Java tutorial
/* * ProActive Parallel Suite(TM): * The Open Source library for parallel and distributed * Workflows & Scheduling, Orchestration, Cloud Automation * and Big Data Analysis on Enterprise Grids & Clouds. * * Copyright (c) 2007 - 2017 ActiveEon * Contact: contact@activeeon.com * * This library is free software: you can redistribute it and/or * modify it under the terms of the GNU Affero General Public License * as published by the Free Software Foundation: version 3 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * * If needed, contact us to obtain a release under GPL Version 2 or 3 * or a different license than the AGPL. */ package org.ow2.proactive.scheduler.task.executors; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.PrintStream; import org.apache.commons.io.FileUtils; import org.objectweb.proactive.extensions.processbuilder.OSProcessBuilder; import org.ow2.proactive.scheduler.common.task.TaskId; import org.ow2.proactive.scheduler.task.TaskResultImpl; import org.ow2.proactive.scheduler.task.context.TaskContext; import org.ow2.proactive.scheduler.task.context.TaskContextSerializer; import org.ow2.proactive.scheduler.task.exceptions.ForkedJvmProcessException; import org.ow2.proactive.scheduler.task.executors.forked.env.ExecuteForkedTaskInsideNewJvm; import org.ow2.proactive.scheduler.task.utils.ProcessStreamsReader; import org.ow2.proactive.utils.CookieBasedProcessTreeKiller; /** * Executor in charge to fork a new process for running a non forked task in a dedicated JVM. * * @see ExecuteForkedTaskInsideNewJvm#fromForkedJVM(String) * @see InProcessTaskExecutor */ public class ForkedTaskExecutor implements TaskExecutor { private final ForkedProcessBuilderCreator forkedJvmProcessBuilderCreator = new ForkedProcessBuilderCreator(); private final TaskContextSerializer taskContextSerializer = new TaskContextSerializer(); private final File workingDir; public ForkedTaskExecutor(File workingDir) { this.workingDir = workingDir; } @Override public TaskResultImpl execute(TaskContext context, PrintStream outputSink, PrintStream errorSink) { CookieBasedProcessTreeKiller taskProcessTreeKiller = null; Process process = null; ProcessStreamsReader processStreamsReader = null; File serializedContext = null; try { if (!workingDir.exists()) { FileUtils.forceMkdir(workingDir); } serializedContext = taskContextSerializer.serializeContext(context, workingDir); OSProcessBuilder processBuilder = forkedJvmProcessBuilderCreator.createForkedProcessBuilder(context, serializedContext, outputSink, errorSink, workingDir); TaskId taskId = context.getTaskId(); String cookieNameSuffix = "Job" + taskId.getJobId().value() + "Task" + taskId.value(); taskProcessTreeKiller = CookieBasedProcessTreeKiller.createProcessChildrenKiller(cookieNameSuffix, processBuilder.environment()); process = processBuilder.start(); processStreamsReader = new ProcessStreamsReader(taskId.toString(), process, outputSink, errorSink); int exitCode = process.waitFor(); if (exitCode != 0) { try { Object error = deserializeTaskResult(serializedContext); if (error instanceof TaskContext) { return createTaskResult(context, new IOException("Forked JVM process returned with exit code " + exitCode + ", see task logs for more information")); } else { Throwable exception = (Throwable) error; return createTaskResult(context, exception); } } catch (Throwable cannotDeserializeResult) { return createTaskResult(context, cannotDeserializeResult); } } return (TaskResultImpl) deserializeTaskResult(serializedContext); } catch (Throwable throwable) { return createTaskResult(context, throwable); } finally { FileUtils.deleteQuietly(serializedContext); if (process != null) { process.destroy(); } if (taskProcessTreeKiller != null) { taskProcessTreeKiller.kill(); } if (processStreamsReader != null) { processStreamsReader.close(); } } } private TaskResultImpl createTaskResult(TaskContext context, Throwable throwable) { return new TaskResultImpl(context.getTaskId(), new ForkedJvmProcessException("Failed to execute task in a forked JVM", throwable)); } // 4 called by forker private Object deserializeTaskResult(File pathToFile) throws IOException, ClassNotFoundException { try (ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(pathToFile))) { return inputStream.readObject(); } catch (IOException e) { throw new ForkedJvmProcessException( "Could not read serialized task result (forked JVM may have been killed by the task or could not write to local space)", e); } finally { FileUtils.deleteQuietly(pathToFile); } } }