Null Pointer Exception occurs in 1.4.2_11.

Configuration :
 UltraSparcII 400[MHz] *2
 4[GB]
 Solaris9

How to reproduce :
1. Compile attached .java programs
2. Launch
    " java -server -cp . TestNPO 100"
  in 1.4.2_11 on Solaris9 box.

The following message will show up.
...
Thread-72 start
Thread-83 start
Thread-54 start
Thread-52 start
Thread-81 start
Thread-88 start
Thread-58 start
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException


NOTE:
The customer did reverse-assembling with java_g -server -XX:+PrintNMethod.
They sent the following report also.

----- Report -----
In compiled code out of NPO_Thread#run(),
the generated code of
 nmw.npoMaker = new NPOMaker(new Foo("f2"));
is inlined.

If the code is not optimized, the code will be

 tmp1 = new Foo();
 tmp1.s = "f2";
 tmp2 = new NPOMaker();
 tmp2.foo = tmp1;
 nmw.npoMaker = tmp2;

However, actual code is

 tmp1 = new Foo();
 tmp2 = new NPOMaker();
 nmw.npoMaker = tmp2;
                    <<-- other trhead exec. nmw.npoMaker.print()
 tmp2.foo = tmp1;
 tmp1.s = "f2";

If other thread executes nmw.npoMaker.print() at the above "<<--"
NullPointerException seems to occur.

According to the source code, nmw.npoMaker is the reference to a variable
which will be referred by plural threads.

We want to clarify if the problem is bug or the implemetation of NPO_Thread.java
(Java Language Specs. Chapter 17.3 Rules about Variables)

----- Report end -----