[ 
https://issues.apache.org/jira/browse/THRIFT-3891?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15874559#comment-15874559
 ] 

ASF GitHub Bot commented on THRIFT-3891:
----------------------------------------

Github user bgedik commented on a diff in the pull request:

    https://github.com/apache/thrift/pull/1196#discussion_r102023002
  
    --- Diff: lib/cpp/src/thrift/server/TNonblockingServer.cpp ---
    @@ -1566,24 +1562,26 @@ void 
TNonblockingIOThread::setCurrentThreadHighPriority(bool value) {
     }
     
     void TNonblockingIOThread::run() {
    -  if (eventBase_ == NULL)
    +  if (eventBase_ == NULL) {
         registerEvents();
    -
    -  GlobalOutput.printf("TNonblockingServer: IO thread #%d entering 
loop...", number_);
    -
    +  }
       if (useHighPriority_) {
         setCurrentThreadHighPriority(true);
       }
     
    -  // Run libevent engine, never returns, invokes calls to eventHandler
    -  event_base_loop(eventBase_, 0);
    +  if (eventBase_ != NULL)
    +  {
    +    GlobalOutput.printf("TNonblockingServer: IO thread #%d entering 
loop...", number_);
    +    // Run libevent engine, never returns, invokes calls to eventHandler
    +    event_base_loop(eventBase_, 0);
     
    -  if (useHighPriority_) {
    -    setCurrentThreadHighPriority(false);
    -  }
    +    if (useHighPriority_) {
    +      setCurrentThreadHighPriority(false);
    +    }
     
    -  // cleans up our registered events
    -  cleanupEvents();
    +    // cleans up our registered events
    +    cleanupEvents();
    +  }
     
       GlobalOutput.printf("TNonblockingServer: IO thread #%d run() done!", 
number_);
    --- End diff --
    
    Is there any way to control the outputting of these messages? When we run 
with TNonblockingServer, we get these output. I couldn't find a way to mask 
them.


> TNonblockingServer configured with more than one IO threads does not always 
> return from serve() upon stop()
> -----------------------------------------------------------------------------------------------------------
>
>                 Key: THRIFT-3891
>                 URL: https://issues.apache.org/jira/browse/THRIFT-3891
>             Project: Thrift
>          Issue Type: Bug
>          Components: C++ - Library
>    Affects Versions: 0.9.3
>            Reporter: Buğra Gedik
>            Assignee: James E. King, III
>            Priority: Minor
>         Attachments: patch.diff
>
>
> Using {{TNonblockingServer}}, when the number of IO threads is > 1, there is 
> race condition in which {{stop()}} does not properly unblock {{serve()}}. 
> The problem manifests itself when {{stop()}} is called (obviously from a 
> different thread) soon after {{serve()}}. 
> The core issue is that, {{event_base_loopbreak()}} is called within the 
> {{stop()}} sequence without checking whether the IO thread has actually 
> entered its event loop. The documentation of {{event_base_loopbreak()}} says 
> (http://www.wangafu.net/~nickm/libevent-book/Ref3_eventloop.html)
> {quote}
> Note also that event_base_loopexit(base,NULL) and event_base_loopbreak(base) 
> act differently when no event loop is running: loopexit schedules the next 
> instance of the event loop to stop right after the next round of callbacks 
> are run (as if it had been invoked with EVLOOP_ONCE) whereas loopbreak only 
> stops a currently running loop, and has no effect if the event loop isn’t 
> running.
> {quote}
> Attached is a patch (against the released 0.9.3 version of the codebase).



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to