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Re: Thread::Use - use a module inside a thread only

Jenda Krynicky
July 30, 2002 07:05
Re: Thread::Use - use a module inside a thread only
Message ID:
Date sent:      	Tue, 30 Jul 2002 15:20:39 +0200
To:             	"Jenda Krynicky" <>, perl5-,
From:           	Elizabeth Mattijsen <>
Subject:        	Re: Thread::Use - use a module inside a thread only

> At 02:54 PM 7/30/02 +0200, Jenda Krynicky wrote:
> >The problem with run-time "useit Foo" instead of compile-time "use
> >Foo" is that the symbols are not exported while compiling, prototypes
> >not "installed", constants not defined, etc. etc. etc.
> Well, I guess YMMV...  prototypes aren't much use in an OO environment
> anyway, exports seems to work fine, judging from the testing that I
> did.  Constants may be another problem, let me check up on that...

Even if there's no prototype defined for a function, the fact that 
perl knows about it already IS important. Try to run this:

	foo 1,2,3;
	sub foo {print join(', ', @_), "\n"};

or this:

	eval q{
		sub foo {print join(', ', @_), "\n"};
	foo 1,2,3;

I bet you'll see the same problems with "useit Module".

> >Would not it be simpler then to require() or do() the whole thread?
> >         use threads;
> >         $thread = threads->create(sub {do '';}) ...
> Simpler by having to have a different file?  That doesn't make it
> simpler for me...  ;-)

Well, for the simple tests and benchmarks it seems to make things 
more complex, but if you have anything longer than a few lines it is 
better to separate it out into a different file anyway.

And if you do not like separating out into a file, you can use an 

Anyway in almost all the threaded programs I ever made in Perl (Perl 
5.6.1, Win32, fork(), no shared variables) I use do() and separate 
files and it seems to work very well.


P.S.: Since I need to be able to create .exe files out of the scripts 
I'll stay on 5.6.1 until there's a version of ActiveState's PDK for 
5.8. At least for production purposes.
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