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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>These patches are for:<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<ol style='margin-top:0in' start=1 type=1>
<li class=MsoNormal style='mso-list:l0 level1 lfo1;text-autospace:none'><font
size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'>Linux+BSD:
Corrected usage of 'select</span></font> <font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>' to avoid packet loss<o:p></o:p></span></font></li>
<li class=MsoNormal style='mso-list:l0 level1 lfo1;text-autospace:none'><font
size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'>Windows:
Better use of WSAGetLastError (instead of errno)<o:p></o:p></span></font></li>
</ol>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>
Note: review to add #ifndef _<i><span style='font-style:italic'>WIN32</span></i>_WCE
if needed<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>Explanation:<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>'select</span></font> <font
size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'>':<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>On Linux and FreeBSD and
similar operating systems, the buffer would fill up and lose packets:<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>The 'select' function resets
an internal "I/O available" flag after it returns for each of the
sockets that are indicated as having available I/O. These internal
"I/O available" flags are not set again until _NEW_ I/O is available
(specifically, for incoming I/O, another packet arrives). In other words,
if you call 'select' and 2 new packets are available for the socket you are
testing, select will return immediately. But if 'recvfrom' only reads a
single packet, the next call to 'select' will _BLOCK_ until another (3rd) new
packet arrives for this socket.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>What is _supposed_ to happen
is repeated calls to 'recvfrom' until there is no more data available.
The best way to test for available data is via the 'FIONREAD' ioctl, which is
what the patch is all about. This is a relatively fast call, and any performance
hits caused by the ioctl are easily made up for by the greater efficiency of
the I/O overall.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>'WSAGetLastError</span></font>
<font size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'>':<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'>We observe live555 'getErrno</span></font>
<font size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'>'
in BasicUsageEnvironment attempts to report the correct Windows socket error
code. However if errno is already 0, the live555 might fail to use the correct
error code. Windows always reports in WSAGetLastError, but will not set errno
unless the compatibility library is also engaged. Therefore we patched this in several
places.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Regards,</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Bryan and Bob<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>http://www.airgain.com<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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