3dan has already answered your question, and you will probably want to do it the way he showed. In the ever-present spirit of TIMTOWTDI, I figured I would show you another approach:

timeout_func($timeout, sub { myfunc($arg1, $arg2) });

sub timeout_func {
  my ($timeout, $coderef) = @_;  
  ...
  $coderef->();
}
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This creates an anonymous subroutine that does nothing but call your function with the given arguments. This is, incidentally, a nice way to get around an API that takes a coderef but doesn't take in "additional arguments" as 3dan's does, so the technique might be useful for you in the future.