/* VMObject.java -- Reference implementation for VM hooks used by Object
   Copyright (C) 1998, 2002, 2005, 2010  Free Software Foundation, Inc.

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
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General Public License for more details.

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02110-1301 USA.

Linking this library statically or dynamically with other modules is
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
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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 (ebb9@email.byu.edu)
 */
final class VMObject
{

  private VMObject() {} // Prohibits instantiation.

  /**
   * 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;
}