Inter Process Communication (1)

Introduction

• Online software uses CORBA to communicate between processes running in a distributed system.
• Currently using ILU (free from Xerox) as the CORBA implementation.
• ipc package is a thin layer hiding direct use of ILU from the rest of the software, thus allowing ILU to be replaced in future if desired.
• The ipc package is also where the basic concepts of partitioning the system are implemented using the CORBA naming service.
• The naming services requires information to be shared via a file (the IPC reference file) whose location is specified by the environment variable IPC_REF_FILE.
• Any process whose objects are accessible via CORBA has to sit in a loop waiting for incoming messages. To do anything else requires another thread (in which you cant run the Online software).