[Ace-users] [ace-bugs] trying to fix an ACE hang

[Steve Huston]

Hi Greg,
 
Thanks for the PROBLEM-REPORT-FORM.
 
Doug poked me to see if I remembered this type of problem. Your
description looks familiar - I've a feeling we've been down this road
before, but can't recall the details. Could you please scan through
the ACE_wrappers/ChangeLogs files for changes in this area to see if
we've tried this fix before?
 
Thanks!
-Steve

--
Steve Huston, Riverace Corporation
Want to take ACE training on YOUR schedule?
See http://www.riverace.com/training.htm


-----Original Message-----
From: ace-bugs-bounces at cse.wustl.edu
[mailto:ace-bugs-bounces at cse.wustl.edu] On Behalf Of Greg Popovitch
Sent: Thursday, November 29, 2007 2:23 PM
To: ace-bugs at cse.wustl.edu
Subject: [ace-bugs] trying to fix an ACE hang



Hi,

 

I have a hang on Windows Vista 64 and also on linux 64 (RHEL 4). 

 

One thread is enqueuing a message on an ACE_Message_Queue for another
thread and hangs on the notification to the WFMO reactor. The
ACE_WFMO_Reactor_Notify::notify() hangs because its internal message
queue is full.

 

The other thread hangs while checking of the message_queue is empty
because it can't grab its ACE_GUARD. Therefore it can't dequeue
messages from the WFMO_Reactor.

 

My question: 

 

In file Message_Queue_T.cpp,

 

Would it be OK to move the "this->notify ()" outside of the scope of
the ACE_GUARD in:

 

template <ACE_SYNCH_DECL> int

ACE_Message_Queue<ACE_SYNCH_USE>::enqueue_head (ACE_Message_Block
*new_item,

                                                ACE_Time_Value
*timeout)

{

  ACE_TRACE ("ACE_Message_Queue<ACE_SYNCH_USE>::enqueue_head");

  int queue_count = 0;

  {

    ACE_GUARD_RETURN (ACE_SYNCH_MUTEX_T, ace_mon, this->lock_, -1);

 

    if (this->state_ == ACE_Message_Queue_Base::DEACTIVATED)

      {

        errno = ESHUTDOWN;

        return -1;

      }

 

    if (this->wait_not_full_cond (ace_mon, timeout) == -1)

      return -1;

 

    queue_count = this->enqueue_head_i (new_item);

 

    if (queue_count == -1)

      return -1;

 

     this->notify ();  //******** move after closing brace below ???
******

  }

  return queue_count;

}

 

 

   ACE VERSION: 5.6

 

    HOST MACHINE and OPERATING SYSTEM:

        Vindows Vista

 

    TARGET MACHINE and OPERATING SYSTEM, if different from HOST:

 

    COMPILER NAME AND VERSION (AND PATCHLEVEL):

        Visual Studio 2005

 

Thanks,

 

greg

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://list.isis.vanderbilt.edu/pipermail/ace-users/attachments/20071129/45ce69ec/attachment-0001.html