wrapper-user

[Wrapper-user] ctrl-break event on windows

[Richard E. <rem...@ed...>]

When a wrapper on windows is not being run in console mode is
there a way to send a ctrl-break event to it?
If so, then why is the call to the method requestDumpJVMState()
in the file wrapper_win.c commented out in the method
wrapperConsoleHandler(..)?

I know one can call requestDumpJVMState() via the JMX
interface. I am interested in knowing if there is any other
way.

Thanks.

RME

Re: [Wrapper-user] ctrl-break event on windows

[Leif M. <le...@ta...>]

Richard,

> When a wrapper on windows is not being run in console mode is
> there a way to send a ctrl-break event to it?
> If so, then why is the call to the method requestDumpJVMState()
> in the file wrapper_win.c commented out in the method
> wrapperConsoleHandler(..)?

That is commented out because it is not needed.  If that call is made 
then two stack traces would actually be dumped.  When CTRL-BREAK is 
pressed, both the Java and Wrapper processes get the signal.  I had not 
known that when I first implemented the feature.  I should really just 
remove it completely.

> I know one can call requestDumpJVMState() via the JMX
> interface. I am interested in knowing if there is any other
> way.

There is no way to directly send a CTRL-BREAK signal to an NT service.
(without using a third party program).    The Wrapper does provide a few 
ways
to work around it though.  The first is to use JMX, the method that you 
already
found.  The second is to instantiate the WrapperActionServer class and 
connect
via telnet to request a thread dump.  (You can see an example of this by 
looking
at the TestWrapper app source code or the javadocs)  The third is to call
WrapperManager.requestThreadDump() method directly from within your
application.

The WrapperActionServer is probably the easiest to get working as it 
just requires
a few lines of isolated code that can really exist pretty much anywhere 
in your
program.

If you have any other ideas, they may make good features for a future 
version.

Cheers,
Leif

Re: [Wrapper-user] ctrl-break event on windows

[<da...@ix...>]

In article <3F7...@ta...>,
Leif Mortenson  <wra...@li...> wrote:
>There is no way to directly send a CTRL-BREAK signal to an NT service.
>(without using a third party program).    The Wrapper does provide a few 

Do you know of such a third party program?  My quick looks haven't been too
successful.

>The WrapperActionServer is probably the easiest to get working as it 
>just requires
>a few lines of isolated code that can really exist pretty much anywhere 
>in your
>program.
>
>If you have any other ideas, they may make good features for a future 
>version.

Couple of feature suggestions then:

If WrapperActionServer is so easy, could you migrate the appropriate code
form the test program over to Wrapper proper and have it controlled by
wrapper.conf?

Another thought, since Wrapper can now do PID files, would it be possible
to add a -d option that would read said PID file, and call
GenerateConsoleCtrlEvent() against it?

mrc
-- 
     Mike Castle      da...@ix...      www.netcom.com/~dalgoda/
    We are all of us living in the shadow of Manhattan.  -- Watchmen
fatal ("You are in a maze of twisty compiler features, all different"); -- gcc