Hi,

I've a question concerning threads and shared objects:
Assume an object of the following class SharedObject
is used by two different threads.

class SharedObject
{
 private String s;

 public void method (int i)
 {
   // preparation code (value of i never changes)

   synchronized (this)
   {
      // do something with member s
      // and use local variable i
      // (value of i never changes)
   }

   // some other code (value of i never changes)
 }
}

What I know is that access to member s should
be protected either by defining the whole method
synchronized or by putting a synchronized block
around the the critical sections of the method.
But what about the local variable i, if i use
a synchronized block and a thread is interrupted
during the preparation code?

Example:
...
SharedObject s;
...
// thread1 calls
s.method(5);
// thread2 calls
s.method(10);
...

assume thread1 is interrupted during the preparation
code and thread2 becomes active. Before thread2
finishes with s.method(10) it's interrupted and
thread1 becomes active again.
What is the value of i now (5 or 10)?

I did some tests whith many thread-instances using
a shared object and it seems, that local variables are
created separately for each thread.
Is this right?
Can i rely on this, or does it depend on the implementation of the JVM?
Is there a separate stack of local variables for each thread?
Maybe someone could explain that?

Thanks in advance!
Martin