Re: [Qemu-devel] [PATCH v2 2/9] python/qemu: improve event_wait method of vm

[John Snow <jsnow@redhat.com>]

On 5/31/19 12:31 PM, Vladimir Sementsov-Ogievskiy wrote:
> Support several names to wait for, which useful, when we don't sure
> which event will we get. For example when mirror fails we get
> BLOCK_JOB_COMPLETE otherwise we get BLOCK_JOB_READY (and only then,
> after completing block-job we get BLOCK_JOB_COMPLETE).
> 
> Also, add filtered version for convenient use.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  python/qemu/__init__.py       | 9 ++++++---
>  tests/qemu-iotests/iotests.py | 5 +++++
>  2 files changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/python/qemu/__init__.py b/python/qemu/__init__.py
> index 81d9657ec0..5e517025b9 100644
> --- a/python/qemu/__init__.py
> +++ b/python/qemu/__init__.py
> @@ -402,7 +402,7 @@ class QEMUMachine(object):
>          self._qmp.clear_events()
>          return events
>  
> -    def event_wait(self, name, timeout=60.0, match=None):
> +    def event_wait(self, names, timeout=60.0, match=None):
>          """
>          Wait for specified timeout on named event in QMP; optionally filter
>          results by match.
> @@ -412,6 +412,9 @@ class QEMUMachine(object):
>             {"foo": {"bar": 1}} matches {"foo": None}
>             {"foo": {"bar": 1}} does not matches {"foo": {"baz": None}}
>          """
> +        if not isinstance(names, list):
> +            names = [names]
> +
>          def event_match(event, match=None):
>              if match is None:
>                  return True
> @@ -430,14 +433,14 @@ class QEMUMachine(object):
>  
>          # Search cached events
>          for event in self._events:
> -            if (event['event'] == name) and event_match(event, match):
> +            if (event['event'] in names) and event_match(event, match):
>                  self._events.remove(event)
>                  return event
>  
>          # Poll for new events
>          while True:
>              event = self._qmp.pull_event(wait=timeout)
> -            if (event['event'] == name) and event_match(event, match):
> +            if (event['event'] in names) and event_match(event, match):
>                  return event
>              self._events.append(event)
>  
> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
> index 7bde380d96..4218fc908b 100644
> --- a/tests/qemu-iotests/iotests.py
> +++ b/tests/qemu-iotests/iotests.py
> @@ -532,6 +532,11 @@ class VM(qtest.QEMUQtestMachine):
>          log(result, filters, indent=indent)
>          return result
>  
> +    def event_wait_log(self, names, **kwargs):
> +        event = self.event_wait(names, **kwargs)
> +        log(event, filters=[filter_qmp_event])
> +        return event
> +
>      # Returns None on success, and an error string on failure
>      def run_job(self, job, auto_finalize=True, auto_dismiss=False):
>          error = None
> 

There's something like this in the queue; see:
[Qemu-devel] [PATCH v3 3/5] QEMUMachine: add events_wait method.

Though yours is a lot shorter, actually, because I made separate
event_wait and events_wait calls instead of just throwing non-iterables
in a list.

--js