Re: [Kimchi-devel] [Wok] [RFC] Issue #122: Make AsyncTask stoppable.

Refreshing the memory and waiting for new comments. If no new comments, I'll submit a patch with this proposal until the end of this week. Best regards, Paulo. On Jun 09 01:07PM, Paulo Ricardo Paz Vital wrote: > On Jun 08 03:38PM, Aline Manera wrote: >> Hi Paulo, >> >> On 06/06/2016 11:21 AM, Paulo Ricardo Paz Vital wrote: >>> This is an RFC for "Make AsyncTask stoppable" in Wok (and any other plugin). The >>> main idea is give to user a way to stop a Task that is still running, cleaning >>> all references and processes and setting the Task status to "killed". >>> >>> To do this, the Task API need to be modified, by implementing the DELETE method >>> in Task Resource. Said that, the API will look like: >>> >>> ### Resource: Task >>> >>> **URI:** /tasks/*:id* >>> >>> A task represents an asynchronous operation that is being performed by the >>> server. >>> >>> **Methods:** >>> >>> * **GET**: Retrieve the full description of the Task >>> * id: The Task ID is used to identify this Task in the API. >>> * status: The current status of the Task >>> * running: The task is running >>> * finished: The task has finished successfully >>> * failed: The task failed >>> + * killed: The task was killed by user >>> * message: Human-readable details about the Task status >>> * target_uri: Resource URI related to the Task >>> +* **DELETE**: Delete the Task >> It is good to mention that this action will put the Task in the 'killed' >> status. >> > Ok. > >>> * **POST**: *See Task Actions* >>> >>> **Actions (POST):** >>> >>> *No actions defined* >>> >>> Since an AsyncTask is basic a thread running in the system and this thread can >>> execute a pure Python method or a background command (by using run_command() >>> from wok.utils), the developer must pass as argument to the add_task() a method >>> to be executed by the DELETE operation, called here as 'kill_cb'. With this >>> idea, the add_task() method and also the AsyncTask constructor will be like: >>> >>> def add_task(target_uri, fn, objstore, kill_cb=None, opaque=None): >> I am not sure it is a good idea to change the parameters order. >> Some plugins may have using the opaque parameter as the third value so it >> will cause issues. >> So unless, you check all references to make sure it will not be a problem, >> I'd recommend to move the kill_cb as the last parameter. >> > I already was expecting this, so this is not a problem to me to check and change > the sequence of parameters. Will not do this only if the modifications are too > many to do ;-) > >>> class AsyncTask(object): >>> def __init__(self, id, target_uri, fn, objstore, kill_cb=None, opaque=None): >> Same I commented above. >> >>> If none kill_cb is passed, the task will not be able to stopped and an error (or >>> warning) message will be raised to user if DELETE operation is executed. >>> Otherwise, the kill_cb method will be executed by kill() method (responsible to >>> execute the DELETE operation) of AsyncTask class and its status set to 'killed'. >> Go for it! =) >> >> Don't forget to add tests to test/exemplify how it will really work. >> > For sure. > >>> If you have any comments or suggestions, please feel free to reply to ML. >>> >>> Thanks and bestr regards, >>> -- >>> Paulo Ricardo Paz Vital >>> Linux Technology Center, IBM Systems >>> http://www.ibm.com/linux/ltc/ >>> >>> _______________________________________________