+/*-
+ * ============LICENSE_START=======================================================
+ * openecomp
+ * ================================================================================
+ * Copyright (C) 2016 - 2017 AT&T
+ * ================================================================================
+ * Licensed 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.
+ * ============LICENSE_END=========================================================
+ */
+
+/*
+ * 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.jdbc.pool;
+
+import java.lang.ref.WeakReference;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Proxy;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+
+/**
+ * Implementation of simple connection pool.
+ * The ConnectionPool uses a {@link PoolProperties} object for storing all the meta information about the connection pool.
+ * As the underlying implementation, the connection pool uses {@link java.util.concurrent.BlockingQueue} to store active and idle connections.
+ * A custom implementation of a fair {@link FairBlockingQueue} blocking queue is provided with the connection pool itself.
+ * @version 1.0
+ */
+public class ConnectionPool {
+
+ /**
+ * Default domain for objects registering with an mbean server
+ */
+ public static final String POOL_JMX_DOMAIN = "tomcat.jdbc";
+ /**
+ * Prefix type for JMX registration
+ */
+ public static final String POOL_JMX_TYPE_PREFIX = POOL_JMX_DOMAIN+":type=";
+
+ /**
+ * Logger
+ */
+ private static final Log log = LogFactory.getLog(ConnectionPool.class);
+
+ //===============================================================================
+ // INSTANCE/QUICK ACCESS VARIABLE
+ //===============================================================================
+ /**
+ * Carries the size of the pool, instead of relying on a queue implementation
+ * that usually iterates over to get an exact count
+ */
+ private AtomicInteger size = new AtomicInteger(0);
+
+ /**
+ * All the information about the connection pool
+ * These are the properties the pool got instantiated with
+ */
+ private PoolConfiguration poolProperties;
+
+ /**
+ * Contains all the connections that are in use
+ * TODO - this shouldn't be a blocking queue, simply a list to hold our objects
+ */
+ private BlockingQueue<PooledConnection> busy;
+
+ /**
+ * Contains all the idle connections
+ */
+ private BlockingQueue<PooledConnection> idle;
+
+ /**
+ * The thread that is responsible for checking abandoned and idle threads
+ */
+ private volatile PoolCleaner poolCleaner;
+
+ /**
+ * Pool closed flag
+ */
+ private volatile boolean closed = false;
+
+ /**
+ * Since newProxyInstance performs the same operation, over and over
+ * again, it is much more optimized if we simply store the constructor ourselves.
+ */
+ private Constructor<?> proxyClassConstructor;
+
+ /**
+ * Executor service used to cancel Futures
+ */
+ private ThreadPoolExecutor cancellator = new ThreadPoolExecutor(0,1,1000,TimeUnit.MILLISECONDS,new LinkedBlockingQueue<Runnable>());
+
+ /**
+ * reference to the JMX mbean
+ */
+ protected org.apache.tomcat.jdbc.pool.jmx.ConnectionPool jmxPool = null;
+
+ /**
+ * counter to track how many threads are waiting for a connection
+ */
+ private AtomicInteger waitcount = new AtomicInteger(0);
+
+ private AtomicLong poolVersion = new AtomicLong(Long.MIN_VALUE);
+
+ /**
+ * The counters for statistics of the pool.
+ */
+ private final AtomicLong borrowedCount = new AtomicLong(0);
+ private final AtomicLong returnedCount = new AtomicLong(0);
+ private final AtomicLong createdCount = new AtomicLong(0);
+ private final AtomicLong releasedCount = new AtomicLong(0);
+ private final AtomicLong reconnectedCount = new AtomicLong(0);
+ private final AtomicLong removeAbandonedCount = new AtomicLong(0);
+ private final AtomicLong releasedIdleCount = new AtomicLong(0);
+
+ //===============================================================================
+ // PUBLIC METHODS
+ //===============================================================================
+
+ /**
+ * Instantiate a connection pool. This will create connections if initialSize is larger than 0.
+ * The {@link PoolProperties} should not be reused for another connection pool.
+ * @param prop PoolProperties - all the properties for this connection pool
+ * @throws SQLException Pool initialization error
+ */
+ public ConnectionPool(PoolConfiguration prop) throws SQLException {
+ //setup quick access variables and pools
+ init(prop);
+ }
+
+
+ /**
+ * Retrieves a Connection future. If a connection is not available, one can block using future.get()
+ * until a connection has become available.
+ * If a connection is not retrieved, the Future must be cancelled in order for the connection to be returned
+ * to the pool.
+ * @return a Future containing a reference to the connection or the future connection
+ * @throws SQLException Cannot use asynchronous connect
+ */
+ public Future<Connection> getConnectionAsync() throws SQLException {
+ try {
+ PooledConnection pc = borrowConnection(0, null, null);
+ if (pc!=null) {
+ return new ConnectionFuture(pc);
+ }
+ }catch (SQLException x) {
+ if (x.getMessage().indexOf("NoWait")<0) {
+ throw x;
+ }
+ }
+ //we can only retrieve a future if the underlying queue supports it.
+ if (idle instanceof FairBlockingQueue<?>) {
+ Future<PooledConnection> pcf = ((FairBlockingQueue<PooledConnection>)idle).pollAsync();
+ return new ConnectionFuture(pcf);
+ } else if (idle instanceof MultiLockFairBlockingQueue<?>) {
+ Future<PooledConnection> pcf = ((MultiLockFairBlockingQueue<PooledConnection>)idle).pollAsync();
+ return new ConnectionFuture(pcf);
+ } else {
+ throw new SQLException("Connection pool is misconfigured, doesn't support async retrieval. Set the 'fair' property to 'true'");
+ }
+ }
+
+ /**
+ * Borrows a connection from the pool. If a connection is available (in the idle queue) or the pool has not reached
+ * {@link PoolProperties#maxActive maxActive} connections a connection is returned immediately.
+ * If no connection is available, the pool will attempt to fetch a connection for {@link PoolProperties#maxWait maxWait} milliseconds.
+ * @return Connection - a java.sql.Connection/javax.sql.PooledConnection reflection proxy, wrapping the underlying object.
