Dear PL/i Cafe - Community!
 

I'm trying to call existing (old/very old) pl/i modules from a thread, created with the ATTACH Statement. The pl/i modules contain sequential file access.

My test results in the following picture: Files are shared between all threads. If one thread reads the first line, a parallel thread is getting the second line on its first read access,... and so on. The results are unpredictable!

Is there any way to sync/serialize file-access between pl/i threads in a z/OS batch environment without modifications of the affected module? (like LE-Parameter or something else)

Greetings from Linz!

Won't the reads be executed in the order in which the procedures are called?

And as the code is old, might it be useful to forget ATTACHing

and make the whole a single compilation unit?

Memories are much larger now.