[libvirt] [PATCH 3/6] use virObject to manage reference-count of virDomainObj

[Hu Tao]

Sorry, I unexpectedly deleted text body.

I changed the code like this:

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index c2a1f9a..8aad0b3 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -514,7 +514,10 @@ int qemuDomainObjBeginJobWithDriver(struct qemud_driver *driver,
             else
                 virReportSystemError(errno,
                                      "%s", _("cannot acquire job mutex"));
+            virDomainObjUnlock(obj);
             qemuDriverLock(driver);
+            virDomainObjLock(obj);
+            virDomainObjUnref(obj);
             return -1;
         }
     }

but still have problem. (see log in previous mail.) The reference count
of virDomainObj becomes 0 while there are still threads accessing it.
This causes two results: one is segmentation fault as shown in the log;
the other is the qemu monitor fd is closed two early, and threads are
polling a closed fd.

Steps of my test:

  1. change the value of max_clients in /etc/libvirt/libvirtd.conf to
     big enough value:
     
     max_clients = 2000000

  2. run libvirtd

  3. run libvirt-test.sh hut-vm1 (hut-vm1 is my vm name) (warning: this
     script forks many processes you have to kill by hand)

(again, the log and script libvirt-test.sh are in my previous mail)