Java threads and garbage collector

Possible Duplicate: Java Thread Garbage collected or not Consider the following class: ``` class Foo implements Runnable { public Foo () { Thread th = new Thread (this); th.start(); } public run() { ... // long task } } ``` If we create several instances of `Foo` by doing ``` new Foo(); new Foo(); new Foo(); new Foo(); ``` (note that we don't keep a pointer to them). Could those instances be removed by the garbage collector before the thread in `run()` ends? (In other words: is there any reference to the `Foo` objects?) And, in the other hand, will those instances be removed by the GC after the thread in `run()' ends, or are we wasting memory ("memory leak")? If either 1. or 2. are a problem, what's the right way to do it? Thanks