--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/SALauncherLoader.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,156 @@
+/*
+ * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package sun.jvm.hotspot;
+
+import java.io.*;
+import java.net.*;
+import java.util.*;
+import java.security.*;
+
+/**
+ * SA uses native debugger back-end library - libsaproc.so on Unix platforms.
+ * Starting from 5.0, in Solaris & Linux JDK "libsaproc.so" is shipped with JDK
+ * and is kept jre/lib/cpu directory (where all other JDK platform libraries
+ * are kept). This implies that always that jre copy of libsaproc.so will be
+ * used and the copy of libsaproc.so built from SA sources here will not
+ * be used at all. We can override libsaproc.so using this class loader
+ * as System class loader using "java.system.class.loader" property. This
+ * class loader loads classes paths specified paths using the System property
+ * "java.class.path". Because, this class loader loads SA debugger classes
+ * (among other classes), JVM calls findLibrary override here. In this
+ * findLibrary, we first check the library in the directories specified through
+ * "sa.library.path" System property. This way updated/latest SA native library
+ * can be loaded instead of the one from JDK's jre/lib directory.
+ */
+public class SALauncherLoader extends URLClassLoader {
+
+    /**
+     * Checks native libraries under directories specified using
+     * the System property "sa.library.path".
+     */
+    public String findLibrary(String name) {
+        name = System.mapLibraryName(name);
+        for (int i = 0; i < libpaths.length; i++) {
+            File file = new File(new File(libpaths[i]), name);
+            if (file.exists()) {
+                return file.getAbsolutePath();
+            }
+        }
+        return null;
+    }
+
+    public SALauncherLoader(ClassLoader parent) {
+        super(getClassPath(), parent);
+        String salibpath = System.getProperty("sa.library.path");
+        if (salibpath != null) {
+            libpaths = salibpath.split(File.pathSeparator);
+        } else {
+            libpaths = new String[0];
+        }
+    }
+
+    /**
+     * Override loadClass so we can checkPackageAccess.
+     */
+    public synchronized Class loadClass(String name, boolean resolve)
+            throws ClassNotFoundException {
+        int i = name.lastIndexOf('.');
+        if (i != -1) {
+            SecurityManager sm = System.getSecurityManager();
+            if (sm != null) {
+                sm.checkPackageAccess(name.substring(0, i));
+            }
+        }
+
+        Class clazz = findLoadedClass(name);
+        if (clazz != null) return clazz;
+
+        /*
+         * NOTE: Unlike 'usual' class loaders, we do *not* delegate to
+         * the parent loader first. We attempt to load the class
+         * ourselves first and use parent loader only if we can't load.
+         * This is because the parent of this loader is 'default'
+         * System loader that can 'see' all SA classes in classpath and
+         * so will load those if delegated. And if parent loads SA classes,
+         * then JVM won't call findNative override in this class.
+         */
+        try {
+            return findClass(name);
+        } catch (ClassNotFoundException cnfe) {
+            return (super.loadClass(name, resolve));
+        }
+    }
+
+    /**
+     * allow any classes loaded from classpath to exit the VM.
+     */
+    protected PermissionCollection getPermissions(CodeSource codesource) {
+        PermissionCollection perms = super.getPermissions(codesource);
+        perms.add(new RuntimePermission("exitVM"));
+        return perms;
+    }
+
+    //-- Internals only below this point
+
+    private String[] libpaths;
+
+    private static URL[] getClassPath() {
+        final String s = System.getProperty("java.class.path");
+        final File[] path = (s == null) ? new File[0] : getClassPath(s);
+
+        return pathToURLs(path);
+    }
+
+    private static URL[] pathToURLs(File[] path) {
+        URL[] urls = new URL[path.length];
+        for (int i = 0; i < path.length; i++) {
+            urls[i] = getFileURL(path[i]);
+        }
+        return urls;
+    }
+
+    private static File[] getClassPath(String cp) {
+        String[] tmp = cp.split(File.pathSeparator);
+        File[] paths = new File[tmp.length];
+        for (int i = 0; i < paths.length; i++) {
+            paths[i] = new File(tmp[i].equals("")? "." : tmp[i]);
+        }
+        return paths;
+    }
+
+    private static URL getFileURL(File file) {
+        try {
+            file = file.getCanonicalFile();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        try {
+            return file.toURL();
+        } catch (MalformedURLException mue) {
+            throw new InternalError(mue.getMessage());
+        }
+    }
+}