/* * Copyright (c) 2004, 2010, Oracle and/or its affiliates. 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. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.corba ; import java.lang.reflect.Field ; import java.lang.reflect.Method ; import java.lang.reflect.Constructor ; import java.lang.reflect.InvocationTargetException ; import java.io.ObjectInputStream ; import java.security.AccessController; import java.security.Permission; import java.security.PrivilegedAction; import sun.misc.Unsafe ; import sun.reflect.ReflectionFactory ; /** This class provides the methods for fundamental JVM operations * needed in the ORB that are not part of the public Java API. This includes: *
* All of these permissions are required to obtain and correctly initialize * the instance of Bridge. No security checks are performed on calls * made to Bridge instance methods, so access to the Bridge instance * must be protected. *
* This class is a singleton (per ClassLoader of course). Access to the * instance is obtained through the Bridge.get() method. */ public final class Bridge { private static final Class[] NO_ARGS = new Class[] {}; private static final Permission getBridgePermission = new BridgePermission( "getBridge" ) ; private static Bridge bridge = null ; // latestUserDefinedLoader() is a private static method // in ObjectInputStream in JDK 1.3 through 1.5. // We use reflection in a doPrivileged block to get a // Method reference and make it accessible. private final Method latestUserDefinedLoaderMethod ; private final Unsafe unsafe ; private final ReflectionFactory reflectionFactory ; private Method getLatestUserDefinedLoaderMethod() { return (Method) AccessController.doPrivileged( new PrivilegedAction() { public Object run() { Method result = null; try { Class io = ObjectInputStream.class; result = io.getDeclaredMethod( "latestUserDefinedLoader", NO_ARGS); result.setAccessible(true); } catch (NoSuchMethodException nsme) { Error err = new Error( "java.io.ObjectInputStream" + " latestUserDefinedLoader " + nsme ); err.initCause(nsme) ; throw err ; } return result; } } ); } private Unsafe getUnsafe() { Field fld = (Field)AccessController.doPrivileged( new PrivilegedAction() { public Object run() { Field fld = null ; try { Class unsafeClass = sun.misc.Unsafe.class ; fld = unsafeClass.getDeclaredField( "theUnsafe" ) ; fld.setAccessible( true ) ; return fld ; } catch (NoSuchFieldException exc) { Error err = new Error( "Could not access Unsafe" ) ; err.initCause( exc ) ; throw err ; } } } ) ; Unsafe unsafe = null; try { unsafe = (Unsafe)(fld.get( null )) ; } catch (Throwable t) { Error err = new Error( "Could not access Unsafe" ) ; err.initCause( t ) ; throw err ; } return unsafe ; } private Bridge() { latestUserDefinedLoaderMethod = getLatestUserDefinedLoaderMethod(); unsafe = getUnsafe() ; reflectionFactory = (ReflectionFactory)AccessController.doPrivileged( new ReflectionFactory.GetReflectionFactoryAction()); } /** Fetch the Bridge singleton. This requires the following * permissions: *
o
at the given offset.
* The result is undefined unless the offset was obtained from
* {@link #objectFieldOffset} on the {@link java.lang.reflect.Field}
* of some Java field and the object referred to by o
* is of a class compatible with that field's class.
* @param o Java heap object in which the field from which the offset
* was obtained resides
* @param offset indication of where the field resides in a Java heap
* object
* @return the value fetched from the indicated Java field
* @throws RuntimeException No defined exceptions are thrown, not even
* {@link NullPointerException}
*/
public final int getInt(Object o, long offset)
{
return unsafe.getInt( o, offset ) ;
}
/**
* Stores a value into a given Java field.
* * The first two parameters are interpreted exactly as with * {@link #getInt(Object, long)} to refer to a specific * Java field. The given value is stored into that field. *
* The field must be of the same type as the method
* parameter x
.
*
* @param o Java heap object in which the field resides, if any, else
* null
* @param offset indication of where the field resides in a Java heap
* object.
* @param x the value to store into the indicated Java field
* @throws RuntimeException No defined exceptions are thrown, not even
* {@link NullPointerException}
*/
public final void putInt(Object o, long offset, int x)
{
unsafe.putInt( o, offset, x ) ;
}
/**
* @see #getInt(Object, long)
*/
public final Object getObject(Object o, long offset)
{
return unsafe.getObject( o, offset ) ;
}
/**
* @see #putInt(Object, long, int)
*/
public final void putObject(Object o, long offset, Object x)
{
unsafe.putObject( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final boolean getBoolean(Object o, long offset)
{
return unsafe.getBoolean( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putBoolean(Object o, long offset, boolean x)
{
unsafe.putBoolean( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final byte getByte(Object o, long offset)
{
return unsafe.getByte( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putByte(Object o, long offset, byte x)
{
unsafe.putByte( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final short getShort(Object o, long offset)
{
return unsafe.getShort( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putShort(Object o, long offset, short x)
{
unsafe.putShort( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final char getChar(Object o, long offset)
{
return unsafe.getChar( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putChar(Object o, long offset, char x)
{
unsafe.putChar( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final long getLong(Object o, long offset)
{
return unsafe.getLong( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putLong(Object o, long offset, long x)
{
unsafe.putLong( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final float getFloat(Object o, long offset)
{
return unsafe.getFloat( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putFloat(Object o, long offset, float x)
{
unsafe.putFloat( o, offset, x ) ;
}
/** @see #getInt(Object, long) */
public final double getDouble(Object o, long offset)
{
return unsafe.getDouble( o, offset ) ;
}
/** @see #putInt(Object, long, int) */
public final void putDouble(Object o, long offset, double x)
{
unsafe.putDouble( o, offset, x ) ;
}
/**
* This constant differs from all results that will ever be returned from
* {@link #objectFieldOffset}.
*/
public static final long INVALID_FIELD_OFFSET = -1;
/**
* Returns the offset of a non-static field.
*/
public final long objectFieldOffset(Field f)
{
return unsafe.objectFieldOffset( f ) ;
}
/** Throw the exception.
* The exception may be an undeclared checked exception.
*/
public final void throwException(Throwable ee)
{
unsafe.throwException( ee ) ;
}
/** Obtain a constructor for Class cl using constructor cons which
* may be the constructor defined in a superclass of cl. This is
* used to create a constructor for Serializable classes that
* constructs an instance of the Serializable class using the
* no args constructor of the first non-Serializable superclass
* of the Serializable class.
*/
public final Constructor newConstructorForSerialization( Class cl,
Constructor cons )
{
return reflectionFactory.newConstructorForSerialization( cl, cons ) ;
}
}