2 * Copyright (c) 2017 Red Hat, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.trace.impl;
10 import static java.util.Objects.requireNonNull;
12 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
13 import org.eclipse.jdt.annotation.Nullable;
16 * Implementation of {@link CloseTracked} which can be used as a field in another class which implements
17 * {@link CloseTracked} and delegates its methods to this.
20 * This is useful if that class already has another parent class. If it does not, then it's typically more convenient to
21 * just extend AbstractCloseTracked.
23 * @author Michael Vorburger.ch
25 final class CloseTrackedTrait<T extends CloseTracked<T>> implements CloseTracked<T> {
26 // NB: It's important that we keep a Throwable here, and not directly the StackTraceElement[] !
27 // This is because creating a new Throwable() is a lot less expensive in terms of runtime overhead
28 // than actually calling its getStackTrace(), which we can delay until we really need to.
29 // see also e.g. https://stackoverflow.com/a/26122232/421602
30 private final @Nullable Throwable allocationContext;
31 private final CloseTrackedRegistry<T> closeTrackedRegistry;
32 private final CloseTracked<T> realCloseTracked;
34 CloseTrackedTrait(final CloseTrackedRegistry<T> transactionChainRegistry, final CloseTracked<T> realCloseTracked) {
35 if (transactionChainRegistry.isDebugContextEnabled()) {
36 // NB: We're NOT doing the (expensive) getStackTrace() here just yet (only below)
37 // TODO When we're on Java 9, then instead use the new java.lang.StackWalker API..
38 allocationContext = new Throwable();
40 allocationContext = null;
42 this.realCloseTracked = requireNonNull(realCloseTracked, "realCloseTracked");
43 closeTrackedRegistry = requireNonNull(transactionChainRegistry, "transactionChainRegistry");
44 closeTrackedRegistry.add(this);
48 @SuppressFBWarnings("PZLA_PREFER_ZERO_LENGTH_ARRAYS")
49 public @Nullable StackTraceElement[] getAllocationContextStackTrace() {
50 final var local = allocationContext;
51 return local != null ? local.getStackTrace() : null;
54 public void removeFromTrackedRegistry() {
55 closeTrackedRegistry.remove(this);
59 public CloseTracked<T> getRealCloseTracked() {
60 return realCloseTracked;