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https://issues.apache.org/jira/browse/ZOOKEEPER-2320?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15353909#comment-15353909
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Patrick Hunt commented on ZOOKEEPER-2320:
-----------------------------------------

I agree that we shouldn't expose this API out to clients. Unfortunately the 
tests operate as a client and as such shouldn't have access to this method, or 
the other methods in that file, and I don't see any way around this the way we 
currently have the code/build structured.

I'm -1 on the patch currently (because of the api change)

> C-client crashes when removing watcher asynchronously in "local" mode
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-2320
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2320
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: c client
>    Affects Versions: 3.5.1
>            Reporter: Hadriel Kaplan
>            Assignee: Abraham Fine
>         Attachments: ZOOKEEPER-2320.patch
>
>
> The C-client library will crash when invoking the asynchronous 
> {{zoo_aremove_watchers()}} API function with the '{{local}}' argument set to 
> 1.
> The reason is: if the local argument is 1/true, then the code does 
> '{{notify_sync_completion((struct sync_completion *)data);}}' But casting the 
> '{{data}}' variable to a {{sync_completion}} struct pointer is bogus/invalid, 
> and when it's later handles as that struct pointer it's accessing invalid 
> memory.
> As a side note: it will work ok when called _synchronously_ through 
> {{zoo_remove_watchers()}}, because that function creates a 
> {{sync_completion}} struct and passes it to the asynch 
> {{zoo_aremove_watchers()}}, but it will not work ok when the asynch function 
> is used directly for the reason stated perviously.
> Another side note: the docs state that setting the 'local' flag makes the 
> C-client remove the watcher "even if there is no server connection" - but 
> really it makes the C-client remove the watcher without notifying the server 
> at *all*, even if the connection to a server is up. (well... that's what it 
> would do if it didn't just crash instead ;)



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