+ * @throws SQLException - if the wait times out or a failure occurs creating a connection
+ */
+ public Connection getConnection() throws SQLException {
+ //check out a connection
+ PooledConnection con = borrowConnection(-1,null,null);
+ return setupConnection(con);
+ }
+
+
+ /**
+ * Borrows a connection from the pool. If a connection is available (in the
+ * idle queue) or the pool has not reached {@link PoolProperties#maxActive
+ * maxActive} connections a connection is returned immediately. If no
+ * connection is available, the pool will attempt to fetch a connection for
+ * {@link PoolProperties#maxWait maxWait} milliseconds.
+ * @param username The user name to use for the connection
+ * @param password The password for the connection
+ * @return Connection - a java.sql.Connection/javax.sql.PooledConnection
+ * reflection proxy, wrapping the underlying object.
+ * @throws SQLException
+ * - if the wait times out or a failure occurs creating a
+ * connection
+ */
+ public Connection getConnection(String username, String password) throws SQLException {
+ // check out a connection
+ PooledConnection con = borrowConnection(-1, username, password);
+ return setupConnection(con);
+ }
+
+ /**
+ * Returns the name of this pool
+ * @return String - the name of the pool
+ */
+ public String getName() {
+ return getPoolProperties().getPoolName();
+ }
+
+ /**
+ * Return the number of threads waiting for a connection
+ * @return number of threads waiting for a connection
+ */
+ public int getWaitCount() {
+ return waitcount.get();
+ }
+
+ /**
+ * Returns the pool properties associated with this connection pool
+ * @return PoolProperties
+ *
+ */
+ public PoolConfiguration getPoolProperties() {
+ return this.poolProperties;
+ }
+
+ /**
+ * Returns the total size of this pool, this includes both busy and idle connections
+ * @return int - number of established connections to the database
+ */
+ public int getSize() {
+ return size.get();
+ }
+
+ /**
+ * Returns the number of connections that are in use
+ * @return int - number of established connections that are being used by the application
+ */
+ public int getActive() {
+ return busy.size();
+ }
+
+ /**
+ * Returns the number of idle connections
+ * @return int - number of established connections not being used
+ */
+ public int getIdle() {
+ return idle.size();
+ }
+
+ /**
+ * Returns true if {@link #close close} has been called, and the connection pool is unusable
+ * @return boolean
+ */
+ public boolean isClosed() {
+ return this.closed;
+ }
+
+ //===============================================================================
+ // PROTECTED METHODS
+ //===============================================================================
+
+
+ /**
+ * configures a pooled connection as a proxy.
+ * This Proxy implements {@link java.sql.Connection} and {@link javax.sql.PooledConnection} interfaces.
+ * All calls on {@link java.sql.Connection} methods will be propagated down to the actual JDBC connection except for the
+ * {@link java.sql.Connection#close()} method.
+ * @param con a {@link PooledConnection} to wrap in a Proxy
+ * @return a {@link java.sql.Connection} object wrapping a pooled connection.
+ * @throws SQLException if an interceptor can't be configured, if the proxy can't be instantiated
+ */
+ protected Connection setupConnection(PooledConnection con) throws SQLException {
+ //fetch previously cached interceptor proxy - one per connection
+ JdbcInterceptor handler = con.getHandler();
+ if (handler==null) {
+ //build the proxy handler
+ handler = new ProxyConnection(this,con,getPoolProperties().isUseEquals());
+ //set up the interceptor chain
+ PoolProperties.InterceptorDefinition[] proxies = getPoolProperties().getJdbcInterceptorsAsArray();
+ for (int i=proxies.length-1; i>=0; i--) {
+ try {
+ //create a new instance
+ JdbcInterceptor interceptor = proxies[i].getInterceptorClass().newInstance();
+ //configure properties
+ interceptor.setProperties(proxies[i].getProperties());
+ //setup the chain
+ interceptor.setNext(handler);
+ //call reset
+ interceptor.reset(this, con);
+ //configure the last one to be held by the connection
+ handler = interceptor;
+ }catch(Exception x) {
+ SQLException sx = new SQLException("Unable to instantiate interceptor chain.");
+ sx.initCause(x);
+ throw sx;
+ }
+ }
+ //cache handler for the next iteration
+ con.setHandler(handler);
+ } else {
+ JdbcInterceptor next = handler;
+ //we have a cached handler, reset it
+ while (next!=null) {
+ next.reset(this, con);
+ next = next.getNext();
+ }
+ }
+
+ try {
+ getProxyConstructor(con.getXAConnection() != null);
+ //create the proxy
+ //TODO possible optimization, keep track if this connection was returned properly, and don't generate a new facade
+ Connection connection = null;
+ if (getPoolProperties().getUseDisposableConnectionFacade() ) {
+ connection = (Connection)proxyClassConstructor.newInstance(new Object[] { new DisposableConnectionFacade(handler) });
+ } else {
+ connection = (Connection)proxyClassConstructor.newInstance(new Object[] {handler});
+ }
+ //return the connection
+ return connection;
+ }catch (Exception x) {
+ SQLException s = new SQLException();
+ s.initCause(x);
+ throw s;
+ }
+
+ }
+
+ /**
+ * Creates and caches a {@link java.lang.reflect.Constructor} used to instantiate the proxy object.
+ * We cache this, since the creation of a constructor is fairly slow.
+ * @param xa Use a XA connection
+ * @return constructor used to instantiate the wrapper object
+ * @throws NoSuchMethodException Failed to get a constructor
+ */
+ public Constructor<?> getProxyConstructor(boolean xa) throws NoSuchMethodException {
+ //cache the constructor
+ if (proxyClassConstructor == null ) {
+ Class<?> proxyClass = xa ?
