Hello M Singh,
If you check the comment at the beginning of the file, it said
Forwarding elements, watermarks, or status status elements must be protected
by synchronizing
* on the given lock object. This ensures that we don't call methods on a
* {@link OneInputStreamOperator} concurrently with the timer callback or
other things.
That means Flink guarantees to never call the timer callback and the
process element function concurrently.
You don't have to do any manual synchronization by yourself.
Best regards,
Kien
On 11/12/2017 10:03 PM, M Singh wrote:
Thanks Kien/Jorn:
I see the code for processElement being called with a lock but did not
see that the timer based invocation is synchronized by the same lock.
Does that mean that I should use synchonization in my code and how
will that impact the performance ? Please let me know if you have any
other recommendation.
Thanks again.
On Sunday, November 12, 2017 1:16 AM, Jörn Franke
<jornfra...@gmail.com> wrote:
Be careful though with racing conditions .
On 12. Nov 2017, at 02:47, Kien Truong <duckientru...@gmail.com
<mailto:duckientru...@gmail.com>> wrote:
Hi Mans,
They're not executed in the same thread, but the methods that called
them are synchronized[1] and therefore thread-safe.
Best regards,
Kien
[1]
https://github.com/apache/flink/blob/1cd3ba3f2af454bc33f2c880163c01dddd4d1738/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/io/StreamInputProcessor.java#L204
On 11/12/2017 4:30 AM, M Singh wrote:
Hi:
I am working on a project and need to save MapState in a process
function and register a timer to check for updates. I wanted to find
out if it is safe to access and modify the state in the
processElement function as well as the time onTimer methods.
The example
https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/stream/process_function.html use
ValueState and does not use synchronization. Is it because
processElement and onTimer are executed in the same thread and so are
thread safe ?
Also, I could not find any thread safety documentation about MapState.
Thanks.
Mans
