[ 
https://issues.apache.org/jira/browse/FLINK-10727?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16670022#comment-16670022
 ] 

ASF GitHub Bot commented on FLINK-10727:
----------------------------------------

NicoK commented on a change in pull request #6974: [FLINK-10727][network] 
remove unnecessary synchronization in SingleInputGate#requestPartitions()
URL: https://github.com/apache/flink/pull/6974#discussion_r229671494
 
 

 ##########
 File path: 
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/consumer/SingleInputGate.java
 ##########
 @@ -477,8 +477,8 @@ public boolean isFinished() {
 
        @Override
        public void requestPartitions() throws IOException, 
InterruptedException {
-               synchronized (requestLock) {
-                       if (!requestedPartitionsFlag) {
+               if (!requestedPartitionsFlag) {
 
 Review comment:
   1. there is no `else` - do you think this would be simpler?
   ```
   if (requestedPartitionsFlag) {
        return;
   }
   
   synchronized (...)
   ```
   
   2. yes - but thereby, I'm making `SingleInputGate` adhere the same standards 
as `UnionInputGate` for this overload of `requestPartitions` - the behaviour 
should be consistent, one way or the other. Should I add a note to the method's 
JavaDoc?

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
[email protected]


> Remove unnecessary synchronization in SingleInputGate#requestPartitions()
> -------------------------------------------------------------------------
>
>                 Key: FLINK-10727
>                 URL: https://issues.apache.org/jira/browse/FLINK-10727
>             Project: Flink
>          Issue Type: Improvement
>          Components: Network
>    Affects Versions: 1.5.5, 1.6.2, 1.7.0
>            Reporter: Nico Kruber
>            Assignee: Nico Kruber
>            Priority: Major
>              Labels: pull-request-available
>
> For every {{SingleInputGate#getNextBufferOrEvent()}}, 
> {{SingleInputGate#requestPartitions()}} is called and this always 
> synchronizes on the {{requestLock}} before checking the 
> {{requestedPartitionsFlag}}. Since {{SingleInputGate#requestPartitions()}} is 
> only called from the same thread (the task thread getting the record), it is 
> enough to check the {{requestedPartitionsFlag}} first before synchronizing 
> for the actual requests (if needed). {{UnionInputGate}} already goes the same 
> way in its {{requestPartitions()}} implementation.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to