1 /*
2 * Copyright (c) 2005, 2008, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores,
20 * CA 94065 USA or visit www.oracle.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 package sun.jvm.hotspot;
26
27 import java.io.*;
28 import java.net.*;
29 import java.util.*;
30 import java.security.*;
31
32 /**
33 * SA uses native debugger back-end library - libsaproc.so on Unix platforms.
34 * Starting from 5.0, in Solaris & Linux JDK "libsaproc.so" is shipped with JDK
35 * and is kept jre/lib/cpu directory (where all other JDK platform libraries
36 * are kept). This implies that always that jre copy of libsaproc.so will be
37 * used and the copy of libsaproc.so built from SA sources here will not
38 * be used at all. We can override libsaproc.so using this class loader
39 * as System class loader using "java.system.class.loader" property. This
40 * class loader loads classes paths specified paths using the System property
41 * "java.class.path". Because, this class loader loads SA debugger classes
42 * (among other classes), JVM calls findLibrary override here. In this
43 * findLibrary, we first check the library in the directories specified through
44 * "sa.library.path" System property. This way updated/latest SA native library
45 * can be loaded instead of the one from JDK's jre/lib directory.
46 */
47 public class SALauncherLoader extends URLClassLoader {
48
49 /**
50 * Checks native libraries under directories specified using
51 * the System property "sa.library.path".
52 */
53 public String findLibrary(String name) {
54 name = System.mapLibraryName(name);
55 for (int i = 0; i < libpaths.length; i++) {
56 File file = new File(new File(libpaths[i]), name);
57 if (file.exists()) {
58 return file.getAbsolutePath();
59 }
60 }
61 return null;
62 }
63
64 public SALauncherLoader(ClassLoader parent) {
65 super(getClassPath(), parent);
66 String salibpath = System.getProperty("sa.library.path");
67 if (salibpath != null) {
68 libpaths = salibpath.split(File.pathSeparator);
69 } else {
70 libpaths = new String[0];
71 }
72 }
73
74 /**
75 * Override loadClass so we can checkPackageAccess.
76 */
77 public synchronized Class loadClass(String name, boolean resolve)
78 throws ClassNotFoundException {
79 int i = name.lastIndexOf('.');
80 if (i != -1) {
81 SecurityManager sm = System.getSecurityManager();
82 if (sm != null) {
83 sm.checkPackageAccess(name.substring(0, i));
84 }
85 }
86
87 Class clazz = findLoadedClass(name);
88 if (clazz != null) return clazz;
89
90 /*
91 * NOTE: Unlike 'usual' class loaders, we do *not* delegate to
92 * the parent loader first. We attempt to load the class
93 * ourselves first and use parent loader only if we can't load.
94 * This is because the parent of this loader is 'default'
95 * System loader that can 'see' all SA classes in classpath and
96 * so will load those if delegated. And if parent loads SA classes,
97 * then JVM won't call findNative override in this class.
98 */
99 try {
100 return findClass(name);
101 } catch (ClassNotFoundException cnfe) {
102 return (super.loadClass(name, resolve));
103 }
104 }
105
106 /**
107 * allow any classes loaded from classpath to exit the VM.
108 */
109 protected PermissionCollection getPermissions(CodeSource codesource) {
110 PermissionCollection perms = super.getPermissions(codesource);
111 perms.add(new RuntimePermission("exitVM"));
112 return perms;
113 }
114
115 //-- Internals only below this point
116
117 private String[] libpaths;
118
119 private static URL[] getClassPath() {
120 final String s = System.getProperty("java.class.path");
121 final File[] path = (s == null) ? new File[0] : getClassPath(s);
122
123 return pathToURLs(path);
124 }
125
126 private static URL[] pathToURLs(File[] path) {
127 URL[] urls = new URL[path.length];
128 for (int i = 0; i < path.length; i++) {
129 urls[i] = getFileURL(path[i]);
130 }
131 return urls;
132 }
133
134 private static File[] getClassPath(String cp) {
135 String[] tmp = cp.split(File.pathSeparator);
136 File[] paths = new File[tmp.length];
137 for (int i = 0; i < paths.length; i++) {
138 paths[i] = new File(tmp[i].equals("")? "." : tmp[i]);
139 }
140 return paths;
141 }
142
143 private static URL getFileURL(File file) {
144 try {
145 file = file.getCanonicalFile();
146 } catch (IOException e) {
147 e.printStackTrace();
148 }
149
150 try {
151 return file.toURI().toURL();
152 } catch (MalformedURLException mue) {
153 throw new InternalError(mue.getMessage());
154 }
155 }
156 }