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<p class=MsoNormal><span style='color:#1F497D'>Hello,<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'>Let me rephrase the question,
maybe someone will help me </span><span style='font-family:Wingdings;
color:#1F497D'>J</span><span style='color:#1F497D'><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'>Is there any chance that ast_mutex
in module will “miss”, for example because of multiple processes (fork() in
core maybe)?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
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<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"'> asterisk-dev-bounces@lists.digium.com
[mailto:asterisk-dev-bounces@lists.digium.com] <b>On Behalf Of </b>Alex
Massover<br>
<b>Sent:</b> <span lang=HE dir=RTL>éåí</span><span dir=LTR></span><span
dir=LTR></span> <span lang=HE dir=RTL>ä</span><span dir=LTR></span><span
dir=LTR></span> 25 <span lang=HE dir=RTL>ôáøåàø</span><span dir=LTR></span><span
dir=LTR></span> 2010 19:58<br>
<b>To:</b> asterisk-dev@lists.digium.com<br>
<b>Subject:</b> [asterisk-dev] ast_mutex_t usage<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Hello,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I have a custom module, that exports foo(), the problem is
that foo() is not safe-thread, i.e. calls to it should be serialized.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I tried to do it with ast_mutex like following:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>AST_MUTEX_DEFINE_STATIC(mp);<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>static int foo(…..)<o:p></o:p></p>
<p class=MsoNormal>{<o:p></o:p></p>
<p class=MsoNormal>….<o:p></o:p></p>
<p class=MsoNormal>ast_mutex_lock(&mp);<o:p></o:p></p>
<p class=MsoNormal>[non-reentrant code here]<o:p></o:p></p>
<p class=MsoNormal>ast_mutex_unlock(&mp);<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><o:p> </o:p></p>
<p class=MsoNormal>But I still see that [non-reentrant] part is entered
more than once concurrently. Each channel can call foo() only once in dialplan,
so it looks like other threads/channels are entering it.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Do I miss something please? Maybe there’re a better ways to
serialize a calls to module function?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>--<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Best
Regards,</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Alex
Massover</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>VoIP
R&D TL</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Jajah
Inc.</span><o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br>
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