Communication Between IPCS Exit Routines

For IPCS and ABEND/SNAP Formatting
One exit routine can communicate with another by invoking the other exit routine and supplying parameters. No mechanism is supplied to remember data between invocations or to share information between separate exit routines when an exit routine is invoked multiple times.
For IPCS Formatting
To avoid repetitive processing, IPCS provides the following functions through the dump directory:
- Definitions of symbols in the IPCS symbol table save repetitive look-up operations for such blocks as the communications vector table (CVT). Centralizing the look-up process for these blocks helps independently-written functions come to the same conclusions regarding whether a usable instance of a block can be found.
  Use the equate symbol service, get symbol service, and symbol service to exploit this communication mechanism.
  
  Defining types of data and naming conventions for IPCS symbols and supplying find routines to locate instances of that data by name will extend the communications mechanism.
- Entries in the IPCS storage map are designed to save repetitive validation of data areas, such as the CVT. IPCS storage map entries have other uses as well.
  Use the get symbol service, storage map service, and symbol service to exploit the IPCS storage map.
  
  Extend the communications mechanism by defining types of data and supplying scan exit routines to determine whether instances of the data appear to be usable.
References
For information about the exit services you can use for communication between exit routines, see the following: