Unloading classes

Sun Nov 3 18:05:00 GMT 2002

On 3 Nov 2002, Anthony Green wrote:
> On Sun, 2002年11月03日 at 17:16, Jeff Sturm wrote:
> > Also, a classloader must keep strong references to its loaded classes.
>> Why is that?

It's the simplest way to satisfy the condition that a class cannot be
unloaded while its classloader is reachable, as described in JLS 12.7:
"Since we can never guarantee that unloading a class or interface whose
loader is potentially reachable will not cause reloading, and reloading is
never transparent, but unloading must be transparent, it follows that one
must not unload a class or interface while its loader is potentially
reachable. A similar line of reasoning can be used to deduce that classes
and interfaces loaded by the bootstrap loader can never be unloaded."
> Another interesting question is how to handle System.loadLibrary(). Can
> we dlclose() them when the class calling System.loadLibrary is
> finalized?

I think you need to guarantee no static method of the class is executing
when you dlclose(). This is hard with the current GC.
Jeff