Name: rmT116609 Date: 10/15/2002


FULL PRODUCT VERSION :
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java HotSpot(TM) Client VM (build 1.4.1-b21, mixed mode)


FULL OPERATING SYSTEM VERSION :
RedHat Linux 7.1 (Seawolf)
glibc-2.2.2-10

A DESCRIPTION OF THE PROBLEM :
A Java process which is launched from another Java 1.4.1
Class has an output buffer (filled via System.out.println)
of only 4096 bytes. If it has more than 4096 bytes the
process hangs / deadlocks.
In Java 1.4.0 This doesn't occur.

REGRESSION. Last worked in version 1.4

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Launch a java process from a Java class in Java 1.4.1
2. In the launched process write (using System.out.println)
4097 bytes.


EXPECTED VERSUS ACTUAL BEHAVIOR :
Expected results (as in 1.4.0): The launched process will
end normally.
Actual results: The launched process hangs and has to be
killed.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
1. This is the first class, the one which launches the process.

import java.io.*;
public class ProcTest
{
    public static void main(String[] args)
    {
        try
        {
            
             String l_aCommand[] = {
                                    "/usr/java/j2sdk1.4.1/bin/java", "-cp",
                                    ".",
                                    "DummyProcess"};
                                                 
            Process p = Runtime.getRuntime().exec(l_aCommand);
            p.waitFor();
            System.out.println(" Process returned " + p.exitValue() );
        }
        catch (Throwable e)
        {
            e.printStackTrace();
        }
    }
}



2. This is the process class, which is launced by the above class.

public class DummyProcess
{
    public static void main(String[] args)
    {
        
        for (int i = 0 ; i < 4097 ; i++ )
        {
            System.out.print("c");
            System.out.flush();
        }
        System.exit(0);
    }
}

---------- END SOURCE ----------

CUSTOMER WORKAROUND :
Workaround - Be sure to clean the Process InputStream
buffer. Two main ways to do that:
1. Direct the Process's OutputStream to a file or another
device by writing (in the Process's Java code) something
like:

FileOutputStream fos = new FileOutputStream("/tmp/out.out");
FileOutputStream ferr = new FileOutputStrea("/tmp/out.err");
System.setOut(new PrintStream(fos));
System.setErr(new PrintStream(ferr))


2. From the class that launched the process get the
Process's inputstream (is = p.getInputStream() ) and read
from it whenever it's available (is.read() ).

Release Regression From : 1.4
The above release value was the last known release where this
bug was known to work. Since then there has been a regression.

(Review ID: 165805)
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