/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.chukwa.util;
import java.io.*;
import java.lang.management.ManagementFactory;
import java.nio.channels.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class PidFile extends Thread {
String name;
private static Log log = LogFactory.getLog(PidFile.class);
private static FileLock lock = null;
private static FileOutputStream pidFileOutput = null;
public PidFile(String name) {
this.name = name;
try {
init();
} catch (IOException ex) {
clean();
System.exit(-1);
}
}
public void init() throws IOException {
String pidLong = ManagementFactory.getRuntimeMXBean().getName();
String[] items = pidLong.split("@");
String pid = items[0];
String chukwaPath = System.getProperty("CHUKWA_HOME");
StringBuffer pidFilesb = new StringBuffer();
String pidDir = System.getenv("CHUKWA_PID_DIR");
if (pidDir == null) {
pidDir = chukwaPath + File.separator + "var" + File.separator + "run";
}
pidFilesb.append(pidDir).append(File.separator).append(name).append(".pid");
try {
File existsFile = new File(pidDir);
if (!existsFile.exists()) {
boolean success = (new File(pidDir)).mkdirs();
if (!success) {
throw (new IOException());
}
}
File pidFile = new File(pidFilesb.toString());
pidFileOutput = new FileOutputStream(pidFile);
pidFileOutput.write(pid.getBytes());
pidFileOutput.flush();
FileChannel channel = pidFileOutput.getChannel();
PidFile.lock = channel.tryLock();
if (PidFile.lock != null) {
log.debug("Initlization succeeded...");
} else {
throw (new IOException("Can not get lock on pid file: " + pidFilesb));
}
} catch (IOException ex) {
System.out.println("Initialization failed: can not write pid file to " + pidFilesb);
log.error("Initialization failed...");
log.error(ex.getMessage());
System.exit(-1);
throw ex;
}
}
public void clean() {
String chukwaPath = System.getenv("CHUKWA_HOME");
StringBuffer pidFilesb = new StringBuffer();
String pidDir = System.getenv("CHUKWA_PID_DIR");
if (pidDir == null) {
pidDir = chukwaPath + File.separator + "var" + File.separator + "run";
}
pidFilesb.append(pidDir).append(File.separator).append(name).append(".pid");
String pidFileName = pidFilesb.toString();
File pidFile = new File(pidFileName);
if (!pidFile.exists()) {
log.error("Delete pid file, No such file or directory: " + pidFileName);
} else {
try {
lock.release();
pidFileOutput.close();
} catch (IOException e) {
log.error("Unable to release file lock: " + pidFileName);
}
}
boolean result = pidFile.delete();
if (!result) {
log.error("Delete pid file failed, " + pidFileName);
}
}
public void run() {
clean();
}
}