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