With that in mind, it may be worth your looking at merlyn's Highlander - allow only one invocation at a time of an expensive CGI script which allows only a single simultaneous invocation of a CGI script. If you combine this with a sleep function within your script such that execution time is greater than a second, this will effectively achieve your goal.

 

perl -e 'print+unpack("N",pack("B32","00000000000000000000000111101100")),"\n"'