Sharing EHLLAPI Presentation Space between Processes

More than one EHLLAPI application can share a presentation space if the applications support sharing (that is, if they were developed to work together or if they exhibit predictable behavior1). To determine which applications support sharing, EHLLAPI applications are specified as one of following types:
  • Supervisory
  • Exclusive write with read privilege allowed
  • Exclusive write without read privilege allowed
  • Super write
  • Read

The type of shared access can be defined by setting the following read and write sharing options for each function in the Set Session Parameters (9) function call:

1 This means that two EHLLAPI programs will not be vying for the same Presentation Space at the same time; or that there is logic in those programs which will allow the program to wait until the PS is available; or that the applications never use the Session in a way which would lock out other applications.