//****************************************************************************** // // File: PJProperties.java // Package: edu.rit.pj // Unit: Class edu.rit.pj.PJProperties // // This Java source file is copyright (C) 2008 by Alan Kaminsky. All rights // reserved. For further information, contact the author, Alan Kaminsky, at // ark@cs.rit.edu. // // This Java source file is part of the Parallel Java Library ("PJ"). PJ 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; either // version 3 of the License, or (at your option) any later version. // // PJ 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. // // Linking this library statically or dynamically with other modules is making a // combined work based on this library. Thus, the terms and conditions of the // GNU General Public License cover the whole combination. // // As a special exception, the copyright holders of this library give you // permission to link this library with independent modules to produce an // executable, regardless of the license terms of these independent modules, and // to copy and distribute the resulting executable under terms of your choice, // provided that you also meet, for each linked independent module, the terms // and conditions of the license of that module. An independent module is a // module which is not derived from or based on this library. If you modify this // library, you may extend this exception to your version of the library, but // you are not obligated to do so. If you do not wish to do so, delete this // exception statement from your version. // // A copy of the GNU General Public License is provided in the file gpl.txt. You // may also obtain a copy of the GNU General Public License on the World Wide // Web at http://www.gnu.org/licenses/gpl.html. // //****************************************************************************** package edu.rit.pj; /** * Class PJProperties provides static methods for reading Java system properties * that control the behavior of Parallel Java. The PJ properties are: * *

* You can specify a PJ property on the Java command line like this: *

*     java -Dpj.nt=4 . . . * * @author Alan Kaminsky * @version 21-May-2008 */ public class PJProperties { // Prevent construction. private PJProperties() { } // Exported operations. /** * Determine the number of backend nodes in a parallel program. *

* If the "pj.nn" Java system property is specified, it must be an * integer greater than or equal to 1. * * @return Number of backend nodes for a parallel program. * * @exception IllegalArgumentException * (unchecked exception) Thrown if the "pj.nn" property value * is not an integer greater than or equal to 1. */ public static int getPjNn() { int k = 1; String pj_nn = System.getProperty ("pj.nn"); if (pj_nn != null) { try { k = Integer.parseInt (pj_nn); } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.nn system property is not an integer >= 1"); } if (k < 1) { throw new IllegalArgumentException ("pj.nn system property is not an integer >= 1"); } } else // (pj_nn == null) { String pj_np = System.getProperty ("pj.np"); if (pj_np != null) { try { k = Integer.parseInt (pj_np); } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.np system property is not an integer >= 1"); } if (k < 1) { throw new IllegalArgumentException ("pj.np system property is not an integer >= 1"); } } } return k; } /** * Determine the number of processes in a parallel program. This is the * number of backend processes set up when the Comm.init() method * is executed (see class {@linkplain Comm}). This is also the size of the * world communicator. *

* If the "pj.np" Java system property is specified, it must be an * integer greater than or equal to 1. * * @return Number of processes for a parallel program. * * @exception IllegalArgumentException * (unchecked exception) Thrown if the "pj.np" property value * is not an integer greater than or equal to 1. */ public static int getPjNp() { int k = 1; String pj_np = System.getProperty ("pj.np"); if (pj_np != null) { try { k = Integer.parseInt (pj_np); } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.np system property is not an integer >= 1"); } if (k < 1) { throw new IllegalArgumentException ("pj.np system property is not an integer >= 1"); } } else // (pj_np == null) { String pj_nn = System.getProperty ("pj.nn"); if (pj_nn != null) { try { k = Integer.parseInt (pj_nn); } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.nn system property is not an integer >= 1"); } if (k < 1) { throw new IllegalArgumentException ("pj.nn system property is not an integer >= 1"); } } } return k; } /** * Determine the number of CPUs per process in a parallel program. This is * the number of threads a {@linkplain ParallelTeam} will have if the number * of threads is not specified as a constructor argument. *

* If the "pj.nt" Java system property is specified, it must be an * integer greater than or equal to 1. *

* If the "pj.nt" Java system property is not specified, this * method returns 0 to signify that all available CPUs should be used. * * @return Number of CPUs per process for a parallel program, or 0 if not * specified. * * @exception IllegalArgumentException * (unchecked exception) Thrown if the "pj.nt" property value * is not an integer greater than or equal to 1. */ public static int getPjNt() { int k = 0; String pj_nt = System.getProperty ("pj.nt"); if (pj_nt != null) { try { k = Integer.parseInt (pj_nt); } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.nt system property is not an integer >= 1"); } if (k < 1) { throw new IllegalArgumentException ("pj.nt system property is not an integer >= 1"); } } return k; } /** * Determine the schedule for a parallel loop in an SMP parallel program. * This is the schedule that will be used if the parallel for loop has a * runtime schedule. For further information, see class {@linkplain * IntegerSchedule} and class {@linkplain LongSchedule}. *

* If the "pj.schedule" Java property is specified, that value * gives the type of schedule, which must be one of the following: *

