/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program 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; version 2 of the License.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Mar 26, 2008
*/
package com.bigdata.counters;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.lang.management.ManagementFactory;
import java.util.LinkedList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.log4j.Logger;
import org.apache.system.SystemUtil;
/**
* Utility to return the PID of the JVM.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class PIDUtil {
static private final Logger log = Logger
.getLogger(PIDUtil.class);
// static protected final boolean INFO = log.isInfoEnabled();
/**
* Return the PID of the Java VM under Linux using bash.
*
* @return The PID.
*
* @throws RuntimeException
* if anything goes wrong.
*/
static public int getLinuxPIDWithBash() {
final List<String> commands = new LinkedList<String>();
final Process pr;
try {
commands.add("/bin/bash");
commands.add("-c");
commands.add("echo $PPID");
ProcessBuilder pb = new ProcessBuilder(commands);
pr = pb.start();
pr.waitFor();
} catch (Exception ex) {
throw new RuntimeException("Problem running command: ["
+ commands + "]", ex);
}
if (pr.exitValue() == 0) {
final BufferedReader outReader = new BufferedReader(
new InputStreamReader(pr.getInputStream()));
final String val;
try {
val = outReader.readLine();
} catch (IOException ex) {
throw new RuntimeException(ex);
} finally {
try {
outReader.close();
} catch (IOException ex) {
log.error(ex, ex);
}
}
if (val == null)
throw new RuntimeException("Nothing read.");
if (log.isInfoEnabled())
log.info("read: [" + val + "]");
final int pid = Integer.parseInt(val.trim());
return pid;
} else {
throw new RuntimeException("Could not get PID: exitValue="
+ pr.exitValue());
}
}
/**
* Return the JVM PID.
*
* @throws UnsupportedOperationException
* if the pid can not be extracted.
*
* @see RuntimeMXBean#getName(), A web search will show that this is
* generally of the form "pid@host". However this is definitely NOT
* guaranteed by the javadoc.
*/
static public int getPIDWithRuntimeMXBean() {
final String name = ManagementFactory.getRuntimeMXBean().getName();
final Matcher matcher = pidPattern.matcher(name);
if (!matcher.find()) {
throw new UnsupportedOperationException(
"Could not extract pid from [" + name + "]");
}
final int pid = Integer.parseInt(matcher.group(1));
if(log.isInfoEnabled())
log.info("pid=" + pid);
return pid;
}
static private final Pattern pidPattern = Pattern.compile("^([0-9]+)@");
/**
* Tries each of the methods in this class and returns the PID as reported
* by the first method that succeeds. The order in which the methods are
* tried SHOULD reflect the likelyhood that the method will get it right.
*
* @return The PID of this JVM (best guess).
*/
public static int getPID() {
try {
if (!SystemUtil.operatingSystem().toLowerCase().startsWith("win")) {
return getLinuxPIDWithBash();
}
} catch (Throwable t) {
log.warn(t);
}
return getPIDWithRuntimeMXBean();
}
/**
* Utility for checking which method works on your platform.
*
* @param args
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
System.out.println("pid=" + getPID());
// gives you a chance to look at top, etc.
Thread.sleep(5000);
}
}