Improve handling of closed connections#148
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Instead of the watcher task blowing up with an exception when the connection is closed, it should exit cleanly and allow the Monitor to report the connection error. Fixes #147
Rather than blocking indefinitely when waiting on a model change that will never happen if the connection gets closed out from under it, this makes `Model.block_until` raise a `websockets.ConnectionClosed` error so that it can be caught and dealt with by the client.
The receiver or all_watcher should immediately reconnect a lost connection, or it will be reconnected automatically upon issuance of the next RPC call. However, there is still a small chance that the disconnect could happen between sending a API call and receiving the response, in which case a websockets.ConnectionClosed error will still be raised to the caller. These should be quite rare, though.
adam-stokes
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+1 On the restarting of the watcher
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| if self._watch_stopping.is_set(): | ||
| # this shouldn't ever actually happen, because | ||
| # the event should trigger before the controller | ||
| # has a chancel to tell us the watcher is stopped |
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This fixes #147 by closing the watcher gracefully when the connection is closed unexpectedly so that the
Monitorcan report it as intended. It also fixes a circular reference between theConnectionandMonitor, improves the logic in the monitor status, and makesModel.block_untilraise awebsockets.ConnectionClosedexception instead of blocking indefinitely.Edit: Also fixes conjure-up/conjure-up#965