parallels: return only success from PCS event handler

2 reasons to to this.
1. PCS SDK really don't care of handler return value.
2. It hard to imagine how notifier can handle
subscriber failures. Even if there are some situations
we probably will use some special error codes and
not just throw error codes we get from SDK itself.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@parallels.com>

src/parallels/parallels_sdk.c

@@ -1534,7 +1534,7 @@ prlsdkNewStateToEvent(VIRTUAL_MACHINE_STATE domainState,
     }
 }
 
-static PRL_RESULT
+static void
 prlsdkHandleVmStateEvent(parallelsConnPtr privconn,
                          PRL_HANDLE prlEvent,
                          unsigned char *uuid)
@@ -1547,18 +1547,16 @@ prlsdkHandleVmStateEvent(parallelsConnPtr privconn,
     virDomainEventType lvEventType = 0;
     int lvEventTypeDetails = 0;
 
+    dom = virDomainObjListFindByUUID(privconn->domains, uuid);
+    if (dom == NULL)
+        return;
+
     pret = PrlEvent_GetParamByName(prlEvent, "vminfo_vm_state", &eventParam);
     prlsdkCheckRetGoto(pret, cleanup);
 
     pret = PrlEvtPrm_ToInt32(eventParam, &domainState);
     prlsdkCheckRetGoto(pret, cleanup);
 
-    dom = virDomainObjListFindByUUID(privconn->domains, uuid);
-    if (dom == NULL) {
-        pret = PRL_ERR_VM_UUID_NOT_FOUND;
-        goto cleanup;
-    }
-
     pdom = dom->privateData;
     if (prlsdkConvertDomainState(domainState, pdom->id, dom) < 0)
         goto cleanup;
@@ -1567,96 +1565,74 @@ prlsdkHandleVmStateEvent(parallelsConnPtr privconn,
                           &lvEventType,
                           &lvEventTypeDetails);
 
-    if (prlsdkSendEvent(privconn, dom, lvEventType, lvEventTypeDetails) < 0) {
-        pret = PRL_ERR_OUT_OF_MEMORY;
-        goto cleanup;
-    }
+    prlsdkSendEvent(privconn, dom, lvEventType, lvEventTypeDetails);
 
  cleanup:
-    if (dom)
-        virObjectUnlock(dom);
-    return pret;
+    virObjectUnlock(dom);
+    return;
 }
 
-static PRL_RESULT
+static void
 prlsdkHandleVmConfigEvent(parallelsConnPtr privconn,
                           unsigned char *uuid)
 {
-    PRL_RESULT pret = PRL_ERR_FAILURE;
     virDomainObjPtr dom = NULL;
 
     dom = virDomainObjListFindByUUID(privconn->domains, uuid);
-    if (dom == NULL) {
-        pret = PRL_ERR_VM_UUID_NOT_FOUND;
-        goto cleanup;
-    }
+    if (dom == NULL)
+        return;
 
     if (prlsdkUpdateDomain(privconn, dom) < 0)
         goto cleanup;
 
-    if (prlsdkSendEvent(privconn, dom, VIR_DOMAIN_EVENT_DEFINED,
-                        VIR_DOMAIN_EVENT_DEFINED_UPDATED) < 0) {
-        pret = PRL_ERR_OUT_OF_MEMORY;
-        goto cleanup;
-    }
+    prlsdkSendEvent(privconn, dom, VIR_DOMAIN_EVENT_DEFINED,
+                        VIR_DOMAIN_EVENT_DEFINED_UPDATED);
 
-    pret = PRL_ERR_SUCCESS;
  cleanup:
-    if (dom)
-        virObjectUnlock(dom);
-    return pret;
+    virObjectUnlock(dom);
+    return;
 }
 
-static PRL_RESULT
+static void
 prlsdkHandleVmAddedEvent(parallelsConnPtr privconn,
                        unsigned char *uuid)
 {
-    PRL_RESULT pret;
     virDomainObjPtr dom = NULL;
 
     dom = prlsdkAddDomain(privconn, uuid);
-    if (!dom)
-        return PRL_ERR_FAILURE;
+    if (dom == NULL)
+        return;
 
-    if (prlsdkSendEvent(privconn, dom, VIR_DOMAIN_EVENT_DEFINED,
-                        VIR_DOMAIN_EVENT_DEFINED_ADDED) < 0) {
-        pret = PRL_ERR_OUT_OF_MEMORY;
-        goto cleanup;
-    }
+    prlsdkSendEvent(privconn, dom, VIR_DOMAIN_EVENT_DEFINED,
+                        VIR_DOMAIN_EVENT_DEFINED_ADDED);
 
-    pret = PRL_ERR_SUCCESS;
- cleanup:
-    if (dom)
-        virObjectUnlock(dom);
-    return pret;
+    virObjectUnlock(dom);
+    return;
 }
 
