1 /* VMObject.java -- Reference implementation for VM hooks used by Object
2 Copyright (C) 1998, 2002, 2005 Free Software Foundation
3
4 This file is part of GNU Classpath.
5
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
37
38 package java.lang;
39
40 /**
41 * Object is the ultimate superclass of every class (excepting interfaces).
42 * As such, it needs help from the VM.
43 *
44 * @author John Keiser
45 * @author Eric Blake (ebb9@email.byu.edu)
46 */
47 final class VMObject
48 {
49 /**
50 * Returns the runtime {@link Class} of a given Object.
51 *
52 * @param obj the object to return the class for.
53 *
54 * @return the class of the Object.
55 */
56 static native Class getClass(Object obj);
57
58 /**
59 * The VM is expected to make a field-for-field shallow copy of the
60 * argument. Thus, the copy has the same runtime type as the argument.
61 * Note, however, that the cloned object must still be finalizable, even
62 * if the original has already had finalize() invoked on it.
63 *
64 * @param c the Cloneable to clone
65 * @return the clone
66 */
67 static native Object clone(Cloneable c);
68
69 /**
70 * Wakes up one of the threads that is waiting on this Object's monitor.
71 * Only the owner of a lock on the Object may call this method. The Thread
72 * to wake up is chosen arbitrarily.
73 *
74 * @param o the object doing the notify
75 * @throw IllegalMonitorStateException if this Thread does not own the
76 * lock on the Object
77 */
78 static native void notify(Object o) throws IllegalMonitorStateException;
79
80 /**
81 * Wakes up all of the threads waiting on this Object's monitor. Only
82 * the owner of the lock on this Object may call this method.
83 *
84 * @param o the object doing the notifyAll
85 * @throws IllegalMonitorStateException if this Thread does not own the
86 * lock on the Object
87 */
88 static native void notifyAll(Object o) throws IllegalMonitorStateException;
89
90 /**
91 * Waits a specified amount of time for notify() or notifyAll() to be
92 * called on this Object. The VM does not have to pay attention to the
93 * ns argument, if it does not have that much granularity.
94 *
95 * @param o the object to suspend on
96 * @param ms milliseconds to wait (1,000 milliseconds = 1 second)
97 * @param ns nanoseconds to wait beyond ms (1,000,000 nanoseconds
98 * == 1 millisecond)
99 * @throws IllegalMonitorStateException if this Thread does not own the
100 * lock on the Object
101 * @throws InterruptedException if some other Thread interrupts this Thread
102 */
103 static native void wait(Object o, long ms, int ns)
104 throws IllegalMonitorStateException, InterruptedException;
105 }
Save This Page