Marko,
I was able to experience some crashes with this test.
They occur once in a while and at random locations...
Sometimes when writing testfile1, and sometimes at the beginning of the program.
Sadly, i was never able to get an usable core file.
Will keep digging,
Cheers,
Gilles
Marko Blatzheim <marko-blatzh...@web.de> wrote:
>Hi Gilles,
>
>
>
>I checked out openMPI Master 2 weeks ago.
>
>JVM is: java version "1.7.0_25"
>Java(TM) SE Runtime Environment (build 1.7.0_25-b15)
>Java HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
>
>command line is: mpirun -np 2 java -jar MPI_open.jar
>
>
>
>The segmentation fault is in the line with: test = is.readObject();
>
>
>
>
>package mpi_open;
>
>import java.io.ByteArrayInputStream;
>import java.io.FileOutputStream;
>import java.io.IOException;
>import java.io.ObjectInputStream;
>import java.io.ObjectOutputStream;
>import java.io.Serializable;
>import java.util.ArrayList;
>import java.util.Random;
>import mpi.File;
>import mpi.MPI;
>import mpi.MPIException;
>import mpi.Status;
>
>
>public class MPI_open {
>
>
> public static void main(String[] args) throws MPIException, IOException,
>ClassNotFoundException {
>
> MPI.Init(args);
> int myRank = MPI.COMM_WORLD.getRank();
> if (myRank == 0) {
> // create file
> int num = 1000000;
> Random r = new Random(1234);
> ArrayList<Serializable> obj0 = new ArrayList<>(num);
> double[] obj1 = new double[num];
> for (int j = 0; j < num; j++) {
> double d = r.nextGaussian();
> obj0.add(d);
> obj1[j] = d;
> }
> obj0.trimToSize();
>
> System.out.println("objects created");
>
> java.io.File f = new java.io.File("testfile0");
> ObjectOutputStream out = null;
> try {
> out = new ObjectOutputStream(new FileOutputStream(f));
> System.out.println("out1");
> out.writeObject(obj1);
> System.out.println("out2");
> } catch (java.lang.ClassCastException x) {
> throw x;
> } finally {
> if (out != null) {
> out.close();
> }
> }
>
> System.out.println("file 1 done");
>
> java.io.File f1 = new java.io.File("testfile1");
> ObjectOutputStream out1 = null;
> try {
> out1 = new ObjectOutputStream(new FileOutputStream(f1));
> out1.writeObject(obj0);
> } catch (java.lang.ClassCastException x) {
> throw x;
> } finally {
> if (out1 != null) {
> out1.close();
> }
> }
> System.out.println("file 2 done");
>
> String filename = "testfile1";
> byte[] readbuf;
>
> File myfile = new File(MPI.COMM_SELF, filename, MPI.MODE_RDONLY);
> int filesize = (int) myfile.getSize();
> readbuf = new byte[filesize];
> Status status = myfile.read(readbuf, filesize, MPI.BYTE);
> Object test = null;
>
> ByteArrayInputStream in = new ByteArrayInputStream(readbuf);
> ObjectInputStream is = new ObjectInputStream(in);
> System.out.println("Program fine until this line!");
> test = is.readObject();
> }
>
> MPI.Finalize();
> }
>}
>
>
>
>Thanks
>
>Marko
>
>
>
>Gesendet: Montag, 25. Januar 2016 um 01:04 Uhr
>Von: "Gilles Gouaillardet" <gil...@rist.or.jp>
>An: "Open MPI Users" <us...@open-mpi.org>
>Betreff: Re: [OMPI users] segmentation fault with java MPI
>
>Marko,
>
>i wrote a test program based on your code snippet and it works for me.
>
>could you please :
>- post a standalone test case that is ready to be compiled and ran
>- which version of OpenMPI are you using ?
>- which JVM are you using ? (vendor and version)
>- post your full command line
>
>Cheers,
>
>Gilles
>
>On 1/25/2016 8:23 AM, Marko Blatzheim wrote:
>> String filename = "testfile";
>> byte[] readbuf;
>>
>> File myfile = new File(MPI.COMM_SELF, filename, MPI.MODE_RDONLY);
>> int filesize = (int) myfile.getSize();
>> readbuf = new byte[filesize];
>>
>> byte[] copyarray = new byte[filesize];
>> Status status = myfile.read(readbuf, filesize, MPI.BYTE);
>> Object test = null;
>> if (myrank == 0) {
>> ByteArrayInputStream in = new ByteArrayInputStream(readbuf);
>> ObjectInputStream is = new ObjectInputStream(in);
>> test = is.readObject(); // This line causes a
>> segmnentation fault
>> }
>
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