Re: [libvirt] [PATCH v2] qemu_migration: Avoid crashing if domain dies too quickly
On 18.10.2013 08:22, Wangyufei (A) wrote:
I'm sorry. I didn't get what you mean.
In virQEMUCapsInitQMP
if (!(xmlopt = virDomainXMLOptionNew(NULL, NULL, NULL)) ||
!(vm = virDomainObjNew(xmlopt)))
goto cleanup;
vm->pid = pid; //Apparently vm is not NULL here.
if (!(mon = qemuMonitorOpen(vm, &config, true, &callbacks, NULL))) { //If
qemuMonitorOpen returns NULL here, but not do mon->vm = virObjectRef(vm); in
qemuMonitorOpenInternal.
ret = 0;
goto cleanup; // We go to cleanup here.
}
virObjectLock(mon);
if (virQEMUCapsInitQMPMonitor(qemuCaps, mon) < 0)
goto cleanup;
ret = 0;
cleanup:
if (mon)
virObjectUnlock(mon);
qemuMonitorClose(mon);
virCommandAbort(cmd);
virCommandFree(cmd);
VIR_FREE(monarg);
VIR_FREE(monpath);
virObjectUnref(vm); //vm is not NULL here, and we'll do something about
vm->refs, right?
Yes. In fact we dispose @vm as we are the only one holding reference to
it and we don't longer need it. If qemuMonitorOpenInternal would do
virObjectRef(vm), then vm->refs = 2 before executing this line. After
the execution, the refs is decremented to 1 as @mon is the only one
holding reference to @vm.
virObjectUnref(xmlopt);