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<p class="MsoNormal"><span lang="EN-US">Hello,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">When I ran programme event-test compiled from event-test.c, I found a problem that, after virEventRegisterDefaultImpl I do virConnectOpenAuth and virConnectClose, there will be handlers of socket
and pipe opened by virConnectOpenAuth leaked after virConnectClose. So I did some analysis, and I found the fact following:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">In the condition that we only have one connection here<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">int <b>virNetSocketAddIOCallback</b>(virNetSocketPtr sock,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> int events,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> virNetSocketIOFunc func,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> void *opaque,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> virFreeCallback ff)<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">{<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> int ret = -1;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> <span style="color:red">
virObjectRef</span>(sock); <span style="color:#00B0F0">//Here we add sock refers once, then we will get refers equal
</span><span style="color:red">2</span><span style="color:#00B0F0"> after<o:p></o:p></span></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> virObjectLock(sock);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> if (sock->watch > 0) {<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> VIR_DEBUG("Watch already registered on socket %p", sock);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> goto cleanup;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> }<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> if ((sock->watch = virEventAddHandle(sock->fd,
<span style="color:#00B0F0">//If we have called virEventRegisterDefaultImpl, then here we’ll get a sock watch non negative and will not go to cleanup.<o:p></o:p></span></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> events,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> virNetSocketEventHandle,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> sock,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> virNetSocketEventFree)) < 0) {<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> VIR_DEBUG("Failed to register watch on socket %p", sock);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> <span style="color:red">
goto cleanup;<o:p></o:p></span></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> }<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> sock->func = func;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> sock->opaque = opaque;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> sock->ff = ff;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> ret = 0;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">cleanup:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> virObjectUnlock(sock);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> if (ret != 0)<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> <span style="color:red">
virObjectUnref</span>(sock);<span style="color:#00B0F0"> //If we haven’t called virEventRegisterDefaultImpl, we’ll be here after virEventAddHandle, and sock refers will decrease to
</span><span style="color:red">1</span><span style="color:#00B0F0"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"> return ret;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">}<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">Condition with virEventRegisterDefaultImpl, we’ll do unrefer action in two places:<o:p></o:p></span></p>
<p class="MsoListParagraph" style="margin-left:42.6pt;text-indent:-21.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span lang="EN-US" style="layout-grid-mode:line"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="layout-grid-mode:line">virEventRunDefaultImpl ->virEventPollRunOnce ->virEventRunDefaultImpl ->virEventPollRunOnce ->virEventPollCleanupHandles -></span><span lang="EN-US">
<span style="layout-grid-mode:line">virNetSocketEventFree -></span> <span style="layout-grid-mode:line">
virObjectUnref<o:p></o:p></span></span></p>
<p class="MsoListParagraph" style="margin-left:42.6pt;text-indent:-21.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span lang="EN-US"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="layout-grid-mode:line">virConnectClose ->virObjectUnref ->virConnectDispose ->remoteConnectClose ->doRemoteClose ->virNetClientClose ->virNetClientCloseInternal -> virNetClientIOEventLoopPassTheBuck
-></span><span lang="EN-US"> <span style="layout-grid-mode:line">virNetClientCloseLocked -></span>
<span style="layout-grid-mode:line">virObjectUnref</span><o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">When <span style="layout-grid-mode:line">
event dealing loop is alive, everything work fine, we’ll get sock refers 2 after </span>
virConnectOpenAuth and unrefer twice in two places above after virConnectClose. But If some accidents happened like we quit event dealing loop or
<span style="layout-grid-mode:line">virEventRunDefaultImpl suspended, then sock refers will never be zero, and handlers will never be freed.<o:p></o:p></span></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US" style="layout-grid-mode:line">In a particular condition we have two threads, thread one doing event dealing loop, thread two doing something like
</span><span lang="EN-US">virConnectOpenAuth and virConnectClose ceaselessly, then we’ll get a big trouble that handlers available will be ate up soon.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">I consider to add something like virEventDeregisterDefaultImpl to set addHandleImpl and his buddy NULL. Apparently it is far away from fixing it completely.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US">At last I have two questions here:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoListParagraph" style="margin-left:42.6pt;text-indent:-21.0pt;mso-list:l1 level1 lfo2">
<![if !supportLists]><span lang="EN-US"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US">Is it a problem that after virEventRegisterDefaultImpl we have handlers leaked?
<o:p></o:p></span></p>
<p class="MsoListParagraph" style="margin-left:42.6pt;text-indent:-21.0pt;mso-list:l1 level1 lfo2">
<![if !supportLists]><span lang="EN-US"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US">If it is a problem, is there anybody any good idea to help me out?<o:p></o:p></span></p>
<p class="MsoNormal" style="text-indent:21.6pt"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left"><span lang="EN-US">Best Regards,<o:p></o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left"><span lang="EN-US">-WangYufei<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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