Am 24.02.2018 um 00:51 hat John Snow geschrieben: > We're about to add several new states, and booleans are becoming > unwieldly and difficult to reason about. It would help to have a > more explicit bookkeeping of the state of blockjobs. To this end, > add a new "status" field and add our existing states in a redundant > manner alongside the bools they are replacing: > > UNDEFINED: Placeholder, default state. Not currently visible to QMP > unless changes occur in the future to allow creating jobs > without starting them via QMP. > CREATED: replaces !!job->co && paused && !busy > RUNNING: replaces effectively (!paused && busy) > PAUSED: Nearly redundant with info->paused, which shows pause_count. > This reports the actual status of the job, which almost always > matches the paused request status. It differs in that it is > strictly only true when the job has actually gone dormant. > READY: replaces job->ready. > STANDBY: Paused, but job->ready is true. > > New state additions in coming commits will not be quite so redundant: > > WAITING: Waiting on transaction. This job has finished all the work > it can until the transaction converges, fails, or is canceled. > PENDING: Pending authorization from user. This job has finished all the > work it can until the job or transaction is finalized via > block_job_finalize. This implies the transaction has converged > and left the WAITING phase. > ABORTING: Job has encountered an error condition and is in the process > of aborting. > CONCLUDED: Job has ceased all operations and has a return code available > for query and may be dismissed via block_job_dismiss. > NULL: Job has been dismissed and (should) be destroyed. Should never > be visible to QMP. > > Some of these states appear somewhat superfluous, but it helps define the > expected flow of a job; so some of the states wind up being synchronous > empty transitions. Importantly, jobs can be in only one of these states > at any given time, which helps code and external users alike reason about > the current condition of a job unambiguously. > > Signed-off-by: John Snow <js...@redhat.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
