What you want is multithread. Take a look at threads.

For multiple executions of multiple tasks you can use modules that help to do that with threads: Thread::Pool, Thread::Isolate::Pool.

Note that you will need Perl-5.8.3+ to can use multithreading. For multithreading is recomended to always use the last Perl version, Perl-5.8.6, specially because 5.8.6 has some memory leak fixes.