Asynchronous event for BlockJob completion

When an operation started by virDomainBlockPull completes (either with
success or with failure), raise an event to indicate the final status.
This API allow users to avoid polling on virDomainGetBlockJobInfo if
they would prefer to use an event mechanism.

* daemon/remote.c: Dispatch events to client
* include/libvirt/libvirt.h.in: Define event ID and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle the new event
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for block_stream completion and emit a libvirt block pull event
* src/remote/remote_driver.c: Receive and dispatch events to application
* src/remote/remote_protocol.x: Wire protocol definition for the event
* src/remote_protocol-structs: structure definitions for protocol verification
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
  from QEMU monitor

2 files changed, 64 insertions, 0 deletions

diff --git a/libvirt-override-virConnect.py b/libvirt-override-virConnect.py
index eeeedf9..65b5342 100644
--- a/libvirt-override-virConnect.py
+++ b/libvirt-override-virConnect.py
@@ -113,6 +113,18 @@
            authScheme, subject, opaque)
         return 0
 
+    def dispatchDomainEventBlockPullCallback(self, dom, path, type, status, cbData):
+        """Dispatches events to python user domain blockJob event callbacks
+        """
+        try:
+            cb = cbData["cb"]
+            opaque = cbData["opaque"]
+
+            cb(self, virDomain(self, _obj=dom), path, type, status, opaque)
+            return 0
+        except AttributeError:
+            pass
+
     def domainEventDeregisterAny(self, callbackID):
         """Removes a Domain Event Callback. De-registering for a
            domain callback will disable delivery of this event type """
diff --git a/libvirt-override.c b/libvirt-override.c
index e89bc97..db76315 100644
--- a/libvirt-override.c
+++ b/libvirt-override.c
@@ -3582,6 +3582,55 @@ libvirt_virConnectDomainEventGraphicsCallback(virConnectPtr conn ATTRIBUTE_UNUSE
     return ret;
 }
 
+static int
+libvirt_virConnectDomainEventBlockJobCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                              virDomainPtr dom,
+                                              const char *path,
+                                              int type,
+                                              int status,
+                                              void *opaque)
+{
+    PyObject *pyobj_cbData = (PyObject*)opaque;
+    PyObject *pyobj_dom;
+    PyObject *pyobj_ret;
+    PyObject *pyobj_conn;
+    PyObject *dictKey;
+    int ret = -1;
+
+    LIBVIRT_ENSURE_THREAD_STATE;
+
+    /* Create a python instance of this virDomainPtr */
+    virDomainRef(dom);
+    pyobj_dom = libvirt_virDomainPtrWrap(dom);
+    Py_INCREF(pyobj_cbData);
+
+    dictKey = libvirt_constcharPtrWrap("conn");
+    pyobj_conn = PyDict_GetItem(pyobj_cbData, dictKey);
+    Py_DECREF(dictKey);
+
+    /* Call the Callback Dispatcher */
+    pyobj_ret = PyObject_CallMethod(pyobj_conn,
+                                    (char*)"dispatchDomainEventBlockPullCallback",
+                                    (char*)"OsiiO",
+                                    pyobj_dom, path, type, status, pyobj_cbData);
+
+    Py_DECREF(pyobj_cbData);
+    Py_DECREF(pyobj_dom);
+
+    if(!pyobj_ret) {
+#if DEBUG_ERROR
+        printf("%s - ret:%p\n", __FUNCTION__, pyobj_ret);
+#endif
+        PyErr_Print();
+    } else {
+        Py_DECREF(pyobj_ret);
+        ret = 0;
+    }
+
+    LIBVIRT_RELEASE_THREAD_STATE;
+    return ret;
+}
+
 static PyObject *
 libvirt_virConnectDomainEventRegisterAny(ATTRIBUTE_UNUSED PyObject * self,
                                          PyObject * args)
@@ -3636,6 +3685,9 @@ libvirt_virConnectDomainEventRegisterAny(ATTRIBUTE_UNUSED PyObject * self,
     case VIR_DOMAIN_EVENT_ID_CONTROL_ERROR:
         cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventGenericCallback);
         break;
+    case VIR_DOMAIN_EVENT_ID_BLOCK_JOB:
+        cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventBlockJobCallback);
+        break;
     }
 
     if (!cb) {