Parallel procedures MTProcs package improvement?

[heju]

Hi all,

I'm quite new to fpc, but having already a lot of fun

Currently I am working on a data processing tool. The required algos are really simple to spread to several threads as nothing depends on each other, but each calculation portion is time consuming.

I got the MTProcs package (http://wiki.freepascal.org/Parallel_procedures) running, which does a perfect job.
Especially the "experimental" feature to parallelize nested procedures is really helpfull
Currently I am using "DoParallelLocalProc" in the following form:

Code: Pascal  [Select][+][-]

1. procedure main();
2.  
3.   procedure DoSomethingParallel(Index: PtrInt; Data: Pointer; Item: TMultiThreadProcItem);
4.   var
5.     i: Integer;
6.   begin
7.     writeln(Index);
8.     for i:=1 to Index*1000000000 do ; // do some work
9.     writeln('done')
10.   end;
11.  
12. begin
13.   ProcThreadPool.DoParallelLocalProc(@DoSomethingParallel,1,5,nil); // address, startindex, endindex, optional data
14. end;
15.  
16.  
17. begin
18.   main();
19.   readln;
20. end.}
21.  

However the wiki page warns: "Beware that calling nested procedures is not yet supported by the compiler and therefore one has to use unsafe type casts."

I am wondering: This info is not up to date anymore:  nested proc vars are available and will help to overcome this unsafe call!
To test this proposal i set this type def in MTProcs.pas as is nested:

Code: Pascal  [Select][+][-]

1. TMTProcedure = procedure(Index: PtrInt; Data: Pointer;
2.                            Item: TMultiThreadProcItem) is nested;
3.  

Now the user can use "DoParallel" for both local procedures and normal procedures, without unsafe calls!

Code: Pascal  [Select][+][-]

1. program partest;
2.  
3. {$mode objfpc}{$H+}
4. {$modeswitch nestedprocvars}
5. uses
6.   {$IFDEF UNIX}
7.   cthreads, cmem,
8.   {$ENDIF}
9.   MTProcs;
10.  
11. // a simple parallel procedure
12.  
13. procedure main();
14.  
15.   procedure DoSomethingParallel(Index: PtrInt; Data: Pointer; Item: TMultiThreadProcItem);
16.   var
17.     i: Integer;
18.   begin
19.     writeln(Index);
20.     for i:=1 to Index*1000000000 do ; // do some work
21.     writeln('done')
22.   end;
23.  
24. begin
25.   ProcThreadPool.DoParallel(@DoSomethingParallel,1,5,nil); // address, startindex, endindex, optional data
26. end;
27.  
28.  
29. begin
30.   main();
31.   readln;
32. end.
33.  

The original wiki testprog is working as well without change.

What do you (more experienced users) say, can this be integrated to the official MTProcs package?


Thanks for reading