/* Licensed to Diennea S.r.l. under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. Diennea S.r.l. 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 blazingcache.services; import java.io.IOException; import java.lang.management.ManagementFactory; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.StandardOpenOption; import java.util.Arrays; /** * Lock sul pid file, per evitare avvii concorrenti del servizio * * @author enrico.olivelli */ public class PidFileLocker implements AutoCloseable { private final Path file; private final byte[] pid; private final static String PIDFILE = System.getProperty("pidfile", ""); public PidFileLocker(Path basePath) { this.file = basePath.resolve(PIDFILE); String _pid = ManagementFactory.getRuntimeMXBean().getName(); int choi = _pid.indexOf('@'); _pid = _pid.substring(0, choi); System.out.println("Current process PID:" + _pid); this.pid = _pid.getBytes(StandardCharsets.UTF_8); } public void lock() throws IOException { if (PIDFILE.isEmpty()) { return; } System.out.println("Creating and locking file " + file.toAbsolutePath()); if (Files.exists(file)) { throw new IOException("file " + file.toAbsolutePath() + " already exists"); } Files.write(file, pid, StandardOpenOption.CREATE_NEW); } public void check() throws Exception { if (PIDFILE.isEmpty()) { return; } if (!Files.isRegularFile(file)) { System.out.println("Lock file " + file.toAbsolutePath() + " does not exists any more. stopping service"); throw new Exception("Lock file " + file.toAbsolutePath() + " does not exists any more. stopping service"); } else { byte[] actualContent; try { actualContent = Files.readAllBytes(file); } catch (IOException err) { System.out.println("Lock file " + file.toAbsolutePath() + " cannot be read (" + err + "). stopping service"); throw new Exception("Lock file " + file.toAbsolutePath() + " cannot be read (" + err + "). stopping service", err); } if (!Arrays.equals(pid, actualContent)) { System.out.println("Lock file " + file.toAbsolutePath() + " changed, now contains " + new String(actualContent, StandardCharsets.UTF_8) + ". stopping service"); throw new Exception("Lock file " + file.toAbsolutePath() + " changed, now contains " + new String(actualContent, StandardCharsets.UTF_8) + ". stopping service"); } } } @Override public void close() { if (PIDFILE.isEmpty()) { return; } try { Files.deleteIfExists(file); } catch (IOException err) { } } }