+ Proxy.getProxyClass(ConnectionPool.class.getClassLoader(), new Class[] {java.sql.Connection.class,javax.sql.PooledConnection.class, javax.sql.XAConnection.class}) :
+ Proxy.getProxyClass(ConnectionPool.class.getClassLoader(), new Class[] {java.sql.Connection.class,javax.sql.PooledConnection.class});
+ proxyClassConstructor = proxyClass.getConstructor(new Class[] { InvocationHandler.class });
+ }
+ return proxyClassConstructor;
+ }
+
+ /**
+ * Closes the pool and all disconnects all idle connections
+ * Active connections will be closed upon the {@link java.sql.Connection#close close} method is called
+ * on the underlying connection instead of being returned to the pool
+ * @param force - true to even close the active connections
+ */
+ protected void close(boolean force) {
+ //are we already closed
+ if (this.closed) return;
+ //prevent other threads from entering
+ this.closed = true;
+ //stop background thread
+ if (poolCleaner!=null) {
+ poolCleaner.stopRunning();
+ }
+
+ /* release all idle connections */
+ BlockingQueue<PooledConnection> pool = (idle.size()>0)?idle:(force?busy:idle);
+ while (pool.size()>0) {
+ try {
+ //retrieve the next connection
+ PooledConnection con = pool.poll(1000, TimeUnit.MILLISECONDS);
+ //close it and retrieve the next one, if one is available
+ while (con != null) {
+ //close the connection
+ if (pool==idle)
+ release(con);
+ else
+ abandon(con);
+ if (pool.size()>0) {
+ con = pool.poll(1000, TimeUnit.MILLISECONDS);
+ } else {
+ break;
+ }
+ } //while
+ } catch (InterruptedException ex) {
+ if (getPoolProperties().getPropagateInterruptState()) {
+ Thread.currentThread().interrupt();
+ }
+ }
+ if (pool.size()==0 && force && pool!=busy) pool = busy;
+ }
+ if (this.getPoolProperties().isJmxEnabled()) this.jmxPool = null;
+ PoolProperties.InterceptorDefinition[] proxies = getPoolProperties().getJdbcInterceptorsAsArray();
+ for (int i=0; i<proxies.length; i++) {
+ try {
+ JdbcInterceptor interceptor = proxies[i].getInterceptorClass().newInstance();
+ interceptor.setProperties(proxies[i].getProperties());
+ interceptor.poolClosed(this);
+ }catch (Exception x) {
+ log.debug("Unable to inform interceptor of pool closure.",x);
+ }
+ }
+ } //closePool
+
+
+ /**
+ * Initialize the connection pool - called from the constructor
+ * @param properties PoolProperties - properties used to initialize the pool with
+ * @throws SQLException if initialization fails
+ */
+ protected void init(PoolConfiguration properties) throws SQLException {
+ poolProperties = properties;
+
+ //make sure the pool is properly configured
+ checkPoolConfiguration(properties);
+
+ //make space for 10 extra in case we flow over a bit
+ busy = new LinkedBlockingQueue<>();
+ //busy = new FairBlockingQueue<PooledConnection>();
+ //make space for 10 extra in case we flow over a bit
+ if (properties.isFairQueue()) {
+ idle = new FairBlockingQueue<>();
+ //idle = new MultiLockFairBlockingQueue<PooledConnection>();
+ //idle = new LinkedTransferQueue<PooledConnection>();
+ //idle = new ArrayBlockingQueue<PooledConnection>(properties.getMaxActive(),false);
+ } else {
+ idle = new LinkedBlockingQueue<>();
+ }
+
+ initializePoolCleaner(properties);
+
+ //create JMX MBean
+ if (this.getPoolProperties().isJmxEnabled()) createMBean();
+
+ //Parse and create an initial set of interceptors. Letting them know the pool has started.
+ //These interceptors will not get any connection.
+ PoolProperties.InterceptorDefinition[] proxies = getPoolProperties().getJdbcInterceptorsAsArray();
+ for (int i=0; i<proxies.length; i++) {
+ try {
+ if (log.isDebugEnabled()) {
+ log.debug("Creating interceptor instance of class:"+proxies[i].getInterceptorClass());
+ }
+ JdbcInterceptor interceptor = proxies[i].getInterceptorClass().newInstance();
+ interceptor.setProperties(proxies[i].getProperties());
+ interceptor.poolStarted(this);
+ }catch (Exception x) {
+ log.error("Unable to inform interceptor of pool start.",x);
+ if (jmxPool!=null) jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.NOTIFY_INIT, getStackTrace(x));
+ close(true);
+ SQLException ex = new SQLException();
+ ex.initCause(x);
+ throw ex;
+ }
+ }
+
+ //initialize the pool with its initial set of members
+ PooledConnection[] initialPool = new PooledConnection[poolProperties.getInitialSize()];
+ try {
+ for (int i = 0; i < initialPool.length; i++) {
+ initialPool[i] = this.borrowConnection(0, null, null); //don't wait, should be no contention
+ } //for
+
+ } catch (SQLException x) {
+ log.error("Unable to create initial connections of pool.", x);
+ if (!poolProperties.isIgnoreExceptionOnPreLoad()) {
+ if (jmxPool!=null) jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.NOTIFY_INIT, getStackTrace(x));
+ close(true);
+ throw x;
+ }
+ } finally {
+ //return the members as idle to the pool
+ for (int i = 0; i < initialPool.length; i++) {
+ if (initialPool[i] != null) {
+ try {this.returnConnection(initialPool[i]);}catch(Exception x){/*NOOP*/}
+ } //end if
+ } //for
+ } //catch
+
+ closed = false;
+ }
+
+ public void checkPoolConfiguration(PoolConfiguration properties) {
+ //make sure the pool is properly configured
+ if (properties.getMaxActive()<1) {
+ log.warn("maxActive is smaller than 1, setting maxActive to: "+PoolProperties.DEFAULT_MAX_ACTIVE);
+ properties.setMaxActive(PoolProperties.DEFAULT_MAX_ACTIVE);
+ }
+ if (properties.getMaxActive()<properties.getInitialSize()) {
+ log.warn("initialSize is larger than maxActive, setting initialSize to: "+properties.getMaxActive());
+ properties.setInitialSize(properties.getMaxActive());
+ }
+ if (properties.getMinIdle()>properties.getMaxActive()) {
+ log.warn("minIdle is larger than maxActive, setting minIdle to: "+properties.getMaxActive());
+ properties.setMinIdle(properties.getMaxActive());
+ }
+ if (properties.getMaxIdle()>properties.getMaxActive()) {
+ log.warn("maxIdle is larger than maxActive, setting maxIdle to: "+properties.getMaxActive());
+ properties.setMaxIdle(properties.getMaxActive());
+ }
+ if (properties.getMaxIdle()<properties.getMinIdle()) {
+ log.warn("maxIdle is smaller than minIdle, setting maxIdle to: "+properties.getMinIdle());
+ properties.setMaxIdle(properties.getMinIdle());
+ }
+ }
+
+ public void initializePoolCleaner(PoolConfiguration properties) {
+ //if the evictor thread is supposed to run, start it now
+ if (properties.isPoolSweeperEnabled()) {
+ poolCleaner = new PoolCleaner(this, properties.getTimeBetweenEvictionRunsMillis());
+ poolCleaner.start();
+ } //end if
+ }
+
+ public void terminatePoolCleaner() {
+ if (poolCleaner!= null) {
+ poolCleaner.stopRunning();
+ poolCleaner = null;
+ }
+ }
+
+
+//===============================================================================
+// CONNECTION POOLING IMPL LOGIC
+//===============================================================================
+
+ /**
+ * thread safe way to abandon a connection
+ * signals a connection to be abandoned.
