[libvirt] [PATCH v2 5/8] Added job type VIR_DOMAIN_JOB_PHASE1_COMPLETED

[Cristian Klein]

On 07 Oct 2014, at 22:08 , Jiri Denemark <jdenemar at redhat.com> wrote:

> On Tue, Sep 30, 2014 at 16:39:26 +0200, Cristian Klein wrote:
>> Some jobs feature several phases. For example, post-copy migration is
>> composed of a first phase, from migration start to switching to
>> post-copy, and a second phase, to migration completion. This
>> job type allows to flag that the job has completed the first phase,
>> but is not yet fully completed.
>> 
>> Signed-off-by: Cristian Klein <cristian.klein at cs.umu.se>
>> ---
>> include/libvirt/libvirt.h.in | 1 +
>> tools/virsh-domain.c         | 3 ++-
>> 2 files changed, 3 insertions(+), 1 deletion(-)
>> 
>> diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
>> index 84cd5a4..81044f0 100644
>> --- a/include/libvirt/libvirt.h.in
>> +++ b/include/libvirt/libvirt.h.in
>> @@ -4307,6 +4307,7 @@ typedef enum {
>>     VIR_DOMAIN_JOB_COMPLETED = 3, /* Job has finished, but isn't cleaned up */
>>     VIR_DOMAIN_JOB_FAILED    = 4, /* Job hit error, but isn't cleaned up */
>>     VIR_DOMAIN_JOB_CANCELLED = 5, /* Job was aborted, but isn't cleaned up */
>> +    VIR_DOMAIN_JOB_PHASE1_COMPLETED = 6, /* Job completed first phase, e.g., post-copy activation */
> 
> This is not a job type. If we need to advertise this to libvirt clients,
> we may introduce a new job statistics typed parameter but we should not
> misuse job type. And I'm not entirely convinced we need to advertise
> this. To me it seems the only interested thing is whether a domain is
> still running on the source host or it was already resumed on the
> destination host. And it's easy to get this kind of information via
> existing ways, e.g., listening to domain life cycle events or by
> checking domain's status.

My rationale for introducing this flag was to prevent a future breakage of an internal API. I felt like none of the previous flags where accurately representing the status of this job after post-copy has started. Sure, I could use `job->status.status` in `qemuMigrationWaitForCompletion`, but I was concerned that a future `libvirt` addition might not take this subtly into account and might break post-copy.

If you think I should go ahead, suppress this job type and use `job->status.status` instead, what should I use instead, `VIR_DOMAIN_JOB_UNBOUNDED` or `VIR_DOMAIN_JOB_BOUNDED`? To be honest, I’m not sure to have completely understood the difference between them, except that `VIR_DOMAIN_JOB_BOUNDED` seems to be used to signal that a job is almost complete.