On 07/17/2012 02:25 PM, Eric Blake wrote:
On 07/11/2012 07:35 AM, Daniel P. Berrange wrote:
From: "Daniel P. Berrange" <berrange@redhat.com>
This introduces a fairly basic reference counted virObject type and an associated virClass type, that use atomic operations for ref counting.
+void *virObjectNew(virClassPtr klass) +{ + virObjectPtr obj = NULL; + char *somebytes; + + if (VIR_ALLOC_N(somebytes, klass->objectSize) < 0) { + virReportOOMError(); + return NULL; + } + obj = (void*)somebytes; + + obj->magic = klass->magic; + obj->klass = klass; + virAtomicIntSet(&obj->refs, 1);
In this instance (and no where else), can't we just do 'obj-refs = 1'
obj->refs, obviously
instead of going through virAtomic, since the object hasn't yet been publicized? It might make life slightly faster.
Perhaps answering myself - the only reason that might exist to avoid direct assignment would be if we need the memory fence semantics guaranteed by virAtomicIntSet that we would not have with direct assignment. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org