+ * this will disconnect the connection, and log the stack trace if logAbandoned=true
+ * @param con PooledConnection
+ */
+ protected void abandon(PooledConnection con) {
+ if (con == null)
+ return;
+ try {
+ con.lock();
+ String trace = con.getStackTrace();
+ if (getPoolProperties().isLogAbandoned()) {
+ log.warn("Connection has been abandoned " + con + ":" + trace);
+ }
+ if (jmxPool!=null) {
+ jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.NOTIFY_ABANDON, trace);
+ }
+ //release the connection
+ removeAbandonedCount.incrementAndGet();
+ release(con);
+ } finally {
+ con.unlock();
+ }
+ }
+
+ /**
+ * Thread safe way to suspect a connection. Similar to
+ * {@link #abandon(PooledConnection)}, but instead of actually abandoning
+ * the connection, this will log a warning and set the suspect flag on the
+ * {@link PooledConnection} if logAbandoned=true
+ *
+ * @param con PooledConnection
+ */
+ protected void suspect(PooledConnection con) {
+ if (con == null)
+ return;
+ if (con.isSuspect())
+ return;
+ try {
+ con.lock();
+ String trace = con.getStackTrace();
+ if (getPoolProperties().isLogAbandoned()) {
+ log.warn("Connection has been marked suspect, possibly abandoned " + con + "["+(System.currentTimeMillis()-con.getTimestamp())+" ms.]:" + trace);
+ }
+ if (jmxPool!=null) {
+ jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.SUSPECT_ABANDONED_NOTIFICATION, trace);
+ }
+ con.setSuspect(true);
+ } finally {
+ con.unlock();
+ }
+ }
+
+ /**
+ * thread safe way to release a connection
+ * @param con PooledConnection
+ */
+ protected void release(PooledConnection con) {
+ if (con == null)
+ return;
+ try {
+ con.lock();
+ if (con.release()) {
+ //counter only decremented once
+ size.addAndGet(-1);
+ con.setHandler(null);
+ }
+ releasedCount.incrementAndGet();
+ } finally {
+ con.unlock();
+ }
+ // we've asynchronously reduced the number of connections
+ // we could have threads stuck in idle.poll(timeout) that will never be
+ // notified
+ if (waitcount.get() > 0) {
+ idle.offer(create(true));
+ }
+ }
+
+ /**
+ * Thread safe way to retrieve a connection from the pool
+ * @param wait - time to wait, overrides the maxWait from the properties,
+ * set to -1 if you wish to use maxWait, 0 if you wish no wait time.
+ * @param username The user name to use for the connection
+ * @param password The password for the connection
+ * @return a connection
+ * @throws SQLException Failed to get a connection
+ */
+ private PooledConnection borrowConnection(int wait, String username, String password) throws SQLException {
+
+ if (isClosed()) {
+ throw new SQLException("Connection pool closed.");
+ } //end if
+
+ //get the current time stamp
+ long now = System.currentTimeMillis();
+ //see if there is one available immediately
+ PooledConnection con = idle.poll();
+
+ while (true) {
+ if (con!=null) {
+ //configure the connection and return it
+ PooledConnection result = borrowConnection(now, con, username, password);
+ borrowedCount.incrementAndGet();
+ if (result!=null) return result;
+ }
+
+ //if we get here, see if we need to create one
+ //this is not 100% accurate since it doesn't use a shared
+ //atomic variable - a connection can become idle while we are creating
+ //a new connection
+ if (size.get() < getPoolProperties().getMaxActive()) {
+ //atomic duplicate check
+ if (size.addAndGet(1) > getPoolProperties().getMaxActive()) {
+ //if we got here, two threads passed through the first if
+ size.decrementAndGet();
+ } else {
+ //create a connection, we're below the limit
+ return createConnection(now, con, username, password);
+ }
+ } //end if
+
+ //calculate wait time for this iteration
+ long maxWait = wait;
+ //if the passed in wait time is -1, means we should use the pool property value
+ if (wait==-1) {
+ maxWait = (getPoolProperties().getMaxWait()<=0)?Long.MAX_VALUE:getPoolProperties().getMaxWait();
+ }
+
+ long timetowait = Math.max(0, maxWait - (System.currentTimeMillis() - now));
+ waitcount.incrementAndGet();
+ try {
+ //retrieve an existing connection
+ con = idle.poll(timetowait, TimeUnit.MILLISECONDS);
+ } catch (InterruptedException ex) {
+ if (getPoolProperties().getPropagateInterruptState()) {
+ Thread.currentThread().interrupt();
+ }
+ SQLException sx = new SQLException("Pool wait interrupted.");
+ sx.initCause(ex);
+ throw sx;
+ } finally {
+ waitcount.decrementAndGet();
+ }
+ if (maxWait==0 && con == null) { //no wait, return one if we have one
+ if (jmxPool!=null) {
+ jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.POOL_EMPTY, "Pool empty - no wait.");
+ }
+ throw new PoolExhaustedException("[" + Thread.currentThread().getName()+"] " +
+ "NoWait: Pool empty. Unable to fetch a connection, none available["+busy.size()+" in use].");
+ }
+ //we didn't get a connection, lets see if we timed out
+ if (con == null) {
+ if ((System.currentTimeMillis() - now) >= maxWait) {
+ if (jmxPool!=null) {
+ jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.POOL_EMPTY, "Pool empty - timeout.");
+ }
+ throw new PoolExhaustedException("[" + Thread.currentThread().getName()+"] " +
+ "Timeout: Pool empty. Unable to fetch a connection in " + (maxWait / 1000) +
+ " seconds, none available[size:"+size.get() +"; busy:"+busy.size()+"; idle:"+idle.size()+"; lastwait:"+timetowait+"].");
+ } else {
+ //no timeout, lets try again
+ continue;
+ }
+ }
+ } //while
+ }
+
+ /**
+ * Creates a JDBC connection and tries to connect to the database.