*

* If the "pj.schedule" Java property is not specified, the default * schedule for a runtime schedule is used. Normally this is a fixed * schedule, but a program can specify a different default. * * @return Schedule for a parallel for loop (one of the above strings), or * null if the "pj.schedule" Java property is not * specified. */ public static String getPjSchedule() { return System.getProperty ("pj.schedule"); } /** * Determine the host name of the Job Scheduler Daemon to use when running a * cluster parallel program. The program contacts the Job Scheduler Daemon * when the Comm.init() method is executed (see class {@linkplain * Comm}). For further information, see package {@linkplain * edu.rit.pj.cluster edu.rit.pj.cluster} and class {@linkplain * edu.rit.pj.cluster.JobScheduler}. *

* If the "pj.host" Java system property is specified, it gives the * Job Scheduler Daemon's host name (or IP address). *

* If the "pj.host" Java system property is not specified, a host * name of "localhost" is returned. * * @return Job Scheduler Daemon host name. */ public static String getPjHost() { return System.getProperty ("pj.host", "localhost"); } /** * Determine the port number of the Job Scheduler Daemon to use when running * a cluster parallel program. The program contacts the Job Scheduler Daemon * when the Comm.init() method is executed (see class {@linkplain * Comm}). For further information, see package {@linkplain * edu.rit.pj.cluster edu.rit.pj.cluster} and class {@linkplain * edu.rit.pj.cluster.JobScheduler}. *

* If the "pj.port" Java system property is specified, it gives the * Job Scheduler Daemon's port number. *

* If the "pj.port" Java system property is not specified, the * well-known Parallel Java port number (20617) is returned. * * @return Job Scheduler Daemon port number. * * @exception IllegalArgumentException * (unchecked exception) Thrown if the "pj.port" property value * is not an integer. */ public static int getPjPort() { try { String pj_port = System.getProperty ("pj.port"); int port = pj_port == null ? // edu.rit.pj.cluster.Constants.PJ_PORT : 20617 : Integer.parseInt (pj_port); return port; } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.port system property is not an integer"); } } /** * Determine the maximum amount of time (seconds) the job is allowed to run * when running a cluster parallel program. If a program running in the * Parallel Java job queue has not finished in the given amount of time, the * job frontend process automatically termintes the job when the given * number of seconds have elapsed since the job started executing. If a * program is not running in the Parallel Java job queue (if there is no Job * Scheduler Daemon present), then the job time setting is ignored and the * program will not time out. *

* If the "pj.jobtime" Java system property is specified, it must * be an integer greater than or equal to 1, and that gives the the maximum * job timeout in seconds. *

* If the "pj.jobtime" Java system property is not specified, a * value of 0 is returned to signify that there is no job timeout. * * @return Job timeout (seconds), or 0 if no job timeout. * * @exception IllegalArgumentException * (unchecked exception) Thrown if the "pj.jobtime" property * value is not an integer greater than or equal to 1. */ public static int getPjJobTime() { try { String pj_jobtime = System.getProperty ("pj.jobtime"); if (pj_jobtime == null) { return 0; } else { int jobtime = Integer.parseInt (pj_jobtime); if (jobtime < 1) { throw new IllegalArgumentException ("pj.jobtime system property is not an integer >= 1"); } return jobtime; } } catch (NumberFormatException exc) { throw new IllegalArgumentException ("pj.jobtime system property is not an integer >= 1"); } } /** * Determine the JVM flags to include on the Java command line when running * a backend process in a cluster parallel program. When a job backend * process is started, the JVM flags are included on the command line * immediately after the "java" command. These flags then control * the job backend process's JVM. For further information, see package * {@linkplain edu.rit.pj.cluster edu.rit.pj.cluster}. *

* If the "pj.jvmflags" Java system property is specified, it gives * the JVM flags exactly as they are to appear on the Java command line. If * there are multiple flags separated by whitespace, the * "pj.jvmflags" Java system property must be enclosed in quotation * marks. *

* If the "pj.jvmflags" Java system property is not specified, * there are no JVM flags, and an empty string is returned. *

* Example. To cause the job backend processes' JVMs to use an * initial heap size of 4 MB and a maximum heap size of 128 MB, specify the * "pj.jvmflags" property as follows when running the program: *

*     java -Dpj.jvmflags="-Xms4m -Xmx128m" . . . *

* Note that quotation marks are needed around the property value because of * the embedded whitespace. This property value causes the Job Launcher * Daemon to launch each job backend process's JVM with this command: *

*     java -Xms4m -Xmx128m . . . *

* which in turn tells each job backend process's JVM to use initial and * maximum heap sizes of 4 MB and 128 MB. * * @return JVM flags. */ public static String getPjJvmFlags() { return System.getProperty ("pj.jvmflags", ""); } /** * Determine the fully-qualified class name of the default pseudorandom * number generator (PRNG) class. *

* If the "pj.prng" Java system property is specified, it gives the * fully-qualified class name of the PRNG class that the static * getInstance(long) method in class {@linkplain * edu.rit.util.Random} will construct. Specifying the "pj.prng" * property will substitute a different PRNG algorithm into a program * without needing to recompile. See class {@linkplain edu.rit.util.Random} * for further information. *

* If the "pj.prng" Java system property is not specified, a PRNG * class name of "edu.rit.util.DefaultRandom" is returned. See * class {@linkplain edu.rit.util.DefaultRandom} for further information. * * @return Default PRNG class name. */ public static String getPjPrng() { return System.getProperty ("pj.prng", "edu.rit.util.DefaultRandom"); } }