Comment 8 for bug 1746630

So everything works, until virConnectGetAllDomainStats is called on the
domain:

2016-05-18 06:01:15.922+0000: 3070: debug : virThreadJobSet:96 :
    Thread 3070 (virNetServerHandleJob) is now running job
    remoteDispatchConnectGetAllDomainStats
2016-05-18 06:01:15.922+0000: 3070: debug : virConnectGetAllDomainStats:11489 :
    conn=0x7f5a5c000ec0, stats=0x0, retStats=0x7f5a8124fad0, flags=0x0

The API wants to start a job...

2016-05-18 06:01:15.922+0000: 3070: debug : qemuDomainObjBeginJobInternal:2097 :
    Starting job: query (vm=0x7f5a64009bf0 name=a1, current job=query async=none)
2016-05-18 06:01:15.922+0000: 3070: debug : qemuDomainObjBeginJobInternal:2120 :
    Waiting for job (vm=0x7f5a64009bf0 name=a1)

... and keeps waiting for it. In the meantime, other APIs (which don't require
a job) keep working just fine:

2016-05-18 06:01:45.920+0000: 3069: debug : virThreadJobSet:96 :
    Thread 3069 (virNetServerHandleJob) is now running job
    remoteDispatchDomainGetVcpus
2016-05-18 06:01:45.920+0000: 3069: debug : virDomainGetVcpus:7733 :
    dom=0x7f5a70004070, (VM: name=a1, uuid=048f8624-03fc-4729-8f4d-12cb4387f018),
    info=0x7f5a70002140, maxinfo=2, cpumaps=0x7f5a70002200, maplen=1
...
2016-05-18 06:01:45.920+0000: 3069: debug : virDomainDispose:313 :
    release domain 0x7f5a70004070 a1 048f8624-03fc-4729-8f4d-12cb4387f018
2016-05-18 06:01:45.920+0000: 3069: debug : virThreadJobClear:121 :
    Thread 3069 (virNetServerHandleJob) finished job
    remoteDispatchDomainGetVcpus with ret=0

But when virConnectGetAllDomainStats times out on acquiring a job,

2016-05-18 06:01:45.922+0000: 3070: warning : qemuDomainObjBeginJobInternal:2180 :
    Cannot start job (query, none) for domain a1; current job is (query, none)
    owned by (3066 remoteDispatchDomainGetBlockIoTune, 0 <null>) for (30s, 0s)
2016-05-18 06:01:45.922+0000: 3070: error : qemuDomainObjBeginJobInternal:2192 :
    Timed out during operation: cannot acquire state change lock
    (held by remoteDispatchDomainGetBlockIoTune)
2016-05-18 06:01:45.922+0000: 3070: debug : virCgroupGetValueStr:814 :
    Get value /sys/fs/cgroup/cpu,cpuacct/machine.slice/machine-qemu\x2d1
    \x2da1.scope/cpuacct.usage
2016-05-18 06:01:45.922+0000: 3070: debug : virCgroupGetValueStr:814 :
    Get value /sys/fs/cgroup/cpu,cpuacct/machine.slice/machine-qemu\x2d1
    \x2da1.scope/cpuacct.stat
2016-05-18 06:01:45.922+0000: 3070: debug : qemuGetProcessInfo:1486 :
    Got status for 3500/3505 user=1507 sys=209 cpu=1 rss=531128
2016-05-18 06:01:45.922+0000: 3070: debug : qemuGetProcessInfo:1486 :
    Got status for 3500/3506 user=1150 sys=55 cpu=0 rss=531128

the domain object stays locked and all APIs will be blocked on trying to lock
the domain...

2016-05-18 06:01:45.939+0000: 3068: debug : virThreadJobSet:96 :
    Thread 3068 (virNetServerHandleJob) is now running job
    remoteDispatchDomainGetControlInfo
2016-05-18 06:01:45.939+0000: 3068: debug : virDomainGetControlInfo:2526 :
    dom=0x7f5a6c002b50, (VM: name=a1, uuid=048f8624-03fc-4729-8f4d-12cb4387f018),
    info=0x7f5a79a50ad0, flags=0
...