+ * @param now timestamp of when this was called
+ * @param notUsed Argument not used
+ * @param username The user name to use for the connection
+ * @param password The password for the connection
+ * @return a PooledConnection that has been connected
+ * @throws SQLException Failed to get a connection
+ */
+ protected PooledConnection createConnection(long now, PooledConnection notUsed, String username, String password) throws SQLException {
+ //no connections where available we'll create one
+ PooledConnection con = create(false);
+ if (username!=null) con.getAttributes().put(PooledConnection.PROP_USER, username);
+ if (password!=null) con.getAttributes().put(PooledConnection.PROP_PASSWORD, password);
+ boolean error = false;
+ try {
+ //connect and validate the connection
+ con.lock();
+ con.connect();
+ if (con.validate(PooledConnection.VALIDATE_INIT)) {
+ //no need to lock a new one, its not contented
+ con.setTimestamp(now);
+ if (getPoolProperties().isLogAbandoned()) {
+ con.setStackTrace(getThreadDump());
+ }
+ if (!busy.offer(con)) {
+ log.debug("Connection doesn't fit into busy array, connection will not be traceable.");
+ }
+ createdCount.incrementAndGet();
+ return con;
+ } else {
+ //validation failed, make sure we disconnect
+ //and clean up
+ throw new SQLException("Validation Query Failed, enable logValidationErrors for more details.");
+ } //end if
+ } catch (Exception e) {
+ error = true;
+ if (log.isDebugEnabled())
+ log.debug("Unable to create a new JDBC connection.", e);
+ if (e instanceof SQLException) {
+ throw (SQLException)e;
+ } else {
+ SQLException ex = new SQLException(e.getMessage());
+ ex.initCause(e);
+ throw ex;
+ }
+ } finally {
+ // con can never be null here
+ if (error ) {
+ release(con);
+ }
+ con.unlock();
+ }//catch
+ }
+
+ /**
+ * Validates and configures a previously idle connection
+ * @param now - timestamp
+ * @param con - the connection to validate and configure
+ * @param username The user name to use for the connection
+ * @param password The password for the connection
+ * @return a connection
+ * @throws SQLException if a validation error happens
+ */
+ protected PooledConnection borrowConnection(long now, PooledConnection con, String username, String password) throws SQLException {
+ //we have a connection, lets set it up
+
+ //flag to see if we need to nullify
+ boolean setToNull = false;
+ try {
+ con.lock();
+ if (con.isReleased()) {
+ return null;
+ }
+
+ //evaluate username/password change as well as max age functionality
+ boolean forceReconnect = con.shouldForceReconnect(username, password) || con.isMaxAgeExpired();
+
+ if (!con.isDiscarded() && !con.isInitialized()) {
+ //here it states that the connection not discarded, but the connection is null
+ //don't attempt a connect here. It will be done during the reconnect.
+ forceReconnect = true;
+ }
+
+ if (!forceReconnect) {
+ if ((!con.isDiscarded()) && con.validate(PooledConnection.VALIDATE_BORROW)) {
+ //set the timestamp
+ con.setTimestamp(now);
+ if (getPoolProperties().isLogAbandoned()) {
+ //set the stack trace for this pool
+ con.setStackTrace(getThreadDump());
+ }
+ if (!busy.offer(con)) {
+ log.debug("Connection doesn't fit into busy array, connection will not be traceable.");
+ }
+ return con;
+ }
+ }
+ //if we reached here, that means the connection
+ //is either has another principal, is discarded or validation failed.
+ //we will make one more attempt
+ //in order to guarantee that the thread that just acquired
+ //the connection shouldn't have to poll again.
+ try {
+ con.reconnect();
+ reconnectedCount.incrementAndGet();
+ int validationMode = getPoolProperties().isTestOnConnect() || getPoolProperties().getInitSQL()!=null ?
+ PooledConnection.VALIDATE_INIT :
+ PooledConnection.VALIDATE_BORROW;
+
+ if (con.validate(validationMode)) {
+ //set the timestamp
+ con.setTimestamp(now);
+ if (getPoolProperties().isLogAbandoned()) {
+ //set the stack trace for this pool
+ con.setStackTrace(getThreadDump());
+ }
+ if (!busy.offer(con)) {
+ log.debug("Connection doesn't fit into busy array, connection will not be traceable.");
+ }
+ return con;
+ } else {
+ //validation failed.
+ throw new SQLException("Failed to validate a newly established connection.");
+ }
+ } catch (Exception x) {
+ release(con);
+ setToNull = true;
+ if (x instanceof SQLException) {
+ throw (SQLException)x;
+ } else {
+ SQLException ex = new SQLException(x.getMessage());
+ ex.initCause(x);
+ throw ex;
+ }
+ }
+ } finally {
+ con.unlock();
+ if (setToNull) {
+ con = null;
+ }
+ }
+ }
+ /**
+ * Terminate the current transaction for the given connection.
+ * @param con The connection
+ * @return <code>true</code> if the connection TX termination succeeded
+ * otherwise <code>false</code>
+ */
+ protected boolean terminateTransaction(PooledConnection con) {
+ try {
+ if (Boolean.FALSE.equals(con.getPoolProperties().getDefaultAutoCommit())) {
+ if (this.getPoolProperties().getRollbackOnReturn()) {
+ boolean autocommit = con.getConnection().getAutoCommit();
+ if (!autocommit) con.getConnection().rollback();
+ } else if (this.getPoolProperties().getCommitOnReturn()) {
+ boolean autocommit = con.getConnection().getAutoCommit();
+ if (!autocommit) con.getConnection().commit();
+ }
+ }
+ return true;
+ } catch (SQLException x) {
+ log.warn("Unable to terminate transaction, connection will be closed.",x);
+ return false;
+ }
+
+ }
+
+ /**
+ * Determines if a connection should be closed upon return to the pool.
