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<p class="MsoNormal"><span lang="EN-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:FR">ACE VERSION: 6.2 (probably same thing for newer ACE Versions as the asnmp code has no functional change)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:FR">HOST MACHINE and OPERATING SYSTEM: PC with Windows XP<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA" style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="PT-BR" style="font-family:"Arial",sans-serif">Config.h : #include "ace/config-win32.h"<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="PT-BR" style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<pre><span lang="PT-BR">Microsoft Visual C++<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="PT-BR" style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<pre><span lang="EN-CA">No $ACE_ROOT/bin/MakeProjectCreator/config/default.features file<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA">ASNMP\snmp affected<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA"><o:p> </o:p></span></p>
<pre><span lang="EN-CA">THE PROBLEM AFFECT: EXECUTION<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="EN-CA" style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<pre><span lang="EN-CA">SYNOPSIS:<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="EN-CA">asynchronous get (use of </span><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">Snmp::get( Pdu &pdu, UdpTarget &target, Snmp_Result * cb)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA">will loop / burst affecting CPU and network in a specific scenario<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA"><o:p> </o:p></span></p>
<pre><span lang="EN-CA">DESCRIPTION:<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="EN-CA">Usually, a simple call to </span><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">Snmp::get( Pdu &pdu, UdpTarget &target, Snmp_Result * cb) will be OK<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">But if you use it with a polling (for exemple call each 5s) and you several times disconnect/reconnect network during one minute it can go into trouble.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">In Snmp::result you will have rc == SNMP_CLASS_TIMEOUT, and in this case we must not check pdu_->get_request_id() because this pdu_ won't be updated<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">This (pdu_->get_request_id() == hold_req_id_) check will be False, so the transaction is run, again, and again.. Doing network / CPU burst<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">I have done the following workaround for this :<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">void</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New""> Snmp::result(transaction *t,
<span style="color:blue">int</span> rc)<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""> t->result(*pdu_);<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:green">// verify this is the pdu we are after, except that a result with rc SNMP_CLASS_TIMEOUT or SNMP_CLASS_RESOURCE_UNAVAIL<o:p></o:p></span></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:green">// are special cases build by ASNMP lib in transaction::handle_timeout/handle_input:<o:p></o:p></span></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:green">// in these cases we must not check pdu_->get_request_id() because this pdu_ won't be updated<o:p></o:p></span></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">if</span> ((rc == SNMP_CLASS_TIMEOUT) || (rc == SNMP_CLASS_RESOURCE_UNAVAIL)<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""> || (pdu_->get_request_id() == hold_req_id_))<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New"">
</span><span style="font-size:10.0pt;font-family:"Courier New"">{…</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New""><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA"><o:p> </o:p></span></p>
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