Crash when connection to MySQL db is interrupted

[renblau]

I have noticed that all of my servers that are running the current sqljocky5 version crash from time to time. The connection to MySQL gets interrupted for whatever reason (e.g. mysqld restart). Then, when the program tries to execute a query, this happens:

Unhandled exception:
Bad state: Cannot write to socket, it is closed
#0      BufferedSocket.writeBufferPart (package:sqljocky5/comm/buffered_socket.dart:112:7)
#1      BufferedSocket.writeBuffer (package:sqljocky5/comm/buffered_socket.dart:107:12)
#2      Sender._sendBufferPart (package:sqljocky5/comm/sender.dart:57:19)
<asynchronous suspension>
#3      Sender.send (package:sqljocky5/comm/sender.dart:45:14)
<asynchronous suspension>
#4      Comm._processHandler (package:sqljocky5/comm/comm.dart:114:19)
<asynchronous suspension>
#5      Comm.execHandler.<anonymous closure> (package:sqljocky5/comm/comm.dart:120:36)
#6      new Future.sync (dart:async/future.dart:224:31)
#7      Pool.withResource.<anonymous closure> (package:pool/pool.dart:126:18)
#8      _RootZone.runUnary (dart:async/zone.dart:1379:54)
#9      _FutureListener.handleValue (dart:async/future_impl.dart:126:18)
#10     Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:639:45)
#11     Future._propagateToListeners (dart:async/future_impl.dart:668:32)
#12     Future._completeWithValue (dart:async/future_impl.dart:483:5)
#13     Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:513:7)
#14     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#15     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#16     _runPendingImmediateCallback (dart:isolate/runtime/libisolate_patch.dart:115:13)
#17     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:172:5)

Furthermore, I wasn't able to catch the error to handle it myself (i.e. create a new connection and retry the query):
Edit: That was my fault, catching works fine. I guess I have to implement a reconnect mechanism into my application now.

Would be cool though if the library detected disconnects itself. Ideally before the user is trying to execute a query. Something like: _connection.onDisconnect.listen( ... )

[tejainece]

I will fix this.

[hoylen]

This goal is related to the "unhandled exception" reported in #26. But the specific exception is different, since I can't seem to catch the other exception (not without trying to use zones etc.).

[tejainece]

@renblau
onDisconnect is a brilliant idea.