+ * @param con - the connection
+ * @param action - the validation action that should be performed
+ * @return <code>true</code> if the connection should be closed
+ */
+ protected boolean shouldClose(PooledConnection con, int action) {
+ if (con.getConnectionVersion() < getPoolVersion()) return true;
+ if (con.isDiscarded()) return true;
+ if (isClosed()) return true;
+ if (!con.validate(action)) return true;
+ if (!terminateTransaction(con)) return true;
+ if (con.isMaxAgeExpired()) return true;
+ else return false;
+ }
+
+ /**
+ * Returns a connection to the pool
+ * If the pool is closed, the connection will be released
+ * If the connection is not part of the busy queue, it will be released.
+ * If {@link PoolProperties#testOnReturn} is set to true it will be validated
+ * @param con PooledConnection to be returned to the pool
+ */
+ protected void returnConnection(PooledConnection con) {
+ if (isClosed()) {
+ //if the connection pool is closed
+ //close the connection instead of returning it
+ release(con);
+ return;
+ } //end if
+
+ if (con != null) {
+ try {
+ returnedCount.incrementAndGet();
+ con.lock();
+ if (con.isSuspect()) {
+ if (poolProperties.isLogAbandoned() && log.isInfoEnabled()) {
+ log.info("Connection(" + con + ") that has been marked suspect was returned."
+ + " The processing time is " + (System.currentTimeMillis()-con.getTimestamp()) + " ms.");
+ }
+ if (jmxPool!=null) {
+ jmxPool.notify(org.apache.tomcat.jdbc.pool.jmx.ConnectionPool.SUSPECT_RETURNED_NOTIFICATION,
+ "Connection(" + con + ") that has been marked suspect was returned.");
+ }
+ }
+ if (busy.remove(con)) {
+
+ if (!shouldClose(con,PooledConnection.VALIDATE_RETURN)) {
+ con.setStackTrace(null);
+ con.setTimestamp(System.currentTimeMillis());
+ if (((idle.size()>=poolProperties.getMaxIdle()) && !poolProperties.isPoolSweeperEnabled()) || (!idle.offer(con))) {
+ if (log.isDebugEnabled()) {
+ log.debug("Connection ["+con+"] will be closed and not returned to the pool, idle["+idle.size()+"]>=maxIdle["+poolProperties.getMaxIdle()+"] idle.offer failed.");
+ }
+ release(con);
+ }
+ } else {
+ if (log.isDebugEnabled()) {
+ log.debug("Connection ["+con+"] will be closed and not returned to the pool.");
+ }
+ release(con);
+ } //end if
+ } else {
+ if (log.isDebugEnabled()) {
+ log.debug("Connection ["+con+"] will be closed and not returned to the pool, busy.remove failed.");
+ }
+ release(con);
+ }
+ } finally {
+ con.unlock();
+ }
+ } //end if
+ } //checkIn
+
+ /**
+ * Determines if a connection should be abandoned based on
+ * {@link PoolProperties#abandonWhenPercentageFull} setting.
+ * @return <code>true</code> if the connection should be abandoned
+ */
+ protected boolean shouldAbandon() {
+ if (!poolProperties.isRemoveAbandoned()) return false;
+ if (poolProperties.getAbandonWhenPercentageFull()==0) return true;
+ float used = busy.size();
+ float max = poolProperties.getMaxActive();
+ float perc = poolProperties.getAbandonWhenPercentageFull();
+ return (used/max*100f)>=perc;
+ }
+
+ /**
+ * Iterates through all the busy connections and checks for connections that have timed out
+ */
+ public void checkAbandoned() {
+ try {
+ if (busy.size()==0) return;
+ Iterator<PooledConnection> locked = busy.iterator();
+ int sto = getPoolProperties().getSuspectTimeout();
+ while (locked.hasNext()) {
+ PooledConnection con = locked.next();
+ boolean setToNull = false;
+ try {
+ con.lock();
+ //the con has been returned to the pool or released
+ //ignore it
+ if (idle.contains(con) || con.isReleased())
+ continue;
+ long time = con.getTimestamp();
+ long now = System.currentTimeMillis();
+ if (shouldAbandon() && (now - time) > con.getAbandonTimeout()) {
+ busy.remove(con);
+ abandon(con);
+ setToNull = true;
+ } else if (sto > 0 && (now - time) > (sto * 1000L)) {
+ suspect(con);
+ } else {
+ //do nothing
+ } //end if
+ } finally {
+ con.unlock();
+ if (setToNull)
+ con = null;
+ }
+ } //while
+ } catch (ConcurrentModificationException e) {
+ log.debug("checkAbandoned failed." ,e);
+ } catch (Exception e) {
+ log.warn("checkAbandoned failed, it will be retried.",e);
+ }
+ }
+
+ /**
+ * Iterates through the idle connections and resizes the idle pool based on parameters
+ * {@link PoolProperties#maxIdle}, {@link PoolProperties#minIdle}, {@link PoolProperties#minEvictableIdleTimeMillis}
+ */
+ public void checkIdle() {
+ checkIdle(false);
+ }
+
+ public void checkIdle(boolean ignoreMinSize) {
+
+ try {
+ if (idle.size()==0) return;
+ long now = System.currentTimeMillis();
+ Iterator<PooledConnection> unlocked = idle.iterator();
+ while ( (ignoreMinSize || (idle.size()>=getPoolProperties().getMinIdle())) && unlocked.hasNext()) {
+ PooledConnection con = unlocked.next();
+ boolean setToNull = false;
+ try {
+ con.lock();
+ //the con been taken out, we can't clean it up
+ if (busy.contains(con))
+ continue;
+ long time = con.getTimestamp();
+ if (shouldReleaseIdle(now, con, time)) {
+ releasedIdleCount.incrementAndGet();
+ release(con);
+ idle.remove(con);
+ setToNull = true;
+ } else {
+ //do nothing
+ } //end if
+ } finally {
+ con.unlock();
+ if (setToNull)
+ con = null;
+ }
+ } //while
+ } catch (ConcurrentModificationException e) {
+ log.debug("checkIdle failed." ,e);
+ } catch (Exception e) {
+ log.warn("checkIdle failed, it will be retried.",e);
+ }
+
+ }
+
+
+ protected boolean shouldReleaseIdle(long now, PooledConnection con, long time) {
+ if (con.getConnectionVersion() < getPoolVersion()) return true;
+ else return (con.getReleaseTime()>0) && ((now - time) > con.getReleaseTime()) && (getSize()>getPoolProperties().getMinIdle());
+ }
+
+ /**
+ * Forces a validation of all idle connections if {@link PoolProperties#testWhileIdle} is set.
