Status of a subsystem

NOT-CREATED

The subsystem has been declared in the current system, but has not yet been activated by a START-SUBSYSTEM command, or has been deactivated again since being activated. Tasks cannot access this subsystem until it has been activated.

IN-CREATE

The subsystem is being activated, but loading and initialization have not been completed. Tasks cannot access this subsystem yet.

CREATED

The subsystem has been loaded and initialized. Tasks can access the subsystem.

IN-DELETE

The subsystem has been deactivated by a STOP-SUBSYSTEM command. Unloading and deinitialization have not yet been completed.
Other tasks can no longer access this subsystem. Processing of tasks still connected to the subsystem will be completed.

IN-HOLD

The subsystem has been suspended by a HOLD-SUBSYSTEM command. Deinitialization has not yet been completed.
Other tasks can no longer access this subsystem. Processing of tasks still connected to the subsystem will be completed.

IN-RESUME

The subsystem is being resumed by a RESUME-SUBSYSTEM command. Reinitialization has not yet been completed. Tasks cannot yet access this subsystem.

NOT-RESUMED

The subsystem has been suspended by a HOLD-SUBSYSTEM command. Deinitialization has been completed. Tasks cannot access this subsystem until a RESUME-SUBSYSTEM command has been issued and successfully executed.

LOCKED

An unrecoverable error has occurred while the subsystem was active or was being activated, deactivated, resumed or suspended. Any further attempt to issue the corresponding commands will be rejected.

The following situations can put a subsystem into the LOCKED status:

• if the change to this status is specified in the INIT, DEINIT, STOPCOM or CLOSE-CTRL routine (applies only to privileged subsystems);

• if the subsystem’s holder task has terminated abnormally and either no restart is provided for this task, or it cannot be executed (see "Error handling in DSSM") or

• if a problem occurs in deactivating the old version during a version swap that entails an interruption of subsystem availability; regardless of the value of the RESTART operand, the subsystem is in the LOCKED status; activation of the new version is continued.

When a subsystem is activated, deactivated, suspended or resumed, its status changes, i.e. it progresses from an initial status to a final status (for example, when a subsystem is activated, its final status is CREATED).
The initial status for a request may not always be the same; e.g. a START-SUBSYSTEM command is acceptable for a subsystem with the status NOT-CREATED or IN-DELETE if the parameter RESET=*YES has been set.

The different statuses possible for a subsystem are summarized in the following table. The changes of status caused by a DSSM command are shown on a single line. The initial status of the subsystem is indicatesd by a 1. The highest digit in the line denotes the final status attainable by the appropriate DSSM command. Possible intermediate statuses are also shown.

DSSM commands	States of a subsystem							Operand of the DSSM command1
	NOT- CREATED	IN- CREATE	CREATED	IN- DELETE	IN-HOLD	IN- RESUME	NOT- RESUMED
START- SUBSYSTEM	1 1	2 2 2	3 3 3 3 3 3	1	1	2 2 2	1 1	--- RESET=*YES RESET=*YES RESET=*YES RESET=*YES RESET=*YES
STOP- SUBSYSTEM	3 3 2 2		1	2 2 1	1		1	--- --- FORCED=*YES FORCED=*YES
HOLD- SUBSYSTEM			1		2 1		3 2	--- FORCED=*YES
RESUME- SUBSYSTEM			3 3 3		1	2 2 2	1 1	--- RESET=*YES RESET=*YES

¹Operand of the DSSM command which must be set in order to change t he status

Table 4: Statuses of a subsystem