1 /*
2 * Copyright (c) 2003, 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 sun.security.pkcs11;
27
28 import java.lang.ref.*;
29 import java.util.*;
30 import java.util.concurrent.atomic.AtomicInteger;
31
32 import java.security.*;
33
34 import sun.security.pkcs11.wrapper.*;
35
36 /**
37 * A session object. Sessions are obtained via the SessionManager,
38 * see there for details. Most code will only ever need one method in
39 * this class, the id() method to obtain the session id.
40 *
41 * @author Andreas Sterbenz
42 * @since 1.5
43 */
44 final class Session implements Comparable<Session> {
45
46 // time after which to close idle sessions, in milliseconds (3 minutes)
47 private final static long MAX_IDLE_TIME = 3 * 60 * 1000;
48
49 // token instance
50 final Token token;
51
52 // session id
53 private final long id;
54
55 // number of objects created within this session
56 private final AtomicInteger createdObjects;
57
58 // time this session was last used
59 // not synchronized/volatile for performance, so may be unreliable
60 // this could lead to idle sessions being closed early, but that is harmless
61 private long lastAccess;
62
63 private final SessionRef sessionRef;
64
65 Session(Token token, long id) {
66 this.token = token;
67 this.id = id;
68 createdObjects = new AtomicInteger();
69 id();
70 sessionRef = new SessionRef(this, id, token);
71 }
72
73 public int compareTo(Session other) {
74 if (this.lastAccess == other.lastAccess) {
75 return 0;
76 } else {
77 return (this.lastAccess < other.lastAccess) ? -1 : 1;
78 }
79 }
80
81 boolean isLive(long currentTime) {
82 return currentTime - lastAccess < MAX_IDLE_TIME;
83 }
84
85 long idInternal() {
86 return id;
87 }
88
89 long id() {
90 if (token.isPresent(this.id) == false) {
91 throw new ProviderException("Token has been removed");
92 }
93 lastAccess = System.currentTimeMillis();
94 return id;
95 }
96
97 void addObject() {
98 int n = createdObjects.incrementAndGet();
99 // XXX update statistics in session manager if n == 1
100 }
101
102 void removeObject() {
103 int n = createdObjects.decrementAndGet();
104 if (n == 0) {
105 token.sessionManager.demoteObjSession(this);
106 } else if (n < 0) {
107 throw new ProviderException("Internal error: objects created " + n);
108 }
109 }
110
111 boolean hasObjects() {
112 return createdObjects.get() != 0;
113 }
114
115 void close() {
116 if (hasObjects()) {
117 throw new ProviderException(
118 "Internal error: close session with active objects");
119 }
120 sessionRef.dispose();
121 }
122 }
123
124 /*
125 * NOTE: Use PhantomReference here and not WeakReference
126 * otherwise the sessions maybe closed before other objects
127 * which are still being finalized.
128 */
129 final class SessionRef extends PhantomReference<Session>
130 implements Comparable<SessionRef> {
131
132 private static ReferenceQueue<Session> refQueue =
133 new ReferenceQueue<Session>();
134
135 private static Set<SessionRef> refList =
136 Collections.synchronizedSortedSet(new TreeSet<SessionRef>());
137
138 static ReferenceQueue<Session> referenceQueue() {
139 return refQueue;
140 }
141
142 static int totalCount() {
143 return refList.size();
144 }
145
146 private static void drainRefQueueBounded() {
147 while (true) {
148 SessionRef next = (SessionRef) refQueue.poll();
149 if (next == null) break;
150 next.dispose();
151 }
152 }
153
154 // handle to the native session
155 private long id;
156 private Token token;
157
158 SessionRef(Session session, long id, Token token) {
159 super(session, refQueue);
160 this.id = id;
161 this.token = token;
162 refList.add(this);
163 // TBD: run at some interval and not every time?
164 drainRefQueueBounded();
165 }
166
167 void dispose() {
168 refList.remove(this);
169 try {
170 if (token.isPresent(id)) {
171 token.p11.C_CloseSession(id);
172 }
173 } catch (PKCS11Exception e1) {
174 // ignore
175 } catch (ProviderException e2) {
176 // ignore
177 } finally {
178 this.clear();
179 }
180 }
181
182 public int compareTo(SessionRef other) {
183 if (this.id == other.id) {
184 return 0;
185 } else {
186 return (this.id < other.id) ? -1 : 1;
187 }
188 }
189 }