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interrupting in a zone
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import 'dart:async'; | |
void main(List<String> arguments) { | |
var stop = false; | |
final checkShouldStop = () { | |
if (stop) { | |
throw StopException(); | |
} | |
}; | |
runZoned( | |
run, | |
zoneSpecification: ZoneSpecification( | |
registerCallback: <R>(self, parent, zone, f) { | |
checkShouldStop(); | |
return f; | |
}, | |
registerUnaryCallback: <R, T>(self, parent, zone, f) { | |
checkShouldStop(); | |
return f; | |
}, | |
registerBinaryCallback: <R, T, U>(self, parent, zone, f) { | |
checkShouldStop(); | |
return f; | |
}, | |
), | |
); | |
// Cause an interrupt after some time | |
Future.delayed(Duration(milliseconds: 750), () { | |
stop = true; | |
}); | |
} | |
Future<void> run() async { | |
print('run'); | |
await something(1, 2, 3, 4); | |
print('done something'); | |
final output = await slowlyMakeString(['foo', 'bar', 'baz']); | |
print(output); | |
} | |
Future<String> slowlyMakeString(List<String> args) async { | |
final needToCleanUp = <String>[]; | |
try { | |
print('slowlyMakeString'); | |
final output = StringBuffer(); | |
for (final arg in args) { | |
print('awaiting delay'); | |
await Future.delayed(Duration(milliseconds: 500)); | |
output.write(arg); | |
needToCleanUp.add(arg); | |
} | |
return output.toString(); | |
} on StopException { | |
print('cleaning up: $needToCleanUp'); | |
rethrow; | |
} | |
} | |
Future<void> something(int a, int b, int c, int d) async { | |
print('doing something'); | |
return; | |
} | |
class StopException implements Exception {} |
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