/* * Copyright (c) 2005, 2008, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.net.www.http; import java.io.IOException;import java.util.LinkedList;import sun.net.NetProperties;import java.security.AccessController;import java.security.PrivilegedAction; /** * This class is used to cleanup any remaining data that may be on a KeepAliveStream * so that the connection can be cached in the KeepAliveCache. * Instances of this class can be used as a FIFO queue for KeepAliveCleanerEntry objects. * Executing this Runnable removes each KeepAliveCleanerEntry from the Queue, reads * the reamining bytes on its KeepAliveStream, and if successful puts the connection in * the KeepAliveCache. * * @author Chris Hegarty */ @SuppressWarnings("serial")  // never serializedclass KeepAliveStreamCleaner    extends LinkedList<KeepAliveCleanerEntry>    implements Runnable{    // maximum amount of remaining data that we will try to cleanup    protected static int MAX_DATA_REMAINING = 512;     // maximum amount of KeepAliveStreams to be queued    protected static int MAX_CAPACITY = 10;     // timeout for both socket and poll on the queue    protected static final int TIMEOUT = 5000;     // max retries for skipping data    private static final int MAX_RETRIES = 5;     static {        final String maxDataKey = "http.KeepAlive.remainingData";        int maxData = AccessController.doPrivileged(            new PrivilegedAction<Integer>() {                public Integer run() {                    return NetProperties.getInteger(maxDataKey, MAX_DATA_REMAINING);                }}).intValue() * 1024;        MAX_DATA_REMAINING = maxData;         final String maxCapacityKey = "http.KeepAlive.queuedConnections";        int maxCapacity = AccessController.doPrivileged(            new PrivilegedAction<Integer>() {                public Integer run() {                    return NetProperties.getInteger(maxCapacityKey, MAX_CAPACITY);                }}).intValue();        MAX_CAPACITY = maxCapacity;     }      @Override    public boolean offer(KeepAliveCleanerEntry e) {        if (size() >= MAX_CAPACITY)            return false;         return super.offer(e);    }     @Override    public void run()    {        KeepAliveCleanerEntry kace = null;         do {            try {                synchronized(this) {                    long before = System.currentTimeMillis();                    long timeout = TIMEOUT;                    while ((kace = poll()) == null) {                        this.wait(timeout);                         long after = System.currentTimeMillis();                        long elapsed = after - before;                        if (elapsed > timeout) {                            /* one last try */                            kace = poll();                            break;                        }                        before = after;                        timeout -= elapsed;                    }                }                 if(kace == null)                    break;                 KeepAliveStream kas = kace.getKeepAliveStream();                 if (kas != null) {                    synchronized(kas) {                        HttpClient hc = kace.getHttpClient();                        try {                            if (hc != null && !hc.isInKeepAliveCache()) {                                int oldTimeout = hc.getReadTimeout();                                hc.setReadTimeout(TIMEOUT);                                long remainingToRead = kas.remainingToRead();                                if (remainingToRead > 0) {                                    long n = 0;                                    int retries = 0;                                    while (n < remainingToRead && retries < MAX_RETRIES) {                                        remainingToRead = remainingToRead - n;                                        n = kas.skip(remainingToRead);                                        if (n == 0)                                            retries++;                                    }                                    remainingToRead = remainingToRead - n;                                }                                if (remainingToRead == 0) {                                    hc.setReadTimeout(oldTimeout);                                    hc.finished();                                } else                                    hc.closeServer();                            }                        } catch (IOException ioe) {                            hc.closeServer();                        } finally {                            kas.setClosed();                        }                    }                }            } catch (InterruptedException ie) { }        } while (kace != null);    }}