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Hi,
I have a application which multiple modules. Each module do some task.
I have a signal handler defined in the main.pl which is the starting
point to run the application.
I want to define signal handler in each module which will do specific
task and again raised a signal which will be handled by the global
signal handler.
The signal to be caught are same throughout, not specific to any class
or the global handler.
Scenario :
application.pl define a a signal handler &globalhandler
application.pl creates a object out of foo.pm and foo.pm defines
a handle &foo_cleaner
when the execution is under the context of foo.pm object , a
INT signal caught. It will clean up the required things populated
by foo.pm and then raised the same signal from foo_cleaner. After
raising the &globalhandler should be called means the global handler
will be caught.
I tried but didnt succeded.

Do you have guys any idea whether there is some way out???
Can i get two handlers with the same signal???

sanjeeb <> wrote:
> I have a application which multiple modules. Each module do some task.
> I have a signal handler defined in the main.pl which is the starting
> point to run the application.
> I want to define signal handler in each module which will do specific
> task and again raised a signal which will be handled by the global
> signal handler.
> The signal to be caught are same throughout, not specific to any class
> or the global handler.
> Scenario :
> application.pl define a a signal handler &globalhandler
> application.pl creates a object out of foo.pm and foo.pm defines
> a handle &foo_cleaner
> when the execution is under the context of foo.pm object , a

What do you mean with "the context of foo.pm object"?

> INT signal caught. It will clean up the required things populated
> by foo.pm and then raised the same signal from foo_cleaner. After
> raising the &globalhandler should be called means the global handler
> will be caught.
> I tried but didnt succeded.

> Do you have guys any idea whether there is some way out???
> Can i get two handlers with the same signal???

You can have only a single signal handler for each signal. So
if the signal has been dealt with by foo_cleaner() then it's
used up. Raising it again would only lead to foo_cleaner() being
called again as long as it's still installed as the handler for
that signal.

What you can do is to simply call global_handler() from
foo_cleaner(). You can figure out its address by inspecting
the value of $SIG{INT} before you install foo_cleaner() as
the new signal handler. I.e. do

my $old_handler = $SIG{ INT };
$SIG{ INT } = \&new_handler;

sub new_handler {
do_something;
&$old_handler( @_ );
}
Regards, Jens
--
\ Jens Thoms Toerring ___
\__________________________ http://toerring.de

On Nov 19, 10:24*pm, j...@toerring.de (Jens Thoms Toerring) wrote:
> sanjeeb <sanjee...@gmail.com> wrote:
> > I have a application which multiple modules. Each module do some task.
> > I have a signal handler defined in the main.pl which is the starting
> > point to run the application.
> > I want to define signal handler in each module which will do specific
> > task and again raised a signal which will be handled by the global
> > signal handler.
> > The signal to be caught are same throughout, not specific to any class
> > or the global handler.
> > Scenario :
> > application.pl * define a a signal handler &globalhandler
> > * * * application.pl creates a object out of foo.pm and foo.pm defines
> > a handle &foo_cleaner
> > * * * *when the execution is under the context of foo.pm object, a
>
> What do you mean with "the context of foo.pm object"?
>
> > INT signal caught. It will clean * *up the required things populated
> > by foo.pm and then raised the same signal from foo_cleaner. After
> > raising the &globalhandler should be called means the global handler
> > will be caught.
> > I tried but didnt succeded.
> > Do you have guys any idea whether there is some way out???
> > Can i get two handlers with the same signal???
>
> You can have only a single signal handler for each signal. So
> if the signal has been dealt with by foo_cleaner() then it's
> used up. Raising it again would only lead to foo_cleaner() being
> called again as long as it's still installed as the handler for
> that signal.
>
> What you can do is to simply call global_handler() from
> foo_cleaner(). You can figure out its address by inspecting
> the value of $SIG{INT} before you install foo_cleaner() as
> the new signal handler. I.e. do
>
> my $old_handler = $SIG{ INT };
> $SIG{ INT } = \&new_handler;
>
> sub new_handler {
> * * do_something;
> * * &$old_handler( @_ );}
>
> * * * * * * * * * * * * * * *Regards, Jens
> --
> * \ * Jens Thoms Toerring *___ * * *j...@toerring.de
> * *\__________________________ * * *http://toerring.de

Thanks.
I tried this before but it is not working in a threaded environment.
In context means , the object is created in a thread, but the signal
handler is installed at the
main application. Here is the flow.
../main.pl creates a thread -> object of Execution.pm is created in the
thread -> The signal handler should be installed in this context when
the thread created the object of Execution.pm.

i am hunting for the solution, let me know if you found anything,
thanks.

On Thu, 19 Nov 2009 22:10:31 -0800, sanjeeb wrote:

> I tried this before but it is not working in a threaded environment. In
> context means , the object is created in a thread, but the signal
> handler is installed at the
> main application. Here is the flow.
> ./main.pl creates a thread -> object of Execution.pm is created in the
> thread -> The signal handler should be installed in this context when
> the thread created the object of Execution.pm.
>
> i am hunting for the solution, let me know if you found anything,
> thanks.

Threads and signals don't mix, as noted in the threads documentation.
This makes Perl threads absolutely useless in my opinion. Try a fork
based solution instead.

M4