vmobject.java

gcc的组建

/* VMObject.java -- Reference implementation for VM hooks used by Object
   Copyright (C) 1998, 2002, 2005  Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */

package java.lang;

/**
 * Object is the ultimate superclass of every class (excepting interfaces).
 * As such, it needs help from the VM.
 *
 * @author John Keiser
 * @author Eric Blake ([e-mail])
 */
final class VMObject
{
  /**
   * Returns the runtime {@link Class} of a given Object.
   *
   * @param obj the object to return the class for.
   *
   * @return the class of the Object.
   */
  static native Class getClass(Object obj);
  
  /**
   * The VM is expected to make a field-for-field shallow copy of the
   * argument. Thus, the copy has the same runtime type as the argument.
   * Note, however, that the cloned object must still be finalizable, even
   * if the original has already had finalize() invoked on it.
   *
   * @param c the Cloneable to clone
   * @return the clone
   */
  static native Object clone(Cloneable c);

  /**
   * Wakes up one of the threads that is waiting on this Object's monitor.
   * Only the owner of a lock on the Object may call this method. The Thread
   * to wake up is chosen arbitrarily.
   *
   * @param o the object doing the notify
   * @throw IllegalMonitorStateException if this Thread does not own the
   *        lock on the Object
   */
  static native void notify(Object o) throws IllegalMonitorStateException;

  /**
   * Wakes up all of the threads waiting on this Object's monitor.  Only
   * the owner of the lock on this Object may call this method.
   *
   * @param o the object doing the notifyAll
   * @throws IllegalMonitorStateException if this Thread does not own the
   *         lock on the Object
   */
  static native void notifyAll(Object o) throws IllegalMonitorStateException;

  /**
   * Waits a specified amount of time for notify() or notifyAll() to be
   * called on this Object.  The VM does not have to pay attention to the
   * ns argument, if it does not have that much granularity.
   *
   * @param o the object to suspend on
   * @param ms milliseconds to wait (1,000 milliseconds = 1 second)
   * @param ns nanoseconds to wait beyond ms (1,000,000 nanoseconds
   *        == 1 millisecond)
   * @throws IllegalMonitorStateException if this Thread does not own the
   *         lock on the Object
   * @throws InterruptedException if some other Thread interrupts this Thread
   */
  static native void wait(Object o, long ms, int ns)
    throws IllegalMonitorStateException, InterruptedException;
}