util: Introduce and use virObjectRWUnlock

Rather than overload virObjectUnlock as commit id '77f4593b' has
done, create a separate virObjectRWUnlock API that will force the
consumers to make the proper decision regarding unlocking the
RWLock's. Similar to the RWLockRead and RWLockWrite, use the
virObjectGetRWLockableObj helper. This restores the virObjectUnlock
code to using the virObjectGetLockableObj.

Signed-off-by: John Ferlan <jferlan@redhat.com>

src/conf/virdomainobjlist.c

@@ -122,7 +122,7 @@ virDomainObjListFindByIDInternal(virDomainObjListPtr doms,
     obj = virHashSearch(doms->objs, virDomainObjListSearchID, &id, NULL);
     if (ref) {
         virObjectRef(obj);
-        virObjectUnlock(doms);
+        virObjectRWUnlock(doms);
     }
     if (obj) {
         virObjectLock(obj);
@@ -134,7 +134,7 @@ virDomainObjListFindByIDInternal(virDomainObjListPtr doms,
         }
     }
     if (!ref)
-        virObjectUnlock(doms);
+        virObjectRWUnlock(doms);
     return obj;
 }
 
@@ -166,7 +166,7 @@ virDomainObjListFindByUUIDInternal(virDomainObjListPtr doms,
     obj = virHashLookup(doms->objs, uuidstr);
     if (ref) {
         virObjectRef(obj);
-        virObjectUnlock(doms);
+        virObjectRWUnlock(doms);
     }
     if (obj) {
         virObjectLock(obj);
@@ -178,7 +178,7 @@ virDomainObjListFindByUUIDInternal(virDomainObjListPtr doms,
         }
     }
     if (!ref)
-        virObjectUnlock(doms);
+        virObjectRWUnlock(doms);
     return obj;
 }
 
@@ -207,7 +207,7 @@ virDomainObjPtr virDomainObjListFindByName(virDomainObjListPtr doms,
     virObjectRWLockRead(doms);
     obj = virHashLookup(doms->objsName, name);
     virObjectRef(obj);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     if (obj) {
         virObjectLock(obj);
         if (obj->removing) {
@@ -329,7 +329,7 @@ virDomainObjPtr virDomainObjListAdd(virDomainObjListPtr doms,
 
     virObjectRWLockWrite(doms);
     ret = virDomainObjListAddLocked(doms, def, xmlopt, flags, oldDef);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     return ret;
 }
 
@@ -355,7 +355,7 @@ void virDomainObjListRemove(virDomainObjListPtr doms,
     virHashRemoveEntry(doms->objsName, dom->def->name);
     virObjectUnlock(dom);
     virObjectUnref(dom);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
 }
 
 
@@ -420,7 +420,7 @@ virDomainObjListRename(virDomainObjListPtr doms,
 
     ret = 0;
  cleanup:
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     VIR_FREE(old_name);
     return ret;
 }
@@ -609,7 +609,7 @@ virDomainObjListLoadAllConfigs(virDomainObjListPtr doms,
     }
 
     VIR_DIR_CLOSE(dir);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     return ret;
 }
 
@@ -655,7 +655,7 @@ virDomainObjListNumOfDomains(virDomainObjListPtr doms,
     struct virDomainObjListData data = { filter, conn, active, 0 };
     virObjectRWLockRead(doms);
     virHashForEach(doms->objs, virDomainObjListCount, &data);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     return data.count;
 }
 
@@ -699,7 +699,7 @@ virDomainObjListGetActiveIDs(virDomainObjListPtr doms,
                                     0, maxids, ids };
     virObjectRWLockRead(doms);
     virHashForEach(doms->objs, virDomainObjListCopyActiveIDs, &data);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     return data.numids;
 }
 
@@ -753,7 +753,7 @@ virDomainObjListGetInactiveNames(virDomainObjListPtr doms,
     size_t i;
     virObjectRWLockRead(doms);
     virHashForEach(doms->objs, virDomainObjListCopyInactiveNames, &data);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     if (data.oom) {
         for (i = 0; i < data.numnames; i++)
             VIR_FREE(data.names[i]);
@@ -794,7 +794,7 @@ virDomainObjListForEach(virDomainObjListPtr doms,
     };
     virObjectRWLockRead(doms);
     virHashForEach(doms->objs, virDomainObjListHelper, &data);
-    virObjectUnlock(doms);
+    virObjectRWUnlock(doms);
     return data.ret;
 }
 
