/*
* Copyright (c) 2004, 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.management;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.Iterator;
import java.util.Set;
import java.io.IOException;
import sun.misc.Perf;
import sun.management.counter.Units;
import sun.management.counter.Counter;
import sun.management.counter.perf.PerfInstrumentation;
/**
* A utility class to support the exporting and importing of the address
* of a connector server using the instrumentation buffer.
*
* @since 1.5
*/
public class ConnectorAddressLink {
private static final String CONNECTOR_ADDRESS_COUNTER =
"sun.management.JMXConnectorServer.address";
/**
* Exports the specified connector address to the instrumentation buffer
* so that it can be read by this or other Java virtual machines running
* on the same system.
*
* @param address The connector address.
*/
public static void export(String address) {
if (address == null || address.length() == 0) {
throw new IllegalArgumentException("address not specified");
}
Perf perf = Perf.getPerf();
perf.createString(CONNECTOR_ADDRESS_COUNTER, 1, Units.STRING.intValue(), address);
}
/**
* Imports the connector address from the instrument buffer
* of the specified Java virtual machine.
*
* @param vmid an identifier that uniquely identifies a local
* Java virtual machine, or <code>0</code> to indicate
* the current Java virtual machine.
*
* @return the value of the connector address, or <code>null</code>
* if the target VM has not exported a connector address.
*
* @throws IOException An I/O error occurred while trying to acquire
* the instrumentation buffer.
*/
public static String importFrom(int vmid) throws IOException {
Perf perf = Perf.getPerf();
ByteBuffer bb;
try {
bb = perf.attach(vmid, "r");
} catch (IllegalArgumentException iae) {
throw new IOException(iae.getMessage());
}
List counters = (new PerfInstrumentation(bb)).findByPattern(CONNECTOR_ADDRESS_COUNTER);
Iterator i = counters.iterator();
if (i.hasNext()) {
Counter c = (Counter)i.next();
return (String)c.getValue();
} else {
return null;
}
}
}