Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
InboundConnectionCache |
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| 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 | } |