+ */
+ public void testAllIdle() {
+ try {
+ if (idle.size()==0) return;
+ Iterator<PooledConnection> unlocked = idle.iterator();
+ while (unlocked.hasNext()) {
+ PooledConnection con = unlocked.next();
+ try {
+ con.lock();
+ //the con been taken out, we can't clean it up
+ if (busy.contains(con))
+ continue;
+ if (!con.validate(PooledConnection.VALIDATE_IDLE)) {
+ idle.remove(con);
+ release(con);
+ }
+ } finally {
+ con.unlock();
+ }
+ } //while
+ } catch (ConcurrentModificationException e) {
+ log.debug("testAllIdle failed." ,e);
+ } catch (Exception e) {
+ log.warn("testAllIdle failed, it will be retried.",e);
+ }
+
+ }
+
+ /**
+ * Creates a stack trace representing the existing thread's current state.
+ * @return a string object representing the current state.
+ * TODO investigate if we simply should store {@link java.lang.Thread#getStackTrace()} elements
+ */
+ protected static String getThreadDump() {
+ Exception x = new Exception();
+ x.fillInStackTrace();
+ return getStackTrace(x);
+ }
+
+ /**
+ * Convert an exception into a String
+ * @param x - the throwable
+ * @return a string representing the stack trace
+ */
+ public static String getStackTrace(Throwable x) {
+ if (x == null) {
+ return null;
+ } else {
+ java.io.ByteArrayOutputStream bout = new java.io.ByteArrayOutputStream();
+ java.io.PrintStream writer = new java.io.PrintStream(bout);
+ x.printStackTrace(writer);
+ String result = bout.toString();
+ return (x.getMessage()!=null && x.getMessage().length()>0)? x.getMessage()+";"+result:result;
+ } //end if
+ }
+
+
+ /**
+ * Create a new pooled connection object. Not connected nor validated.
+ * @param incrementCounter <code>true</code> to increment the connection count
+ * @return a pooled connection object
+ */
+ protected PooledConnection create(boolean incrementCounter) {
+ if (incrementCounter) size.incrementAndGet();
+ PooledConnection con = new PooledConnection(getPoolProperties(), this);
+ return con;
+ }
+
+ /**
+ * Purges all connections in the pool.
+ * For connections currently in use, these connections will be
+ * purged when returned on the pool. This call also
+ * purges connections that are idle and in the pool
+ * To only purge used/active connections see {@link #purgeOnReturn()}
+ */
+ public void purge() {
+ purgeOnReturn();
+ checkIdle(true);
+ }
+
+ /**
+ * Purges connections when they are returned from the pool.
+ * This call does not purge idle connections until they are used.
+ * To purge idle connections see {@link #purge()}
+ */
+ public void purgeOnReturn() {
+ poolVersion.incrementAndGet();
+ }
+
+ /**
+ * Hook to perform final actions on a pooled connection object once it has been disconnected and will be discarded
+ * @param con The connection
+ */
+ protected void finalize(PooledConnection con) {
+ JdbcInterceptor handler = con.getHandler();
+ while (handler!=null) {
+ handler.reset(null, null);
+ handler=handler.getNext();
+ }
+ }
+
+ /**
+ * Hook to perform final actions on a pooled connection object once it has been disconnected and will be discarded
+ * @param con The connection
+ * @param finalizing <code>true</code> if finalizing the connection
+ */
+ protected void disconnectEvent(PooledConnection con, boolean finalizing) {
+ JdbcInterceptor handler = con.getHandler();
+ while (handler!=null) {
+ handler.disconnected(this, con, finalizing);
+ handler=handler.getNext();
+ }
+ }
+
+ /**
+ * Return the object that is potentially registered in JMX for notifications
+ * @return the object implementing the {@link org.apache.tomcat.jdbc.pool.jmx.ConnectionPoolMBean} interface
+ */
+ public org.apache.tomcat.jdbc.pool.jmx.ConnectionPool getJmxPool() {
+ return jmxPool;
+ }
+
+ /**
+ * Create MBean object that can be registered.
+ */
+ protected void createMBean() {
+ try {
+ jmxPool = new org.apache.tomcat.jdbc.pool.jmx.ConnectionPool(this);
+ } catch (Exception x) {
+ log.warn("Unable to start JMX integration for connection pool. Instance["+getName()+"] can't be monitored.",x);
+ }
+ }
+
+ /**
+ * The total number of connections borrowed from this pool.
+ * @return the borrowed connection count
+ */
+ public long getBorrowedCount() {
+ return borrowedCount.get();
+ }
+
+ /**
+ * The total number of connections returned to this pool.
+ * @return the returned connection count
+ */
+ public long getReturnedCount() {
+ return returnedCount.get();
+ }
+
+ /**
+ * The total number of connections created by this pool.
+ * @return the created connection count
+ */
+ public long getCreatedCount() {
+ return createdCount.get();
+ }
+
+ /**
+ * The total number of connections released from this pool.
+ * @return the released connection count
+ */
+ public long getReleasedCount() {
+ return releasedCount.get();
+ }
+
+ /**
+ * The total number of connections reconnected by this pool.
+ * @return the reconnected connection count
+ */
+ public long getReconnectedCount() {
+ return reconnectedCount.get();
+ }
+
+ /**
+ * The total number of connections released by remove abandoned.
+ * @return the PoolCleaner removed abandoned connection count
+ */
+ public long getRemoveAbandonedCount() {
+ return removeAbandonedCount.get();
+ }
+
+ /**
+ * The total number of connections released by eviction.
+ * @return the PoolCleaner evicted idle connection count
+ */
+ public long getReleasedIdleCount() {
+ return releasedIdleCount.get();
+ }
+
+ /**
+ * reset the statistics of this pool.
+ */
+ public void resetStats() {
+ borrowedCount.set(0);
+ returnedCount.set(0);
+ createdCount.set(0);
+ releasedCount.set(0);
+ reconnectedCount.set(0);
+ removeAbandonedCount.set(0);
+ releasedIdleCount.set(0);
+ }
+
+ /**
+ * Tread safe wrapper around a future for the regular queue
+ * This one retrieves the pooled connection object
+ * and performs the initialization according to
+ * interceptors and validation rules.
