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https://issues.apache.org/jira/browse/ZOOKEEPER-4299?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17951197#comment-17951197
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Kezhu Wang commented on ZOOKEEPER-4299:
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Hi [~gowrima] , {{completion_head_t}} is capable of multi-threading, does not
mean it should be locked everywhere. In case of {{zoo_amulti}}, the
{{completion_head_t}} is used there since there are multiple {{zoo_op_t}}. In
contrast, you could take a look at {{sent_requests}} and
{{completions_to_process}} in {{struct _zhandle}} which are used concurrently
by multiple threads.
Besides, can we move the discussion to github since you have created the pr ?
> List head do not initialize before using it in zoo_amulti that will cause
> segment errors.
> -----------------------------------------------------------------------------------------
>
> Key: ZOOKEEPER-4299
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-4299
> Project: ZooKeeper
> Issue Type: Bug
> Components: c client
> Affects Versions: 3.5.4, 3.7.0, 3.6.2
> Reporter: hong
> Assignee: Gowrima
> Priority: Blocker
> Labels: pull-request-available
> Original Estimate: 2h
> Time Spent: 20m
> Remaining Estimate: 1h 40m
>
> int zoo_amulti(zhandle_t *zh, int count, const zoo_op_t *ops,
> zoo_op_result_t *results, void_completion_t completion, const void *data)
> { struct RequestHeader h = \\{get_xid(), ZOO_MULTI_OP}
> ;
> struct MultiHeader mh = \{-1, 1, -1};
> struct oarchive *oa = create_buffer_oarchive();
> {color:#ff0000}completion_head_t clist = \{ 0 }; // not initialize for cond
> or lock{color}
> int rc = serialize_RequestHeader(oa, "header", &h);
> ....
>
> {color:#ff0000}queue_completion(&clist, entry, 0); //queue it will segment
> errors{color}
>
>
> {color:#FF0000}// do lock or unlock which have not been initialized!!{color}
> static void queue_completion(completion_head_t *list, completion_list_t *c,
> int add_to_front)
> { lock_completion_list(list); queue_completion_nolock(list, c,
> add_to_front); unlock_completion_list(list); }
> {color:#FF0000}// oh my god!!{color}
> int unlock_completion_list(completion_head_t *l)
> { p_thread_cond_broadcast(&l->cond); return
> p_thread_mutex_unlock(&l->lock); }
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