-static PRL_RESULT
+static void
 prlsdkHandleVmRemovedEvent(parallelsConnPtr privconn,
                            unsigned char *uuid)
 {
     virDomainObjPtr dom = NULL;
-    PRL_RESULT pret = PRL_ERR_SUCCESS;
 
     dom = virDomainObjListFindByUUID(privconn->domains, uuid);
-    if (dom == NULL) {
-        /* domain was removed from the list from the libvirt
-         * API function in current connection */
-        return PRL_ERR_SUCCESS;
-    }
+    /* domain was removed from the list from the libvirt
+     * API function in current connection */
+    if (dom == NULL)
+        return;
 
-    if (prlsdkSendEvent(privconn, dom, VIR_DOMAIN_EVENT_UNDEFINED,
-                        VIR_DOMAIN_EVENT_UNDEFINED_REMOVED) < 0)
-        pret = PRL_ERR_OUT_OF_MEMORY;
+    prlsdkSendEvent(privconn, dom, VIR_DOMAIN_EVENT_UNDEFINED,
+                        VIR_DOMAIN_EVENT_UNDEFINED_REMOVED);
 
     virDomainObjListRemove(privconn->domains, dom);
-    return pret;
+    return;
 }
 
-static PRL_RESULT
+static void
 prlsdkHandleVmEvent(parallelsConnPtr privconn, PRL_HANDLE prlEvent)
 {
-    PRL_RESULT pret;
+    PRL_RESULT pret = PRL_ERR_FAILURE;
     char uuidstr[VIR_UUID_STRING_BUFLEN + 2];
     unsigned char uuid[VIR_UUID_BUFLEN];
     PRL_UINT32 bufsize = ARRAY_CARDINALITY(uuidstr);
@@ -1669,67 +1645,64 @@ prlsdkHandleVmEvent(parallelsConnPtr privconn, PRL_HANDLE prlEvent)
     prlsdkCheckRetGoto(pret, error);
 
     if (prlsdkUUIDParse(uuidstr, uuid) < 0)
-        return PRL_ERR_FAILURE;
+        return;
 
     switch (prlEventType) {
         case PET_DSP_EVT_VM_STATE_CHANGED:
-            return prlsdkHandleVmStateEvent(privconn, prlEvent, uuid);
+            prlsdkHandleVmStateEvent(privconn, prlEvent, uuid);
+            break;
         case PET_DSP_EVT_VM_CONFIG_CHANGED:
-            return prlsdkHandleVmConfigEvent(privconn, uuid);
+            prlsdkHandleVmConfigEvent(privconn, uuid);
+            break;
         case PET_DSP_EVT_VM_CREATED:
         case PET_DSP_EVT_VM_ADDED:
-            return prlsdkHandleVmAddedEvent(privconn, uuid);
+            prlsdkHandleVmAddedEvent(privconn, uuid);
+            break;
         case PET_DSP_EVT_VM_DELETED:
         case PET_DSP_EVT_VM_UNREGISTERED:
-            return prlsdkHandleVmRemovedEvent(privconn, uuid);
+            prlsdkHandleVmRemovedEvent(privconn, uuid);
             break;
         default:
             virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("Can't handle event of type %d"), prlEventType);
-            return PRL_ERR_FAILURE;
     }
 
  error:
-    return PRL_ERR_FAILURE;
+    return;
 }
 
 static PRL_RESULT
 prlsdkEventsHandler(PRL_HANDLE prlEvent, PRL_VOID_PTR opaque)
 {
     parallelsConnPtr privconn = opaque;
-    PRL_RESULT pret = PRL_ERR_UNINITIALIZED;
+    PRL_RESULT pret = PRL_ERR_FAILURE;
     PRL_HANDLE_TYPE handleType;
     PRL_EVENT_ISSUER_TYPE prlIssuerType = PIE_UNKNOWN;
 
     pret = PrlHandle_GetType(prlEvent, &handleType);
     prlsdkCheckRetGoto(pret, cleanup);
 
-    if (handleType != PHT_EVENT) {
-        /* Currently, there is no need to handle anything but events */
-        pret = PRL_ERR_SUCCESS;
+    /* Currently, there is no need to handle anything but events */
+    if (handleType != PHT_EVENT)
         goto cleanup;
-    }
 
-    if (privconn == NULL) {
-        pret = PRL_ERR_INVALID_ARG;
+    if (privconn == NULL)
         goto cleanup;
-    }
 
     PrlEvent_GetIssuerType(prlEvent, &prlIssuerType);
     prlsdkCheckRetGoto(pret, cleanup);
 
     switch (prlIssuerType) {
         case PIE_VIRTUAL_MACHINE:
-            pret = prlsdkHandleVmEvent(privconn, prlEvent);
+            prlsdkHandleVmEvent(privconn, prlEvent);
             break;
         default:
             VIR_DEBUG("Skipping event of issuer type %d", prlIssuerType);
     }
 
-    pret = PRL_ERR_SUCCESS;
  cleanup:
     PrlHandle_Free(prlEvent);
-    return pret;
+    return PRL_ERR_SUCCESS;
 }
 
 int prlsdkSubscribeToPCSEvents(parallelsConnPtr privconn)