+ * This class is thread safe and is cancellable
+ *
+ */
+ protected class ConnectionFuture implements Future<Connection>, Runnable {
+ Future<PooledConnection> pcFuture = null;
+ AtomicBoolean configured = new AtomicBoolean(false);
+ CountDownLatch latch = new CountDownLatch(1);
+ volatile Connection result = null;
+ SQLException cause = null;
+ AtomicBoolean cancelled = new AtomicBoolean(false);
+ volatile PooledConnection pc = null;
+ public ConnectionFuture(Future<PooledConnection> pcf) {
+ this.pcFuture = pcf;
+ }
+
+ public ConnectionFuture(PooledConnection pc) throws SQLException {
+ this.pc = pc;
+ result = ConnectionPool.this.setupConnection(pc);
+ configured.set(true);
+ }
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public boolean cancel(boolean mayInterruptIfRunning) {
+ if (pc!=null) {
+ return false;
+ } else if ((!cancelled.get()) && cancelled.compareAndSet(false, true)) {
+ //cancel by retrieving the connection and returning it to the pool
+ ConnectionPool.this.cancellator.execute(this);
+ }
+ return true;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public Connection get() throws InterruptedException, ExecutionException {
+ try {
+ return get(Long.MAX_VALUE, TimeUnit.MILLISECONDS);
+ }catch (TimeoutException x) {
+ throw new ExecutionException(x);
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public Connection get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
+ PooledConnection pc = this.pc!=null?this.pc:pcFuture.get(timeout,unit);
+ if (pc!=null) {
+ if (result!=null) return result;
+ if (configured.compareAndSet(false, true)) {
+ try {
+ pc = borrowConnection(System.currentTimeMillis(),pc, null, null);
+ result = ConnectionPool.this.setupConnection(pc);
+ } catch (SQLException x) {
+ cause = x;
+ } finally {
+ latch.countDown();
+ }
+ } else {
+ //if we reach here, another thread is configuring the actual connection
+ latch.await(timeout,unit); //this shouldn't block for long
+ }
+ if (result==null) throw new ExecutionException(cause);
+ return result;
+ } else {
+ return null;
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public boolean isCancelled() {
+ return pc==null && (pcFuture.isCancelled() || cancelled.get());
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public boolean isDone() {
+ return pc!=null || pcFuture.isDone();
+ }
+
+ /**
+ * run method to be executed when cancelled by an executor
+ */
+ @Override
+ public void run() {
+ try {
+ Connection con = get(); //complete this future
+ con.close(); //return to the pool
+ }catch (ExecutionException ex) {
+ //we can ignore this
+ }catch (Exception x) {
+ ConnectionPool.log.error("Unable to cancel ConnectionFuture.",x);
+ }
+ }
+
+ }
+
+
+
+ private static volatile Timer poolCleanTimer = null;
+ private static HashSet<PoolCleaner> cleaners = new HashSet<>();
+
+ private static synchronized void registerCleaner(PoolCleaner cleaner) {
+ unregisterCleaner(cleaner);
+ cleaners.add(cleaner);
+ if (poolCleanTimer == null) {
+ ClassLoader loader = Thread.currentThread().getContextClassLoader();
+ try {
+ Thread.currentThread().setContextClassLoader(ConnectionPool.class.getClassLoader());
+ // Create the timer thread in a PrivilegedAction so that a
+ // reference to the web application class loader is not created
+ // via Thread.inheritedAccessControlContext
+ PrivilegedAction<Timer> pa = new PrivilegedNewTimer();
+ poolCleanTimer = AccessController.doPrivileged(pa);
+ } finally {
+ Thread.currentThread().setContextClassLoader(loader);
+ }
+ }
+ poolCleanTimer.schedule(cleaner, cleaner.sleepTime,cleaner.sleepTime);
+ }
+
+ private static synchronized void unregisterCleaner(PoolCleaner cleaner) {
+ boolean removed = cleaners.remove(cleaner);
+ if (removed) {
+ cleaner.cancel();
+ if (poolCleanTimer != null) {
+ poolCleanTimer.purge();
+ if (cleaners.size() == 0) {
+ poolCleanTimer.cancel();
+ poolCleanTimer = null;
+ }
+ }
+ }
+ }
+
+ private static class PrivilegedNewTimer implements PrivilegedAction<Timer> {
+ @Override
+ public Timer run() {
+ return new Timer("Tomcat JDBC Pool Cleaner["+ System.identityHashCode(ConnectionPool.class.getClassLoader()) + ":"+
+ System.currentTimeMillis() + "]", true);
+ }
+ }
+
+ public static Set<TimerTask> getPoolCleaners() {
+ return Collections.<TimerTask>unmodifiableSet(cleaners);
+ }
+
+ public long getPoolVersion() {
+ return poolVersion.get();
+ }
+
+ public static Timer getPoolTimer() {
+ return poolCleanTimer;
+ }
+
+ protected static class PoolCleaner extends TimerTask {
+ protected WeakReference<ConnectionPool> pool;
+ protected long sleepTime;
+
+ PoolCleaner(ConnectionPool pool, long sleepTime) {
+ this.pool = new WeakReference<>(pool);
+ this.sleepTime = sleepTime;
+ if (sleepTime <= 0) {
+ log.warn("Database connection pool evicter thread interval is set to 0, defaulting to 30 seconds");
+ this.sleepTime = 1000 * 30;
+ } else if (sleepTime < 1000) {
+ log.warn("Database connection pool evicter thread interval is set to lower than 1 second.");
+ }
+ }
+
+ @Override
+ public void run() {
+ ConnectionPool pool = this.pool.get();
+ if (pool == null) {
+ stopRunning();
+ } else if (!pool.isClosed()) {
+ try {
+ if (pool.getPoolProperties().isRemoveAbandoned()
+ || pool.getPoolProperties().getSuspectTimeout() > 0)
+ pool.checkAbandoned();
+ if (pool.getPoolProperties().getMinIdle() < pool.idle
+ .size())
+ pool.checkIdle();
+ if (pool.getPoolProperties().isTestWhileIdle())
+ pool.testAllIdle();
+ } catch (Exception x) {
+ log.error("", x);
+ }
+ }
+ }
+
+ public void start() {
+ registerCleaner(this);
+ }
+
+ public void stopRunning() {
+ unregisterCleaner(this);
+ }
+ }
+}