Coverage Report - com.sun.grizzly.connectioncache.spi.transport.InboundConnectionCache
 
Classes in this File Line Coverage Branch Coverage Complexity
InboundConnectionCache
N/A
N/A
0
 
 1  
 /*
 2  
  * 
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  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 4  
  * 
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  * Copyright 2007-2008 Sun Microsystems, Inc. All rights reserved.
 6  
  * 
 7  
  * The contents of this file are subject to the terms of either the GNU
 8  
  * General Public License Version 2 only ("GPL") or the Common Development
 9  
  * and Distribution License("CDDL") (collectively, the "License").  You
 10  
  * may not use this file except in compliance with the License. You can obtain
 11  
  * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 12  
  * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 13  
  * language governing permissions and limitations under the License.
 14  
  * 
 15  
  * When distributing the software, include this License Header Notice in each
 16  
  * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 17  
  * Sun designates this particular file as subject to the "Classpath" exception
 18  
  * as provided by Sun in the GPL Version 2 section of the License file that
 19  
  * accompanied this code.  If applicable, add the following below the License
 20  
  * Header, with the fields enclosed by brackets [] replaced by your own
 21  
  * identifying information: "Portions Copyrighted [year]
 22  
  * [name of copyright owner]"
 23  
  * 
 24  
  * Contributor(s):
 25  
  * 
 26  
  * If you wish your version of this file to be governed by only the CDDL or
 27  
  * only the GPL Version 2, indicate your decision by adding "[Contributor]
 28  
  * elects to include this software in this distribution under the [CDDL or GPL
 29  
  * Version 2] license."  If you don't indicate a single choice of license, a
 30  
  * recipient has the option to distribute your version of this file under
 31  
  * either the CDDL, the GPL Version 2 or to extend the choice of license to
 32  
  * its licensees as provided above.  However, if you add GPL Version 2 code
 33  
  * and therefore, elected the GPL Version 2 license, then the option applies
 34  
  * only if the new code is made subject to such option by the copyright
 35  
  * holder.
 36  
  *
 37  
  */
 38  
 
 39  
 package com.sun.grizzly.connectioncache.spi.transport;
 40  
 
 41  
 import java.io.Closeable;
 42  
 
 43  
 /** A concurrent connection cache for passively created connections (e.g.
 44  
  * from an acceptor).  Here a Connection is an 
 45  
  * abstraction of a Socket or SocketChannel: basically some sort of resource 
 46  
  * that is expensive to acquire, and can be re-used freely.  
 47  
  * The cache maintains a loose
 48  
  * upper bound on the number of cached connections, and reclaims connections as
 49  
  * needed.
 50  
  * <P>
 51  
  * This cache places minimal requirements on the Connections that it contains:
 52  
  * <ol>
 53  
  * <li>A Connection must implement a close() method.  This is called when idle
 54  
  * connections are reclaimed.
 55  
  * <li>A Connection must be usable as a HashMap key.  
 56  
  * </ol>
 57  
  * <P>
 58  
  * Some simple methods are provided for monitoring the state of the cache:
 59  
  * numbers of busy and idle connections, and the total number of 
 60  
  * connections in the cache.
 61  
  * <P>
 62  
  * Access is also provided to the cache configuration: maxParallelConnections,
 63  
  * highWaterMark, and numberToReclaim.  Currently these can only be set when
 64  
  * the cache is created.
 65  
  *
 66  
  * XXX We may wish to make the cache configuration dynamically configurable.
 67  
  * @param C  a connection
 68  
  */
 69  
 public interface InboundConnectionCache<C extends Closeable> extends ConnectionCache<C> {
 70  
    /** Mark a connection as busy because a request is being processed
 71  
      * on the connection.  The connection may or may not be previously
 72  
      * known to the cache when this method is called.
 73  
      * Busy connections cannot be reclaimed.
 74  
      * This provides an early indication that a Connection is in use,
 75  
      * before we know how many responses still need to be sent on 
 76  
      * the Connection for this request.  This reduces the likelyhood 
 77  
      * of reclaiming a connection on which we are processing a request.
 78  
      * <P>
 79  
      * Note that this problem is inherent in a distributed system.
 80  
      * We could in any case reclaim a connection AFTER a client
 81  
      * has sent a request but BEFORE the request is received.
 82  
      * Note that AFTER and BEFORE refer to global time which does
 83  
      * not really exist in a distributed system (or at least we 
 84  
      * want to pretend it is not available).
 85  
      *
 86  
      * XXX Should we age out connections?  
 87  
      * This would require actual time stamps, rather than just an LRU queue.
 88  
      * @param conn  a connection
 89  
     */
 90  
     void requestReceived( C conn ) ;
 91  
 
 92  
     /** Indicate that request processing has been completed for a request
 93  
      * received on conn.  This indicates that a Connection that received
 94  
      * a request as indicated in a previous call to requestReceived has
 95  
      * completed request processing for that request.  Responses may still 
 96  
      * need to be sent.  Some number of
 97  
      * responses (usually 0 or 1) may be expected ON THE SAME CONNECTION
 98  
      * even for an idle connection.  We maintain a count of the number of 
 99  
      * outstanding responses we expect for protocols that return the response
 100  
      * on the same connection on which the request was received.  This is
 101  
      * necessary to prevent reclamation of a Connection that is idle, but
 102  
      * still needed to send responses to old requests.
 103  
      * @param conn  a connection
 104  
      * @param numResponseExpected  number of connections in which a response is expected
 105  
      */
 106  
     void requestProcessed( C conn, int numResponseExpected ) ;
 107  
 
 108  
     /** Inform the cache that a response has been sent on a particular
 109  
      * connection.  
 110  
      * <P>
 111  
      * When a Connection is idle, and has no pending responses, it is
 112  
      * eligible for reclamation.
 113  
      * @param conn  a connection
 114  
      */
 115  
     void responseSent( C conn ) ;
 116  
 }