Asynchronous event for BlockPull completion

When an operation started by virDomainBlockPullAll completes (either with
success or with failure), raise an event to indicate the final status.  This
allows an API user to avoid polling on virDomainBlockPullInfo if they would
prefer to use the 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/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
  from QEMU monitor

Signed-off-by: Adam Litke <agl@us.ibm.com>

2 files changed, 63 insertions, 0 deletions

diff --git a/libvirt-override-virConnect.py b/libvirt-override-virConnect.py
index e344303..362be75 100644
--- a/libvirt-override-virConnect.py
+++ b/libvirt-override-virConnect.py
@@ -124,6 +124,18 @@
         except AttributeError:
             pass
 
+    def dispatchDomainEventBlockPullCallback(self, dom, path, status, cbData):
+        """Dispatches events to python user domain blockPull event callbacks
+        """
+        try:
+            cb = cbData["cb"]
+            opaque = cbData["opaque"]
+
+            cb(self, virDomain(self, _obj=dom), path, 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 cbdbc54..61d5b7d 100644
--- a/libvirt-override.c
+++ b/libvirt-override.c
@@ -3476,6 +3476,54 @@ libvirt_virConnectDomainEventGraphicsCallback(virConnectPtr conn ATTRIBUTE_UNUSE
     return ret;
 }
 
+static int
+libvirt_virConnectDomainEventBlockPullCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                               virDomainPtr dom,
+                                               const char *path,
+                                               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*)"OsiO",
+                                    pyobj_dom, path, 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)
@@ -3534,6 +3582,9 @@ 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_PULL:
+        cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventBlockPullCallback);
+        break;
     }
 
     if (!cb) {