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<p class=MsoNormal><span lang=EN-US>The mutex lock in “Sp.c” uses a
dangerous assumption that doesn’t hold on Win32. The mbox will be
assigned the opened win32 socket handle that could be greater than 0xFF, and
for most time is.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New";color:blue'>int</span><span
lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:#020002'>SP_connect_timeout</span>( <span style='color:blue'>const</span>
<span style='color:blue'>char</span> *<span style='color:#020002'>spread_name</span>,
<span style='color:blue'>const</span> <span style='color:blue'>char</span> *<span
style='color:#020002'>private_name</span>,<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>int</span> <span style='color:#020002'>priority</span>, <span
style='color:blue'>int</span> <span style='color:#020002'>group_membership</span>,
<span style='color:#020002'>mailbox</span> *<span style='color:#020002'>mbox</span>,<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>char</span> *<span style='color:#020002'>private_group</span>,
<span style='color:#020002'>sp_time</span> <span style='color:#020002'>time_out</span>
)<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'>{<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";
color:#020002'>s</span><span lang=EN-US style='font-size:10.0pt;font-family:
"Courier New"'> = <span style='color:#020002'>socket</span>( <span
style='color:#020002'>AF_UNIX</span>, <span style='color:#020002'>SOCK_STREAM</span>,
0 );<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>*<span
style='color:#020002'>mbox</span> = <span style='color:#020002'>s</span>;<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>}<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>The following code is bad on win32, masking
with 0xFF will generate different socket handles using the same mutex and could
cause deadlock during multithreaded applications.<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New";color:#020002'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New";color:blue'>int</span><span
lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:#020002'>SP_scat_receive</span>( <span style='color:#020002'>mailbox</span>
<span style='color:#020002'>mbox</span>, <span style='color:#020002'>service</span>
*<span style='color:#020002'>service_type</span>, <span style='color:blue'>char</span>
<span style='color:#020002'>sender</span>[<span style='color:#020002'>MAX_GROUP_NAME</span>],<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>int</span> <span style='color:#020002'>max_groups</span>, <span
style='color:blue'>int</span> *<span style='color:#020002'>num_groups</span>, <span
style='color:blue'>char</span> <span style='color:#020002'>groups</span>[][<span
style='color:#020002'>MAX_GROUP_NAME</span>],<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:#020002'>int16</span> *<span style='color:#020002'>mess_type</span>,
<span style='color:blue'>int</span> *<span style='color:#020002'>endian_mismatch</span>,<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'> </span><span
style='font-size:10.0pt;font-family:"Courier New";color:#020002'>scatter</span><span
style='font-size:10.0pt;font-family:"Courier New"'> *<span style='color:#020002'>scat_mess</span>
)<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Courier New"'>{<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New";color:#020002'>.<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New";color:#020002'>.<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New";color:#020002'>Mutex_lock</span><span
lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>( &<span
style='color:#020002'>Mbox_mutex</span>[<span style='color:#020002'>mbox</span>
& <span style='color:#020002'>MAX_MUTEX_MASK</span>][1] );<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'>.<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'>.<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'>}<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-US
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><span lang=EN-US
style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Mats Dal</span></b><span
lang=EN-US style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br>
</span><span lang=EN-US style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>Senior Software Engineer 1<br>
<br>
Tel 861<br>
Fax +46 8 658 78 99<br>
Cell 0709-549851<br>
</span><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'><a href="mailto:Mats.Dal@dice.se"><span lang=EN-US
style='color:blue'>Mats.Dal@dice.se</span></a></span><span lang=EN-US
style='font-size:7.5pt;font-family:"Arial","sans-serif";color:black'><br>
<br>
</span><b><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:black'>DICE</span></b><span lang=EN-US style='font-size:12.0pt;
font-family:"Times New Roman","serif"'><br>
</span><span lang=EN-US style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'><br>
EA Digital Illusions CE AB<br>
Katarinavägen 15<br>
P.O. Box 20068<br>
SE-104 60 Stockholm, Sweden<br>
</span><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'><a href="http://www.dice.se"><span lang=EN-US style='color:blue'>www.dice.se</span></a></span><span
lang=EN-US style='font-size:7.5pt;font-family:"Arial","sans-serif";color:black'><br>
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<o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
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color:black'><o:p></o:p></span></p>
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