creating simaltaneous threads

hi gurus,

I want to create 100 threads/processes  simaltaneoulsy (at the same time),
and those 100 threads/processes  should  execute a subrountine at the same
time.

can anybody help me giving some ideas reagarding this, I tried creating this
100  process using fork in a for loop but that does not server the purpose.

I even tried with Parallel::ForkManager; but it did not work for me.

Please help me in this.

Thanks,
Siva