rev 13664 : 8139965: Hang seen when using com.sun.jndi.ldap.search.replyQueueSize
Reviewed-by: dfuchs

   1 /*
   2  * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.jndi.ldap;
  27 
  28 import java.io.IOException;
  29 import java.util.concurrent.BlockingQueue;
  30 import java.util.concurrent.LinkedBlockingQueue;
  31 import javax.naming.CommunicationException;

  32 
  33 final class LdapRequest {
  34 
  35     LdapRequest next;   // Set/read in synchronized Connection methods
  36     int msgId;          // read-only
  37 
  38     private int gotten = 0;
  39     private BlockingQueue<BerDecoder> replies;
  40     private int highWatermark = -1;
  41     private boolean cancelled = false;
  42     private boolean pauseAfterReceipt = false;
  43     private boolean completed = false;
  44 
  45     LdapRequest(int msgId, boolean pause) {
  46         this(msgId, pause, -1);
  47     }


  48 
  49     LdapRequest(int msgId, boolean pause, int replyQueueCapacity) {
  50         this.msgId = msgId;
  51         this.pauseAfterReceipt = pause;
  52         if (replyQueueCapacity == -1) {
  53             this.replies = new LinkedBlockingQueue<BerDecoder>();
  54         } else {
  55             this.replies =
  56                 new LinkedBlockingQueue<BerDecoder>(replyQueueCapacity);
  57             highWatermark = (replyQueueCapacity * 80) / 100; // 80% capacity
  58         }
  59     }
  60 
  61     synchronized void cancel() {
  62         cancelled = true;


  63 
  64         // Unblock reader of pending request
  65         // Should only ever have atmost one waiter
  66         notify();
  67     }
  68 
  69     synchronized boolean addReplyBer(BerDecoder ber) {
  70         if (cancelled) {
  71             return false;
  72         }
  73 
  74         // Add a new reply to the queue of unprocessed replies.
  75         try {
  76             replies.put(ber);
  77         } catch (InterruptedException e) {
  78             // ignore
  79         }
  80 
  81         // peek at the BER buffer to check if it is a SearchResultDone PDU
  82         try {
  83             ber.parseSeq(null);
  84             ber.parseInt();
  85             completed = (ber.peekByte() == LdapClient.LDAP_REP_RESULT);
  86         } catch (IOException e) {
  87             // ignore
  88         }
  89         ber.reset();
  90 
  91         notify(); // notify anyone waiting for reply
  92         /*
  93          * If a queue capacity has been set then trigger a pause when the
  94          * queue has filled to 80% capacity. Later, when the queue has drained
  95          * then the reader gets unpaused.
  96          */
  97         if (highWatermark != -1 && replies.size() >= highWatermark) {
  98             return true; // trigger the pause
  99         }

 100         return pauseAfterReceipt;
 101     }
 102 
 103     synchronized BerDecoder getReplyBer() throws CommunicationException {












 104         if (cancelled) {
 105             throw new CommunicationException("Request: " + msgId +
 106                 " cancelled");
 107         }
 108 
 109         /*
 110          * Remove a reply if the queue is not empty.
 111          * poll returns null if queue is empty.
 112          */
 113         BerDecoder reply = replies.poll();
 114         return reply;
 115     }
 116 
 117     synchronized boolean hasSearchCompleted() {
 118         return completed;
 119     }
 120 }
--- EOF ---