Re: threading in rpg. was RPG and Web.. (was Using OO conceptsinRPG)

[Hans Boldt <boldt@xxxxxxxxxx>]

Steve Richter wrote:
> As of V5R2, with IO direct into a data struct, procs dont have to use any
> global variables.  And if files are opened and accessed using some sort of a
> handle, then file I/O could be thread safe.
>
> Interestingly, a lot of the changes that would make an rpg proc threadsafe,
> like no global mapping of fields thru a data struct, file opens that are
> local to a proc and passed with a handle from proc to proc, would make the
> code more modular and less error prone.

Steve: I think you're still missing something here. If the only 
issue were user defined variables, there would be no problem with 
threading. At least there wouldn't be a problem for the compiler - 
all the synchronization issues would fall squarely on the back of 
the RPG programmer. No, the problem is with the compiler-generated 
internal data structures. Things like file control blocks and 
feedback areas, and also data structures involved with the RPG 
exception model.

If you really think you have to do a threaded application, and you 
want part of it RPG, go right ahead. The way to do it now would be 
to write some of your code in C, which calls RPG procedures in 
modules compiled with THREAD(*SERIALIZE). If you can understand all 
the issues involved with threading, you can certainly handle a bit 
of C programming. ;-)

Cheers! Hans