<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<title>Message</title>
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
span.EmailStyle18
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><span style='color:#1F497D'>YES! I think found exactly this
issue:<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Sun May 5 19:14:34 2002
Douglas C. Schmidt <schmidt@macarena.cs.wustl.edu><o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> *
ace/Message_Queue_T.cpp: Modified all the enqueue*() methods so that<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> their calls to
notify() occur *outside* of the monitor lock.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> This change
prevents deadlock from occurring when a reactor's<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> notification
pipe is full. Thanks to Sasha Agranov<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>
<sagranov@COMGATES.co.il> for reporting this.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Did it creep back in somehow?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>greg<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Steve Huston
[mailto:shuston@riverace.com] <br>
<b>Sent:</b> Thursday, November 29, 2007 4:15 PM<br>
<b>To:</b> Greg Popovitch; ace-bugs@cse.wustl.edu<br>
<b>Subject:</b> RE: [ace-bugs] trying to fix an ACE hang<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Hi Greg,</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Thanks for the PROBLEM-REPORT-FORM.</span><span style='font-size:
12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>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?</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Thanks!<br>
-Steve</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<p><span style='font-size:10.0pt'>--<br>
Steve Huston, Riverace Corporation<br>
Want to take ACE training on YOUR schedule?<br>
See <a href="http://www.riverace.com/training.htm">http://www.riverace.com/training.htm</a></span><o:p></o:p></p>
<blockquote style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt;
margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'>-----Original Message-----<br>
<b>From:</b> ace-bugs-bounces@cse.wustl.edu
[mailto:ace-bugs-bounces@cse.wustl.edu] <b>On Behalf Of </b>Greg Popovitch<br>
<b>Sent:</b> Thursday, November 29, 2007 2:23 PM<br>
<b>To:</b> ace-bugs@cse.wustl.edu<br>
<b>Subject:</b> [ace-bugs] trying to fix an ACE hang</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal>Hi,<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>I have a hang on Windows Vista 64 and also on linux 64 (RHEL
4). <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>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.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>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.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>My question: <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>In file Message_Queue_T.cpp,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Would it be OK to move the “this->notify ()” outside of
the scope of the ACE_GUARD in:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>template <ACE_SYNCH_DECL> int<o:p></o:p></p>
<p class=MsoNormal>ACE_Message_Queue<ACE_SYNCH_USE>::enqueue_head (ACE_Message_Block
*new_item,<o:p></o:p></p>
<p class=MsoNormal>
ACE_Time_Value *timeout)<o:p></o:p></p>
<p class=MsoNormal>{<o:p></o:p></p>
<p class=MsoNormal> ACE_TRACE
("ACE_Message_Queue<ACE_SYNCH_USE>::enqueue_head");<o:p></o:p></p>
<p class=MsoNormal> int queue_count = 0;<o:p></o:p></p>
<p class=MsoNormal> {<o:p></o:p></p>
<p class=MsoNormal> ACE_GUARD_RETURN (ACE_SYNCH_MUTEX_T,
ace_mon, this->lock_, -1);<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> if (this->state_ ==
ACE_Message_Queue_Base::DEACTIVATED)<o:p></o:p></p>
<p class=MsoNormal> {<o:p></o:p></p>
<p class=MsoNormal> errno =
ESHUTDOWN;<o:p></o:p></p>
<p class=MsoNormal> return -1;<o:p></o:p></p>
<p class=MsoNormal> }<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> if (this->wait_not_full_cond (ace_mon,
timeout) == -1)<o:p></o:p></p>
<p class=MsoNormal> return -1;<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> queue_count = this->enqueue_head_i
(new_item);<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> if (queue_count == -1)<o:p></o:p></p>
<p class=MsoNormal> return -1;<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> this->notify ();
//******** move after closing brace below ??? ******<o:p></o:p></p>
<p class=MsoNormal> }<o:p></o:p></p>
<p class=MsoNormal> return queue_count;<o:p></o:p></p>
<p class=MsoNormal>}<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> ACE VERSION: 5.6<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> HOST MACHINE and OPERATING SYSTEM:<o:p></o:p></p>
<p class=MsoNormal> Vindows Vista<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> TARGET MACHINE and OPERATING SYSTEM, if
different from HOST:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal> COMPILER NAME AND VERSION (AND
PATCHLEVEL):<o:p></o:p></p>
<p class=MsoNormal> Visual Studio
2005<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>greg<o:p></o:p></p>
</blockquote>
</div>
</body>
</html>