Task

JES2 Main Task (Initialization) – JES2 dispatcher disabled

The following JES2 initialization steps have been performed before your exit routine gets control. Essentially all JES2 initialization is done, but the JES2 warm start processor has not been dispatched yet to perform its initialization-like processing.

You must specify ENVIRON=JES2 on the $MODULE macro.

The JES2 initialization options are obtained from the operator or the PARM parameter on the EXEC statement and converted into status bits.
The JES2 initialization statement data set is read and processed.
The direct-access devices are scanned, and eligible spooling volumes are identified and allocated to JES2.
The spooling and checkpoint data sets are examined and initialized for JES2 processing.
The subsystem interface control blocks are constructed and initialized.
The unit-record devices, remote job entry lines, and network job entry lines are scanned; eligible and specified devices are located and allocated.
JES2 subtasks are attached, and exit routines are located.
SMF processing is started by generating a type 43 SMF record.
The JES2 control blocks, such as the HASP communications table (HCT), the device control tables (DCT), the data control blocks (DCB), the processor control elements (PCE), the data extent blocks (DEB), and the buffers (IOB), are constructed and initialized.