/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.harmony.kernel.vm;
/**
* This class must be implemented by the vm vendor. Represents the running
* virtual machine. All VM specific API are implemented on this class.
* <p>
* Note that all methods in VM are static. There is no singleton instance which
* represents the actively running VM.
*/
public final class VM {
/*
* kernelVersion has the format: aabbxxyy where: aa - major version of
* kernel. Must equal that stored in jcl. bb - minor version of kernel. Must
* be >= that in jcl. xx - major version of jcl. Must equal that stored in
* kernel. yy - minor version of jcl. Must be >= that in kernel.
*/
private static final int kernelVersion = 0x01000100;
/**
* This method must be provided by the vm vendor, as it is used by
* org.apache.harmony.kernel.vm.MsgHelp.setLocale() to get the bootstrap
* ClassLoader. MsgHelp uses the bootstrap ClassLoader to find the resource
* bundle of messages packaged with the bootstrap classes. Returns the
* ClassLoader of the method (including natives) at the specified depth on
* the stack of the calling thread. Frames representing the VM
* implementation of java.lang.reflect are not included in the list. This is
* not a public method as it can return the bootstrap class loader, which
* should not be accessed by non-bootstrap classes. Notes:
* <ul>
* <li>This method operates on the defining classes of methods on stack.
* NOT the classes of receivers.</li>
* <li>The item at depth zero is the caller of this method</li>
* </ul>
*
* @param depth the stack depth of the requested ClassLoader
* @return the ClassLoader at the specified depth
* @see java.lang.ClassLoader#getStackClassLoader
*/
static final ClassLoader getStackClassLoader(int depth) {
return null;
};
/**
* This method must be provided by the vm vendor, as it is used by other
* provided class implementations. For example,
* java.io.ObjectInputStream.readObject() and
* java.io.ObjectInputStream.resolveProxyClass(). It is also useful for
* other classes, such as java.rmi.server.RMIClassLoader. Walk the stack and
* answer the most recent non-null and non-bootstrap ClassLoader on the
* stack of the calling thread. If no such ClassLoader is found, null is
* returned. Notes: 1) This method operates on the defining classes of
* methods on stack. NOT the classes of receivers.
*
* @return the first non-bootstrap ClassLoader on the stack
*/
static public final ClassLoader getNonBootstrapClassLoader() {
return null;
};
/**
* Initialize the classloader.
*
* @param loader ClassLoader the ClassLoader instance
* @param bootLoader boolean true for the bootstrap class loader
*/
public final static void initializeClassLoader(ClassLoader loader, boolean bootLoader) {
return;
};
/**
* This method must be provided by the vm vendor.
*
* Searches an internal table of strings for a string equal to the specified
* String. If the string is not in the table, it is added. Returns the
* string contained in the table which is equal to the specified String. The
* same string object is always answered for strings which are equal.
*
* @param string the String to intern
*
* @return the interned string equal to the specified String
*/
public static final String intern(String string) {
return null;
}
/**
* Native used to find and load a class using the VM
*
* @return java.lang.Class the class or null.
* @param className String the name of the class to search for.
* @param classLoader the classloader to do the work
*/
static Class<?> findClassOrNull(String className, ClassLoader classLoader) {
return null;
}
/**
* This method must be included, as it is used by
* ResourceBundle.getBundle(), and other places as well. The reference
* implementation of this method uses the getStackClassLoader() method.
* Returns the ClassLoader of the method that called the caller. i.e. A.x()
* calls B.y() calls callerClassLoader(), A's ClassLoader will be returned.
* Returns null for the bootstrap ClassLoader.
*
* @return a ClassLoader or null for the bootstrap ClassLoader
* @throws SecurityException when called from a non-bootstrap Class
*/
public static ClassLoader callerClassLoader() {
return null;
}
/**
* This method must be provided by the vm vendor, as it is used by
* org.apache.harmony.luni.util.MsgHelp.setLocale() to get the bootstrap
* ClassLoader. MsgHelp uses the bootstrap ClassLoader to find the resource
* bundle of messages packaged with the bootstrap classes. The reference
* implementation of this method uses the getStackClassLoader() method.
