
- private <T> Callable<T> wrapCallable(final Callable<T> delagate) {
+ private <T> @NonNull Callable<T> wrapCallable(final @NonNull Callable<T> task) {
+ requireNonNull(task);
return () -> {
final SettableBoolean b = primeDetector();
try {
- return delagate.call();
+ return task.call();
} finally {
b.reset();
}
};
}
- private <T> ListenableFuture<T> wrapListenableFuture(final ListenableFuture<T> delegate) {
+ private <T> @NonNull ListenableFuture<T> wrapListenableFuture(final @NonNull ListenableFuture<T> delegate) {
/*
* This creates a forwarding Future that overrides calls to get(...) to check, via the
* ThreadLocal, if the caller is doing a blocking call on a thread from this executor. If
* practice somewhere, either on the client side for doing a blocking call or in the
* framework's threading model.
*/
- return new ForwardingListenableFuture.SimpleForwardingListenableFuture<T>(delegate) {
+ return new SimpleForwardingListenableFuture<T>(delegate) {
@Override
public T get() throws InterruptedException, ExecutionException {
checkDeadLockDetectorTL();
}
@Override
- public T get(final long timeout, @Nonnull final TimeUnit unit)
- throws InterruptedException, ExecutionException, TimeoutException {
+ public T get(final long timeout, final TimeUnit unit) throws InterruptedException, ExecutionException,
+ TimeoutException {
checkDeadLockDetectorTL();
return super.get(timeout, unit);
}
Code Review / yangtools.git / blobdiff