| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| InboundConnectionCache |
|
| 0.0;0 |
| 1 | /* | |
| 2 | * | |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. | |
| 4 | * | |
| 5 | * 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 | } |