*
* Returns the ClassLoader of the method that called the caller. i.e. A.x()
* calls B.y() calls callerClassLoader(), A's ClassLoader will be returned.
* Returns null for the bootstrap ClassLoader.
*
* @return a ClassLoader
*
* @throws SecurityException when called from a non-bootstrap Class
*/
public static ClassLoader bootCallerClassLoader() {
return null;
}
/**
* Native used to dump a string to the system console for debugging.
*
* @param str String the String to display
*/
public static void dumpString(String str) {
return;
}
/**
* Get the classpath entry that was used to load the class that is the arg.
* <p>
* This method is for internal use only.
*
* @param targetClass Class the class to set the classpath of.
* @see java.lang.Class
*/
static int getCPIndexImpl(Class<?> targetClass) {
return 0;
}
/**
* Does internal initialization required by VM.
*
*/
static void initializeVM() {
}
/**
* Registers a new virtual-machine shutdown hook. This is equivalent to the
* 1.3 API of the same name.
*
* @param hook the hook (a Thread) to register
*/
public static void addShutdownHook(Thread hook) {
return;
}
/**
* De-registers a previously-registered virtual-machine shutdown hook. This
* is equivalent to the 1.3 API of the same name.
*
* @param hook the hook (a Thread) to de-register
* @return true if the hook could be de-registered
*/
public static boolean removeShutdownHook(Thread hook) {
return false;
}
/**
* This method must be provided by the vm vendor. Called to signal that the
* org.apache.harmony.luni.internal.net.www.protocol.jar.JarURLConnection
* class has been loaded and JarURLConnection.closeCachedFiles() should be
* called on VM shutdown.
*/
public static void closeJars() {
return;
}
/**
* This method must be provided by the vm vendor. Called to signal that the
* org.apache.harmony.luni.util.DeleteOnExit class has been loaded and
* DeleteOnExit.deleteOnExit() should be called on VM shutdown.
*/
public static void deleteOnExit() {
return;
}
// Constants used by getClassPathEntryType to indicate the class path entry
// type
static final int CPE_TYPE_UNKNOWN = 0;
static final int CPE_TYPE_DIRECTORY = 1;
static final int CPE_TYPE_JAR = 2;
static final int CPE_TYPE_TCP = 3;
static final int CPE_TYPE_UNUSABLE = 5;
/**
* Return the type of the specified entry on the class path for a
* ClassLoader. Valid types are: CPE_TYPE_UNKNOWN CPE_TYPE_DIRECTORY
* CPE_TYPE_JAR CPE_TYPE_TCP - this is obsolete CPE_TYPE_UNUSABLE
*
* @param classLoader the ClassLoader
* @param cpIndex the index on the class path
*
* @return a int which specifies the class path entry type
*/
static final int getClassPathEntryType(Object classLoader, int cpIndex) {
return 0;
}
/**
* Returns command line arguments passed to the VM. Internally these are
* broken into optionString and extraInfo. This only returns the
* optionString part.
* <p>
*
* @return a String array containing the optionString part of command line
* arguments
*/
public static String[] getVMArgs() {
return null;
}
/**
* Return the number of entries on the bootclasspath.
*
* @return an int which is the number of entries on the bootclasspath
*/
static int getClassPathCount() {
return 0;
}
/**
* Return the specified bootclasspath entry.
*
* @param index the index of the bootclasspath entry
*
* @return a byte array containing the bootclasspath entry
* specified in the vm options
*/
static byte[] getPathFromClassPath(int index) {
return null;
}
/**
* This method must be provided by the vm vendor.
*
* Returns an int containing the version number of the kernel. Used to check for kernel
* compatibility.
*
* @return an int containing the kernel version number
*/
public static int getKernelVersion() {
return kernelVersion;
}
}