Name: rmT116609 Date: 10/15/2002


FULL PRODUCT VERSION :
java version "1.4.1"
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 : Linux Red Hat 7.3 (2.4 kernel)


A DESCRIPTION OF THE PROBLEM :
The Process object will not always return the correct exitStatus when running on Linux Red Hat v7.3. Other UNIX OSes seem to work fine.


The following code demonstrates the problem:


public class foo {
 public static void main(String args[]) {
  while(true) {
   try {
    Runtime runtime = Runtime.getRuntime();
    Process p = runtime.exec("/bin/false");
    p.waitFor();
    System.out.println("Exit status: " + p.exitValue() );
   }catch(Exception e) {}
  }
 }
}



This code should always return 1, but the following output
shows what happens:


$ java foo
Exit status: 1
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 1
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 0
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 0
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 0
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 0
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 0
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 0
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
Exit status: 1
$


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. run the enclosed program


EXPECTED VERSUS ACTUAL BEHAVIOR :
if exitStatus of zero is printed, that's bad


REPRODUCIBILITY :
This bug can be reproduced often.

---------- BEGIN SOURCE ----------
public class foo {
 public static void main(String args[]) {
  while(true) {
   try {
    Runtime runtime = Runtime.getRuntime();
    Process p = runtime.exec("/bin/false");
    p.waitFor();
    System.out.println("Exit status: " + p.exitValue() );
   }catch(Exception e) {}
  }
 }
}


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

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: 165615)
======================================================================


###@###.### 2002-12-09

Same bug has been reported by a CAP member:

J2SE Version (please include all output from java -version flag):
  J2SDK 1.4.1_01 and J2SDK 1.4.2 cap build 08

  Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_01-b01)
  Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-beta-b08)

Does this problem occur on J2SE 1.3 or 1.4?
  No.

  Not reproducable with JDK 1.3.1 and J2SDK 1.4.0:

  Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_06-b01)
  Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0_03-b04)

Operating System Configuration Information (be specific):
  Redhat Linux 8.0 with all errata up to Dec. 08 2002. Other platforms
  untested so far.

Hardware Configuration Information (be specific):
  Athlon 1.2GHz, 512MB RAM, Geforce graphics adapter.


Bug Description:
  Process.waitFor() and Process.exitValue() incorrectly return 0 sometimes
  (non-determistic) even if the exit value of the executed process is
  always non-zero.

Steps to Reproduce (be specific):
  Run the attached program(ExitTest.java) on J2SDK 1.4.1 on J2SDK 1.4.2
  build08 and observe the output. The attached program starts "/bin/mv"
  without arguments 1000 times (sequentially) and checks the return code.
  It reports how many times zero was incorrectly returned as the exit value.

Test program:(ExitTest.java)

  public class ExitTest
  {
public static void main(String[] args) throws Throwable
{
int wrongExitCodes = 0;
for (int i = 0; i < 1000; i++)
{
Process p = Runtime.getRuntime().exec("/bin/mv");
int exitCode = p.waitFor();
exitCode = p.exitValue();
if (exitCode == 0)
wrongExitCodes++;
}
System.out.println("wrong exit code count: "+wrongExitCodes);
}
  }

Test result:

  Sample output with J2SDK 1.4.1_01 (WRONG):

  wrong exit code count: 137

  Sample output with J2SDK 1.4.0_03 (CORRECT):

  wrong exit code count: 0