private void RemoveParent(THandle obj,
UnmanagedObjectContext <THandleClass, THandle> trackedObjectContext,
Tuple <THandleClass, THandle> dep)
{
if (trackedObjectContext.parentCollection == null ||
!trackedObjectContext.parentCollection.Remove(dep.Item1, dep.Item2))
{
throw new EParentNotFound <THandleClass, THandle>(dep.Item1, dep.Item2);
}
Unregister(dep.Item1, dep.Item2);
}
private void AddParent(UnmanagedObjectContext <THandleClass, THandle> trackedObjectContext,
Tuple <THandleClass, THandle> dep)
{
UnmanagedObjectContext <THandleClass, THandle> depContext;
if (!_trackedObjects.TryGetValue(dep, out depContext))
{
throw new EObjectNotFound <THandleClass, THandle>(dep.Item1, dep.Item2);
}
if (trackedObjectContext.parentCollection == null)
{
trackedObjectContext.InitParentCollection();
}
if (trackedObjectContext.parentCollection.Add(dep.Item1, dep.Item2))
{
depContext.AddRefCount();
}
}
public void Register(THandleClass handleClass, THandle obj,
UnmanagedObjectContext <THandleClass, THandle> .DestroyHandleDelegate destroyHandle = null,
HandleCollection <THandleClass, THandle> parentCollection = null)
{
UnmanagedObjectContext <THandleClass, THandle> existingContextObj;
var handleContainer = new HandleContainer(handleClass, obj);
var trackedObject = new UnmanagedObjectContext <THandleClass, THandle>
{
DestroyHandle = destroyHandle,
parentCollection = parentCollection
};
do
{
if ((existingContextObj = _trackedObjects.GetOrAdd(handleContainer, trackedObject)) == trackedObject)
{
if (parentCollection == null)
{
return;
}
foreach (var dep in trackedObject.parentCollection)
{
UnmanagedObjectContext <THandleClass, THandle> depContext;
if (!_trackedObjects.TryGetValue(dep, out depContext))
{
throw new EObjectNotFound <THandleClass, THandle>(dep.Item1, dep.Item2);
}
depContext.AddRefCount();
}
return;
}
/* If object already existed, under normal conditions AddRefCount() must return a value > 1.
* If it returns <= 1 it means it just got decremented in another thread, reached zero and
* it's about to be destroyed. So we will have to wait for that to happen and try again our
* entire operation */
var newRefCount = existingContextObj.AddRefCount();
if (newRefCount <= 0)
{
throw new EInvalidRefCount <THandleClass, THandle>(handleClass, obj, newRefCount);
}
if (newRefCount > 1)
{
break;
}
/* Object is getting removed in another thread. Let's spin while we wait for it to be gone
* from our _trackedObjects container */
while (_trackedObjects.TryGetValue(handleContainer, out existingContextObj))
{
Thread.Yield();
}
} while (true);
/* Object already exists, could be an stale object not yet garbage collected,
* so we will set the new cleanup methods in place of the current ones */
existingContextObj.DestroyHandle = destroyHandle;
if (parentCollection == null)
{
return;
}
foreach (var dep in parentCollection)
{
AddParent(existingContextObj, dep);
}
}
