[jira] [Updated] (ZOOKEEPER-2320) C-client crashes when removing watcher asynchronously in "local" mode

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ZOOKEEPER-2320?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

ASF GitHub Bot updated ZOOKEEPER-2320:
--------------------------------------
    Labels: pull-request-available  (was: )

> 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
>            Priority: Major
>              Labels: pull-request-available
>         Attachments: ZOOKEEPER-2320.patch, 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 ;)



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