Re: [tcljava-user] Some questions ( no HTML now )

[D. J. H. <dha...@mi...>]

"Jesus M. Salvo Jr." wrote:
> D.J.: You mentioned that they would show as child processes with linux's "ps"
> command. However, I tried that several times .... within a tclsh just after
> "package require java", after a "[java::new ]" .... and I do not see such
> child processes.

Only if you start creating/running threads in the Java code.  E.g.,

--------- TestThread.java ---------------
public class TestThread implements Runnable {
    private boolean flag_ = true;
    private boolean interrupted_ = false;
    public void run() {
        while( !interrupted_ ) {
            System.out.println(flag_ ? "Tick" : "Tock");
            System.out.flush();
            flag_ = !flag_;
            try {
                Thread.sleep(1000L);
            } catch( InterruptedException ex ) {
                interrupted_ = true;
            }
        }
    }
}
------------------------------------------

    javac TestThread.java
    jtclsh
    package require java
    set tt [java::new Thread [java::new TestThread]]
    $tt start

And now, on Linux, if your JVM is set to use native threads, you'll 
see a child process off your jtclsh process.  If your JVM is set to
use green threads, you will still only see one process.  (on linux,
green threads are a *lot* less resource intensive on a single-processor
box).

Hopefully Mo can answer your other questions, but some of it can
really only be answered through tests.

For instance, create two interps in tclsh, package require java
into both of them, and then do something like:

    java::call System setProperty interp1prop Hi

System properties are exclusive per VM, so if, in fact, there
were two VMs created, the second interp would not be able to 
find the property you set in the first interp.  With TclJava
1.2.6, this does not appear to be the case:

% java::call System setProperty interp1prop Hi
%
% set ni [interp create]
interp0
% $ni eval "package require java"
1.2.6
% $ni eval {java::call System getProperty interp1prop}
Hi

I don't have a thread-enabled Tcl to perform a similar test with
threads, but perhaps you could do so with the interp that comes
with Vignette?

Hope this helps,

			-=- D. J.