public virtual (IReplica Replica, bool IsNew) GetOrRegister(PublicationRef publicationRef, Func <IReplica> replicaFactory)
{
var random = publicationRef.PublicationId.HashCode;
OnOperation(random);
var spinWait = new SpinWait();
var newReplica = (IReplica?)null; // Just to make sure we store this ref
while (true)
{
// ReSharper disable once HeapView.CanAvoidClosure
var handle = _handles.GetOrAdd(publicationRef, _ => {
newReplica = replicaFactory.Invoke();
return(_gcHandlePool.Acquire(newReplica, random));
});
var target = (IReplica?)handle.Target;
if (target != null)
{
if (target == newReplica)
{
return(target, true);
}
(newReplica as IReplicaImpl)?.DisposeTemporaryReplica();
return(target, false);
}
// GCHandle target == null => we have to recycle it
if (_handles.TryRemove(publicationRef, handle))
{
// The thread that succeeds in removal releases gcHandle as well
_gcHandlePool.Release(handle, random);
}
// And since we didn't manage to add the replica, let's retry
spinWait.SpinOnce();
}
}
public virtual void Register(IComputed computed)
{
// Debug.WriteLine($"{nameof(Register)}: {computed}");
var key = computed.Input;
var random = Randomize(key.HashCode);
OnOperation(random);
var spinWait = new SpinWait();
GCHandle?newHandle = null;
while (computed.ConsistencyState != ConsistencyState.Invalidated)
{
if (_storage.TryGetValue(key, out var handle))
{
var target = (IComputed?)handle.Target;
if (target == computed)
{
break;
}
if (target == null || target.ConsistencyState == ConsistencyState.Invalidated)
{
if (_storage.TryRemove(key, handle))
{
_gcHandlePool.Release(handle, random);
}
}
else
{
// This typically triggers Unregister -
// except for ReplicaClientComputed.
target.Invalidate();
}
}
else
{
newHandle ??= _gcHandlePool.Acquire(computed, random);
if (_storage.TryAdd(key, newHandle.GetValueOrDefault()))
{
if (computed.ConsistencyState == ConsistencyState.Invalidated)
{
if (_storage.TryRemove(key, handle))
{
_gcHandlePool.Release(handle, random);
}
}
break;
}
}
spinWait.SpinOnce();
}
}