While working on the Alarm skill I discovered several issues with the
event scheduler. This PR cleans up those findings and resolves several
other potential issues:
1) To avoid thread synchronization issues, the EventScheduler had several
queues which independently held objects to be added/deleted/updated. However, the order of the events was undefined and got mixed since they were all batched together. So, for instance, if skill code performed:
self.add_event("foo", self.handle_foo)
if SomeReason:
self.cancel_event("foo")
The actual order of queue handling would perform Remove first, then Add which resulted in "foo" not being found for delete, but then added and left as an active event.
Now the EventScheduler protects the list using a Lock and the queues have been removed. Modifications to the list happen immediately after obtaining the lock and are not batched up.
2) One-time events were triggered while the event was still in the EventScheduler list. Now the entry is removed before invoking the handler.
3) Within the MycroftSkill.add_event(name, handler) is a local 'wrapper' method that actually makes the callback. The MycroftSkill.remove_event(name) method attempted to find entries in the events list and the associated handler entries in the self.emitter to remove. However, the emitter actually held the wrapper(handler), not the handler itself. So the emitter handlers were left behind.
This was a quiet bug until the next time you scheduled an event of the same name. When that second event finally triggered, it would fire off both the new and the old handler -- which snowballed in the 'skill-alarm:Beep' case, doubling and redoubling with every beep.
Now this cancels all the emitter listeners by name. There is a very slim chance that someone has registered a listener with the same name, but since it is namespaced to "skill-name:Event" I think this is pretty safe.
Not technically related, but a failure that has been lurking for
some time and is a French unit test that doesn't work depending
on the time of day when the test is run.
Previously if duplicates of a skill should be launched or a skill isn't properly
shutdown when reloaded multiple handlers could be registred. This commit disables multiples of repeating events.
If the scheduler was frozen for some time and the repeating event
scheduled time passes it would trigger the event constantly until the
next time is in the future again.
This will make the scheduler to disallow scheduling in the past and
instead schedule the next call one repeat period from now.
Add Python 2/3 compatibility
==== Tech Notes ====
This allows the main bus, skills and cli to be run in both python 2.7 and
3.5+.
Mainly trivial changes
- syntax for exceptions
- logic for importing correct Queue module
- .iteritems -> future.utils.iteritems when accessing dicts key value
pairs
* Allow audio service to be run in python 3
* Make speech client work with python 3
* Importing of Queue version dependent
* Exception syntax corrected
* Creating sound buffer is version dependant
- Adapt context use range from builtins
- Use compatible next() instead of .next() when walking the skill
directory
* Make CLI Python 3 Compatible
- Use compatible BytesIO instead of StringsIO
- Open files as text instead of binary
- Make sure integer divisions are used
* Make messagebus send compatible
* Fix failing travis
Re-add future 0.16.0
* Make string checks compatible
* basestring doesn't exist in python 3 so it's imported from the "past"
* Fix latest compatibility issues in speech client
- handle urllib
- handle encoding before calling md5
* Make Api.build_json() python 2/3 compatible
This commit officially switches the mycroft-core repository from
GPLv3.0 licensing to Apache 2.0. All dependencies on GPL'ed code
have been removed and we have contacted all previous contributors
with still-existing code in the repository to agree to this change.
Going forward, all contributors will sign a Contributor License
Agreement (CLA) by visiting https://mycroft.ai/cla, then they will
be included in the Mycroft Project's overall Contributor list,
found at: https://github.com/MycroftAI/contributors. This cleanly
protects the project, the contributor and all who use the technology
to build upon.
Futher discussion can be found at this blog post:
https://mycroft.ai/blog/right-license/
This commit also removes all __author__="" from the code. These
lines are painful to maintain and the etiquette surrounding their
maintainence is unclear. Do you remove a name from the list if the
last line of code the wrote gets replaced? Etc. Now all
contributors are publicly acknowledged in the aforementioned repo,
and actual authorship is maintained by Github in a much more
effective and elegant way!
Finally, a few references to "Mycroft AI" were changed to the correct
legal entity name "Mycroft AI Inc."
==== Fixed Issues ====
#403 Update License.md and file headers to Apache 2.0
#400 Update LICENSE.md
==== Documentation Notes ====
Deprecated the ScheduledSkill and ScheduledCRUDSkill classes.
These capabilities have been superceded by the more flexible MycroftSkill
class methods schedule_event(), schedule_repeating_event(), update_event(),
and cancel_event().
==== Tech Notes ====
If cancel + add event messages arrive at roughly the same time the add
would be overridden by the cancel. More intuitive to handle cancel first
and add new arrived events after.
==== Tech Notes ====
A single thread handling scheduled events. The skills interact with this
using the self.schedule_event() self.schedule_repeating_event
self.update_event() and self.remove_event().
This is an improvement over scheduledSkill since each skill creates
their own Thread and has to handle storing/restoring scheduled events
between starts.
All pending events are stored in a json file at shutdown for future
sessions.
==== Documentation Notes ====
Needs to be documented
==== Protocol Notes ====
new messagebus event handlers:
- mycroft.scheduler.schedule_event
- mycroft.scheduler.remove_event
- mycroft.scheduler.update_event
Steve Penrod
Åke
Matthew D. Scholefield
jarbasal
Michael Nguyen
Matthew D. Scholefield