Run unit

A run unit is a set of programs that are related by local calls or (in some cases) by transfers. Each run unit has these characteristics:

• The programs operate together as a group. When a hard error occurs but is not handled, all the programs in the run unit are removed from memory.

• The programs share the same run-time properties. The same databases and files are available throughout the run unit, for example, and when you invoke sysLib.connect or sysLib.connectionService to connect to a database dynamically, the connection is present in any program that receives control in the same run unit.

The Java run unit is composed of programs that run in a single thread. A new run unit can start with a main program, as when the user invokes the program. A transfer statement also invokes a main program but continues the same run unit.

In the following cases, a called program is the initial program of a run unit:

• The call is a call from an EJB session bean; or

• The call is a remote call, except that the same run unit continues in the following case--
  • The called program is generated by EGL or VisualAge Generator; and

  • No TCP/IP listener is involved in the call.

All programs in a Java run unit are affected by the same Java run-time properties.

Related concepts
Java run-time properties
Linkage options part

Related reference
Default database

sysLib.connect
sysLib.connectionService