xref: /titanic_44/usr/src/cmd/pools/poold/com/sun/solaris/service/kstat/KstatCtl.java (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  *
26  * ident	"%Z%%M%	%I%	%E% SMI"
27  */
28 
29 package com.sun.solaris.service.kstat;
30 
31 /**
32  * <code>kstat</code> controlling object.  Allows kstats to be looked up
33  * so they can later be sampled.
34  */
35 public final class KstatCtl
36 {
37 	static {
38 		System.loadLibrary("jkstat");
KstatCtl.init()39 		KstatCtl.init();
40 	}
41 
42 	/**
43 	 * Pointer to a <code>kstat_ctl_t</code>.
44 	 */
45 	private long kctl;
46 
47 	/**
48 	 * Invokes <code>kstat_open(3KSTAT)</code>.  The returned object
49 	 * should be explicitly finalized when it's no longer needed.
50 	 */
KstatCtl()51 	public KstatCtl()
52 	{
53 		kctl = open();
54 		assert(kctl != 0);
55 	}
56 
57 	/**
58 	 * Calls <code>kstat_close(3KSTAT)</code>.
59 	 */
finalize()60 	public void finalize()
61 	{
62 		close(kctl);
63 		kctl = 0;
64 	}
65 
66 	/**
67 	 * Invokes <code>kstat_open(3KSTAT)</code>.
68 	 */
open()69 	private native long open();
70 
71 	/**
72 	 * Invokes <code>kstat_close(3KSTAT)</code>.
73 	 */
close(long kctl)74 	private native int close(long kctl);
75 
76 	/**
77 	 * Invokes <code>kstat_lookup(3KSTAT)</code> and returns a Kstat
78 	 * for any result, or null if none is found.
79 	 */
lookup(String module, int instance, String name)80 	public native Kstat lookup(String module, int instance, String name);
81 
82 	/**
83 	 * Invokes <code>kstat_chain_update(3KSTAT)</code>.
84 	 *
85 	 * @throws KstatChainUpdateException if the native function
86 	 * returns -1.
87 	 */
chainUpdate()88 	public native void chainUpdate() throws KstatChainUpdateException;
89 
90 	/**
91 	 * Initialize cached class, method, and field IDs.
92 	 */
init()93 	private static native void init();
94 }
95