>The distinction between COBOL's distinction of WORKING-STORAGE and >LOCAL-STORAGE is essentially the same as the PL/I and then C >distinction of static and automatic storage. > >As far as I can judge from earlier posts in this thread the shared >facility is not a dynamic shared control block; it is a read-only >table; and the serialization of accesses to such a table is required >only if it is replaced from time to time DURING the execution of the >multithreaded application. > >Serialization is possible from, although not within, COBOL. One >writes a pair of simple COBOL-callable assembly-language to do it; and >it is also possible and useful to write such a pair of subroutines to >LOAD and DELETE [load module or program object] tables.
There is some locking available in COBOL, for I/O. If you have a file that has one record, you could READ it from the thread that wants a 'lock' on resources and then CLOSE the file when done. COBOL uses Mutexes internally to prevent multiple accesses to a file record when compiled with THREAD. You are right though, there is no explicit Mutex technology accessible directly with COBOL language. We have not had a request for such a feature, if anyone wants it...ask for it via the RFE site! Cheers, TomR >> COBOL is the Language of the Future! << ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
