Re: TODO : Allow parallel cores to be used by vacuumdb [ WIP ] - Mailing list pgsql-hackers

<div class="WordSection1"><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">On</span><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"></span><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">25October 2014 17:52, Amit Kapila Wrote,</span><p
class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>***************</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>*** 358,363 ****
handle_sigint(SIGNAL_ARGS)</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>---358,364 ----</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> </span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>  /* Send
QueryCancelif we are processing a database query */</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> if (cancelConn != NULL)</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>  {</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>+ inAbort =
true;</span><pclass="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> 
if(PQcancel(cancelConn, errbuf, sizeof(errbuf)))</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> fprintf(stderr, _("Cancel request
sent\n"));</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> else</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> </span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>Dowe need to set inAbort flag incase
PQcancelis successful?</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>Basicallyif PQCancel fails due to any
reason,I think behaviour</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>canbe undefined as the executing thread
canassume that cancel is</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>done.</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> </span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>***391,396 **** consoleHandler(DWORD
dwCtrlType)</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>---392,399 ----</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> 
                          EnterCriticalSection</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>(&cancelConnLock);</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">> 
                          if (cancelConn != NULL)</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>                            {</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>+
                                         inAbort = </span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>true;</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">>+</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black"> </span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">In“<b>handle_sigint</b>” function if we are
goingto cancel the query that time I am setting the flag <b>inAbort </b>(even when it is success), so that in
“<b>select_loop</b>”function </span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">If<b>select(maxFd + 1, workerset, NULL, NULL,
&tv);</b>come out, we can know whether it came out because of cancel query and handle it accordingly. </span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                i =
select(maxFd+ 1, workerset, NULL, NULL, NULL);</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black"> </span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                               if (in_abort()) 
<b>//loopbreak because of cancel query, so return fail…</b></span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                               {</span><p
class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                                               
return-1;</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                               }</span><p
class="MsoNormal"><spanstyle="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black"> </span><p
class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                               if (i < 0
&&errno == EINTR)</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">                                               
continue;</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Regards,</span><pclass="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">DilipKumar</span><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span></div>