unknown
idle
processing
stopped
Hows this for a state transition diagram
+----------+ +-----------+
| | | |
| | T2 | |
| UNKN |<------>| IDLE |
| | | |
| | | |
+----------+ +-----------+
^ \ T3/ ^
| \ / |
| \ / |
| \/ |T6
|T1 /\ |
| / \T4 |
| / \ |
v / \ v
+----------+ +-----------+
| | | |
| | T5 | |
| PROC |<------>| STOP |
| | | |
| | | |
+----------+ +-----------+
IDLE = Idle
UNKN = Unknown
PROC = Processing
STOP = Stop
T1: UNKN -> PROC
A job was submitted even though the state was unkown. The state
became known at the same moment it started processing the job OR
the state became known and the printer is Processing.
T1: PROC -> UNKN
Something happened, it is just now unknown
T2: UNKN -> IDLE
The state became known and the printer is idle
T2: IDLE -> UNKN
Something happened, it is just now unknown
T3: PROC -> IDLE
Printer is now less busy than it used to be
T3: IDLE -> PROC
Printer is now more busy than it used to be
T4: UNKN -> STOP
The state became known and the printer is idle.
T4: STOP -> UNKN
Something happened, it is just now unknown
T5: PROC -> STOP
A critical error has occurred. There is new info in
printer-state-reasons. The printer will probably return
to the Processing state when errors are cleared.
T5: STOP -> PROC
All critical errors have been fixed, the printer is fairly
busy
T6: IDLE -> STOP
A critical error has occurred. There is new info in
printer-state-reasons. The printer will probably return
to the Idle state when errors are cleared.
T6: STOP -> IDLE
All critical errors have been fixed, the printer is not
too busy
Also, in explaining the definintions of IDLE and PROC using the expected
state of a jobs if they were to be submitted, people tend to say:
You mean that Idle should be "Ready" and Processing should be "Busy".
What do people think about these name changes, no semantic changes?
Scott
************************************************************
Scott A. Isaacson
Print Services Consulting Engineer
Novell Inc., 122 E 1700 S, Provo, UT 84606
V: (801) 861-7366, (800) 453-1267 x17366
F: (801) 861-4025, E: scott_isaacson@novell.com
W: http://www.novell.com
************************************************************