<?php

function myfunc($args) 
{
  $modules = get_modules(); // whatever to get your module list
  foreach($modules as $module)
  {
    if(is_callable($module,'myfunc')) // check if there is a hook function
    {
      $module->myfunc($args); // run the hook function
    }
  }
  // continue to do whatever needs to be done in this function
}

?>