| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.tomcat.dbcp.dbcp2; |
| |
| import java.lang.ref.WeakReference; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.tomcat.dbcp.pool2.TrackedUse; |
| |
| /** |
| * Tracks db connection usage for recovering and reporting |
| * abandoned db connections. |
| * |
| * The JDBC Connection, Statement, and ResultSet classes |
| * extend this class. |
| * |
| * @author Glenn L. Nielsen |
| * @since 2.0 |
| */ |
| public class AbandonedTrace implements TrackedUse { |
| |
| /** A list of objects created by children of this object */ |
| private final List<WeakReference<AbandonedTrace>> traceList = new ArrayList<>(); |
| /** Last time this connection was used */ |
| private volatile long lastUsed = 0; |
| |
| /** |
| * Create a new AbandonedTrace without config and |
| * without doing abandoned tracing. |
| */ |
| public AbandonedTrace() { |
| init(null); |
| } |
| |
| /** |
| * Construct a new AbandonedTrace with a parent object. |
| * |
| * @param parent AbandonedTrace parent object |
| */ |
| public AbandonedTrace(final AbandonedTrace parent) { |
| init(parent); |
| } |
| |
| /** |
| * Initialize abandoned tracing for this object. |
| * |
| * @param parent AbandonedTrace parent object |
| */ |
| private void init(final AbandonedTrace parent) { |
| if (parent != null) { |
| parent.addTrace(this); |
| } |
| } |
| |
| /** |
| * Get the last time this object was used in ms. |
| * |
| * @return long time in ms |
| */ |
| @Override |
| public long getLastUsed() { |
| return lastUsed; |
| } |
| |
| /** |
| * Set the time this object was last used to the |
| * current time in ms. |
| */ |
| protected void setLastUsed() { |
| lastUsed = System.currentTimeMillis(); |
| } |
| |
| /** |
| * Set the time in ms this object was last used. |
| * |
| * @param time time in ms |
| */ |
| protected void setLastUsed(final long time) { |
| lastUsed = time; |
| } |
| |
| /** |
| * Add an object to the list of objects being |
| * traced. |
| * |
| * @param trace AbandonedTrace object to add |
| */ |
| protected void addTrace(final AbandonedTrace trace) { |
| synchronized (this.traceList) { |
| this.traceList.add(new WeakReference<>(trace)); |
| } |
| setLastUsed(); |
| } |
| |
| /** |
| * Clear the list of objects being traced by this |
| * object. |
| */ |
| protected void clearTrace() { |
| synchronized(this.traceList) { |
| this.traceList.clear(); |
| } |
| } |
| |
| /** |
| * Get a list of objects being traced by this object. |
| * |
| * @return List of objects |
| */ |
| protected List<AbandonedTrace> getTrace() { |
| final int size = traceList.size(); |
| if (size == 0) { |
| return Collections.emptyList(); |
| } |
| final ArrayList<AbandonedTrace> result = new ArrayList<>(size); |
| synchronized (this.traceList) { |
| final Iterator<WeakReference<AbandonedTrace>> iter = traceList.iterator(); |
| while (iter.hasNext()) { |
| final WeakReference<AbandonedTrace> ref = iter.next(); |
| if (ref.get() == null) { |
| // Clean-up since we are here anyway |
| iter.remove(); |
| } else { |
| result.add(ref.get()); |
| } |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Remove a child object this object is tracing. |
| * |
| * @param trace AbandonedTrace object to remove |
| */ |
| protected void removeTrace(final AbandonedTrace trace) { |
| synchronized(this.traceList) { |
| final Iterator<WeakReference<AbandonedTrace>> iter = traceList.iterator(); |
| while (iter.hasNext()) { |
| final WeakReference<AbandonedTrace> ref = iter.next(); |
| if (trace.equals(ref.get())) { |
| iter.remove(); |
| break; |
| } else if (ref.get() == null) { |
| // Clean-up since we are here anyway |
| iter.remove(); |
| } |
| } |
| } |
| } |
| } |