| [reply] |
I recently looked at POE to perform heavy processing for multiple tasks at the same time. I was impressed. However, I hit a brick wall since some of the important modules of POE would not compile and/or install on Win32 (according to activestate testing results, and some personal attempts) due to the lack of adequate support of forking on win32. What I needed was Wheel::Run and POE::Component::Child and that turned out to be a dead-end for me. Anyone with more experience on Win32 and POE?
Right now, I'm playing with threading and IO::Socket to perform these tasks.
Hope this helps.
| [reply] |
My thought is to have the service start a new thread that handles socket connections and responses while the main thread runs the looping processes. Would it be hard for it to view some main thread variables to obtain status?
No, no problem at all. Just share the variables that you want the status thread to be able to see, and add:
my $sharedVar : shared;
....
{ lock( $sharedVar ); #do stuff with $sharedVar }
around each access to those shared variables in both pieces of code.
If your going to use a package like IO::Socket::INET to provide the communications within the status thread, require it within that thread rather than useing it at the top of the script.
In essence that is all there is to it.
There are some limitations about what types of variable can be shared--filehandles (hackable) and objects or tied vars (not easily hackable)--but that needn't be a great limitation.
Does anyone have any thoughts on a direction for this task?
From your description so far, using a thread would seem the ideal route to me.
Of course, the devil is in the detail--in this case, the detail of exactly what information you want to share between the threads.
Examine what is said, not who speaks.
Silence betokens consent.
Love the truth but pardon error.
| [reply]
[d/l] |
use strict;
use Thread;
my $time : shared;
my $t = Thread->new(\&listener,\$time);
while (1) {
$time = localtime;
print $time,"\n";
sleep 1;
}
sub listener {
my $time_ref = shift;
while (1) {
{
lock($$time_ref);
print "\tThread time: [$time]\n";
print "\tThread time: [$main::time]\n";
print "\tThread time: [$$time_ref]\n";
}
sleep 3;
}
}
Which prints out:
Wed Feb 9 08:06:02 2005
Thread time: []
Thread time: []
Thread time: []
Wed Feb 9 08:06:03 2005
Wed Feb 9 08:06:04 2005
Wed Feb 9 08:06:05 2005
Thread time: []
Thread time: []
Thread time: []
Wed Feb 9 08:06:06 2005
Indicating to me that the thread only sees the initial value like it has it's own copy. Is that right? How do I access the main threads $time var? Hmmmmm. | [reply]
[d/l]
[select] |
use strict;
use threads;
use threads::shared;
my $time : shared;
sub listener {
my $array_ref = shift;
while (1) {
{
lock $time;
print "\tThread time: [$time]\n";
}
{
lock($array_ref);
print "\tThread time: [@$array_ref]\n";
}
sleep 3;
}
}
my @array : shared;
my $t = threads->new( \&listener, \@array );
while (1) {
{ lock $time; $time = localtime; }
print $time,"\n";
{ lock @array; push @array, $time; }
sleep 1;
}
__END__
[16:09:17.53] P:\test>429405
Wed Feb 9 16:09:31 2005
Thread time: [Wed Feb 9 16:09:31 2005]
Thread time: []
Wed Feb 9 16:09:32 2005
Wed Feb 9 16:09:33 2005
Thread time: [Wed Feb 9 16:09:33 2005]
Thread time: [Wed Feb 9 16:09:31 2005 Wed Feb 9 16:09:32 200
+5 Wed Feb 9 16:09:33 2005]
Wed Feb 9 16:09:34 2005
Wed Feb 9 16:09:35 2005
Wed Feb 9 16:09:36 2005
Terminating on signal SIGINT(2)
I switched your code around a bit not because there was anything wrong with the ordering, but to allow me to demonstrate a couple of points.
I've stopped passing the scalar ref to the sub and am passing a reference to an array that is also updated in the main thread.
Because $time is visible to your listener() sub, it is accessible, via closure in the normal way, without being explicitly passed it to the thread.
The array however, was not existing when the sub was declared, so it must be passed explicitly.
Basically, all the normal perl scoping rules apply--once you are using the correct modules :) I should have mentioned that before. Sorry!
Examine what is said, not who speaks.
Silence betokens consent.
Love the truth but pardon error.
| [reply]
[d/l]
[select] |
In my humility I guess I don't know the difference between 'Thread' and 'threads'. After shifting the code to use 'threads' and 'threads::shared', I am able to access my variable. What the heck is the 'Thread' module for then?
| [reply] |
Thanks o wise ones!
I have looked at POE before and have not undertaken the learning curve and found the documentation, well, open sourc'ish...lol
I will go down the enlightened path of using a thread as I really only have to access a string var in the main code. Sounds easy enough given BrowserUk's description.
$OP = 'Most Humbly Bows'; | [reply] |
Might be completely OT (apologies if it is) - but you mentioned Win32-Process etc. Have you looked at WMI? You can find out just about anything -hardware, processes, installed applications, services (and do things e.g. spawn processes, etc.) on the local machine or remote machines.
Start at
Microsoft WMI docs
I haven't use WMI from Perl, but I have in Tcl using Tcom, so I'm sure Perl can do it!
| [reply] |
