Using the Parallel Programming Library in the real world: Parallel For/Join

One of the first loops that any programmer becomes familiar with is the for loop. In this recipe, we'll see a particular type of for loop—the parallel one. To be clear, this parallel for loop is not a new language feature, but is kind of implemented as a static class method.

The parallel for loop is part of the Parallel Programming Library, and is implemented by the TParallel class. Here's one of its (overloaded) versions and a utilization example:

//declaration 
class method TParallel.&For(ALowInclusive, AHighInclusive:  
  Integer; const AIteratorEvent: TProc<Integer>): TLoopResult; 
 
//used as follows 
TParallel.&For(1,10, 
  procedure(Index: Integer) 
  begin 
    //executed 10 times with index 1..10 
  end); 

What is different about the classic for? The difference is that the anonymous method passed to the for method is executed on different threads concurrently; this is the reason it's a parallel...