@@ -928,12 +928,12 @@ virDomainObjListCollect(virDomainObjListPtr domlist,
     virObjectRWLockRead(domlist);
     sa_assert(domlist->objs);
     if (VIR_ALLOC_N(data.vms, virHashSize(domlist->objs)) < 0) {
-        virObjectUnlock(domlist);
+        virObjectRWUnlock(domlist);
         return -1;
     }
 
     virHashForEach(domlist->objs, virDomainObjListCollectIterator, &data);
-    virObjectUnlock(domlist);
+    virObjectRWUnlock(domlist);
 
     virDomainObjListFilter(&data.vms, &data.nvms, conn, filter, flags);
 
@@ -972,7 +972,7 @@ virDomainObjListConvert(virDomainObjListPtr domlist,
             if (skip_missing)
                 continue;
 
-            virObjectUnlock(domlist);
+            virObjectRWUnlock(domlist);
             virReportError(VIR_ERR_NO_DOMAIN,
                            _("no domain with matching uuid '%s' (%s)"),
                            uuidstr, dom->name);
@@ -982,12 +982,12 @@ virDomainObjListConvert(virDomainObjListPtr domlist,
         virObjectRef(vm);
 
         if (VIR_APPEND_ELEMENT(*vms, *nvms, vm) < 0) {
-            virObjectUnlock(domlist);
+            virObjectRWUnlock(domlist);
             virObjectUnref(vm);
             goto error;
         }
     }
-    virObjectUnlock(domlist);
+    virObjectRWUnlock(domlist);
 
     sa_assert(*vms);
     virDomainObjListFilter(vms, nvms, conn, filter, flags);

src/libvirt_private.syms

@@ -2313,6 +2313,7 @@ virObjectRef;
 virObjectRWLockableNew;
 virObjectRWLockRead;
 virObjectRWLockWrite;
+virObjectRWUnlock;
 virObjectUnlock;
 virObjectUnref;
 

src/util/virobject.c

@@ -428,7 +428,7 @@ virObjectLock(void *anyobj)
  * @anyobj: any instance of virObjectRWLockable
  *
  * Acquire a read lock on @anyobj. The lock must be
- * released by virObjectUnlock.
+ * released by virObjectRWUnlock.
  *
  * The caller is expected to have acquired a reference
  * on the object before locking it (eg virObjectRef).
@@ -457,7 +457,7 @@ virObjectRWLockRead(void *anyobj)
  * @anyobj: any instance of virObjectRWLockable
  *
  * Acquire a write lock on @anyobj. The lock must be
- * released by virObjectUnlock.
+ * released by virObjectRWUnlock.
  *
  * The caller is expected to have acquired a reference
  * on the object before locking it (eg virObjectRef).
@@ -483,26 +483,39 @@ virObjectRWLockWrite(void *anyobj)
 
 /**
  * virObjectUnlock:
- * @anyobj: any instance of virObjectLockable or virObjectRWLockable
+ * @anyobj: any instance of virObjectLockable
  *
  * Release a lock on @anyobj. The lock must have been acquired by
- * virObjectLock, virObjectRWLockRead, or virObjectRWLockWrite.
+ * virObjectLock.
  */
 void
 virObjectUnlock(void *anyobj)
 {
-    if (virObjectIsClass(anyobj, virObjectLockableClass)) {
-        virObjectLockablePtr obj = anyobj;
-        virMutexUnlock(&obj->lock);
-    } else if (virObjectIsClass(anyobj, virObjectRWLockableClass)) {
-        virObjectRWLockablePtr obj = anyobj;
-        virRWLockUnlock(&obj->lock);
-    } else {
-        virObjectPtr obj = anyobj;
-        VIR_WARN("Object %p (%s) is not a virObjectLockable "
-                 "nor virObjectRWLockable instance",
-                 anyobj, obj ? obj->klass->name : "(unknown)");
-    }
+    virObjectLockablePtr obj = virObjectGetLockableObj(anyobj);
+
+    if (!obj)
+        return;
+
+    virMutexUnlock(&obj->lock);
+}
+
+
+/**
+ * virObjectRWUnlock:
+ * @anyobj: any instance of virObjectRWLockable
+ *
+ * Release a lock on @anyobj. The lock must have been acquired by
+ * virObjectRWLockRead or virObjectRWLockWrite.
+ */
+void
+virObjectRWUnlock(void *anyobj)
+{
+    virObjectRWLockablePtr obj = virObjectGetRWLockableObj(anyobj);
+
+    if (!obj)
+        return;
+
+    virRWLockUnlock(&obj->lock);
 }
 
 

src/util/virobject.h

@@ -136,6 +136,10 @@ void
 virObjectUnlock(void *lockableobj)
     ATTRIBUTE_NONNULL(1);
 
+void
+virObjectRWUnlock(void *lockableobj)
+    ATTRIBUTE_NONNULL(1);
+
 void
 virObjectListFree(void *list);