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<p class="MsoNormal"><span style="font-size:10.0pt">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt">I’m using winpcap to capture a ~3mb/s stream of UDP packets. We need to capture for long periods (e.g., 24 hours); our application processes the payload, extracts statistics, and logs the statistics to disk
over time. This usually works for about 4 or so hours, and then repeated calls to pcap_next_ex() return timeout (no data), and finally stop returning altogether (block). Notably, I’m certain data is still coming in (I can see it in wireshark).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt">The app is written in java, and I’ve written a JNI interface in VS2010 which bridges Java to the winpcap.dll API.<span style="color:#1F497D"> I believe we are seeing the problem on a relatively modern HP workstation
w/ built-in Intel GB/s NICs, under Win7/64, running WinPcap 4.1.2.<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt">I open the device as follows:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">pcap = pcap_open(adapterName, 65536, PCAP_OPENFLAG_PROMISCUOUS, 1000, NULL, NULL);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">I then set the following filter:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">"(ip and udp) and (udp[8] & 0xEF = 0x80)" // RTP packets<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">Using:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">pcap_compile()<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">and<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">pcap_setfilter()<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt">I then continually call<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">pcap_next_ex()<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">and memcpy the resulting data into a reused memory buffer which is passed up to java through JNI NIO Direct Buffers.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">This all works splendidly well until 4+ hours of capture, at which point pcap_next_ex() starts continually returning timeouts, and then eventually just blocks
altogether.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">I am not setting pcap_setmintocopy().<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">If I monitor the memory usage of my java process, there does not appear to be a memory leak.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">Any ideas? Presumably, winpcap should support long captures without issue? Anyone experience something similar?<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas">Ty<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt"><o:p> </o:p></span></p>
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