blockjobs: add waiting status
commite8af5686ff6f63a81120f6b8e291f220475796ce
authorJohn Snow <jsnow@redhat.com>
Sat, 10 Mar 2018 08:27:41 +0000 (10 03:27 -0500)
committerKevin Wolf <kwolf@redhat.com>
Mon, 19 Mar 2018 11:01:24 +0000 (19 12:01 +0100)
treebec21d76eaef8ca484f5ec75a3e956f467f49f2d
parent2da4617a5457a6542b0ff702caa983e78d6fe5d6
blockjobs: add waiting status

For jobs that are stuck waiting on others in a transaction, it would
be nice to know that they are no longer "running" in that sense, but
instead are waiting on other jobs in the transaction.

Jobs that are "waiting" in this sense cannot be meaningfully altered
any longer as they have left their running loop. The only meaningful
user verb for jobs in this state is "cancel," which will cancel the
whole transaction, too.

Transitions:
Running -> Waiting:   Normal transition.
Ready   -> Waiting:   Normal transition.
Waiting -> Aborting:  Transactional cancellation.
Waiting -> Concluded: Normal transition.

Removed Transitions:
Running -> Concluded: Jobs must go to WAITING first.
Ready   -> Concluded: Jobs must go to WAITING first.

Verbs:
Cancel: Can be applied to WAITING jobs.

             +---------+
             |UNDEFINED|
             +--+------+
                |
             +--v----+
   +---------+CREATED+-----------------+
   |         +--+----+                 |
   |            |                      |
   |         +--v----+     +------+    |
   +---------+RUNNING<----->PAUSED|    |
   |         +--+-+--+     +------+    |
   |            | |                    |
   |            | +------------------+ |
   |            |                    | |
   |         +--v--+       +-------+ | |
   +---------+READY<------->STANDBY| | |
   |         +--+--+       +-------+ | |
   |            |                    | |
   |         +--v----+               | |
   +---------+WAITING<---------------+ |
   |         +--+----+                 |
   |            |                      |
+--v-----+   +--v------+               |
|ABORTING+--->CONCLUDED|               |
+--------+   +--+------+               |
                |                      |
             +--v-+                    |
             |NULL<--------------------+
             +----+

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blockjob.c
qapi/block-core.json