Mercurial > hg > truffle
annotate agent/src/share/classes/sun/jvm/hotspot/jdi/SAJDIClassLoader.java @ 152:c70a245cad3a
6670684: 4/5 SA command universe did not print out CMS space information
Summary: Forward port of Yumin's fix for 6670684 from HSX-11; Yumin verified the port was correct.
Reviewed-by: dcubed
| author | dcubed |
|---|---|
| date | Fri, 09 May 2008 08:55:13 -0700 |
| parents | a61af66fc99e |
| children | d1605aabd0a1 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 2003-2004 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 package sun.jvm.hotspot.jdi; | |
| 26 | |
| 27 import java.io.*; | |
| 28 import java.net.*; | |
| 29 | |
| 30 /* | |
| 31 * This class loader is used for two different reasons: | |
| 32 * | |
| 33 * 1) To support multiple simultaneous debuggees. | |
| 34 * | |
| 35 * SA's architecture does not allow us to use multiple simultaneous | |
| 36 * debuggees. This is because of lots of static fields caching | |
| 37 * vmStruct fields and singleton assumption in classes such as | |
| 38 * 'sun.jvm.hotspot.runtime.VM'. Hence, we use instances of this | |
| 39 * class loader to create a separate namespace for each debuggee VM. | |
| 40 * | |
| 41 * 2) To support cross VM version debugging. | |
| 42 * | |
| 43 * SA has very close dependency on VM data structures. Due to this, a | |
| 44 * version of SA can only support debuggees running a same dot-dot release and | |
| 45 * update releases only. For eg. this version of SA supports only 1.4.2 and | |
| 46 * 1.4.2_xx releases only. But, users may want to debug debuggees running | |
| 47 * a different version of VM. To support this, we use an instance of this | |
| 48 * class loader to load classes from corresponding sa-jdi.jar. | |
| 49 * | |
| 50 * Note that JDI classes would still be loaded from the debugger's tools.jar | |
| 51 * and not from debuggee's tools.jar. This means that if JDI interface evolved | |
| 52 * b/w debuggee and debugger VM versions, user may still get problems. This is | |
| 53 * the case when debugger runs on 1.5.0 and debuggee runs on 1.4.2. Because JDI | |
| 54 * evolved b/w these versions (generics, enum, varargs etc.), 1.4.2 sa-jdi.jar | |
| 55 * won't implement 1.5.0 JDI properly and user would get verifier errors. This | |
| 56 * class loader solution is suited for different dot-dot release where JDI will | |
| 57 * not evolve but VM data structures might change and SA implementation might | |
| 58 * have to change. For example, a debuggee running 1.5.1 VM can be debugged | |
| 59 * with debugger running on 1.5.0 VM. Here, JDI is same but VM data structures | |
| 60 * could still change. | |
| 61 */ | |
| 62 | |
| 63 class SAJDIClassLoader extends URLClassLoader { | |
| 64 private static final boolean DEBUG; | |
| 65 static { | |
| 66 DEBUG = System.getProperty("sun.jvm.hotspot.jdi.SAJDIClassLoader.DEBUG") != null; | |
| 67 } | |
| 68 | |
| 69 private ClassLoader parent; | |
| 70 private boolean classPathSet; | |
| 71 | |
| 72 SAJDIClassLoader(ClassLoader parent) { | |
| 73 super(new URL[0], parent); | |
| 74 this.parent = parent; | |
| 75 } | |
| 76 | |
| 77 SAJDIClassLoader(ClassLoader parent, String classPath) { | |
| 78 this(parent); | |
| 79 this.classPathSet = true; | |
| 80 try { | |
|
152
c70a245cad3a
6670684: 4/5 SA command universe did not print out CMS space information
dcubed
parents:
0
diff
changeset
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81 addURL(new File(classPath).toURI().toURL()); |
| 0 | 82 } catch(MalformedURLException mue) { |
| 83 throw new RuntimeException(mue); | |
| 84 } | |
| 85 } | |
| 86 | |
| 87 public synchronized Class loadClass(String name) | |
| 88 throws ClassNotFoundException { | |
| 89 // First, check if the class has already been loaded | |
| 90 Class c = findLoadedClass(name); | |
| 91 if (c == null) { | |
| 92 /* If we are loading any class in 'sun.jvm.hotspot.' or any of the | |
| 93 * sub-packages (except for 'debugger' sub-pkg. please refer below), | |
| 94 * we load it by 'this' loader. Or else, we forward the request to | |
| 95 * 'parent' loader, system loader etc. (rest of the code follows | |
| 96 * the patten in java.lang.ClassLoader.loadClass). | |
| 97 * | |
| 98 * 'sun.jvm.hotspot.debugger.' and sub-package classes are | |
| 99 * also loaded by parent loader. This is done for two reasons: | |
| 100 * | |
| 101 * 1. to avoid code bloat by too many classes. | |
| 102 * 2. to avoid loading same native library multiple times | |
| 103 * from multiple class loaders (which results in getting a | |
| 104 * UnsatisifiedLinkageError from System.loadLibrary). | |
| 105 */ | |
| 106 | |
| 107 if (name.startsWith("sun.jvm.hotspot.") && | |
| 108 !name.startsWith("sun.jvm.hotspot.debugger.")) { | |
| 109 return findClass(name); | |
| 110 } | |
| 111 if (parent != null) { | |
| 112 c = parent.loadClass(name); | |
| 113 } else { | |
| 114 c = findSystemClass(name); | |
| 115 } | |
| 116 } | |
| 117 return c; | |
| 118 } | |
| 119 | |
| 120 protected Class findClass(String name) throws ClassNotFoundException { | |
| 121 if (DEBUG) { | |
| 122 System.out.println("SA/JDI loader: about to load " + name); | |
| 123 } | |
| 124 if (classPathSet) { | |
| 125 return super.findClass(name); | |
| 126 } else { | |
| 127 byte[] b = null; | |
| 128 try { | |
| 129 InputStream in = getResourceAsStream(name.replace('.', '/') + ".class"); | |
| 130 // Read until end of stream is reached | |
| 131 b = new byte[1024]; | |
| 132 int total = 0; | |
| 133 int len = 0; | |
| 134 while ((len = in.read(b, total, b.length - total)) != -1) { | |
| 135 total += len; | |
| 136 if (total >= b.length) { | |
| 137 byte[] tmp = new byte[total * 2]; | |
| 138 System.arraycopy(b, 0, tmp, 0, total); | |
| 139 b = tmp; | |
| 140 } | |
| 141 } | |
| 142 // Trim array to correct size, if necessary | |
| 143 if (total != b.length) { | |
| 144 byte[] tmp = new byte[total]; | |
| 145 System.arraycopy(b, 0, tmp, 0, total); | |
| 146 b = tmp; | |
| 147 } | |
| 148 } catch (Exception exp) { | |
| 149 throw (ClassNotFoundException) new ClassNotFoundException().initCause(exp); | |
| 150 } | |
| 151 return defineClass(name, b, 0, b.length); | |
| 152 } | |
| 153 } | |
| 154 } |